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Sample records for surface antigen hbsag

  1. Prevalence of hepatitis b virus surface antigens (HBsag) and ...

    African Journals Online (AJOL)

    The prevalences of hepatitis B virus surface antigen (HBsAg) and hepatitis C virus (HCV) antibodies were determined in 560 blood donors sera using ELISA kits (DIALAB., Austria). Forty eight (8.57%) of these were positive for hepatitis B virus infection, while 33(5.89%) were positive to hepatitis C virus antibodies. The sex ...

  2. Breaking tolerance in hepatitis B surface antigen (HBsAg) transgenic mice by vaccination with cross-reactive, natural HBsAg variants

    DEFF Research Database (Denmark)

    Schirmbeck, Reinhold; Dikopoulos, Nektarios; Kwissa, Marcin

    2003-01-01

    Processing exogenous hepatitis B surface antigen (HBsAg) of the hepatitis B virus (HBV) generates the K(b)-binding S(208-215) epitope 1; processing endogenous HBsAg generates the K(b)-binding S(190-197) epitope 2. Cross-reactive CD8(+) T cell responses were primed to epitope 1 but not epitope 2...... HBs-tg mice showed reduced antigenemia. Hence, vaccination with natural HBsAg variants from different HBV sero/genotypes can prime cross-reactive, specific CD8(+) T cell immunity that breaks tolerance to HBsAg....

  3. Analysis of hepatitis B surface antigen (HBsAg) using high-sensitivity HBsAg assays in hepatitis B virus carriers in whom HBsAg seroclearance was confirmed by conventional assays.

    Science.gov (United States)

    Ozeki, Itaru; Nakajima, Tomoaki; Suii, Hirokazu; Tatsumi, Ryoji; Yamaguchi, Masakatsu; Kimura, Mutsuumi; Arakawa, Tomohiro; Kuwata, Yasuaki; Ohmura, Takumi; Hige, Shuhei; Karino, Yoshiyasu; Toyota, Joji

    2018-02-01

    We investigated the utility of high-sensitivity hepatitis B surface antigen (HBsAg) assays compared with conventional HBsAg assays. Using serum samples from 114 hepatitis B virus (HBV) carriers in whom HBsAg seroclearance was confirmed by conventional HBsAg assays (cut-off value, 0.05 IU/mL), the amount of HBsAg was re-examined by high-sensitivity HBsAg assays (cut-off value, 0.005 IU/mL). Cases negative for HBsAg in both assays were defined as consistent cases, and cases positive for HBsAg in the high-sensitivity HBsAg assay only were defined as discrepant cases. There were 55 (48.2%) discrepant cases, and the range of HBsAg titers determined by high-sensitivity HBsAg assays was 0.005-0.056 IU/mL. Multivariate analysis showed that the presence of nucleos(t)ide analog therapy, liver cirrhosis, and negative anti-HBs contributed to the discrepancies between the two assays. Cumulative anti-HBs positivity rates among discrepant cases were 12.7%, 17.2%, 38.8%, and 43.9% at baseline, 1 year, 3 years, and 5 years, respectively, whereas the corresponding rates among consistent cases were 50.8%, 56.0%, 61.7%, and 68.0%, respectively. Hepatitis B virus DNA negativity rates were 56.4% and 81.4% at baseline, 51.3% and 83.3% at 1 year, and 36.8% and 95.7% at 3 years, among discrepant and consistent cases, respectively. Hepatitis B surface antigen reversion was observed only in discrepant cases. Re-examination by high-sensitivity HBsAg assays revealed that HBsAg was positive in approximately 50% of cases. Cumulative anti-HBs seroconversion rates and HBV-DNA seroclearance rates were lower in these cases, suggesting a population at risk for HBsAg reversion. © 2017 The Japan Society of Hepatology.

  4. Hepatitis B surface antigen (HBsAg) expression in plant cell culture: Kinetics of antigen accumulation in batch culture and its intracellular form.

    Science.gov (United States)

    Smith, Mark L; Mason, Hugh S; Shuler, Michael L

    2002-12-30

    The production of edible vaccines in transgenic plants and plant cell culture may be improved through a better understanding of antigen processing and assembly. The hepatitis B surface antigen (HBsAg) was chosen for study because it undergoes substantial and complex post-translational modifications, which are necessary for its immunogenicity. This antigen was expressed in soybean (Glycine max L. Merr. cv Williams 82) and tobacco NT1 (Nicotiana tabacum L.) cell suspension cultures, and HBsAg production in batch culture was characterized. The plant-derived antigen consisted predominantly of disulfide cross-linked HBsAg protein (p24(s)) dimers, which were all membrane associated. Similar to yeast, the plant-expressed HBsAg was retained intracellularly. The maximal HBsAg titers were obtained with soybean suspension cultures (20-22 mg/L) with titers in tobacco cultures being approximately 10-fold lower. For soybean cells, electron microscopy and immunolocalization demonstrated that all the HBsAg was localized to the endoplasmic reticulum (ER) and provoked dilation and proliferation of the ER network. Sucrose gradient analysis of crude extracts showed that HBsAg had a complex size distribution uncharacteristic of the antigen's normal structure of uniform 22-nm virus-like particles. The extent of authentic epitope formation was assessed by comparing total p24(s) synthesized to that reactive by polyclonal and monoclonal immunoassays. Depending on culture age, between 40% and 100% of total p24(s) was polyclonal antibody reactive whereas between 6% and 37% was recognized by a commercial monoclonal antibody assay. Possible strategies to increase HBsAg production and improve post-translational processing are discussed. Copyright 2002 Wiley Periodicals, Inc.

  5. Expression of Hepatitis B virus surface antigen (HBsAg from genotypes A, D and F and influence of amino acid variations related or not to genotypes on HBsAg detection

    Directory of Open Access Journals (Sweden)

    Natalia M. Araujo

    Full Text Available The impact of hepatitis B virus (HBV genotypes on the sensitivity of surface antigen (HBsAg detection assays has been poorly investigated. Here, plasmids carrying consensus or variant coding sequences for HBV surface proteins from genotypes A, D and F, were constructed. HBsAg levels were evaluated in medium and extracts of transfected CHO cells by a commercial polyclonal-based assay. We show that HBsAg detection values of consensus forms from genotypes D and F were, respectively, 37% and 30% lower than those obtained by genotype A. However, the presence of two single variations, T143M in genotype A, and T125M in genotype D, produced a decrease of 44% and an increase of 34%, respectively, on HBsAg mean values in comparison with their consensus forms. In conclusion, HBsAg detection levels varied among HBV genotypes. However, unique amino acid substitutions not linked to genotypes, such as T125M and T143M described here, should have more implications in HBV immunological diagnostics than the set of variations characteristic of each HBV genotype.

  6. Clinical Characteristics and Correlation Analysis of Subjects with Chronic Hepatitis B Virus (HBV) Infection and Sustained Low Levels of Hepatitis B Surface Antigen (HBsAg)

    Science.gov (United States)

    Cheng, Jun; Dai, Yuzhu; Yan, Li; Zhou, Huajun; Xu, Xujian

    2018-01-01

    Background The aim of this study was to investigate the clinical characteristics of individuals with chronic hepatitis B virus (HBV) infection with persistent low levels of hepatitis B surface antigen (HBsAg) and to undertake a correlation analysis of the clinical characteristics. Material/Methods The study included 1,204 subjects with chronic HBV infection. Serum HBsAg, HBV envelope antigen (HBeAg), and HBV core antigen (HBcAg) levels were measured using the chemiluminescent microparticle immunoassay (CMIA) and the neutralization test. HBV DNA was measured using real-time fluorescence quantitative polymerase chain reaction (RT-FQ-PCR). Results There were 1,023 subjects in the high-level HBsAg group (HBsAg level ≥10 IU/mL) and 181 subjects in the low-level HBsAg group (HBsAg level HBV-M2), and the asymptomatic carrier (ASC) status was 98.34%. The low-level HBsAg group had a lower HBV DNA-positive rate compared with the high-level HBsAg group (40.33% vs. 75.07%), with a normal distribution across all age groups (P>0.05). The low-level HBsAg group included an older age group. A low-level of HBsAg was positively correlated with a low level of replication of HBV DNA (r=0.452). Conclusions The findings of this study showed that individuals with chronic HBV infection and sustained low-levels of HBsAg were an older population and had a lower level of replicating HBV DNA when compared with individuals with high levels of HBsAg, and the majority (93.7%) were also HBsAg and HBeAg and HBcAg-positive. PMID:29593208

  7. Construction of a hepatitis B virus neutralizing chimeric monoclonal antibody recognizing escape mutants of the viral surface antigen (HBsAg).

    Science.gov (United States)

    Golsaz-Shirazi, Forough; Amiri, Mohammad Mehdi; Farid, Samira; Bahadori, Motahareh; Bohne, Felix; Altstetter, Sebastian; Wolff, Lisa; Kazemi, Tohid; Khoshnoodi, Jalal; Hojjat-Farsangi, Mohammad; Chudy, Michael; Jeddi-Tehrani, Mahmood; Protzer, Ulrike; Shokri, Fazel

    2017-08-01

    Hepatitis B virus (HBV) infection is a global burden on the health-care system and is considered as the tenth leading cause of death in the world. Over 248 million patients are currently suffering from chronic HBV infection worldwide and annual mortality rate of this infection is 686000. The "a" determinant is a hydrophilic region present in all antigenic subtypes of hepatitis B surface antigen (HBsAg), and antibodies against this region can neutralize the virus and are protective against all subtypes. We have recently generated a murine anti-HBs monoclonal antibody (4G4), which can neutralize HBV infection in HepaRG cells and recognize most of the escape mutant forms of HBsAg. Here, we describe the production and characterization of the chimeric human-murine antibody 4G4 (c-4G4). Variable region genes of heavy and light chains of the m-4G4 were cloned and fused to constant regions of human kappa and IgG1 by splice overlap extension (SOE) PCR. The chimeric antibody was expressed in Chinese Hamster Ovary (CHO)-K1 cells and purified from culture supernatant. Competition ELISA proved that both antibodies bind the same epitope within HBsAg. Antigen-binding studies using ELISA and Western blot showed that c-4G4 has retained the affinity and specificity of the parental murine antibody, and displayed a similar pattern of reactivity to 13 escape mutant forms of HBsAg. Both, the parental and c-4G4 showed a comparably high HBV neutralization capacity in cell culture even at the lowest concentration (0.6μg/ml). Due to the ability of c-4G4 to recognize most of the sub-genotypes and escape mutants of HBsAg, this antibody either alone or in combination with other anti-HBs antibodies could be considered as a potent alternative for Hepatitis B immune globulin (HBIG) as an HBV infection prophylactic or for passive immunotherapy against HBV infection. Copyright © 2017 Elsevier B.V. All rights reserved.

  8. Rational design and evaluation of HBsAg polymeric nanoparticles as antigen delivery carriers.

    Science.gov (United States)

    Dewangan, Hitesh Kumar; Pandey, Tarun; Maurya, Lakshmi; Singh, Sanjay

    2018-05-01

    The present work is focused on the development and evaluation of single dose sustained-release Hepatitis B surface antigen (HBsAg) loaded nanovaccine for Hepatitis B. The conventional treatment suffers from repeated administration and hence requires a booster dose. Therefore, polymeric nanovaccine of HBsAg was developed by double emulsion solvent evaporation technique, utilizing central composite design for formulation optimization. The effects of independent variables (like polymer amount, stabilizer concentration, aqueous/organic phase ratio and homogenizer speed) were also studied on critical quality attributes like particle size and entrapment efficiency. Nanovaccine was characterized in terms of physicochemical parameters, release, internalization and in vivo immunological evaluation in BALB/c mice after administration by different routes such as oral, sub-cutaneous, nasal and intramuscular. The designed nanovaccine demonstrated nanometric size with smooth surface, negative zeta potential, maximum entrapment, sustained release and better internalization in macrophage and MRC-5 cell line. The immune-stimulating activity of nanovaccine administered by different routes was evaluated by measuring anti-HBsAg titre like specific immunoglobulin IgG and IgA response and cytokine level (interleukin-2, interferon-Y) measurement. The results indicated that the nanovaccine administered by intramuscular route produced better humoral as well as cellular responses and potential carriers for antigen delivery at single dose administration via intramuscular route. Copyright © 2018 Elsevier B.V. All rights reserved.

  9. Use of nitrocellulose blotting for the study of hepatitis B surface antigen electrophoresed in agarose gels

    Energy Technology Data Exchange (ETDEWEB)

    McMichael, J C; Greisiger, L M; Millman, I [Institute for Cancer Research, Philadelphia, PA (USA). Fox Chase Cancer Center

    1981-08-28

    Nitrocellulose-protein blotting of serum electrophoresed in agarose gels has been adapted for the study of hepatitis B surface antigen (HBsAg). /sup 125/I-labeled anti-HBs was used as the antigen probe, and the electrophoretic migration was monitored by autoradiography. The method required 3 ..mu..l or less of serum and could detect as little as 1 pg of purified HBsAg. Typically, the authors observed two bands of HBsAg; a moving band which migrated about one-third the distance moved by human serum albumin and a non-migratory band which remained at the loading site. Some examples of the use of the method include: (1) empirical methods for correlating HBsAg concentration in serum to film darkness; (2) observations of mobility changes in serial sera from dialysis patients with chronic HBsAg antigenemia; and (3) detection of related antigens such as antigen from the PLC/PRF/5 hepatoma tissue culture line and the cross-reacting woodchuck hepatitis virus surface antigen (WHsAg).

  10. Evaluation of a semi-automatic radioimmunoassay for hepatitis B surface antigen (HBsAg)

    International Nuclear Information System (INIS)

    Vries, J. de; Kruining, J.; Heijtink, R.A.

    1983-01-01

    The recently developed semi-automatic Hepatube system was evaluated in comparison to another radioimmunoassay for the detection of hepatitis B surface antigen (HBsAg), the manual Ausria II-125 test. After incubation of serum in anti-HBs coated tubes, the Hepatube system uses a machine to wash the tubes and to add tracer. After a second incubation, tubes are washed again in the machine and are manually transferred to the #betta# counter. Two machines were used. Machine 1 had an undefined defect. Of 1490 samples tested, 69 (4.6%) gave false-positive results versus 11 (0.7%) in the Ausria II-125 test. Machine 2 had one false-positive result among 920 samples versus 5 in the Ausria II-125 test. The sensitivity was measured with reference panels from Wellcome and Abbott as well as in titration series. The Hepatube system was found to be a factor three less sensitive than the Ausria II-125 test. The Hepatube processor is easy to handle; radioactive material can be held at a distance during the whole procedure; waste material is limited and less voluminous than in the Ausria II-125 test. (Auth.)

  11. Application of a Newly Developed High-Sensitivity HBsAg Chemiluminescent Enzyme Immunoassay for Hepatitis B Patients with HBsAg Seroclearance

    OpenAIRE

    Shinkai, Noboru; Matsuura, Kentaro; Sugauchi, Fuminaka; Watanabe, Tsunamasa; Murakami, Shuko; Iio, Etsuko; Ogawa, Shintaro; Nojiri, Shunsuke; Joh, Takashi; Tanaka, Yasuhito

    2013-01-01

    We modified and automated a highly sensitive chemiluminescent enzyme immunoassay (CLEIA) for surface antigen (HBsAg) detection using a combination of monoclonal antibodies, each for a specific epitope of HBsAg, and by improving an earlier conjugation technique. Of 471 hepatitis B virus (HBV) carriers seen in our hospital between 2009 and 2012, 26 were HBsAg seronegative as determined by the Abbott Architect assay. The Lumipulse HBsAg-HQ assay was used to recheck those 26 patients who demonstr...

  12. Prevalence of Hepatitis-B Surface Antigen among Blood Donors in ...

    African Journals Online (AJOL)

    Information is scarce on the prevalence of Hepatitis-B Virus (HBV) infection among blood donors in Taraba State. Hepatitis-B surface antigen (HBsAg) ELISA [Gudans Industrial Hong 2 Kou, China] was used to determine the prevalence of HBsAg among 804 blood donors aged between 11 and 65 years in Federal Medical ...

  13. Comparative study of methods of detection of hepatitis ′B′ surface antigen (HBsAg.

    Directory of Open Access Journals (Sweden)

    Parab V

    1989-04-01

    Full Text Available The serum samples were collected from 52 patients of acute viral hepatitis and 235 hospital staff from Kasturba Hospital for Infectious Diseases. HBsAg was detected in their sera by counter-immuno-electrophoresis (CIEP, reverse passive hemogglutination (RPHA and by micro-enzyme-linked-immunosorbent assay (ELISA technique. Among the patients, HBsAg was detected in 12 cases (23% by CIEP, in 18 cases (34% by RPHA and in 23 patients (45% by ELISA. In the hospital staff, HBsAg was detected in 4 samples (1.7% by CIEP, in 8 samples (3.5% by RPHA and in 32 samples (13.5% by ELISA. Thus ELISA was found to be the most sensitive technique in detecting HBsAg.

  14. Antigens of hepatitis B virus: failure to detect HBeAg on the surfaces of HBsAg forms

    Energy Technology Data Exchange (ETDEWEB)

    Gerin, J L [Oak Ridge National Lab., Rockville, MD; Shih, J W.K.; McAuliffee, V J; Purcell, R H

    1978-01-01

    The particulate forms of HBsAg were analysed for the presence of HBeAG on their surfaces. By immunodiffusion analysis, anti-HBe did not form precipitin bands with the purified forms of HBsAg and hyperimmune guinea pig antisera to these forms did not react with HBeAg. Lines of non-identity were observed between the HBeAg determinants (e/sub 1/ and e/sub 2/) and the Dane particles and filaments isolated from an HBeAg-positive serum. Finally, anti-HBe failed to precipitate the polymerase-positive subpopulation of Dane particles, indicating that anti-HBe has no direct role in virus neutralization.

  15. Hepatitis B surface antigen (HBsAg) and core antigen (HBcAg) combine CpG oligodeoxynucletides as a novel therapeutic vaccine for chronic hepatitis B infection.

    Science.gov (United States)

    Li, Jianqiang; Ge, Jun; Ren, Sulin; Zhou, Tong; Sun, Ying; Sun, Honglin; Gu, Yue; Huang, Hongying; Xu, Zhenxing; Chen, Xiaoxiao; Xu, Xiaowei; Zhuang, Xiaoqian; Song, Cuiling; Jia, Fangmiao; Xu, Aiguo; Yin, Xiaojin; Du, Sean X

    2015-08-20

    Hepatitis B virus infection is a non-cytopathic hepatotropic virus which can lead to chronic liver disease and hepatocellular carcinoma. Traditional therapies fail to provide sustained control of viral replication and liver damage in most patients. As an alternative strategy, immunotherapeutic approaches have shown promising efficacy in the treatment of chronic hepatitis B patients. Here, we investigated the efficacy of a novel therapeutic vaccine formulation consisting of two HBV antigens, HBsAg and HBcAg, and CpG adjuvant. This vaccine formulation elicits forceful humoral responses directed against HBsAg/HBcAg, and promotes a Th1/Th2 balance response against HBsAg and a Th1-biased response against HBcAg in both C57BL/6 and HBV transgenic mice. Vigorous cellular immune response was also detected in HBV transgenic mice, for a significantly higher number of HBs/HBc-specific IFN-γ secreting CD4+ and CD8+ T cells was generated. Moreover, vaccinated mice elicited significantly intense in vivo CTL attack, reduced serum HBsAg level without causing liver damage in HBV transgenic mice. In summary, this study demonstrates a novel therapeutic vaccine with the potential to elicit vigorous humoral and cellular response, overcoming tolerance in HBV transgenic mice. Copyright © 2015 Elsevier Ltd. All rights reserved.

  16. [One example of false negative hepatitis B surface antigen (EIA) result due to variant S area strain and reagment reactiveness related to hepatitis B surface antigen].

    Science.gov (United States)

    Matsuda, Chikashi; Moriyama, Hidehiko; Taketani, Takeshi; Shibata, Hiroshi; Nagai, Atsushi

    2011-01-01

    The presence in serum of the Hepatitis B surface antigen (HBsAg), the outer envelope of the hepatitis B virus (HBV), indicates viral infection, used in laboratory tests to confirm this. We report a case of discrepancy among HBsAg test results detected between measurements in a subject with HB infection. Gene analysis demonstrated several S region gene mutations, not detected previously. We tested 12 measurements e.g., EIA, CLIA, CLEIA, F-EIA, MAT, and IC for whether they could detect our subject's HBsAg and found that it was not recognized by a method using only a single monoclonal antibody to detect HBsAg in two detection processes, in contrast to the 11 other measurements, which used two different antibodies. This case shows that amino acid substitution may cause a false negative result for HBsAg. Gene mutations known to occur in HBV, should thus trigger an awareness of the need to keep in mind that false negative results can happen in case such as ours.

  17. Relation between laboratory test results and histological hepatitis activity in individuals positive for hepatitis B surface antigen and antibodies to hepatitis B e antigen

    NARCIS (Netherlands)

    ter Borg, F.; ten Kate, F. J.; Cuypers, H. T.; Leentvaar-Kuijpers, A.; Oosting, J.; Wertheim-van Dillen, P. M.; Honkoop, P.; Rasch, M. C.; de Man, R. A.; van Hattum, J.; Chamuleau, R. A.; Reesink, H. W.; Jones, E. A.

    1998-01-01

    BACKGROUND: Hepatitis B surface antigen (HBsAg) and antibodies to hepatitis B e antigen (anti-HBe) commonly coexist, and laboratory tests are often requested to assess histological hepatitis activity. An optimum panel of tests has not been found and the usefulness of hepatitis B virus (HBV) DNA

  18. Hepatitis B surface antigen incorporated in dissolvable microneedle array patch is antigenic and thermostable.

    Science.gov (United States)

    Poirier, Danielle; Renaud, Frédéric; Dewar, Vincent; Strodiot, Laurent; Wauters, Florence; Janimak, Jim; Shimada, Toshio; Nomura, Tatsuya; Kabata, Koki; Kuruma, Koji; Kusano, Takayuki; Sakai, Masaki; Nagasaki, Hideo; Oyamada, Takayoshi

    2017-11-01

    Alternatives to syringe-based administration are considered for vaccines. Intradermal vaccination with dissolvable microneedle arrays (MNA) appears promising in this respect, as an easy-to-use and painless method. In this work, we have developed an MNA patch (MNAP) made of hydroxyethyl starch (HES) and chondroitin sulphate (CS). In swines, hepatitis B surface antigen (HBsAg) formulated with the saponin QS-21 as adjuvant, both incorporated in HES-based MNAP, demonstrated the same level of immunogenicity as a commercially available aluminum-adjuvanted HBsAg vaccine, after two immunizations 28 days apart. MNAP application was associated with transient skin reactions (erythema, lump, scab), particularly evident when the antigen was delivered with the adjuvant. The thermostability of the adjuvanted antigen when incorporated in the HES-based matrix was also assessed by storing MNAP at 37, 45 or 50 °C for up to 6 months. We could demonstrate that antigenicity was retained at 37 and 45 °C and only a 10% loss was observed after 6 months at 50 °C. Our results are supportive of MNAP as an attractive alternative to classical syringe-based vaccination. Copyright © 2017 The Authors. Published by Elsevier Ltd.. All rights reserved.

  19. Application of a newly developed high-sensitivity HBsAg chemiluminescent enzyme immunoassay for hepatitis B patients with HBsAg seroclearance.

    Science.gov (United States)

    Shinkai, Noboru; Matsuura, Kentaro; Sugauchi, Fuminaka; Watanabe, Tsunamasa; Murakami, Shuko; Iio, Etsuko; Ogawa, Shintaro; Nojiri, Shunsuke; Joh, Takashi; Tanaka, Yasuhito

    2013-11-01

    We modified and automated a highly sensitive chemiluminescent enzyme immunoassay (CLEIA) for surface antigen (HBsAg) detection using a combination of monoclonal antibodies, each for a specific epitope of HBsAg, and by improving an earlier conjugation technique. Of 471 hepatitis B virus (HBV) carriers seen in our hospital between 2009 and 2012, 26 were HBsAg seronegative as determined by the Abbott Architect assay. The Lumipulse HBsAg-HQ assay was used to recheck those 26 patients who demonstrated seroclearance by the Abbott Architect assay. The performance of the Lumipulse HBsAg-HQ assay was compared with that of a quantitative HBsAg detection system (Abbott Architect) and the Roche Cobas TaqMan HBV DNA assay (CTM) (lower limit of detection, 2.1 log copies/ml) using blood serum samples from patients who were determined to be HBsAg seronegative by the Abbott Architect assay. Ten patients had spontaneous HBsAg loss. Of 8 patients treated with nucleotide analogues (NAs), two were HBsAg seronegative after stopping lamivudine therapy and 6 were HBsAg seronegative during entecavir therapy. Eight acute hepatitis B (AH) patients became HBsAg seronegative. Of the 26 patients, 16 were HBsAg positive by the Lumipulse HBsAg-HQ assay but negative by the Abbott Architect assay. The differences between the two assays in terms of detectable HBsAg persisted over the long term in the spontaneous loss group (median, 10 months), the NA-treated group (2.5 months), and the AH group (0.5 months). In 9 patients, the Lumipulse HBsAg-HQ assay detected HBsAg when HBV DNA was negative by the CTM assay. HBsAg was also detected by the Lumipulse HBsAg-HQ assay in 4 patients with an anti-HBs concentration of >10 mIU/ml, 3 of whom had no HBsAg escape mutations. The automatic, highly sensitive HBsAg CLEIA Lumipulse HBsAg-HQ is a convenient and precise assay for HBV monitoring.

  20. An observation on positive rate of HBsAg in the urine of patients suffering from positive serum HBsAg

    Energy Technology Data Exchange (ETDEWEB)

    Peixun, Lin; Mingzheng, Zeng; Xiaoling, Chai [Wuhan Eighth Municipal Hospital, HB (China). Dept. of Laboratory

    1989-08-01

    In 1983, the Virus Research Office of the Shanxi Research Insitute of Preventive Medicine found out the granules of hepatitis B virus from the urine of patients and proved that this kind of virus can be spread through the urine. With the help of self-developed method of radio immunoelectrophoresis, our research office has purified and concentrated the urine of the patients suffering from positive serum HBsAg (hepatitis B surface antigen). Among them 25 are male, and another 25 are female. The result shows that the positive rate of HBsAg accounts for 80%. This is of important significance to the care of urine specimens, the protection of experimentalists and the development of clinical medicine.

  1. Comparison of serum HBsAg quantitation by four immunoassays, and relationships of HBsAg level with HBV replication and HBV genotypes.

    Directory of Open Access Journals (Sweden)

    Edouard Tuaillon

    Full Text Available BACKGROUND: The decline in hepatitis B virus surface antigen (HBsAg may be an early predictor of the viral efficacy of Hepatitis B virus (HBV therapy. The HBsAg levels obtained by different immunoassays now need comparing and the relationships between levels of HBsAg and HBV DNA alongside HBsAg and genotype must be evaluated. METHODOLOGY/PRINCIPAL FINDINGS: HBsAg levels were compared among 80 patients using the Abbott Architect assay, a commercial immunoassay approved for HBsAg detection and quantitation, and three other assays derived from immunoassays approved for HBsAg detection (manufactured by Diasorin, Bio-Rad and Roche. Good correlation was found between the Abbot vs. Diasorin, Bio-Rad and Roche assays with narrow 95% limits of agreement and small mean differences: -0.06 to 0.11, -0.09 log(10 IU/mL; -0.57 to 0.64, -0.04 log(10 IU/mL; -0.09 to 0.45, -0.27 log(10 IU/mL, respectively. These agreements were not affected by genotypes A or D. HBsAg was weakly correlated with HBV DNA, whatever the HBsAg assay used: Abbott, ρ = 0.36 p = 0.001, Diasorin ρ = 0.34, p = 0.002; Bio-Rad ρ = 0.37, p<0.001; or Roche ρ = 0.41, p<0.001. This relationship between levels of HBsAg and HBV DNA seemed to depend on genotypes. Whereas HBsAg (Abbott assay tended to correlate with HBV DNA for genotype A (ρ = 0.44, p = 0.02, no such correlation was significant for genotypes D (ρ = 0.29, p = 0.15. CONCLUSION/SIGNIFICANCE: The quantitation of HBsAg in routine clinical samples is comparable between the reference assay and the adapted assays with acceptable accuracy limits, low levels of variability and minimum discrepancy. While HBsAg quantitation is not affected by HBV genotype, the observed association between levels of HBsAg and HBV DNA seems genotype dependent.

  2. Surface antigen-negative hepatitis B virus infection in Dutch blood donors

    NARCIS (Netherlands)

    Lieshout-Krikke, R. W.; Molenaar-de Backer, M. W. A.; van Swieten, P.; Zaaijer, H. L.

    2014-01-01

    Hepatitis B virus (HBV) surface antigen (HBsAg) is a reliable marker for HBV infection, but HBsAg-negative forms of HBV infection occur. The introduction of HBV DNA screening of Dutch blood donors, which were not preselected for absence of HBV core antibodies, enabled the characterization of

  3. [Clinical evaluation of a novel HBsAg quantitative assay].

    Science.gov (United States)

    Takagi, Kazumi; Tanaka, Yasuhito; Naganuma, Hatsue; Hiramatsu, Kumiko; Iida, Takayasu; Takasaka, Yoshimitsu; Mizokami, Masashi

    2007-07-01

    The clinical implication of the hepatitis B surface antigen (HBsAg) concentrations in HBV-infected individuals remains unclear. The aim of this study was to evaluate a novel fully automated Chemiluminescence Enzyme Immunoassay (Sysmex HBsAg quantitative assay) by comparative measurements of the reference serum samples versus two independent commercial assays (Lumipulse f or Architect HBsAg QT). Furthermore, clinical usefulness was assessed for monitoring of the serum HBsAg levels during antiviral therapy. A dilution test using 5 reference-serum samples showed linear correlation curve in range from 0.03 to 2,360 IU/ml. The HBsAg was measured in total of 400 serum samples and 99.8% had consistent results between Sysmex and Lumipulse f. Additionally, a positive linear correlation was observed between Sysmex and Architect. To compare the Architect and Sysmex, both methods were applied to quantify the HBsAg in serum samples with different HBV genotypes/subgenotypes, as well as in serum contained HBV vaccine escape mutants (126S, 145R). Correlation between the methods was observed in results for escape mutants and common genotypes (A, B, C) in Japan. Observed during lamivudine therapy, an increase in HBsAg and HBV DNA concentrations preceded the aminotransferase (ALT) elevation associated with drug-resistant HBV variant emergence (breakthrough hepatitis). In conclusion, reliability of the Sysmex HBsAg quantitative assay was confirmed for all HBV genetic variants common in Japan. Monitoring of serum HBsAg concentrations in addition to HBV DNA quantification, is helpful in evaluation of the response to lamivudine treatment and diagnosis of the breakthrough hepatitis.

  4. Human immunodeficiency virus (HIV) seropositivity and hepatitis B surface antigenemia (HBSAG) among blood donors in Benin city, Edo state, Nigeria.

    Science.gov (United States)

    Umolu, Patience Idia; Okoror, Lawrence Ehis; Orhue, Philip

    2005-03-01

    Human Immunodeficiency Virus and Hepatitis B virus are blood borne pathogens that can be transmitted through blood transfusion and could pose a huge problem in areas where mechanisms of ensuring blood safety are suspect. This study became necessary in a population where most of the blood for transfusion is from commercial blood donors. A total of 130 donors comprising 120 commercial donors and 10 voluntary donors were tested for antibodies to human immunodeficiency virus and hepatitis B surface antigen in Benin city using Immunocomb HIV - 1 and 2 Biospot kit and Quimica Clinica Aplicada direct latex agglutination method respectively. Thirteen (10%) samples were HIV seropositive and 7(5.8%) were HBsAg positive. The age bracket 18 - 25years had the highest numbers of donors and also had the highest number of HBsAg positive cases (7.8%) while the age group 29 - 38years had highest number of HIV seropositive cases. High prevalence of HIV antibodies and Hepatitis B surface antigen was found among commercial blood donors. Appropriate and compulsory screening of blood donors using sensitive methods, must be ensured to prevent post transfusion hepatitis and HIV.

  5. Radioimmunoassay in the detection of the hepatitis Be antigen/antibody system in asymptomatic carriers of hepatitis B surface antigen

    International Nuclear Information System (INIS)

    Pastore, G.; Dentico, P.; Angarano, G.; Schiraldi, O.; Zanetti, A.R.; Ferroni, P.

    1980-01-01

    A radioimmunoassay for hepatitis e antigen (HBeAg) and antibody to e (anti-HBe) was developed and sera of 71 asymptomatic chronic carriers of hepatitis B surface antigen (HBsAg), in 44 of whom liver biopsy was obtained, were tested. In addition, testing for Dane particle associated DNA polymerase activity was performed in all sera. HBeAg was detected in 14 subjects (19.7%) and anti-HBe in 46 (64.8%). The highest proportion of HBeAg positivity (40%) was found among carriers with histological evidence of chronic hepatitis, whereas anti-HBe was present in 80% of carriers with normal liver histology, in 58% of carriers with non-specific reactive hepatitis and in 60% of carriers with chronic liver lesions. DNA polymerase activity was present in 92.8% of sera positive for HBeAg, in 13% of sera positive for anti HBe, and in 9% of sera negative for both markers. Our results demonstrate that not all HBsAg carriers reactive to HBeAg show evidence of chronic hepatitis nor, conversely, that anti-HBe is invariably associated with the healthy carrier state of HBsAg. Finally, circulating Dane particles, as revealed by the presence of serum specific DNA polymerase activity, may also be present in anti-HBe positive sera other than those of some HBsAg carriers lacking both HBeAg and anti-HBe. (orig.) [de

  6. RIA Quick, AUSRIA II-125, AUSAB. Comparative study on isolated and simultaneous radioimmunoassay of hepatitis B surface antigen and antibodies

    Energy Technology Data Exchange (ETDEWEB)

    Kselikova, M; Urbankova, J [Institut fuer Haematologie und Bluttransfusion, Prag (Czechoslovakia)

    1983-01-01

    The surface antigen of hepatitis B (HBsAg) and the antibodies against HBsAg can be determined separately by the radioimmunoassay (RIA) test kits AUSRIA II-125 and AUSAB, respectively. Using the test kit RIA Quick (IMMUNO, Wien) it is possible to perform both the determinations in one preparation simultaneously. The sensitivity of RIA Quick for HBsAg corresponds to that of AUSRIA II-125 and for HBsAB it is considerably lower than that of AUSAB. RIA Quick is of excellent technical design and is by a quarter cheaper than the kits for isolated determination of HBsAg and HBsAb.

  7. Spontaneous HBsAg loss in Korean patients: relevance of viral genotypes, S gene mutations, and covalently closed circular DNA copy numbers

    Directory of Open Access Journals (Sweden)

    Kyun-Hwan Kim

    2014-09-01

    Full Text Available Background/AimsOccult HBV infection can persist following HBsAg loss and be transmitted, but the virological features are not well defined.MethodsHere we investigated 25 Korean patients who lost HBsAg during follow up, either spontaneously or subsequent to therapy.ResultsWhereas subtype adr (genotype C was found in 96% of HBsAg positive patients, 75 % of patients who lost HBsAg spontaneously were seemed to be infected with the ayw subtype with sequence similar to genotype D. Mutations in the major hydrophilic region (MHR of HBsAg were found in 7 patients who lost HBsAg spontaneously. The mutations include T123S, M125I/N, C139R, D144E, V177A, L192F, and W196L, some of which have not been reported before. Functional analysis via transfection experiments indicate that the C139R and D144E mutations drastically reduced HBsAg antigenicity, while the Y225del mutation found in one interferon-treated patient impaired HBsAg secretion.ConclusionsLack of detectable HBsAg in patient serum could be explained by low level of ccc DNA in liver tissue, low antigenicity of the surface protein, or its secretion defect.

  8. Enhanced cell disruption strategy in the release of recombinant hepatitis B surface antigen from Pichia pastoris using response surface methodology

    Science.gov (United States)

    2012-01-01

    Background Cell disruption strategies by high pressure homogenizer for the release of recombinant Hepatitis B surface antigen (HBsAg) from Pichia pastoris expression cells were optimized using response surface methodology (RSM) based on the central composite design (CCD). The factors studied include number of passes, biomass concentration and pulse pressure. Polynomial models were used to correlate the above mentioned factors to project the cell disruption capability and specific protein release of HBsAg from P. pastoris cells. Results The proposed cell disruption strategy consisted of a number of passes set at 20 times, biomass concentration of 7.70 g/L of dry cell weight (DCW) and pulse pressure at 1,029 bar. The optimized cell disruption strategy was shown to increase cell disruption efficiency by 2-fold and 4-fold for specific protein release of HBsAg when compared to glass bead method yielding 75.68% cell disruption rate (CDR) and HBsAg concentration of 29.20 mg/L respectively. Conclusions The model equation generated from RSM on cell disruption of P. pastoris was found adequate to determine the significant factors and its interactions among the process variables and the optimum conditions in releasing HBsAg when validated against a glass bead cell disruption method. The findings from the study can open up a promising strategy for better recovery of HBsAg recombinant protein during downstream processing. PMID:23039947

  9. Membranous glomerulonephritis in a child asymptomatic for hepatitis B virus. Concomitant seropositivity for HBsAG and anti-HBs.

    Science.gov (United States)

    Hirsch, H Z; Ainsworth, S K; DeBeukelaer, M; Brissie, R M; Hennigar, G R

    1981-04-01

    The presence of hepatitis B surface antigen (HBsAg) in association with immunoglobulins and complement components within the glomerular basement membranes of adults having chronic active hepatitis has been well documented. In addition, investigators in Poland have demonstrated HBsAg immune complexes in glomeruli of children who did not have clinical evidence of hepatitis. More recently, a single case of childhood membranous glomerulonephritis in an asymptomatic carrier of hepatitis B virus was cited by observers in Canada. Reported here is the deposition of HBsAg immune complexes in the glomerular basement membranes of a 13-year-old black boy who had membranous glomerulopathy but not clinical evidence of hepatitis. This may be the first reported case in the United States of HbsAg-associated membranous glomerulonephritis in a child asymptomatic for hepatitis B virus, and only the second such case in North America. However, unlike previous studies of childhood glomerulopathy in association with hepatitis B virus, this patient is seropositive for both HBsAg and anti-HBs (antibody for hepatitis B surface antigen). Similar "rare" serologic findings were found for the patient's eldest male sib.

  10. Enhanced immunogenicity of DNA fusion vaccine encoding secreted hepatitis B surface antigen and chemokine RANTES

    International Nuclear Information System (INIS)

    Kim, Seung Jo; Suh, Dongchul; Park, Sang Eun; Park, Jeong-Sook; Byun, Hyang-Min; Lee, Chan; Lee, Sun Young; Kim, Inho; Oh, Yu-Kyoung

    2003-01-01

    To increase the potency of DNA vaccines, we constructed genetic fusion vaccines encoding antigen, secretion signal, and/or chemokine RANTES. The DNA vaccines encoding secreted hepatitis B surface antigen (HBsAg) were constructed by inserting HBsAg gene into an expression vector with an endoplasmic reticulum (ER)-targeting secretory signal sequence. The plasmid encoding secretory HBsAg (pER/HBs) was fused to cDNA of RANTES, generating pER/HBs/R. For comparison, HBsAg genes were cloned into pVAX1 vector with no signal sequence (pHBs), and further linked to the N-terminus of RANTES (pHBs/R). Immunofluorescence study showed the cytoplasmic localization of HBsAg protein expressed from pHBs and pHBs/R, but not from pER/HBs and pER/HBs/R at 48 h after transfection. In mice, RANTES-fused DNA vaccines more effectively elicited the levels of HBsAg-specific IgG antibodies than pHBs. All the DNA vaccines induced higher levels of IgG 2a rather than IgG 1 antibodies. Of RANTES-fused vaccines, pER/HBs/R encoding the secreted fusion protein revealed much higher humoral and CD8 + T cell-stimulating responses compared to pHBs/R. These results suggest that the immunogenicity of DNA vaccines could be enhanced by genetic fusion to a secretory signal peptide sequence and RANTES

  11. Changing serum levels of quantitative hepatitis B surface antigen and hepatitis B virus DNA in hepatitis B virus surface antigen carriers: A follow-up study of an elderly cohort

    Directory of Open Access Journals (Sweden)

    Yuan-Hung Kuo

    2015-02-01

    Full Text Available This study was to elucidate longitudinally quantitative changes of hepatitis B virus (HBV surface antigen (HBsAg and HBV DNA in elder HBsAg carriers in a community. Among 1002 residents screened for HBsAg in 2005, 405 responded to this follow-up study in 2010. Fifty-nine (14.6% were HBsAg carriers in 2005; HBsAg quantification and HBV DNA were measured. HBsAg quantification (cutoff 1600 IU/mL and HBV DNA (cutoff 2000 IU/mL were combined to stratify the participants between two screens. A total of 30 men and 29 women with a mean age of 63.9 ± 7.9 years were enrolled. Quantitative levels of HBsAg and HBV DNA were significantly correlated in 2005 (r = 0.509, p < 0.001 and 2010 (r = 0.777, p < 0.001. Concentrations of HBsAg (IU/mL significantly decreased from 2.2 ± 1.0 log in 2005 to 1.7 ± 1.5 log in 2010 (p < 0.001. The level of HBsAg was decreased in 48 (81.4% individuals and HBsAg was undetectable in eight (13.6%. The annual incidence of HBsAg clearance was 2.7%. These 59 HBsAg carriers in 2005 were divided into four groups: low HBsAg low HBV DNA (n = 32, high HBsAg low HBV DNA (n = 5, low HBsAg high HBV DNA (n = 12 and high HBsAg high HBV DNA (n = 10. All 32 individuals in the low HBsAg low HBV DNA group were still in that group in 2010, whereas only two of the high HBsAg high HBV DNA group became inactive. As with a younger cohort in hospital, HBsAg quantification was still well correlated with HBV DNA in elderly HBsAg carriers in the community. Lower levels of both HBsAg and HBV DNA might represent an inactive HBV infection.

  12. Ultra-deep sequencing reveals high prevalence and broad structural diversity of hepatitis B surface antigen mutations in a global population.

    Science.gov (United States)

    Gencay, Mikael; Hübner, Kirsten; Gohl, Peter; Seffner, Anja; Weizenegger, Michael; Neofytos, Dionysios; Batrla, Richard; Woeste, Andreas; Kim, Hyon-Suk; Westergaard, Gaston; Reinsch, Christine; Brill, Eva; Thu Thuy, Pham Thi; Hoang, Bui Huu; Sonderup, Mark; Spearman, C Wendy; Pabinger, Stephan; Gautier, Jérémie; Brancaccio, Giuseppina; Fasano, Massimo; Santantonio, Teresa; Gaeta, Giovanni B; Nauck, Markus; Kaminski, Wolfgang E

    2017-01-01

    The diversity of the hepatitis B surface antigen (HBsAg) has a significant impact on the performance of diagnostic screening tests and the clinical outcome of hepatitis B infection. Neutralizing or diagnostic antibodies against the HBsAg are directed towards its highly conserved major hydrophilic region (MHR), in particular towards its "a" determinant subdomain. Here, we explored, on a global scale, the genetic diversity of the HBsAg MHR in a large, multi-ethnic cohort of randomly selected subjects with HBV infection from four continents. A total of 1553 HBsAg positive blood samples of subjects originating from 20 different countries across Africa, America, Asia and central Europe were characterized for amino acid variation in the MHR. Using highly sensitive ultra-deep sequencing, we found 72.8% of the successfully sequenced subjects (n = 1391) demonstrated amino acid sequence variation in the HBsAg MHR. This indicates that the global variation frequency in the HBsAg MHR is threefold higher than previously reported. The majority of the amino acid mutations were found in the HBV genotypes B (28.9%) and C (25.4%). Collectively, we identified 345 distinct amino acid mutations in the MHR. Among these, we report 62 previously unknown mutations, which extends the worldwide pool of currently known HBsAg MHR mutations by 22%. Importantly, topological analysis identified the "a" determinant upstream flanking region as the structurally most diverse subdomain of the HBsAg MHR. The highest prevalence of "a" determinant region mutations was observed in subjects from Asia, followed by the African, American and European cohorts, respectively. Finally, we found that more than half (59.3%) of all HBV subjects investigated carried multiple MHR mutations. Together, this worldwide ultra-deep sequencing based genotyping study reveals that the global prevalence and structural complexity of variation in the hepatitis B surface antigen have, to date, been significantly underappreciated.

  13. Multiple surface antigen mutations in five blood donors with occult hepatitis B virus infection

    NARCIS (Netherlands)

    Zaaijer, H. L.; Torres, P.; Ontañón, A.; Ponte, L. González; Koppelman, M. H. G. M.; Lelie, P. N.; Hemert, F. J. van; Boot, H. J.

    2008-01-01

    Occult hepatitis B virus (HBV) infection is characterized by the presence of HBV DNA while the HBV surface antigen (HBsAg) remains undetectable. The HBV genomes in five asymptomatic blood donors with occult HBV infection and low viremia ( <10 to 1,000 HBV DNA copies/mL, genotype D) were studied. An

  14. Serum hepatitis B surface antigen and hepatitis B e antigen titers: disease phase influences correlation with viral load and intrahepatic hepatitis B virus markers.

    Science.gov (United States)

    Thompson, Alexander J V; Nguyen, Tin; Iser, David; Ayres, Anna; Jackson, Kathy; Littlejohn, Margaret; Slavin, John; Bowden, Scott; Gane, Edward J; Abbott, William; Lau, George K K; Lewin, Sharon R; Visvanathan, Kumar; Desmond, Paul V; Locarnini, Stephen A

    2010-06-01

    Although threshold levels for hepatitis B surface antigen (HBsAg) and hepatitis B e antigen (HBeAg) titers have recently been proposed to guide therapy for chronic hepatitis B (CHB), their relationship to circulating hepatitis B virus (HBV) DNA and intrahepatic HBV replicative intermediates, and the significance of emerging viral variants, remains unclear. We therefore tested the hypothesis that HBsAg and HBeAg titers may vary independently of viral replication in vivo. In all, 149 treatment-naïve CHB patients were recruited (HBeAg-positive, n = 71; HBeAg-negative, n = 78). Quantification of HBeAg and HBsAg was performed by enzyme immunoassay. Virological characterization included serum HBV DNA load, HBV genotype, basal core promoter (BCP)/precore (PC) sequence, and, in a subset (n = 44), measurement of intrahepatic covalently closed circular DNA (cccDNA) and total HBV DNA, as well as quantitative immunohistochemical (IHC) staining for HBsAg. In HBeAg-positive CHB, HBsAg was positively correlated with serum HBV DNA and intrahepatic cccDNA and total HBV DNA (r = 0.69, 0.71, 0.76, P < 0.01). HBeAg correlated with serum HBV DNA (r = 0.60, P < 0.0001), although emerging BCP/PC variants reduced HBeAg titer independent of viral replication. In HBeAg-negative CHB, HBsAg correlated poorly with serum HBV DNA (r = 0.28, P = 0.01) and did not correlate with intrahepatic cccDNA nor total HBV DNA. Quantitative IHC for hepatocyte HBsAg confirmed a relationship with viral replication only in HBeAg-positive patients. The correlation between quantitative HBsAg titer and serum and intrahepatic markers of HBV replication differs between patients with HBeAg-positive and HBeAg-negative CHB. HBeAg titers may fall independent of viral replication as HBeAg-defective variants emerge prior to HBeAg seroconversion. These findings provide new insights into viral pathogenesis and have practical implications for the use of quantitative serology as a clinical biomarker.

  15. [Diagnostic advantages of the test system "DS-EIA-HBsAg-0.01" for detection of HBV surface antigen].

    Science.gov (United States)

    Egorova, N I; Pyrenkova, I Iu; Igolkina, S N; Sharipova, I N; Puzyrev, V F; Obriadina, A P; Burkov, A N; Kornienko, N V; Fields, H A; Korovkin, A S; Shalunova, N V; Bektemirov, T A; Kuznetsov, K V; Koshcheeva, N A; Ulanova, T I

    2009-01-01

    The new highly sensitive test system "DS-EIA-HBsAg-0.01" (Priority Certificate No. 2006129019 of August 10, 2006) in detecting hepatitis B surface antigen (HBsAg) was assessed. The sensitivity of the test was estimated using the federal standards sample HBsAg 42-28-311-06, panels' samples Boston Biomedica Inc. (West Bridgewater, Mass, USA) and ZeptoMetrix Corp. (Buffalo, NY, USA). The findings have indicated that "DS-EIA-HBsAg-0.01" is equally effective in detecting different subtypes of HBsAg during a seroconversion period earlier than alternative assays. Along with its high analytical and diagnostic sensitivity, the system shows a high diagnostic specificity.

  16. Recombinant hepatitis B surface antigen production in Aspergillus niger: evaluating the strategy of gene fusion to native glucoamylase

    CSIR Research Space (South Africa)

    James, ER

    2012-10-01

    Full Text Available Microbiology and Biotechnology October 2012/ Vol. 96, No.2 Recombinant hepatitis B surface antigen production in Aspergillus niger: evaluating the strategy of gene fusion to native glucoamylase ER James a,c & WH van Zyl b & PJ van Zyl c & JF Görgens..., Pretoria 0001, South Africa Abstract This study demonstrates the potential of Aspergillus niger as a candidate expression system for virus- like particle production using gene fusion. Hepatitis B surface antigen (HBsAg) production, targeted...

  17. Reactivation of hepatitis B virus infection with persistently negative HBsAg on three HBsAg assays in a lymphoma patient undergoing chemotherapy.

    Science.gov (United States)

    Cheung, Wing-I; Chan, Henry Lik-Yuen; Leung, Vincent King-Sun; Tse, Chi-Hang; Fung, Kitty; Lin, Shek-Ying; Wong, Ann; Wong, Vincent Wai-Sun; Chau, Tai-Nin

    2010-02-01

    In patients with occult hepatitis B virus (HBV) infection, acute exacerbation may occur when they become immunocompromised. Usually, these patients develop hepatitis B surface antigen (HBsAg) seroreversion during the flare. Here we report on a patient with occult HBV infection, who developed HBV exacerbation after chemotherapy for diffuse large B-cell lymphoma. The resurgence of HBV DNA preceded the elevation of liver enzymes for 20 weeks. Atypically, despite high viraemia, serological tests showed persistently negative HBsAg using three different sensitive HBsAg assays (i.e., Architect, Murex and AxSYM). On comparing the amino acid sequence of the index patient with the consensus sequence, five mutations were found at pre-S1, five at pre-S2 and twenty-three mutations at the S region. Six amino acid mutations were located in the 'a' determinant, including P120T, K122R, M133T, F134L, D144A and G145A. The mutants K122R, F134L and G145A in our patient have not been tested for their sensitivity to Architect and Murex assays by the previous investigators and might represent the escape mutants to these assays.

  18. Detection of hepatitis B surface antigen by solid phase radioimmunoassay and immunometric assay (using enhanced luminescence)

    International Nuclear Information System (INIS)

    Nicholson, S.; Efandis, T.; Gust, I.

    1991-01-01

    A study was performed to assess the sensitivity and specificity of the amerlite monoclonal immunoassay for detection of hepatitis B surface antigen (HBsAG) by comparison with the Abbott Ausria II radioimmunoassay (RI). Serial bleeds from 34 patients with acute or chronic hepatitis B were tested by both assays. The Abbott Ausria II assay detected HBsAG longer than the Amersham Amerlite assay on two occasions and earlier on one occasion. Twelve patients with low HBsAg positive results (confirmed by Ausria II) were tested by the Amerlite assay, four were repeatably positive, five repeatably negative and three gave borderline results (which on repeat testing were negative). A similar trend was seen when a panel of sera containing known concentrations of HBsAG was tested. Replicate testing of 10 specimens eight times showed very good reproducibility by the Amerlite assay. Overall, the specificity of both assays was comparable, however differences in sensitivity were observed. 3 tabs

  19. Positive hepatitis B surface antigen tests due to recent vaccination: a persistent problem

    Directory of Open Access Journals (Sweden)

    Rysgaard Carolyn D

    2012-09-01

    Full Text Available Abstract Background Hepatitis B virus (HBV is a common cause of viral hepatitis with significant health complications including cirrhosis and hepatocellular carcinoma. Assays for hepatitis B surface antigen (HBsAg are the most frequently used tests to detect HBV infection. Vaccination for HBV can produce transiently detectable levels of HBsAg in patients. However, the time course and duration of this effect is unclear. The objective of this retrospective study was to clarify the frequency and duration of transient HBsAg positivity following vaccination against HBV. Methods The electronic medical record at an academic tertiary care medical center was searched to identify all orders for HBsAg within a 17 month time period. Detailed chart review was performed to identify all patients who were administered HBV vaccine within 180 days prior to HBsAg testing and also to ascertain likely cause of weakly positive (grayzone results. Results During the 17 month study period, 11,719 HBsAg tests were ordered on 9,930 patients. There were 34 tests performed on 34 patients who received HBV vaccine 14 days or less prior to HBsAg testing. Of these 34 patients, 11 had grayzone results for HBsAg that could be attributed to recent vaccination. Ten of the 11 patients were renal dialysis patients who were receiving HBsAg testing as part of routine and ongoing monitoring. Beyond 14 days, there were no reactive or grayzone HBsAg tests that could be attributed to recent HBV vaccination. HBsAg results reached a peak COI two to three days following vaccination before decaying. Further analysis of all the grayzone results within the 17 month study period (43 results out of 11,719 tests revealed that only 4 of 43 were the result of true HBV infection as verified by confirmatory testing. Conclusions Our study confirms that transient HBsAg positivity can occur in patients following HBV vaccination. The results suggest this positivity is unlikely to persist beyond 14 days

  20. Seroprevalence of HDV infection in HBsAg positive population in Ismailia, Egypt.

    Science.gov (United States)

    Gomaa, Nahed I M; Metwally, Lobna A; Nemr, Nader; Younis, Soha

    2013-01-01

    Hepatitis D virus (HDV) is a defective RNA virus that needs hepatitis B surface antigen (HBsAg) from HBV for transmission. HDV can lead to fulminant hepatitis and the progression of chronic liver damage in patients with chronic hepatitis B. The aim of this study was to determine the seroprevalence of HDV among HBsAg positive individuals in Ismailia, Egypt. Serum samples were collected from 170 HBsAg positive healthy individuals from Suez Canal University blood bank over a one year period. All of them were seeking blood donation and found to be HBsAg positive during viral hepatitis screening workups which is routinely done prior to donation. Serum samples were screened for IgG antibodies to hepatitis delta virus (HDV) using enzyme-linked immunosorbent assay (ELISA) method. Anti-HDV antibodies were detected in 8 (4.7%) individuals aged from 29-43 years. Liver function tests showed that serum ALT and AST levels were elevated in the HBsAglanti-HDV positive cases. It is concluded that the rate of HDV infection in Ismailia is high and further investigation is needed to validate the findings and raise awareness about the risk of dual HBV and HDV infection.

  1. Virus-like particle production with yeast: ultrastructural and immunocytochemical insights into Pichia pastoris producing high levels of the Hepatitis B surface antigen

    Directory of Open Access Journals (Sweden)

    Adnan Ahmad

    2011-06-01

    Full Text Available Abstract Background A protective immune response against Hepatitis B infection can be obtained through the administration of a single viral polypeptide, the Hepatitis B surface antigen (HBsAg. Thus, the Hepatitis B vaccine is generated through the utilization of recombinant DNA technology, preferentially by using yeast-based expression systems. However, the polypeptide needs to assemble into spherical particles, so-called virus-like particles (VLPs, to elicit the required protective immune response. So far, no clear evidence has been presented showing whether HBsAg assembles in vivo inside the yeast cell into VLPs or later in vitro during down-stream processing and purification. Results High level production of HBsAg was carried out with recombinant Pichia pastoris using the methanol inducible AOX1 expression system. The recombinant vaccine was isolated in form of VLPs after several down-stream steps from detergent-treated cell lysates. Search for the intracellular localization of the antigen using electron microscopic studies in combination with immunogold labeling revealed the presence of HBsAg in an extended endoplasmic reticulum where it was found to assemble into defined multi-layered, lamellar structures. The distance between two layers was determined as ~6 nm indicating that these lamellas represent monolayers of well-ordered HBsAg subunits. We did not find any evidence for the presence of VLPs within the endoplasmic reticulum or other parts of the yeast cell. Conclusions It is concluded that high level production and intrinsic slow HBsAg VLP assembly kinetics are leading to retention and accumulation of the antigen in the endoplasmic reticulum where it assembles at least partly into defined lamellar structures. Further transport of HBsAg to the Golgi apparatus is impaired thus leading to secretory pathway disfunction and the formation of an extended endoplasmic reticulum which bulges into irregular cloud-shaped formations. As VLPs were

  2. Importance of radioimmunoassays (HBsAg, HBsAb and HBcAb) for reducing the risk of hepatitis B transfer by blood

    International Nuclear Information System (INIS)

    Novak, J.; Kselikova, M.

    1979-01-01

    The principles are reported of the radioimmunoanalytical assay of the hepatitis B surface antigen, antibodies against this antigen which constitute immunologically indirect evidence, and antibodies against the nucleus of Dane's particles, which is circumstantial immunological evidence. The results obtained by radioimmunoassay are compared with those obtained by enzyme immunoassay. The results are presented obtained during the investigations of a total of 79 individuals, blood donors, health workers, and haemodialytic patients. In the whole group the hepatitis B surface antigen was proved by radioimmunoassay in 54%, by enzyme immunoassay in 47%; the antibody against the hepatitis B surface antigen in 19%; the antibody against the nucleus of the hepatitis B virus showed the largest proportion 75%. In 6.3% radioimmunoassay showed symptoms all three of hepatitis B, i.e., the surface antigen, the antibody against it, and the antibody against the hepatitis B virus nucleus; the correlation of the three symptoms is shown. The presence of HBsAg, HBsAb, and HBcAb is believed to be a contraindication of blood taking for routine purposes; the disappearance of HBsAg for a longer time may justify the re-inclusion among blood donors; the presence of HBsAb and HBcAb does not preclude the preparation of the plasma from such blood for the production of a specific anti-HBs immunoglobulin. (author)

  3. Clinical performance of a new hepatitis B surface antigen quantitative assay with automatic dilution

    Directory of Open Access Journals (Sweden)

    Ta-Wei Liu

    2015-01-01

    Full Text Available Hepatitis B virus surface antigen (HBsAg levels reflect disease status and can predict the clinical response to antiviral treatment; however, the emergence of HBsAg mutant strains has become a challenge. The Abbott HBsAg quantification assay provides enhanced detection of HBsAg and HBsAg mutants. We aimed to evaluate the performance of the Abbott HBsAg quantification assay with automatic sample dilutions (shortened as automatic Architect assay, compared with the Abbott HBsAg quantification assay with manual sample dilutions (shortened as manual Architect assay and the Roche HBsAg quantification assay with automatic sample dilutions (shortened as Elecsys. A total of 130 sera samples obtained from 87 hepatitis B virus (HBV-infected patients were collected to assess the correlation between the automatic and manual Architect assays. Among the 87 patients, 41 provided 42 sera samples to confirm the linearity and reproducibility of the automatic Architect assay, and find out the correlation among the Elecsys and two Architect assays. The coefficients of variation (0.44–9.53% and R2 = 0.996–1, which were both determined using values obtained from the automatic Architect assay, showed good reproducibility and linearity. Results of the two Architect assays demonstrated a feasible correlation (n = 130 samples; R = 0.898, p  0.93 in all cases. In conclusion, the correlation between the automatic and manual dilution Architect assays was feasible, particularly in the HBeAg-negative and low DNA groups. With lower labor costs and less human error than the manual version, the Abbott automatic dilution Architect assay provided a good clinical performance with regard to the HBsAg levels.

  4. Prevalence of Hepatitis B Surface Antigen in Pregnant Women in Beheshti Hospital of Kashan, Isfahan.

    Science.gov (United States)

    Afzali, Hasan; Momen Heravi, Mansooreh; Moravveji, Seyyed Alireza; Poorrahnama, Maryam

    2015-07-01

    The transmission of hepatitis B virus (HBV) is parenteral, sexual and prenatal. Prevention of vertical transmission of HBV is extremely important, because HBV infection in early life usually results in a chronic carrier state. There has been so much debate about hepatitis B surface antigen (HBsAg) screening in pregnant women. The aim of this study was to determine the prevalence of HBsAg+ among pregnant women referred to Beheshti hospital in Kashan in 2012. This descriptive study was carried out on 768 pregnant women, hospitalized in Beheshti Hospital of Kashan in 2012. After obtaining consent forms, the questionnaires including demographic and HBV infection-associated risk factors were filled through interview and then 5 mL blood was taken from each patient and HBsAg was examined by the enzyme-linked immunosorbent assay (ELISA) method. These data were analyzed by statistical package for the social science (SPSS) software. A total of 12 (1.56%) out of 768 pregnant women were HBsAg+. The mean age of HBsAg+ cases was 24.5 ± 4 years. Most of the HBsAg+ cases (66.6%) were uneducated; 17.7% of the pregnant women were not Iranian, of which 7.4% were HBsAg+. There was no high-risk job, recent dentistry interruption or skin tattoo among the HBsAg+ cases. In this study, 1.56% of pregnant women were HBsAg+, which was higher than the previous studies. This increasing prevalence may be due to the increase of non-Iranians' migrations to Iran. Control of migration and screening and vaccination of these groups should be considered by health policy makers.

  5. Induction of anti-HBs in HB vaccine nonresponders in vivo by hepatitis B surface antigen-pulsed blood dendritic cells.

    Science.gov (United States)

    Fazle Akbar, Sk Md; Furukawa, Shinya; Yoshida, Osamu; Hiasa, Yoichi; Horiike, Norio; Onji, Morikazu

    2007-07-01

    Antigen-pulsed dendritic cells (DCs) are now used for treatment of patients with cancers, however, the efficacy of these DCs has never been evaluated for prophylactic purposes. The aim of this study was (1) to prepare hepatitis B surface antigen (HBsAg)-pulsed human blood DCs, (2) to assess immunogenicity of HBsAg-pulsed DCs in vitro and (3) to evaluate the efficacy of HBsAg-pulsed DCs in hepatitis B (HB) vaccine nonresponders. Human peripheral blood DCs were cultured with HBsAg to prepare HBsAg-pulsed DCs. The expression of immunogenic epitopes of HBsAg on HBsAg-pulsed DCs was assessed in vitro. Finally, HBsAg-pulsed DCs were administered, intradermally to six HB vaccine nonresponders and the levels of antibody to HBsAg (anti-HBs) in the sera were assessed. HB vaccine nonresponders did not exhibit features of immediate, early or delayed adverse reactions due to administration of HBsAg-pulsed DCs. Anti-HBs were detected in the sera of all HB vaccine nonresponders within 28 days after administration of HBsAg-pulsed DCs. This study opens a new field of application of antigen-pulsed DCs for prophylactic purposes when adequate levels of protective antibody cannot be induced by traditional vaccination approaches.

  6. Purification of HBsAg produced by the human hepatoma cell line PLC/PRE/5 by affinity chromatography using monoclonal antibodies and application for ELISA diagnostic.

    Science.gov (United States)

    Merten, O W; Reiter, S; Scheirer, W; Katinger, H

    1983-01-01

    The human cell line PLC/PRF/5 (5) was used for the production of hepatitis B surface antigen subtype ad (HBsAg ad) and purified by affinity chromatography (AC) with monoclonal antibodies (mAb). mAb to HBsAg from mouse ascites have been purified by Protein A - AC prior coupling to AH-Sepharose 4B (Pharmacia). The combined procedure of ammonium-sulphate-precipitation of HBsAg from culture supernatants and immunosorbent-AC leads to approx. 700-fold purification. ELISA results using the mAb and the HBsAg for diagnostics of human serum, positive for anti-HBsAg-antibodies correlate with the RIA (AUSAB, Abbott).

  7. Prevalence of Hepatitis B Surface Antigen in US-Born and Foreign-Born Asian/Pacific Islander College Students

    Science.gov (United States)

    Quang, Yen N.; Vu, Joanne; Yuk, Jihey; Li, Chin-Shang; Chen, Moon; Bowlus, Christopher L.

    2010-01-01

    The prevalence of chronic hepatitis B (HBV) among college-age US-born Asian and Pacific Islanders (A/PI) is not well known. Objectives: To compare the prevalence of hepatitis B surface antigen (HBsAg) seropositivity in US-born to A/PI-born students at a public university. Participants: Undergraduate who self-identified themselves as A/PI. Results:…

  8. Hepatitis B virus surface antigen and anti-hepatitis C virus rapid tests underestimate hepatitis prevalence among HIV-infected patients.

    Science.gov (United States)

    Hønge, Bl; Jespersen, S; Medina, C; Té, Ds; da Silva, Zj; Ostergaard, L; Laursen, Al; Wejse, C; Krarup, H; Erikstrup, C

    2014-10-01

    In the case of coinfection with HIV and hepatitis B virus (HBV) and/or hepatitis C virus (HCV), hepatic disease progression is often accelerated, with higher rates of liver cirrhosis and liver-related mortality. We aimed to evaluate the performance of the rapid tests used routinely to detect HBV surface antigen (HBsAg) and anti-HCV among HIV-infected patients in Guinea-Bissau. Blood samples from HIV-infected patients in Guinea-Bissau were stored after testing for HBsAg and anti-HCV with rapid tests. Samples were subsequently re-tested for HBsAg and anti-HCV in Denmark. Two rapid tests were used in Guinea-Bissau: HBsAg Strip Ref 2034 (VEDA.LAB, Alençon, France; sensitivity 62.3%; specificity 99.2%) and HEPA-SCAN (Bhat Bio-Tech, Bangalore, India; sensitivity 57.1%; specificity 99.7%). In the two tests the ability to obtain the correct outcome depended on the antigen and antibody concentrations, respectively. Sex, age, CD4 cell count and antiretroviral therapy status did not differ between false negative and true positive samples in either of the tests. The study is limited by a low number of anti-HCV positive samples. New diagnostic rapid tests should always be evaluated in the setting in which they will be used before implementation. © 2014 British HIV Association.

  9. Use of radioimmune assay in investigating reagents to be used in the immunocytochemical localization of hepatitis B surface antigen in immune complexes in the kidney of patients with membranous nephropathy and Australia antigenaemia

    Energy Technology Data Exchange (ETDEWEB)

    Wolfe-Coote, S [South African Medical Research Council, Tygerberg (South Africa). Inst. for Electron Microscopy

    1983-09-01

    Radioimmune assay (RIA) was used to investigate the effect of fixatives on antigenicity of the hepatitis B surface antigen (HBsAg) and the effect of pronase on the elution of antibody (Ab) from the HBsAg-Ab complex. The effect of pronase on Ab elution was also tested on sections of kidney from a patient with the immune complex disease systemic lupus erythematosus (SLE). Immunoglobulin G (IgG) was located in pronase treated and untreated sections using the indirect immunoperoxidase technique. Glutareldehyde was shown to be the fixative of choice for studies involving HBsAg. All fixatives were shown to have less effect on antigenicity at 4/sup 0/C than at room temperature. Osmium tetroxide reduced antigenicity to one-third, even at 4/sup 0/C. RIA and SLE kidney section studies showed that Ab was eluted from immune complexes by pronase. Pre-fixation of the antigen (Ag) by glutaraldehyde appears to have no effect on the final elution, although fixation after pronase treatment seemed to enhance the elution effects. The availability of an RIA kit with HBsAg- and Ab-coated beads was of great assistance in evaluating reagents to be used in immunoperoxidase studies of HBsAg in immune complexes of patients with membranous nephropathy and Australia antigenaemia.

  10. Radioimmunoassay of surface antigen and core antibody of hepatitis B virus. Comparison of kits AUSRIA/CORE; AUSRIA II-125 and CORAB

    Energy Technology Data Exchange (ETDEWEB)

    Kselikova, M; Urbankova, J [Ustav Hematologie a Krevni Transfuze, Prague (Czechoslovakia)

    1984-08-01

    The sensitivity is compared of determination of surface antigen HBsAg and nuclear antibody HBcAb of the hepatitis B virus using kits for separate (AUSRIA II-125, CORAB) and simultaneous (AUSRIAsup(R)/CORE) determinations of third generation tests in selected samples of medical personnel, HBsAg carriers, patients at a dialysis centre, blood donors and in sera of HBsAg carriers diluted in steps from 4x10/sup -2/ to 4x10/sup -7/. HBsAg is always determined using the RIA technique, HBcAb is determined using the technique of radioimmunoassay with the CORAB kit and with the AUSRIA sup(R)/CORE kit using enzymeimmunoassay. The sensitivity of determination using the AUSRIA sup(R)/CORE kit is at least as good for both investigated indicators of the hepatitis B virus and that obtained using separate determination of HBsAg (AUSRIA II-125) and HBcAb (CORAB), this also using modified photocolorimetric determination. Only one AUSRIA/sup R//CORE kit was available for the investigation and the informative character of the report is emphasized.

  11. The impact of maternal HBsAg carrier status on pregnancy outcomes: a case-control study.

    Science.gov (United States)

    Tse, Ka Yu; Ho, Lai Fong; Lao, Terence

    2005-11-01

    To examine the impact of maternal HBsAg carrier status on pregnancy outcomes. Two hundred and fifty-three carriers of hepatitis B surface antigen (HBsAg) with singleton pregnancy, were retrospectively compared with 253 controls matched for age and parity and year of delivery. On univariable analysis, HBsAg carriers had higher incidences of threatened preterm labour at <37 weeks (11.9% vs. 6.3%, P=0.030), preterm birth at <34 weeks (4.7% vs. 1.2%, P=0.033), gestational diabetes mellitus (19.0% vs. 11.1%, P=0.012) and antepartum haemorrhage (11.5% vs. 5.5%, P=0.026). Their infants had lower Apgar scores at the 1st (8.47+/-1.67 vs. 8.87+/-1.07, P=0.001) and 5th minute (9.56+/-1.29 vs. 9.80+/-0.54, P=0.007), and increased incidence of intraventricular haemorrhage (4.7% vs. 0.8%, P=0.007). On multivariable analysis, the association between HBsAg carrier state with antepartum haemorrhage, gestational diabetes mellitus and threatened preterm labour were confirmed. HBsAg carriers have increased risk of gestational diabetes mellitus, antepartum haemorrhage, and threatened preterm labour. This may be related to the chronic inflammatory state in these subjects. The role of chronic HBV infection in pregnancy complications has to be further elucidated.

  12. Optimisation of secretion of recombinant HBsAg virus-like particles: Impact on the development of HIV-1/HBV bivalent vaccines

    NARCIS (Netherlands)

    Michel, Marie; Lone, Yu-Chun; Centlivre, Mireille; Roux, Pascal; Wain-Hobson, Simon; Sala, Monica

    2007-01-01

    The hepatitis B surface antigen (HBsAg) assembles into virus-like particles (VLPs) that can be used as carrier of immunogenic peptides for the development of bivalent vaccine candidates. It is shown here that by respecting certain qualitative features of mammalian preS1 and preS2 protein domains

  13. Hepatitis B Surface Antigen Seroprevalence among Children in Papua New Guinea, 2012–2013

    Science.gov (United States)

    Kitau, Russel; Sankar Datta, Siddhartha; Patel, Minal K.; Hennessey, Karen; Wannemuehler, Kathleen; Sui, Gerard; Lagani, William

    2015-01-01

    Approximately 8% of the population in Papua New Guinea (PNG) has chronic hepatitis B virus (HBV) infection. To decrease the burden of chronic HBV infection, a national 3-dose infant hepatitis B vaccination program was implemented starting in 1989, with a birth dose (BD) added to the schedule in 1992. To assess the impact of the hepatitis B vaccination program, we conducted a serosurvey among children born after vaccine introduction. During 2012–2013, a cross-sectional stratified four-stage cluster survey was conducted to estimate hepatitis B surface antigen (HBsAg) prevalence among children 4–6 years of age. We collected demographic data, vaccination history, and tested children for HBsAg. Of 2,133 participants, 2,130 children had vaccination data by either card or recall: 28% received a BD; 81% received ≥ 3 vaccine doses. Of 2,109 children providing a blood sample, 60 (2.3%) tested positive for HBsAg. This is the largest, most geographically diverse survey of hepatitis B vaccination and HBsAg seroprevalence done in PNG. Progress has been made in PNG toward the Western Pacific Regional goal to reduce the prevalence of chronic HBV infection to < 1% by 2017 among 5-year-old children. Vaccination efforts should be strengthened, including increasing BD coverage and completing the 3-dose series. PMID:25582692

  14. Quantitative Measurement of Serum Hepatitis B Surface Antigen Using an Immunoradiometric Assay in Chronic Hepatitis B

    International Nuclear Information System (INIS)

    Kwon, Hyun Woo; Lee, Ho Young; Kim, Seog Gyun; Kim, Won; Jung, Wong Jin; Kang, Keon Wook; Chung, June Key; Lee, Myung Chul; Lee, Dong Soo

    2011-01-01

    Measurement of serum hepatitis B virus surface antigen (HBsAg) levels is important for the management of chronic hepatitis D patients in terms of monitoring response to antiviral therapy. This study aimed to evaluate the diagnostic performance of a new diagnostic kit, which quantitatively measures serum HBsAg level using an immunoradiometric assay (IRMA) based method. Measurements were compared with those obtained using a chemiluminescent microparticle immunoassay (CMIA) based method. The blood samples of 96 patients with chronic hepatitis B were used in this study. Copy numbers of serum hepatitis B virus (HBV) DNA were determined in 23 of these samples. The correlation between and the concordance of IRMA and CMIA results were determined using Pearson's correlation coefficients. P values of 0.05 were considered to be statistically significant throughout. Laboratory diagnoses based on CMIA. Furthermors, serum HBsAg levels by IRMA were found to be highly correlated with those determined by CMIA (correlation coefficient R 2= 0.838, P 2= 0.067, P=0.316 by IRMA, and R 2= 0.101, P=0.215 by CMIA). The diagnostic performance of the investigated IRMA method of determining HBsAg levels was found to be comparable with that of a CMIA based method in chronic hepatitis B patients

  15. A simple and inexpensive point-of-care test for hepatitis B surface antigen detection: serological and molecular evaluation.

    Science.gov (United States)

    Gish, R G; Gutierrez, J A; Navarro-Cazarez, N; Giang, K; Adler, D; Tran, B; Locarnini, S; Hammond, R; Bowden, S

    2014-12-01

    Early identification of chronic hepatitis B is important for optimal disease management and prevention of transmission. Cost and lack of access to commercial hepatitis B surface antigen (HBsAg) immunoassays can compromise the effectiveness of HBV screening in resource-limited settings and among marginalized populations. High-quality point-of-care (POC) testing may improve HBV diagnosis in these situations. Currently available POC HBsAg assays are often limited in sensitivity. We evaluated the NanoSign(®) HBs POC chromatographic immunoassay for its ability to detect HBsAg of different genotypes and with substitutions in the 'a' determinant. Thirty-seven serum samples from patients with HBV infection, covering HBV genotypes A-G, were assessed for HBsAg titre with the Roche Elecsys HBsAg II quantification assay and with the POC assay. The POC assay reliably detected HBsAg at a concentration of at least 50 IU/mL for all genotypes, and at lower concentrations for some genotypes. Eight samples with substitutions in the HBV 'a' determinant were reliably detected after a 1/100 dilution. The POC strips were used to screen serum samples from 297 individuals at risk for HBV in local clinical settings (health fairs and outreach events) in parallel with commercial laboratory HBsAg testing (Quest Diagnostics EIA). POC testing was 73.7% sensitive and 97.8% specific for detection of HBsAg. Although the POC test demonstrated high sensitivity over a range of genotypes, false negatives were frequent in a clinical setting. Nevertheless, the POC assay offers advantages for testing in both developed and resource-limited countries due to its low cost (0.50$) and immediately available results. © 2014 John Wiley & Sons Ltd.

  16. Quantitative Measurement of Serum Hepatitis B Surface Antigen Using an Immunoradiometric Assay in Chronic Hepatitis B

    Energy Technology Data Exchange (ETDEWEB)

    Kwon, Hyun Woo; Lee, Ho Young; Kim, Seog Gyun; Kim, Won; Jung, Wong Jin; Kang, Keon Wook; Chung, June Key; Lee, Myung Chul; Lee, Dong Soo [Seoul National Univ. Seoul (Korea, Republic of)

    2011-03-15

    Measurement of serum hepatitis B virus surface antigen (HBsAg) levels is important for the management of chronic hepatitis D patients in terms of monitoring response to antiviral therapy. This study aimed to evaluate the diagnostic performance of a new diagnostic kit, which quantitatively measures serum HBsAg level using an immunoradiometric assay (IRMA) based method. Measurements were compared with those obtained using a chemiluminescent microparticle immunoassay (CMIA) based method. The blood samples of 96 patients with chronic hepatitis B were used in this study. Copy numbers of serum hepatitis B virus (HBV) DNA were determined in 23 of these samples. The correlation between and the concordance of IRMA and CMIA results were determined using Pearson's correlation coefficients. P values of 0.05 were considered to be statistically significant throughout. Laboratory diagnoses based on CMIA. Furthermors, serum HBsAg levels by IRMA were found to be highly correlated with those determined by CMIA (correlation coefficient R{sup 2=}0.838, P<0.001). Serum HBsAg level and serum HBV DNA copies were found to be linearly related by both methods (R{sup 2=}0.067, P=0.316 by IRMA, and R{sup 2=}0.101, P=0.215 by CMIA). The diagnostic performance of the investigated IRMA method of determining HBsAg levels was found to be comparable with that of a CMIA based method in chronic hepatitis B patients.

  17. Hepatitis B surface antigen titer is a good indicator of durable viral response after entecavir off-treatment for chronic hepatitis B

    Directory of Open Access Journals (Sweden)

    Han Ah Lee

    2016-09-01

    Full Text Available Background/Aims Clear indicators for stopping antiviral therapy in chronic hepatitis B (CHB patients are not yet available. Since the level of hepatitis B surface antigen (HBsAg is correlated with covalently closed circular DNA, the HBsAg titer might be a good indicator of the off-treatment response. This study aimed to determine the relationship between the HBsAg titer and the entecavir (ETV off-treatment response. Methods This study analyzed 44 consecutive CHB patients (age, 44.6±11.4 years, mean±SD; men, 63.6%; positive hepatitis B envelope antigen (HBeAg at baseline, 56.8%; HBV DNA level, 6.8±1.3 log10 IU/mL treated with ETV for a sufficient duration and in whom treatment was discontinued after HBsAg levels were measured. A virological relapse was defined as an increase in serum HBV DNA level of >2000 IU/mL, and a clinical relapse was defined as a virological relapse with a biochemical flare, defined as an increase in the serum alanine aminotransferase level of >2 × upper limit of normal. Results After stopping ETV, virological relapse and clinical relapse were observed in 32 and 24 patients, respectively, during 20.8±19.9 months of follow-up. The cumulative incidence rates of virological relapse were 36.2% and 66.2%, respectively, at 6 and 12 months, and those of clinical relapse were 14.3% and 42.3%. The off-treatment HBsAg level was an independent factor associated with clinical relapse (hazard ratio, 2.251; 95% confidence interval, 1.076–4.706; P=0.031. When patients were grouped according to off-treatment HBsAg levels, clinical relapse did not occur in patients with an off-treatment HBsAg level of ≤2 log10 IU/mL (n=5, while the incidence rates of clinical relapse at 12 months after off-treatment were 28.4% and 55.7% in patients with off-treatment HBsAg levels of >2 and ≤3 log10 IU/mL (n=11 and >3 log10 IU/mL (n=28, respectively. Conclusion The off-treatment HBsAg level is closely related to clinical relapse after treatment

  18. Hepatitis B surface antigen quantity positively correlates with plasma levels of microRNAs differentially expressed in immunological phases of chronic hepatitis B in children

    DEFF Research Database (Denmark)

    Winther, Thilde Nordmann; Heiberg, Ida Louise; Bang-Berthelsen, Claus Heiner

    2013-01-01

    Children with chronic hepatitis B (CHB) are at high risk of progressive liver disease. It is suggested that a newly-identified panel of 16 microRNAs is important in the pathogenesis of CHB in children. Subviral hepatitis B surface antigen (HBsAg) particles are produced in large excess over infect...

  19. Poly-ϵ-caprolactone/chitosan nanoparticles provide strong adjuvant effect for hepatitis B antigen.

    Science.gov (United States)

    Jesus, Sandra; Soares, Edna; Borchard, Gerrit; Borges, Olga

    2017-10-01

    This work aims to investigate the adjuvant effect of poly-ϵ-caprolactone/chitosan nanoparticles (NPs) for hepatitis B surface antigen (HBsAg) and the plasmid DNA encoding HBsAg (pRC/CMV-HBs). Both antigens were adsorbed onto preformed NPs. Vaccination studies were performed in C57BL/6 mice. Transfection efficiency was investigated in A549 cell line. HBsAg-adsorbed NPs generated strong anti-HBsAg IgG titers, mainly of IgG1 isotype, and induced antigen-specific IFN-γ and IL-17 secretion by spleen cells. The addition of pRC/CMV-HBs to the HBsAg-adsorbed NPs inhibited IL-17 secretion but had minor effect on IFN-γ levels. Lastly, pRC/CMV-HBs-loaded NPs generated a weak serum antibody response. Poly-ϵ-caprolactone/chitosan NPs provide a strong humoral adjuvant effect for HBsAg and induce a Th1/Th17-mediated cellular immune responses worth explore for hepatitis B virus vaccination.

  20. A novel method for sensitive, low-cost and portable detection of hepatitis B surface antigen using a personal glucose meter.

    Science.gov (United States)

    Taebi, Saeed; Keyhanfar, Mehrnaz; Noorbakhsh, Abdollah

    2018-04-12

    Hepatitis B virus (HBV) infection is the major public health problem leading cause of death worldwide. The most important diagnostic marker for this infection is hepatitis B surface antigen (HBsAg). In this study, a novel, inexpensive, portable and sensitive ELISA method was designed and investigated for diagnosis of HBsAg based on the functionalized Fe 3 O 4 and Al 2 O 3 nanoparticles, with the strategy for detecting the concentration of glucose using a cheap and accessible personal glucose meter (PGM). The ELISA system was constructed using hepatitis B antibody against HBsAg immobilized on streptavidin coated magnetic iron oxide particles (S-Fe 3 O 4 ) as the capture antibody (Ab 1 ). In addition, another hepatitis B antibody against different epitope of HBsAg (Ab 2 ) and glucoamylase both were immobilized on Al 2 O 3 nanoparticles. After formation of the sandwich immune complex between Ab 1 and Ab 2 immobilized on S-Fe 3 O 4 and Al 2 O 3 NPs, respectively, through HBsAg, starch was converted into glucose using glucoamylase. Then, the glucose concentration was measured using PGM. The concentration of HBsAg was calculated based on the linear relation between the concentrations of HBsAg and glucose. Under optimal conditions, this assay showed detection limit values of 0.3 to 0.4 ng ml -1 for "ay" and "ad" subtypes of HBsAg, respectively. The results indicate that the designed assay is comparable to the commercial kits in terms of sensitivity, on-site, specificity, cost, simplicity, portability and reproducibility. The presented method can be used in disadvantaged areas of the world and blood transfusion centers. To the best of our knowledge, this is the first report of using PGMs for HBSAg detection. Copyright © 2018 Elsevier B.V. All rights reserved.

  1. A self-amplified transistor immunosensor under dual gate operation: highly sensitive detection of hepatitis B surface antigen

    Science.gov (United States)

    Lee, I.-K.; Jeun, M.; Jang, H.-J.; Cho, W.-J.; Lee, K. H.

    2015-10-01

    Ion-sensitive field-effect transistors (ISFETs), although they have attracted considerable attention as effective immunosensors, have still not been adopted for practical applications owing to several problems: (1) the poor sensitivity caused by the short Debye screening length in media with high ion concentration, (2) time-consuming preconditioning processes for achieving the highly-diluted media, and (3) the low durability caused by undesirable ions such as sodium chloride in the media. Here, we propose a highly sensitive immunosensor based on a self-amplified transistor under dual gate operation (immuno-DG ISFET) for the detection of hepatitis B surface antigen. To address the challenges in current ISFET-based immunosensors, we have enhanced the sensitivity of an immunosensor by precisely tailoring the nanostructure of the transistor. In the pH sensing test, the immuno-DG ISFET showed superior sensitivity (2085.53 mV per pH) to both standard ISFET under single gate operation (58.88 mV per pH) and DG ISFET with a non-tailored transistor (381.14 mV per pH). Moreover, concerning the detection of hepatitis B surface antigens (HBsAg) using the immuno-DG ISFET, we have successfully detected trace amounts of HBsAg (22.5 fg mL-1) in a non-diluted 1× PBS medium with a high sensitivity of 690 mV. Our results demonstrate that the proposed immuno-DG ISFET can be a biosensor platform for practical use in the diagnosis of various diseases.Ion-sensitive field-effect transistors (ISFETs), although they have attracted considerable attention as effective immunosensors, have still not been adopted for practical applications owing to several problems: (1) the poor sensitivity caused by the short Debye screening length in media with high ion concentration, (2) time-consuming preconditioning processes for achieving the highly-diluted media, and (3) the low durability caused by undesirable ions such as sodium chloride in the media. Here, we propose a highly sensitive immunosensor

  2. Long-term effect of interferon plus ribavirin on hepatitis B surface antigen seroclearance in patients dually infected with hepatitis B and C viruses.

    Directory of Open Access Journals (Sweden)

    Ming-Lun Yeh

    Full Text Available BACKGROUND: Interferon-α/ribavirin combination therapy might promote hepatitis B surface antigen (HBsAg seroclearance in patients dually infected with hepatitis B and C viruses (HBV/HCV, but the long-term effect remains unclear. We aimed to investigate the rate of and the factors associated with HBsAg seroclearance during long-term follow-up after interferon-α/ribavirin combination therapy in HBV/HCV dually-infected patients. METHODOLOGY/PRINCIPAL FINDINGS: Eighty-one patients who received interferon-α/ribavirin combination therapy for 24 weeks with a follow-up period of >24 weeks were enrolled. HBV serological markers and HBV DNA were determined every 6 months. Early and late HBsAg seroclearance were defined as HBsAg loss in less or more than 6 months after end-of-treatment, respectively. Fifteen (18.5% patients had HBsAg seroclearance during a mean follow-up period of 3.4 (0.5-5.1 years. The 5-year cumulative incidence was 25.6%. Baseline cirrhosis and HBV DNA negativity 1 year after end-of-treatment were independently predictive of HBsAg seroclearance with an odds ratio (OR, 95% confidence intervals (CI of 16.6, 1.8-153 and 9.2, 1.4-62.1, respectively, by Cox regression hazard analysis. Four patients developed early and 11 developed late HBsAg seroclearance, respectively. Cox regression hazard analysis showed no factor was associated with early HBsAg seroclearance, whilst HBV DNA negativity 1 year after end-of-treatment was the only significant factor predicting late HBsAg loss (OR, 43.0; CI, 2.5-745. Five patients had HBsAg seroconversion with a 5-year cumulative incidence of 8.3%. HBV DNA negativity at baseline and one year after EOT had a trend for HBsAg seroconversion. HCV response did not correlate to HBsAg loss. CONCLUSIONS: We demonstrated that interferon-α/ribavirin had long-term effect on HBsAg seroclearance in dually HBV/HCV-infected patients. Baseline cirrhosis and seroclearance of HBV DNA 1 year after end-of-treatment were

  3. Strong and multi-antigen specific immunity by hepatitis B core antigen (HBcAg)-based vaccines in a murine model of chronic hepatitis B: HBcAg is a candidate for a therapeutic vaccine against hepatitis B virus.

    Science.gov (United States)

    Akbar, Sheikh Mohammad Fazle; Chen, Shiyi; Al-Mahtab, Mamun; Abe, Masanori; Hiasa, Yoichi; Onji, Morikazu

    2012-10-01

    Experimental evidence suggests that hepatitis B core antigen (HBcAg)-specific cytotoxic T lymphocytes (CTL) are essential for the control of hepatitis B virus (HBV) replication and prevention of liver damage in patients with chronic hepatitis B (CHB). However, most immune therapeutic approaches in CHB patients have been accomplished with hepatitis B surface antigen (HBsAg)-based prophylactic vaccines with unsatisfactory clinical outcomes. In this study, we prepared HBsAg-pulsed dendritic cells (DC) and HBcAg-pulsed DC by culturing spleen DC from HBV transgenic mice (HBV TM) and evaluated the immunomodulatory capabilities of these antigens, which may serve as a better therapy for CHB. The kinetics of HBsAg, antibody levels against HBsAg (anti-HBs), proliferation of HBsAg- and HBcAg-specific lymphocytes, production of antigen-specific CTL, and activation of endogenous DC were compared between HBV TM vaccinated with either HBsAg- or HBcAg-pulsed DC. Vaccination with HBsAg-pulsed DC induced HBsAg-specific immunity, but failed to induce HBcAg-specific immunity in HBV TM. However, immunization of HBV TM with HBcAg-pulsed DC resulted in: (1) HBsAg negativity, (2) production of anti-HBs, and (3) development of HBsAg- and HBcAg-specific T cells and CTL in the spleen and the liver. Additionally, significantly higher levels of activated endogenous DC were detected in HBV TM immunized with HBcAg-pulsed DC compared to HBsAg-pulsed DC (pdamage suggests that HBcAg should be an integral component of the therapeutic vaccine against CHB. Copyright © 2012 Elsevier B.V. All rights reserved.

  4. [Prevalence of hepatitis B surface antigen and its associated factors in Senegalese military personnel sent on mission to Darfur].

    Science.gov (United States)

    Diop, Moustapha; Diouf, Assane; Seck, Said Malaobé; Lo, Gora; Ka, Daye; Massaly, Aminata; Dieye, Alassane; Fall, Ndeye Maguette; Cisse-Diallo, Viviane Marie Pierre; Diallo-Mbaye, Khardiata; Lakhe, Ndèye Aissatou; Fortes-Déguénonvo, Louise; Ndour, Cheikh Tidiane; Soumaré, Maserigne; Seydi, Moussa

    2017-01-01

    In Senegal, 85% of the adult population have been exposed to the hepatitis B virus and about 11% of them are chronic surface antigen (HBsAg) carriers. This infection is poorly documented among Senegalese Armed Forces. The aim of this study was to assess the prevalence of HBsAg in Senegalese military personnel on mission to Darfur (Sudan) and to identify its associated factors. We conducted a cross-sectional study among Senegalese military personnel stationed in Darfur from 1 July 2014 to 31 July 2014. HBsAg test was performed on serum of participants using immunochromatographic method. The search for associated factors was carried out using multivariate logistic regression. Our study included 169 male military personnel. The average age was 36.6 ± 9.5 years. A history of familial chronic liver disease, blood exposure and sexual exposure were found in 12.4%, 24.9% and 45.6% of the study population respectively. HBsAg was found in 24 participants [14.2% (CI 95% = 8.9-19.5)]. After adjusting for potential confounding factors, age (OR = 0.9 CI 95% = 0.9-1.0), university level (OR = 9.5 CI 95% = 1.3 - 67 , 1>) and sexual exposure (OR = 3.3 <; CI 95% = 1.0 - 10.3) were independently associated with hepatitis B. Our study shows high prevalence of HBsAg and underlines the need for further evaluation of hepatitis B in this population.

  5. Viral hepatitis and rapid diagnostic test based screening for HBsAg in HIV-infected patients in rural Tanzania.

    Directory of Open Access Journals (Sweden)

    Fabian C Franzeck

    Full Text Available BACKGROUND: Co-infection with hepatitis B virus (HBV is highly prevalent in people living with HIV in Sub-Saharan Africa. Screening for HBV surface antigen (HBsAg before initiation of combination antiretroviral therapy (cART is recommended. However, it is not part of diagnostic routines in HIV programs in many resource-limited countries although patients could benefit from optimized antiretroviral therapy covering both infections. Screening could be facilitated by rapid diagnostic tests for HBsAg. Operating experience with these point of care devices in HIV-positive patients in Sub-Saharan Africa is largely lacking. We determined the prevalence of HBV and Hepatitis C virus (HCV infection as well as the diagnostic accuracy of the rapid test device Determine HBsAg in an HIV cohort in rural Tanzania. METHODS: Prospectively collected blood samples from adult, HIV-1 positive and antiretroviral treatment-naïve patients in the Kilombero and Ulanga antiretroviral cohort (KIULARCO in rural Tanzania were analyzed at the point of care with Determine HBsAg, a reference HBsAg EIA and an anti-HCV EIA. RESULTS: Samples of 272 patients were included. Median age was 38 years (interquartile range [IQR] 32-47, 169/272 (63% subjects were females and median CD4+ count was 250 cells/µL (IQR 97-439. HBsAg was detected in 25/272 (9.2%, 95% confidence interval [CI] 6.2-13.0% subjects. Of these, 7/25 (28% were positive for HBeAg. Sensitivity of Determine HBsAg was rated at 96% (95% CI 82.8-99.6% and specificity at 100% (95% CI, 98.9-100%. Antibodies to HCV (anti-HCV were found in 10/272 (3.7%, 95% CI 2.0-6.4% of patients. CONCLUSION: This study reports a high prevalence of HBV in HIV-positive patients in a rural Tanzanian setting. The rapid diagnostic test Determine HBsAg is an accurate assay for screening for HBsAg in HIV-1 infected patients at the point of care and may further help to guide cART in Sub-Saharan Africa.

  6. Liver cancer: expression features of hepatitis B antigens

    Directory of Open Access Journals (Sweden)

    V. A. Tumanskiy

    2013-12-01

    Full Text Available Introduction. Hepatocellular carcinoma (HCC is currently the fifth most common malignancy in men and the eighth in women worldwide. According to the latest European Union countries’ statistics the incidence of HC cancer is about 8,29 per 100000 accidents, cholangiocellular (CC cancer – 0,9-1,3 per 100 thousand of population per year[10,14]. Hepatitis B virus (HBV is the major etiologic factor for the development of HCC [18]. People chronically infected with HBV are 20 times more likely to develop liver cancer than uninfected people [1,22,28]. Many studies have shown the association between Hepatitis B virus (HBV and hepatitis C virus (HCV infections and the development of cholangiocarcinoma (CCA [4,6,9,11,12]. At the same time, the expression features of HBsAg, HBcAg in HCC and CCA have not been studied clearly yet. Aim of investigation: to study the expression features of hepatitis B antigens in tumor tissue from patients with hepatocellular carcinoma and cholangiocarcinoma. Materials and methods. The complex pathomorphological research was performed using liver biopsies of 87 patients aged from 33 up to 83 years, where 50 (57,47% of them had HCC carcinoma and 37 (42,53% had cholangiocellular cancer. 15 patients among examined 87 ones were ill with chronic viral hepatitis (11 were ill with HCV, 3 – HBV B, 1 – HBV + HCV before, 72 cancer patients, corresponding to the clinical data, never had this one in their past medical history. The localization of hepatitis B surface antigen (HBsAg and core antigen (HBcAg was investigated by an indirect immunoperoxidase method in formalin-fixed, paraffin-embedded liver specimens obtained from 50 (57,47% patients with hepatocellular carcinoma and 37 (42,53% patients with cholangiocarcinoma. using antibodies Rb a-Hu Primary Hepatitis B Virus Core Antigen (HBcAg and Mo a-Hu Primary Hepatitis B Virus Surface Antigen (HBsAg, Сlone 3E7, and visualization system DAKO EnVision+ with diaminobenzidine. Liver

  7. Hepatitis B virus surface antigen impairs myeloid dendritic cell function: a possible immune escape mechanism of hepatitis B virus

    Science.gov (United States)

    Op den Brouw, Marjoleine L; Binda, Rekha S; van Roosmalen, Mark H; Protzer, Ulrike; Janssen, Harry L A; van der Molen, Renate G; Woltman, Andrea M

    2009-01-01

    Chronic hepatitis B virus (HBV) infection is the result of an inadequate immune response towards the virus. Myeloid dendritic cells (mDC) of patients with chronic HBV are impaired in their maturation and function, resulting in more tolerogenic rather than immunogenic responses, which may contribute to viral persistence. The mechanism responsible for altered mDC function remains unclear. The HBV-infected patients display large amounts of HBV particles and viral proteins in their circulation, especially the surface antigen HBsAg, which allows multiple interactions between the virus, its viral proteins and DC. To assess whether HBV directly influences mDC function, the effects of HBV and HBsAg on human mDC maturation and function were investigated in vitro. As already described for internalization of HBV by DC, the present study shows that peripheral blood-derived mDC of healthy controls also actively take up HBsAg in a time-dependent manner. Cytokine-induced maturation in the presence of HBV or HBsAg resulted in a significantly more tolerogenic mDC phenotype as demonstrated by a diminished up-regulation of costimulatory molecules and a decreased T-cell stimulatory capacity, as assessed by T-cell proliferation and interferon-γ production. In addition, the presence of HBV significantly reduced interleukin-12 production by mDC. These results show that both HBV particles and purified HBsAg have an immune modulatory capacity and may directly contribute to the dysfunction of mDC in patients with chronic HBV. The direct immune regulatory effect of HBV and circulating HBsAg particles on the function of DC can be considered as part of the mechanism by which HBV escapes immunity. PMID:18624732

  8. Detection of hepatitis B virus infection in HBsAg-negative patients by monoclonal antibodies against HBsAg

    Energy Technology Data Exchange (ETDEWEB)

    Fujita, Y K

    1986-11-01

    The technique of producing antibody secreting hybridomas has made available high-affinity antibodies of predefined specificity for use as diagnostic reagents. Recently, high-affinity monoclonal antibodies to hepatitis B surface antigens (HBsAg) were produced and characterized. Immunoassay was developed using these antibodies for the detection of HBsAg-associated determinants. The present study indicated the significance of the enhanced detection by monoclonal radioimmunoassay (M-RIA) of HBsAg in sera of patients with hepatitis B virus infection. The M-RIA detected HBsAg in sera of hemodialysis patients and blood donor defined as HBsAg-negative by polyclonal RIA (2.2 %, 0.14 %, respectively). Furthermore, individuals with chronic liver diseases were reactive only in the M-RIA (chronic hepatitis 4.8 %, liver cirrhosis 10.0 %, hepatocellular carcinoma 22.2 %). It is noteworthy that some of these patients were diagnosesed as so-called non-A non-B hepatitis because of no serological markers of hepatitis B virus infection such as HBsAb and HBcAb. The enhanced performance of the monoclonal RIA compared to conventional RIA was due to the increased sensitivity of the assay (55 pg vs 230 pg/ml). In immunohistochemical study, one of the monoclonal antibody named 5C3 was applied for detection of HBsAg in the formalin-fixed paraffin-embedded liver. HBsAg was detected in 6 out of 41 HBsAg-seronegative liver specimen. Thus, the studies showed the importance of the clinical application of monoclonal antibodies such as immunoassay and immunohistochemical study in the diagnosis of hepatitis B virus infection.

  9. Detection of hepatitis B virus infection in HBsAg-negative patients by monoclonal antibodies against HBsAg

    International Nuclear Information System (INIS)

    Fujita, Y.K.

    1986-01-01

    The technique of producing antibody secreting hybridomas has made available high-affinity antibodies of predefined specificity for use as diagnostic reagents. Recently, high-affinity monoclonal antibodies to hepatitis B surface antigens (HBsAg) were produced and characterized. Immunoassay was developed using these antibodies for the detection of HBsAg-associated determinants. The present study indicated the significance of the enhanced detection by monoclonal radioimmunoassay (M-RIA) of HBsAg in sera of patients with hepatitis B virus infection. The M-RIA detected HBsAg in sera of hemodialysis patients and blood donor defined as HBsAg-negative by polyclonal RIA (2.2 %, 0.14 %, respectively). Furthermore, individuals with chronic liver diseases were reactive only in the M-RIA (chronic hepatitis 4.8 %, liver cirrhosis 10.0 %, hepatocellular carcinoma 22.2 %). It is noteworthy that some of these patients were diagnosesed as so-called non-A non-B hepatitis because of no serological markers of hepatitis B virus infection such as HBsAb and HBcAb. The enhanced performance of the monoclonal RIA compared to conventional RIA was due to the increased sensitivity of the assay (55 pg vs 230 pg/ml). In immunohistochemical study, one of the monoclonal antibody named 5C3 was applied for detection of HBsAg in the formalin-fixed paraffin-embedded liver. HBsAg was detected in 6 out of 41 HBsAg-seronegative liver specimen. Thus, the studies showed the importance of the clinical application of monoclonal antibodies such as immunoassay and immunohistochemical study in the diagnosis of hepatitis B virus infection. (author)

  10. Genetic variation of hepatitis B surface antigen among acute and chronic hepatitis B virus infections in The Netherlands.

    Science.gov (United States)

    Cremer, Jeroen; Hofstraat, Sanne H I; van Heiningen, Francoise; Veldhuijzen, Irene K; van Benthem, Birgit H B; Benschop, Kimberley S M

    2018-05-24

    Genetic variation within hepatitis B surface antigen (HBsAg), in particular within the major hydrophobic region (MHR), is related to immune/vaccine and test failures and can have a significant impact on the vaccination and diagnosis of acute infection. This study shows, for the first time, variation among acute cases and compares the amino acid variation within the HBsAg between acute and chronic infections. We analyzed the virus isolated from 1231 acute and 585 chronic cases reported to an anonymized public health surveillance database between 2004 and 2014 in The Netherlands. HBsAg analysis revealed the circulation of 6 genotypes (Gt); GtA was the dominant genotype followed by GtD among both acute (68.2% and 17.4%, respectively) and chronic (34.9% and 34.2%, respectively) cases. Variation was the highest among chronic strains compared to that among acute strains. Both acute and chronic GtD showed the highest variation compared to that of other genotypes (P < .01). Substitutions within the MHR were found in 8.5% of the acute strains and 18.6% of the chronic strains. Specific MHR substitutions described to have an impact on vaccine/immune escape and/or HBsAg test failure were found among 4.1% of the acute strains and 7.0% of the chronic strains. In conclusion, we show a high variation of HBsAg among acute and chronic hepatitis B virus-infected cases in The Netherlands, in particular among those infected with GtD, and compare, for the first time, variation in frequencies between acute and chronic cases. Additional studies on the impact of these variations on vaccination and test failure need to be conducted, as well as whether HBsAg false-negative variants have been missed. © 2018 The Authors. Journal of Medical Virology Published by Wiley Periodicals, Inc.

  11. Construction and expression of hepatitis B surface antigen escape variants within the "a" determinant by site directed mutagenesis.

    Science.gov (United States)

    Golsaz Shirazi, Forough; Amiri, Mohammad Mehdi; Mohammadi, Hamed; Bayat, Ali Ahmad; Roohi, Azam; Khoshnoodi, Jalal; Zarnani, Amir Hassan; Jeddi-Tehrani, Mahmood; Kardar, Gholam Ali; Shokri, Fazel

    2013-09-01

    The antibody response to hepatitis B surface antigen (HBsAg) controls hepatitis B virus infection. The "a" determinant of HBsAg is the most important target for protective antibody response, diagnosis and immunoprophylaxis. Mutations in this area may induce immune escape mutants and affect the performance of HBsAg assays. To construct clinically relevant recombinant mutant forms of HBsAg and assessment of their reactivity with anti-HBs monoclonal antibodies (MAbs). Wild type (wt) and mutant (mt) HBsAg genes were constructed by site directed mutagenesis and SEOing PCR. The amplified genes were inserted into pCMV6-neo plasmid and transfected in CHO cell line. The expression of wt- and mtHBsAg was assessed by commercial ELISA assays and stable cells were established and cloned by limiting dilution. The recombinant mutants were further characterized using a panel of anti-HBs monoclonal antibodies (MAbs) and the pattern of their reactivity was assessed by ELISA. Ten HBsAg mutants having single mutation within the "a" determinant including P120E, T123N, Q129H, M133L, K141E, P142S, D144A, G145R, N146S and C147S together with a wt form were successfully constructed and expressed in CHO cells. Reactivity of anti-HBs MAbs with mtHBsAgs displayed different patterns. The effect of mutations on antibody binding differed depending on the amino acid involved and its location within the ''a'' determinant. Mutation at amino acids 123 and 145 resulted in either complete loss or significant reduction of binding to all anti-HBs MAbs. Our panel of mtHBsAgs is a valuable tool for assessment of the antibody response to HBV escape mutants and may have substantial implications in HBV immunological diagnostics.

  12. Luteolin-7-O-Glucoside Present in Lettuce Extracts Inhibits Hepatitis B Surface Antigen Production and Viral Replication by Human Hepatoma Cells in Vitro

    Directory of Open Access Journals (Sweden)

    Xiao-Xian Cui

    2017-12-01

    Full Text Available Hepatitis B virus (HBV infection is endemic in Asia and chronic hepatitis B (CHB is a major public health issue worldwide. Current treatment strategies for CHB are not satisfactory as they induce a low rate of hepatitis B surface antigen (HBsAg loss. Extracts were prepared from lettuce hydroponically cultivated in solutions containing glycine or nitrate as nitrogen sources. The lettuce extracts exerted potent anti-HBV effects in HepG2 cell lines in vitro, including significant HBsAg inhibition, HBV replication and transcription inhibition, without exerting cytotoxic effects. When used in combination interferon-alpha 2b (IFNα-2b or lamivudine (3TC, the lettuce extracts synergistically inhibited HBsAg expression and HBV replication. By using differential metabolomics analysis, Luteolin-7-O-glucoside was identified and confirmed as a functional component of the lettuce extracts and exhibited similar anti-HBV activity as the lettuce extracts in vitro. The inhibition rate on HBsAg was up to 77.4%. Moreover, both the lettuce extracts and luteolin-7-O-glucoside functioned as organic antioxidants and, significantly attenuated HBV-induced intracellular reactive oxygen species (ROS accumulation. Luteolin-7-O-glucoside also normalized ROS-induced mitochondrial membrane potential damage, which suggests luteolin-7-O-glucoside inhibits HBsAg and HBV replication via a mechanism involving the mitochondria. Our findings suggest luteolin-7-O-glucoside may have potential value for clinical application in CHB and may enhance HBsAg and HBV clearance when used as a combination therapy.

  13. Quantitative HBsAg and HBeAg predict hepatitis B seroconversion after initiation of HAART in HIV-HBV coinfected individuals.

    Directory of Open Access Journals (Sweden)

    Gail V Matthews

    Full Text Available OBJECTIVE: Anti-HBe seroconversion and HBsAg loss are important therapeutic endpoints in patients with hepatitis B virus (HBV infection. Quantitative measures of hepatitis B surface antigen (qHBsAg and e antigen (qHBeAg have been identified as potentially useful indicators of therapeutic response in HBV monoinfection. The aim of this study was to examine serological change including quantitative biomarkers in HIV-HBV coinfected patients initiating HBV active antiretroviral therapy (ART. METHODS: HIV-HBV coinfected individuals from Thailand were followed for up to 168 weeks post ART. Rates and associations of qualitative serological change were determined. Longitudinal changes in qHBsAg and qHBeAg were measured and their utility as predictors of response examined. RESULTS: Forty seven patients were included of whom 27 (57% were HBeAg positive at baseline. Median CD4 count was 48 cells/mm(3. Over a median follow-up of 108 weeks 48% (13/27 lost HBeAg, 12/27 (44% achieved anti-HBe seroconversion and 13% (6/47 HBsAg loss. Anti-HBe seroconversion was associated with higher baseline ALT (p = 0.034, lower qHBsAg (p = 0.015, lower qHBeAg (p = 0.031 and greater HBV DNA decline to week 24 (p = 0.045. Sensitivity and specificity for qHBsAg and qHBeAg decline of >0.5 log at week 12 and >1.0 log at week 24 were high for both anti-HBe seroconversion and HBsAg loss. CONCLUSIONS: Rates of serological change in these HIV-HBV coinfected individuals with advanced immunodeficiency initiating HBV-active ART were high. Baseline and on treatment factors were identified that were associated with a greater likelihood of subsequent anti-HBe seroconversion, including both quantitative HBsAg and HBeAg, suggesting these biomarkers may have utility in this clinical setting.

  14. HBsAg carrier status and the association between gestational diabetes with increased serum ferritin concentration in Chinese women.

    Science.gov (United States)

    Lao, Terence T; Tse, Ka-Yu; Chan, Louis Y; Tam, Kar-Fai; Ho, Lai-Fong

    2003-11-01

    To determine whether the high prevalence of hepatitis B surface antigen (HBsAg) carriage in our population can explain the previous observation of an association between increased maternal serum ferritin concentration and gestational diabetes in Hong Kong Chinese women. A retrospective study was performed on 767 nonanemic women with singleton pregnancy who had iron status assessed at 28-30 weeks. The result of the routine antenatal HBsAg screening was retrieved from patient records. The HBsAg-positive and -negative groups were compared for maternal characteristics, prevalence of gestational diabetes in the third trimester, prevalence of high serum ferritin and iron concentrations, and transferrin saturation, which is defined as a value in the highest quartile established by the measurements obtained from the HBsAg-negative group. The incidences of oral glucose tolerance test and gestational diabetes were significantly increased in the HBsAg-positive group. The HBsAg-positive women with gestational diabetes had significantly increased prevalence of high serum ferritin compared with the HBsAg-negative women, irrespective of the latter's gestational diabetes status. Multiple logistic regression analysis confirmed the independent association between HBsAg carrier status with gestational diabetes (relative risk 3.51, 95% CI 1.83-6.73) but excluded high ferritin as an independent factor. Our results indicate that maternal HBsAg carriage could explain in part the association between increased serum ferritin concentration with gestational diabetes in Hong Kong Chinese women, and that HBsAg carrier status is an independent risk factor for gestational diabetes.

  15. Performance evaluation of new automated hepatitis B viral markers in the clinical laboratory: two quantitative hepatitis B surface antigen assays and an HBV core-related antigen assay.

    Science.gov (United States)

    Park, Yongjung; Hong, Duck Jin; Shin, Saeam; Cho, Yonggeun; Kim, Hyon-Suk

    2012-05-01

    We evaluated quantitative hepatitis B surface antigen (qHBsAg) assays and a hepatitis B virus (HBV) core-related antigen (HBcrAg) assay. A total of 529 serum samples from patients with hepatitis B were tested. HBsAg levels were determined by using the Elecsys (Roche Diagnostics, Indianapolis, IN) and Architect (Abbott Laboratories, Abbott Park, IL) qHBsAg assays. HBcrAg was measured by using Lumipulse HBcrAg assay (Fujirebio, Tokyo, Japan). Serum aminotransferases and HBV DNA were respectively quantified by using the Hitachi 7600 analyzer (Hitachi High-Technologies, Tokyo, Japan) and the Cobas AmpliPrep/Cobas TaqMan test (Roche). Precision of the qHBsAg and HBcrAg assays was assessed, and linearity of the qHBsAg assays was verified. All assays showed good precision performance with coefficients of variation between 4.5% and 5.3% except for some levels. Both qHBsAg assays showed linearity from 0.1 to 12,000.0 IU/mL and correlated well (r = 0.9934). HBsAg levels correlated with HBV DNA (r = 0.3373) and with HBcrAg (r = 0.5164), and HBcrAg also correlated with HBV DNA (r = 0.5198; P < .0001). This observation could provide impetus for further research to elucidate the clinical usefulness of the qHBsAg and HBcrAg assays.

  16. Natural Killer Cell Characteristics in Patients With Chronic Hepatitis B Virus (HBV) Infection Are Associated With HBV Surface Antigen Clearance After Combination Treatment With Pegylated Interferon Alfa-2a and Adefovir

    NARCIS (Netherlands)

    Stelma, Femke; de Niet, Annikki; Tempelmans Plat-Sinnige, Marjan J.; Jansen, Louis; Takkenberg, R. Bart; Reesink, Hendrik W.; Kootstra, Neeltje A.; van Leeuwen, Ester M. M.

    2015-01-01

    The role of natural killer (NK) cells in the process of hepatitis B virus (HBV) surface antigen (HBsAg) clearance and whether their phenotype is related to treatment outcome in patients with chronic hepatitis B are currently unknown. Patients with chronic hepatitis B (HBV DNA load, >17 000 IU/mL)

  17. Serological profile of incidentally detected asymptomatic HBsAg positive subjects (IDAHS)

    International Nuclear Information System (INIS)

    Khokhar, N.; Gill, M.L.

    2004-01-01

    Objective: To evaluate the serological profile of patients with incidentally detected positive hepatitis-B surface antigen (HBsAg) and to asses the risk factors. Design: An observational study. Place and Duration of Study: This study was conducted at Shifa International Hospital, Islamabad from 1999 to 2003. Patients and Methods: All patients who presented to gastroenterology clinic of Shifa Intentional Hospital, Islamabad with positive HBsAg, detected incidentally, were tested for alamine transaminase (ALT), hepatitis Beantigen (HBeAg) and in certain cases hepatitis-B virus DNA (HBV DNA) by polymerase chain reaction (PCR). Their risk factors for acquisition of infection were assessed with specific questions. Results: A total of 224 patients were examined. One hundred sixty-four (73.2%) were male and 60 (26.8%) female. Mean age of all the subjects was 32.45 plus minus 11.85 years. Out of 224 patients, 48 (21.4%) were positive for HBeAg and 176 (78.6%) were negative. Out of 48 subjects who were positive for HBeAg, 36 underwent HBV DNA determination and 32 (88.8%) were positive for HBV DNA. Out of 176 subjects who had negative HBeAg, 46 had elevated ALT and in those HBV DNA was performed and 14 had positive HBV DNA. Most common risk factors detected in these patients were intramuscular injections and surgery, however, in a large number, risk factors were unknown. Conclusion: Twenty-one percent asymptomatic subjects with positive HBsAg were found to be HBeAg positive. A large number of subjects with negative HBeAg had HBV DNA positive suggesting presence of precore mutants. Intramuscular injections and surgery were noted to be frequent risk factors in these subjects. (author)

  18. Models of Community-Based Hepatitis B Surface Antigen Screening Programs in the U.S. and Their Estimated Outcomes and Costs

    Science.gov (United States)

    Rein, David B.; Lesesne, Sarah B.; Smith, Bryce D.; Weinbaum, Cindy M.

    2011-01-01

    Objectives Information on the process and method of service delivery is sparse for hepatitis B surface antigen (HBsAg) testing, and no systematic study has evaluated the relative effectiveness or cost-effectiveness of different HBsAg screening models. To address this need, we compared five specific community-based screening programs. Methods We funded five HBsAg screening programs to collect information on their design, costs, and outcomes of participants during a six-month observation period. We categorized programs into four types of models. For each model, we calculated the number screened, the number screened as per Centers for Disease Control and Prevention (CDC) recommendations, and the cost per screening. Results The models varied by cost per person screened and total number of people screened, but they did not differ meaningfully in the proportion of people screened following CDC recommendations, the proportion of those screened who tested positive, or the proportion of those who newly tested positive. Conclusions Integrating screening into outpatient service settings is the most cost-effective method but may not reach all people needing to be screened. Future research should examine cost-effective methods that expand the reach of screening into communities in outpatient settings. PMID:21800750

  19. Micropropagation of transgenic lettuce containing HBsAg as a method of mass-scale production of standardised plant material for biofarming purposes.

    Science.gov (United States)

    Pniewski, Tomasz; Czyż, Marcin; Wyrwa, Katarzyna; Bociąg, Piotr; Krajewski, Paweł; Kapusta, Józef

    2017-01-01

    Micropropagation protocol of transgenic lettuce bearing S-, M- and L-HBsAg was developed for increased production of uniformised material for oral vaccine preparation. Effective manufacturing of plant-based biopharmaceuticals, including oral vaccines, depends on sufficient content of a protein of interest in the initial material and its efficient conversion into an administrable formulation. However, stable production of plants with a uniformised antigen content is equally important for reproducible processing. This can be provided by micropropagation techniques. Here, we present a protocol for micropropagation of transgenic lettuce lines bearing HBV surface antigens: S-, M- and L-HBsAg. These were multiplied through axillary buds to avoid the risk of somaclonal variation. Micropropagation effectiveness reached 3.5-5.7 per passage, which implies potential production of up to 6600 plant clones within a maximum 5 months. Multiplication and rooting rates were statistically homogenous for most transgenic and control plants. For most lines, more than 90 % of clones obtained via in vitro micropropagation had HBsAg content as high as reference plants directly developed from seeds. Clones were also several times more uniform in HBsAg expression. Variation coefficients of HBsAg content did not exceed 10 % for approximately 40-85 % of clones, or reached a maximum 20 % for 90 % of all clones. Tissue culture did not affect total and leaf biomass yields. Seed production for clones was decreased insignificantly and did not impact progeny condition. Micropropagation facilitates a substantial increase in the production of lettuce plants with high and considerably equalised HBsAg contents. This, together with the previously reported optimisation of plant tissue processing and its long-term stability, constitutes a successive step in manufacturing of a standardised anti-HBV oral vaccine of reliable efficacy.

  20. Higher baseline viral diversity correlates with lower HBsAg decline following PEGylated interferon-alpha therapy in patients with HBeAg-positive chronic hepatitis B.

    Science.gov (United States)

    Li, Hu; Zhang, Li; Ren, Hong; Hu, Peng

    2018-01-01

    Viral diversity seems to predict treatment outcomes in certain viral infections. The aim of this study was to evaluate the association between baseline intra-patient viral diversity and hepatitis B surface antigen (HBsAg) decline following PEGylated interferon-alpha (Peg-IFN-α) therapy. Twenty-six HBeAg-positive patients who were treated with Peg-IFN-α were enrolled. Nested polymerase chain reaction (PCR), cloning, and sequencing of the hepatitis B virus S gene were performed on baseline samples, and normalized Shannon entropy (Sn) was calculated as a measure of small hepatitis B surface protein (SHBs) diversity. Multiple regression analysis was used to estimate the association between baseline Sn and HBsAg decline. Of the 26 patients enrolled in the study, 65.4% were male and 61.5% were infected with hepatitis B virus genotype B. The median HBsAg level at baseline was 4.5 log 10 IU/mL (interquartile range: 4.1-4.9) and declined to 3.0 log 10 IU/mL (interquartile range: 1.7-3.9) after 48 weeks of Peg-IFN-α treatment. In models adjusted for baseline alanine aminotransferase (ALT) and HBsAg, the adjusted coefficients (95% CI) for ΔHBsAg and relative percentage HBsAg decrease were -1.3 (-2.5, -0.2) log 10 IU/mL for higher SHBs diversity (Sn≥0.58) patients and -26.4% (-50.2%, -2.5%) for lower diversity (Sndiversity. Baseline intra-patient SHBs diversity was inverse to HBsAg decline in HBeAg-positive chronic hepatitis B (CHB) patients receiving Peg-IFN-α monotherapy. Also, more sequence variations within the "a" determinant upstream flanking region and the first loop of the "a" determinant were the main sources of the higher SHBs diversity.

  1. No response to hepatitis B vaccine in infants born to HBsAg(+) mothers is associated to the transplacental transfer of HBsAg.

    Science.gov (United States)

    Wang, Jing; He, Yingli; Jin, Dongfang; Liu, Jinfeng; Zheng, Jie; Yuan, Ningxia; Bai, Yun; Yan, Taotao; Yang, Yuan; Liu, Yong; Zhang, Shulin; Zhao, Yingren; Chen, Tianyan

    2017-08-01

    No or low hepatitis B (HB) vaccine response is more frequent in infants from HBsAg(+) mothers than those from HBsAg(-). Our previous study found temporary positivity of HBsAg in infants from HBsAg(+) mothers. In this study, we hypothesized that HBsAg in infant blunt immune response to standard hepatitis B vaccination. A total of 328 consecutive HBsAg(+) mothers and their offspring were enrolled. Blood samples were taken from mothers and their infants and quantified for HBsAg, anti-HBs titer and HBV DNA load concentration; Placenta samples were collected to stain for HBsAg. First, 6.7% infants (22/328) showed anti-HBs titer lower than 10 mIU/mL after HB vaccination (non-response to HB vaccine). HBsAg(+) newborns showed higher risk of non-response than HBsAg(-) infants (13.0% versus 5.0%, p = 0.016). Infants from high HBsAg titer mothers displayed higher risk of HBsAg positivity at birth than those from low titer mothers (45.3% versus 2.8%, p < 0.001). HBsAg titer in mothers of HBsAg(+) newborns was much higher than mothers of HBsAg(-) newborns (p < 0.001). All those data supported HBsAg can be transferred through placenta. Our hypothesis was further reinforced by immunostaining with specific antibody against HBsAg, a substantial higher prevalence (87.5% versus 30.8%, p = 0.024) and stronger immunostaining (p = 0.008) was demonstrated in HBsAg(+) group comparing with placenta of the HBsAg(-) group. No response to HB vaccine in infants of HBsAg(+) mothers was associated to the transplacental transfer of HBsAg.

  2. Construction and immunological evaluation of truncated hepatitis B core particles carrying HBsAg amino acids 119–152 in the major immunodominant region (MIR)

    Energy Technology Data Exchange (ETDEWEB)

    Su, Qiudong; Yi, Yao [National Institute for Viral Disease Control and Prevention, China Center for Disease Control and Prevention, Changbai Road 155, Changping District, Beijing 102206 (China); Guo, Minzhuo [Beijing Entry-Exit Inspection and Quarantine Beureau, Tianshuiyuan Lane 6, Chaoyang District, Beijing 100026 (China); Qiu, Feng; Jia, Zhiyuan; Lu, Xuexin; Meng, Qingling [National Institute for Viral Disease Control and Prevention, China Center for Disease Control and Prevention, Changbai Road 155, Changping District, Beijing 102206 (China); Bi, Shengli, E-mail: shengli_bi@163.com [National Institute for Viral Disease Control and Prevention, China Center for Disease Control and Prevention, Changbai Road 155, Changping District, Beijing 102206 (China)

    2013-09-13

    Highlights: •The conformational HBV neutralization antigen domain was successfully displayed on the surface of truncated HBc particles. •Appropriate dialysis procedures to support the renaturing environment for the protein refolding. •Efficient purification procedures to obtain high purity and icosahedral particles of mosaic HBV antigen. •Strong immune responses not only including neutralization antibody response but also Th1 cell response were induced in mice. -- Abstract: Hepatitis B capsid protein expressed in Escherichia coli can reassemble into icosahedral particles, which could strongly enhance the immunogenicity of foreign epitopes, especially those inserted into its major immunodominant region. Herein, we inserted the entire ‘α’ antigenic determinant amino acids (aa) 119–152 of HBsAg into the truncated HBc (aa 1–144), between Asp{sup 78} and Pro{sup 79}. Prokaryotic expression showed that the mosaic HBc was mainly in the form of inclusion bodies. After denaturation with urea, it was dialyzed progressively for protein renaturation. We observed that before and after renaturation, mosaic HBc was antigenic as determined by HBsAg ELISA and a lot of viruslike particles were observed after renaturation. Thus, we further purified the mosaic viruslike particles by (NH{sub 4}){sub 2}SO{sub 4} precipitation, DEAE chromatography, and Sepharose 4FF chromatography. Negative staining electron microscopy demonstrated the morphology of the viruslike particles. Immunization of Balb/c mice with mosaic particles induced the production of anti-HBs antibody and Th1 cell immune response supported by ELISPOT and CD4/CD8 proportions assay. In conclusion, we constructed mosaic hepatitis core particles displaying the entire ‘α’ antigenic determinant on the surface and laid a foundation for researching therapeutic hepatits B vaccines.

  3. Highly sensitive radioimmunoassay technique for subtyping the antibody to hepatitis B surface antigen

    Energy Technology Data Exchange (ETDEWEB)

    Fang, C T; Nath, N; Berberian, H; Dodd, R Y [American Red Cross, Blood Research Laboratory, Bethesda, MD, USA

    1978-12-01

    A highly sensitive technique for determining the subtype specificity of antibody to hepatitis B surface antigen (anti-HBs) is described. Immunoadsorbent consisting of controlled pore glass coated with subtype specific HBsAg was used to remove homologous antibody from the test samples before testing them for residual antibody by a commercially available radioimmunoassay (RIA). A total of 73 anti-HBs-positive samples from asymptomatic blood donors were tested. In nearly 80% of these samples the subtype reactivity could be determined by this technique. Only 67% could be typed by conventional liquid phase absorption RIA and 22% by passive hemagglutination inhibition techniques. Among the samples with low anti-HBs titer, ad and ay subtypes were found with equal frequency; however, with the increase in anti-HBs titer, considerably higher proportion of ad specificity was detected.

  4. Frequency of pregnant women with HBsAg in a Brazilian community Freqüência de gestantes portadoras do HBsAg em uma comunidade brasileira

    Directory of Open Access Journals (Sweden)

    Geraldo Duarte

    1997-01-01

    Full Text Available The work reported here points up the real benefits provided by neonatal immunoprophylaxis of newborns delivered by mothers who are seropositive for the hepatitis B virus surface antigen HBsAg and underscores the need to properly identify such mothers in Brazil so that immunoprophylaxis can be undertaken. To help determine levels of hepatitis B virus (HBV infection and seropositivity for various HBV markers among pregnant women in Southeast Brazil, investigators studied 7992 pregnant women delivering at the Clinical Hospital of the University of São Paulo's Ribeirão Preto School of Medicine in Ribeirão Preto, Brazil. Seroreactivity for HBsAg was determined first by serologic screening with an enzyme-linked immunosorbent assay (ELISA procedure in which the sera were incubated for 2 hours and then by confirmation with another ELISA in which the sera were incubated for 18 hours. Subsequently, tests for anti-HBsAg, HBeAg, anti-HBeAg, and anti-HBcAg markers were conducted using confirmed positive samples. Initial screening found 84 of the 7992 samples (1.05%, 95% CI: 0.84-1.30 to be positive for HBsAg; however, this HBsAg positivity was confirmed in only 76 (0.95%, 95% CI: 0.75-1.19. The positivity rate was significantly higher among subjects whose pregnancies terminated in miscarriage (1.84% than among those with live births (0.83% (chi2, Yates correction = 7.6; P = 0.005. Anamnesis was able to identify HBV risk factors in only 27.6% of the confirmed HBsAg-positive subjects or close household contacts. However, 21.3% (95% CI: 1.04-30.56 of the confirmed HBsAg-positive subjects were found positive for HBeAg, indicating a high risk of vertical transmission of the virus. These results demonstrate a need to conduct specific serologic research at term, in order to provide effective neonatal immunoprophylactic benefits.Visando aferir a tasa de reatividade sérica do HBsAg e de outros marcadores da infecção pelo VHB em parturientes, além de avaliar

  5. A highly sensitive radioimmunoassay technique for subtyping the antibody to hepatitis B surface antigen

    International Nuclear Information System (INIS)

    Fang, C.T.; Nath, N.; Berberian, H.; Dodd, R.Y.

    1978-01-01

    A highly sensitive technique for determining the subtype specificity of antibody to hepatitis B surface antigen (anti-HBs) is described. Immunoadsorbent consisting of controlled pore glass coated with subtype specific HBsAg was used to remove homologous antibody from the test samples before testing them for residual antibody by a commercially available radioimmunoassay (RIA). A total of 73 anti-HBs-positive samples from asymptomatic blood donors were tested. In nearly 80% of these samples the subtype reactivity could be determined by this technique. Only 67% could be typed by conventional liquid phase absorption RIA and 22% by passive hemagglutination inhibition techniques. Among the samples with low anti-HBs titer, ad and ay subtypes were found with equal frequency; however, with the increase in anti-HBs titer, considerably higher proportion of ad specificity was detected. (Auth.)

  6. A rapid one-step radiometric assay for hepatitis B surface antigen utilising monoclonal antibodies

    International Nuclear Information System (INIS)

    Goodall, A.H.; Meek, F.L.; Waters, J.A.; Miescher, G.C.; Janossy, G.; Thomas, H.C.

    1982-01-01

    A two-site antigen assay for HBsAg has been developed that employs 3 monoclonal antibodies. The antibodies were selected for their high affinity and their particular epitope specificity to establish an assay with a sensitivity for the antigen comparable with that of a conventional assay with heterologous antisera. In addition, by selecting a monoclonal antibody for use as a tracer which does not compete for antigenic binding sites with the solid-phase monoclonal antibodies, it has been possible to perform a two-site assay in a single 1 h incubation step, achieving the same degree of sensitivity. This principle of using monoclonal antibodies in a one-step assay therefore gives advantages of speed and simplicity over assays using heterologous antisera and would be applicable to a variety of antigen assays for which appropriate monoclonal antibodies are available. (Auth.)

  7. Diagnostic accuracy of tests to detect hepatitis B surface antigen: a systematic review of the literature and meta-analysis

    Directory of Open Access Journals (Sweden)

    Ali Amini

    2017-11-01

    Full Text Available Abstract Background Chronic Hepatitis B Virus (HBV infection is characterised by the persistence of hepatitis B surface antigen (HBsAg. Expanding HBV diagnosis and treatment programmes into low resource settings will require high quality but inexpensive rapid diagnostic tests (RDTs in addition to laboratory-based enzyme immunoassays (EIAs to detect HBsAg. The purpose of this review is to assess the clinical accuracy of available diagnostic tests to detect HBsAg to inform recommendations on testing strategies in 2017 WHO hepatitis testing guidelines. Methods The systematic review was conducted according to the Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA guidelines using 9 databases. Two reviewers independently extracted data according to a pre-specified plan and evaluated study quality. Meta-analysis was performed. HBsAg diagnostic accuracy of rapid diagnostic tests (RDTs was compared to enzyme immunoassay (EIA and nucleic-acid test (NAT reference standards. Subanalyses were performed to determine accuracy among brands, HIV-status and specimen type. Results Of the 40 studies that met the inclusion criteria, 33 compared RDTs and/or EIAs against EIAs and 7 against NATs as reference standards. Thirty studies assessed diagnostic accuracy of 33 brands of RDTs in 23,716 individuals from 23 countries using EIA as the reference standard. The pooled sensitivity and specificity were 90.0% (95% CI: 89.1, 90.8 and 99.5% (95% CI: 99.4, 99.5 respectively, but accuracy varied widely among brands. Accuracy did not differ significantly whether serum, plasma, venous or capillary whole blood was used. Pooled sensitivity of RDTs in 5 studies of HIV-positive persons was lower at 72.3% (95% CI: 67.9, 76.4 compared to that in HIV-negative persons, but specificity remained high. Five studies evaluated 8 EIAs against a chemiluminescence immunoassay reference standard with a pooled sensitivity and specificity of 88.9% (95% CI: 87.0, 90.6 and

  8. Prevalence and chemotherapy-induced reactivation of occult hepatitis B virus among hepatitis B surface antigen negative patients with diffuse large B-cell lymphoma: Significance of hepatitis B core antibodies screening

    International Nuclear Information System (INIS)

    Elbedewy, T.A.; Elashtokhy, H.A.; Rabee, E.S.; Kheder, G.E.

    2015-01-01

    Background: Occult hepatitis B infection (OBI) is characterized by negative hepatitis B surface antigen (HBsAg) and detectable hepatitis B virus (HBV)-DNA in the liver and/or serum, with or without hepatitis B core antibody (anti-HBc). Anti-HBc is the most sensitive marker of previous HBV. HBV reactivation in patients under immunosuppressive treatment is life-threatening, occurring in both overt and occult HBV especially in hematological malignancies. Aim of the work: To evaluate the prevalence and chemotherapy-induced reactivation of OBI among hepatitis B surface antigen negative patients with diffuse large B-cell lymphoma (DLBCL) patients and to determine the significance of anti-HBc screening among this group of patients before receiving chemotherapy. Patients and methods: This cross-sectional study included 72 DLBCL patients negative for HBsAg, HBsAb and hepatitis C virus antibodies (anti-HCV). Patients were subjected to investigations including anti-HBc. All patients underwent alanine transaminase (ALT) monitoring before each cycle of chemotherapy and monthly for 12 months after the end of chemotherapy. Patients with suspected OBI were tested for HBV-DNA using real-time polymerase chain reaction (PCR). Results: Anti-HBc was detected in 10 of 72 HBsAg negative sera (13.89%) (95% confidence interval 6.9-22.2%). Five of the 10 anti-HBc positive patients in this study had OBI reactivation. Conclusion: The study concluded that anti-HBc screening is mandatory before chemotherapy. HBsAg-negative/anti-HBc-positive patients should be closely observed for signs of HBV reactivation through the regular monitoring of ALT. Prophylaxis lamivudine is recommended for anti-HBc positive patients before chemotherapy.

  9. Detection of Hepatitis B Virus Antigens in Paraffin-embedded Liver Specimens from the Amazon Region, Brazil

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    Simonetti SRR

    2002-01-01

    Full Text Available Hepatic viscerotomy of paraffin-preserved old specimens, collected in the period from 1934 to 1967, were analyzed by immunohistochemical assays to detect hepatitis B, hepatitis D, dengue and yellow fever virus antigens. The material belongs to the Yellow Fever Collection, Department of Pathology, Instituto Oswaldo Cruz, Rio de Janeiro, Brazil and the cases were diagnosed at that time according to clinical aspects and histopathological findings reporting viral hepatitis, yellow fever, focal necrosis and hepatic atrophy. From the 79 specimens, 69 were collected at the Labrea Region and the other 10 in different other localities in the Amazon Region. The five micra thick histological slices were analyzed for the presence of hepatitis B surface antigen (HBsAg and hepatitis B core antigen (HBcAg by immunoperoxidase technique. An immunofluorescence assay was applied to the detection of hepatitis D, yellow fever and dengue virus antigens. Nine (11.4% histological samples were HBsAg reactive and 5 (6.3% were HBcAg reactive. The oldest reactive sample was from 1934. Viral antigens related to the other pathologies were not detected in this study. Our results confirm that the methodology described may be used to elucidate the aetiology of hepatitis diseases even after a long time of conservation of the specimens.

  10. Hepatitis B Surface AntigenemiaAmong Transfused Children with ...

    African Journals Online (AJOL)

    Patients with sickle cell anaemia (SCA), a common haematological disorder inNigeria,may have complications that require blood transfusion, thus exposing them to the risk. Objective: To determine the prevalence of hepatitis B surface antigen (HBsAg) among transfused childrenwith SCAin Enugu. Subjects and Method: ...

  11. HBsAg RIA QUICK and Anti-HBs RIA QUICK. Information of a new technique of radioimmunoassay of hepatitis B virus surface antigen and the corresponding antibody using kits by IMMUNO Vienna

    Energy Technology Data Exchange (ETDEWEB)

    Kselikova, M; Urbankova, J

    1985-11-01

    With regard to the high sensitivity of HBsAg and anti-HBs detection using kits HBsAg RIA QUICK and Anti-HBs RIA QUICK, and with regard to the excellent technical set-up which substantially reduces demands on manual work and eliminates the need to equip the department with a rinser, and also with regard to the lower price as compared with similar kits by Abbott Co., the above mentioned two kits will be imported to Czechoslovakia.

  12. Hepatitis B surface antigen concentrations in patients with HIV/HBV co-infection.

    Directory of Open Access Journals (Sweden)

    Jerzy Jaroszewicz

    Full Text Available HBsAg clearance is associated with clinical cure of chronic hepatitis B virus (HBV infection. Quantification of HBsAg may help to predict HBsAg clearance during the natural course of HBV infection and during antiviral therapy. Most studies investigating quantitative HBsAg were performed in HBV mono-infected patients. However, the immune status is considered to be important for HBsAg decline and subsequent HBsAg loss. HIV co-infection unfavorably influences the course of chronic hepatitis B. In this cross-sectional study we investigated quantitative HBsAg in 173 HBV/HIV co-infected patients from 6 centers and evaluated the importance of immunodeficiency and antiretroviral therapy. We also compared 46 untreated HIV/HBV infected patients with 46 well-matched HBV mono-infected patients. HBsAg levels correlated with CD4 T-cell count and were higher in patients with more advanced HIV CDC stage. Patients on combination antiretroviral therapy (cART including nucleos(tide analogues active against HBV demonstrated significant lower HBsAg levels compared to untreated patients. Importantly, HBsAg levels were significantly lower in patients who had a stronger increase between nadir CD4 and current CD4 T-cell count during cART. Untreated HIV/HBV patients demonstrated higher HBsAg levels than HBV mono-infected patients despite similar HBV DNA levels. In conclusion, HBsAg decline is dependent on an effective immune status. Restoration of CD4 T-cells during treatment with cART including nucleos(tide analogues seems to be important for HBsAg decrease and subsequent HBsAg loss.

  13. Seroprevalence of Hepatitis B Surface Antigen and Occupational Risk Factors Among Health Care Workers in Ekiti State, Nigeria.

    Science.gov (United States)

    Alese, Oluwole Ojo; Alese, Margaret Olutayo; Ohunakin, Afolabi; Oluyide, Peter Olumuyiwa

    2016-02-01

    Hepatitis B virus (HBV) infection is contracted from blood and other body fluid making healthcare workers (HCW) prone to the infection especially in the developing world. Though it is a vaccine preventable disease, the level of awareness and universal precaution among HCW is low in sub-Saharan African and Asia. The study was aimed at determining the seroprevalence of hepatitis B surface antigen and occupational risk factors among health care workers at Ekiti State University Teaching Hospital, Ado Ekiti. One hundred and eighty-seven (187) blood samples were collected from volunteer subjects who comprised of medical doctors, nurses, health attendants, and porters who are in regular contact with blood, body fluids and patients after informed consent. Well detailed and structured questionnaires were used to obtain demographic and other relevant data from the subjects. Blood samples were tested by Enzyme Linked Immunosorbent assay (ELISA) for hepatitis B surface antigen. Out of the 187 HCWs there were 91 males (48.7%) and 96 (51.3%) females. Only 2 participants tested positive to hepatitis B surface antigen with a prevalence of 1.1%. Also, only 30 (16.0%) of the participants had been fully vaccinated against the infection while the remaining 157(84.0%) had no adult vaccination. It is obvious that the awareness of the infection is low among the HCWs studied thus the need to incorporate screening for HbsAg and vaccination against HBV into the periodic/pre-employment health intervention programmes by employers to help in the protection of HCWs and control the spread of the virus.

  14. HBsAg d and y subtypes determined by inhibition radio-immunoassay

    Energy Technology Data Exchange (ETDEWEB)

    Wilkinson, R [Border Blood Transfusion Service, East London (South Africa)

    1981-12-01

    An inhibition radioimmunoassay for the detection of HBsAg/d and HBsAg/y antigens is described. A survey of 211 asymptomatic HBsAg positive blood donors showed 190 to be of type HBsAg/d and 3 to be of type HBsAg/y, while the remaining 18 could not be typed. Of 43 patients with acute hepatitis 39 were type HBsAg/d and 4 were type HBsAg/y. The statistically significant (p smaller than 0,01) increase in type HBsAg/y may reflect a changing pattern in offending viral strain with the passage of time.

  15. Detection of S-gene 'a' determinant variants in hepatitis B patients with both positive HBsAg and HBsAb markers

    International Nuclear Information System (INIS)

    Wu Yueping; Ling Yongwu; Huang Songping; Wang Shipeng; Chen Yufeng; Mao Liping; Lu Jianrong

    2005-01-01

    Objective: To explore the S-gene 'a' determinant variants in hepatitis B patients with both positive HBsAg and HBsAb markers and the effect on the antigenicity of HBsAg. Methods: Quantitative determination of HBV - DNA with competent PCR microfluidic chit method was performed in eight sera specimens from seven hepatitis B patients with both positive HBsAg and HBsAb markers. HBV S-gene was amplified with nested PCR, the PCR product was directly examined for any sequence variant of the amino acids. HBV markers were tested with the very sensitive ELISA/MEIA method in these seven patients. The above rests were also performed in 15 children after failed immunization with hepatitis B vaccine and 9 recipients of liver transplantation for terminal hepatitis B treated with HBIG and lamivudine, serving as controls. Results: The HBsAb contents in the seven patients were all below 80 mIu/ml. Two of the patients with positive HBV-DNA showed no 'a' determinant variant. Two of the four HBV-DNA negative patients demonstrated amino-acid variants (126, 131). One patients who was originally HBV-DNA positive but later turned negative after treatment with interferon and lamivudine demonstrated variant (126). In the 9 patients after successful liver transplantation, the HBsAb contents were all about 150mIu/ml with negative HBV-DNA and no variant. In the 15 immunization failures, HBV-DNA was positive in 14 of them, with 2 cases of variant at 145, 1 case at 126 and 1 case at 134. Conclusion: In some patients with chronic B hepatitis with both positive HBsAg and HBsAb markers, as well as in some vaccine immunization failures, there were 'a' determinant variants, which might alter the antigenicity of HBsAg with escape from the neutralization of low HBsAb. The 'a' determinant variant might also affect the replication of the virus. In this study, no variant was shown in patients after successful liver transplantation. However, the number of patients was too small and the result was of no

  16. Detection of different categories of hepatitis B virus (HBV) infection in a multi-regional study comparing the clinical sensitivity of hepatitis B surface antigen and HBV-DNA testing

    DEFF Research Database (Denmark)

    Lelie, Nico; Bruhn, Roberta; Busch, Michael

    2017-01-01

    BACKGROUND: Twenty-two users of individual donation nucleic acid amplification technology (ID-NAT) in six geographical regions provided detailed hepatitis B virus (HBV) infection data in first-time, lapsed, and repeat donations and classified confirmed HBV-positive donors into different infection...... categories. These data were used to compare the clinical sensitivity of hepatitis B surface antigen (HBsAg) and HBV-DNA testing. STUDY DESIGN AND METHODS: In total 10,981,776 donations from South Africa, Egypt, the Mediterranean, North and Central Europe, South East Asia, and Oceania were screened for HBV...

  17. GAMBARAN ANTI HBc POSITIF PADA DONOR DARAH DENGAN HbsAG NEGATIF

    Directory of Open Access Journals (Sweden)

    Susila Sastri

    2009-09-01

    Full Text Available AbstrakPemeriksaan HBsAg saja untuk skrining hepatitis B (HBV belum dapat menjamin donor darah bebas dari HBV sehingga darah donor belum memenuhi persyaratan untuk ditransfusikan. Darah donor yang akan ditranfusikan hendaklah memenuhi syarat diantaranya donor tidak pernah menderita HBV. Skrining darah donor terhadap HBV pada PMI hanya dengan uji HBsAg saja dimana HBsAg akan negatif pada stadium HBV tertentu, pada hal donor menderita atau dalam masa penyembuhan HBV. Anti-HBc dapat memberi informasi tentang perjalanan HBV bila digabungkan dengan marker HBV lain dan anti-HBc bertahan lebih lama dalam darah dibandingkan dengan marker lain. Donor darah HBsAg negatif dengan anti-HBc positif dari beberapa penelitian terdahulu masih ada yang mengandung HBV-DNA dan dapat menularkan HBV.Telah dilakukan penelitian terhadap donor darah dengan melakukan uji anti-HBc secara deskriptif terhadap donor darah dengan HBsAg negatif (n=100 pada UTD PMI Cabang Padang secara cross sectional study. Sampel diambil secara proportional random sampling. Darah sampel adalah darah HBsAg negatif dengan VDRL, HVC, HIV  negatif , semuanya diperiksa dengan dengan ELISATujuan penelitian untuk melihat gambaran anti-HBc positif pada donor darah dengan HBsAg negatif dan melihat hubungan antara indeks HBsAg dengan indeks anti-HBc. Pemeriksaan anti-HBc dilakukan dengan ELISA, alat dan reagen keluaran yang sama.Hasil penelitian menunjukkan frekuensi anti-HBc positif pada donor darah dengan HBsAg negatif sebanyak 27%, terutama pada laki-laki berumur antara 20-29 tahun (44,4%. Terdapat korelasi positif antara indeks HBsAg negatif dengan indeks anti-HBc (r = 0,02. Anti-HBc positif banyak ditemukan pada indeks HBsAg negatif 0,21-0,60 (76%.Kesimpulan, darah donor dengan HBsAg negatif yang selama ini dianggap aman untuk transfusi terbukti masih mungkin menularkan HBV dengan ditemukannya anti-HBc yang positif. Karena itu perlu pemeriksaan lanjutan DNA HBV pada donor darah dengan HbsAg

  18. Virus-specific immune response in HBeAg-negative chronic hepatitis B: relationship with clinical profile and HBsAg serum levels.

    Directory of Open Access Journals (Sweden)

    Elisabetta Loggi

    Full Text Available BACKGROUND AIMS: The immune impairment characterizing chronic hepatitis B (cHBV infection is thought to be the consequence of persistent exposure to viral antigens. However, the immune correlates of different clinical stages of cHBV and their relation with different levels of HBsAg have not been investigated. The aim of the present study was to evaluate the relationship between HBV-specific T cells response and the degree of in vivo HBV control and HBsAg serum levels in HBeAg-HBeAb+ cHBV. METHODS: Peripheral blood mononuclear cells from 42 patients with different clinical profiles (treatment-suppressed, inactive carriers and active hepatitis of cHBV, 6 patients with resolved HBV infection and 10 HBV-uninfected individuals were tested with overlapping peptides spanning the entire HBV proteome. The frequency and magnitude of HBV-specific T cell responses was assessed by IFNγ ELISPOT assay. Serum HBsAg was quantified with a chemiluminescent immunoassay. RESULTS: The total breadth and magnitude of HBV-specific T cell responses did not differ significantly between the four groups. However, inactive carriers targeted preferentially the core region. In untreated patients, the breadth of the anti-core specific T cell response was inversely correlated with serum HBsAg concentrations as well as HBV-DNA and ALT levels and was significantly different in patients with HBsAg levels either above or below 1000 IU/mL. The same inverse association between anti-core T cell response and HBsAg levels was found in treated patients. CONCLUSIONS: Different clinical outcomes of cHBV infection are associated with the magnitude, breadth and specificity of the HBV-specific T cell response. Especially, robust anti-core T cell responses were found in the presence of reduced HBsAg serum levels, suggesting that core-specific T cell responses can mediate a protective effect on HBV control.

  19. Lack of immune potentiation by complexing HBsAg in a heat-inactivated hepatitis B vaccine with antibody in hepatitis B immunoglobulin

    NARCIS (Netherlands)

    Lelie, P. N.; van Amelsfoort, P. J.; Martine de Groot, C. S.; Bakker, E.; Schaasberg, W.; Niessen, J. C.; Reesink, H. W.

    1989-01-01

    In a randomized, dose-response study among 305 health care workers, we examined whether the immunogenicity of a heat-inactivated hepatitis B vaccine could be enhanced when HBsAg was complexed by anti-HBs contained in hepatitis B immunoglobulin either at equivalent proportions or at 10-fold antigen

  20. Historic and current hepatitis B viral DNA and quantitative HBsAg level are not associated with cirrhosis in non-Asian women with chronic hepatitis B.

    Science.gov (United States)

    Harkisoen, S; Arends, J E; van den Hoek, J A R; Whelan, J; van Erpecum, K J; Boland, G J; Hoepelman, A I M

    2014-12-01

    Some studies done in Asian patients have shown that serum levels of hepatitis B virus (HBV) DNA predict the development of cirrhosis. However, it is unclear whether this also applies for non-Asian patients. This study investigated historic and current HBV DNA and quantitative hepatitis B surface antigen (HBsAg) levels as predictors of cirrhosis in non-Asian women with chronic HBV. A retrospective cohort study of non-Asian women with chronic HBV was performed. Among other variables, HBV DNA and quantitative HBsAg levels were measured in stored historic serum samples obtained during pregnancy (period 1990-2004) and current serum samples (period 2011-2012) to determine any association with liver cirrhosis by liver stiffness measurement (LSM). One hundred and nineteen asymptomatic, treatment-naïve non-Asian women were included; the median number of years between the historic sample and the current sample was 17 (interquartile range (IQR) 13-20). The median historic log HBV DNA and quantitative log HBsAg levels were 2.5 (IQR 1.9-3.4) IU/ml and 4.2 (IQR 3.6-4.5) IU/ml, respectively. LSM diagnosed 14 patients (12%) with F3-F4 fibrosis, i.e. stiffness >8.1kPa. No association of cirrhosis was found with historic HBV DNA (relative risk (RR) 0.34, 95% confidence interval (CI) 0.05-2.44) or with the quantitative HBsAg level (HBsAg level >1000 IU/ml, RR 0.35, 95% CI 0.11-1.11). Multivariable analysis identified alcohol consumption (odds ratio (OR) 6.4, 95% CI 1.3-30.1), aspartate aminotransferase >0.5 times the upper limit of normal (OR 15.4, 95% CI 1.9-122.6), and prothrombin time (OR 12.0, 95% CI 1.2-120.4), but not HBV DNA or quantitative HBsAg level, to be independent predictors of the presence of cirrhosis. Neither historic nor current HBV DNA or the quantitative HBsAg level is associated with the development of HBV-related cirrhosis in non-Asian women. Copyright © 2014 The Authors. Published by Elsevier Ltd.. All rights reserved.

  1. Prevalence of Hepatitis B surface antigen in children with sickle cell anemia

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    Baba Jibrin

    2014-01-01

    Full Text Available Background: Hepatitis B virus is known to be endemic in Africa. The seroepidemiological studies of HBV have shown that infection commonly occurs in childhood in Africa resulting in an increased tendency to chronicity. This cross-sectional study was undertaken to determine the seroprevalence of hepatitis B surface antigen among pediatric patients with homozygous hemoglobin S. Materials and Methods: Three hundred sickle cell anemia children aged 6 months-15 years (both in steady state and in crises attending the SCA clinic and on admission in emergency pediatrics unit and pediatrics medical ward, Usmanu Danfodiyo University Teaching Hospital, Sokoto, Nigeria, were screened for hepatitis B infection using HBsAg as marker of infection. The sensitive enzyme linked immunosorbent assay method was used for detection of the marker. Three hundred children with minor illness attending pediatrics outpatient department and on admission in EPU/PMW for various treatment in the same hospital served as gender- and age-marched controls cohorts. Results: The sero-prevalence of HBsAg seropositivity for hepatitis B virus infection among SCA children was 17.3% (52/300 compared to 10.7% (32/300 of the control (P = 0.0875. The peak prevalence age group for HBV infection among SCA children was in the age group 1.1-5.0 years (6% compared to 10.1-15.0 years (4.7% in the control. Risk factors for HBV infection such as blood transfusion, traditional scarification/circumcision/uvulectomy, and tattooing did not significantly affect the prevalence of HBV infection in both SCA children and controls. Conclusion: Hepatitis B infection is common in Sokoto. The need for strict adherence to HBV immunization and further community-based studies on the risk factors are recommended.

  2. Seroprevalence of Hepatitis B Surface Antigen and Occupational Risk Factors Among Health Care Workers in Ekiti State, Nigeria

    Science.gov (United States)

    Alese, Oluwole Ojo; Ohunakin, Afolabi; Oluyide, Peter Olumuyiwa

    2016-01-01

    Introduction Hepatitis B virus (HBV) infection is contracted from blood and other body fluid making healthcare workers (HCW) prone to the infection especially in the developing world. Though it is a vaccine preventable disease, the level of awareness and universal precaution among HCW is low in sub-Saharan African and Asia. Aim The study was aimed at determining the seroprevalence of hepatitis B surface antigen and occupational risk factors among health care workers at Ekiti State University Teaching Hospital, Ado Ekiti. Materials and Methods One hundred and eighty-seven (187) blood samples were collected from volunteer subjects who comprised of medical doctors, nurses, health attendants, and porters who are in regular contact with blood, body fluids and patients after informed consent. Well detailed and structured questionnaires were used to obtain demographic and other relevant data from the subjects. Blood samples were tested by Enzyme Linked Immunosorbent assay (ELISA) for hepatitis B surface antigen. Results Out of the 187 HCWs there were 91 males (48.7%) and 96 (51.3%) females. Only 2 participants tested positive to hepatitis B surface antigen with a prevalence of 1.1%. Also, only 30 (16.0%) of the participants had been fully vaccinated against the infection while the remaining 157(84.0%) had no adult vaccination. Conclusion It is obvious that the awareness of the infection is low among the HCWs studied thus the need to incorporate screening for HbsAg and vaccination against HBV into the periodic/pre-employment health intervention programmes by employers to help in the protection of HCWs and control the spread of the virus. PMID:27042489

  3. 21 CFR 660.40 - Hepatitis B Surface Antigen.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 7 2010-04-01 2010-04-01 false Hepatitis B Surface Antigen. 660.40 Section 660.40...) BIOLOGICS ADDITIONAL STANDARDS FOR DIAGNOSTIC SUBSTANCES FOR LABORATORY TESTS Hepatitis B Surface Antigen § 660.40 Hepatitis B Surface Antigen. (a) Proper name and definition. The proper name of this product...

  4. Seroprevalence of hepatitis B e antigen (HBe antigen and B core antibodies (IgG anti-HBcore and IgM anti-HBcore among hepatitis B surface antigen positive blood donors at a Tertiary Centre in Nigeria

    Directory of Open Access Journals (Sweden)

    Akinbami Akinsegun A

    2012-03-01

    Full Text Available Abstract Background Hepatitis B virus (HBV is a common cause of liver disease throughout the world. HBV is transmitted through blood and other body fluids, including semen and saliva. Chronic replication of HBV virons is characterized by persistence circulation of HBsAg, HBeAg and HBV DNA; usually with anti-HBc and occasionally with anti-HBs. Aim: To determine the prevalence of HBeAg, IgG anti-HBcore and IgM anti-HBcore amongst HBsAg positive blood donors. These parameters are reflective of transmissibility and active hepatitis B infection. A cross sectional study was carried out at the blood donor clinics of Lagos State University Teaching Hospital Ikeja and Lagos University Teaching Hospital Idiaraba. A total of 267 donors were recruited to determine HBe antigen, IgG and IgM anti-HBcore antibodies amongst hepatitis BsAg positive donors. Five milliliters of blood was collected from those who tested positive to HBsAg screen during donation. The sera were subjected to enzyme linked immunosorbent assay (ELISA. Pearson chi-squared test was used for the analytical assessment. Findings A total number of 267 HBsAg positive blood donors were studied. A seroprevalence of 8.2% (22 of 267 HBeAg was obtained, 4 of 267 (1.5% were indeterminate while 241 (90.3% tested negative. Only 27 out of 267 donors (10.1% tested positive to IgM anti-HBcore, 234(87.6% tested negative, while 6(2.2% were indeterminate. A higher percentage of 60.7% (162 of 267 tested positive to IgG anti-HBcore, while 39.3% (105 of 267 tested negative. Conclusion There is a low seroprevalence rate of HBeAg-positive chronic hepatitis and relatively high IgG anti-HBcore and IgM anti-HBcore rates in South West Nigeria.

  5. Cultural Influences on Hepatitis B Surface Antigen Seropositivity in ...

    African Journals Online (AJOL)

    Objective: To determine the role of cultural influences, namely: circumcision, ear piercing and traditional scarification, on HbsAg seropositivity among primary school children in Nnewi. Subjects and Method: Two hundred and thirty seven randomly selected primary school children aged 5-12 years, were screened for HbsAg.

  6. The HBsAg Prevalence Among Blood Donors From Eastern Mediterranean and Middle Eastern Countries: A Systematic Review and Meta-Analysis.

    Science.gov (United States)

    Babanejad, Mehran; Izadi, Neda; Najafi, Farid; Alavian, Seyed Moayed

    2016-03-01

    The world health organization (WHO) recommends that all blood donations should be screened for evidence of infections, such as hepatitis B. The present study aimed to determine the prevalence of hepatitis B surface antigen (HBsAg) in blood donors at the eastern Mediterranean region office (EMRO) of the WHO and middle eastern countries. A meta-analysis was carried out based on the results of an electronic literature search of PubMed, Ovid, Scopus, and Google Scholar for articles published from January 1, 2000, to August 31, 2015. In accordance with a significant homogeneity test and a large value of I2, the random effects model was used to aggregate data from the studies and produce the pooled estimates using the "Metan" command. We included 66 eligible studies. The pooled prevalence of HBsAg in blood donors of both EMRO and middle eastern (E and M) countries was 2.03% (95% confidence interval [CI]: 1.79 - 2.26). In addition, the prevalence rates in the EMRO countries was 1.99% (95% CI: 1.84 - 2.14) and 1.62% in the Middle Eastern countries (95% CI: 1.36 - 1.88). The prevalence among blood donors with more than one study was 1.58% in Egypt, 0.58% in Iran, 0.67% in Iraq, 2.84% in Pakistan, 3.02% in Saudi Arabia, 1.68% in Turkey, and 5.05% in Yemen. Based on the WHO classification of hepatitis B virus (HBV) prevalence, the prevalence of HBsAg in blood donors from E and M countries reached an intermediate level. However, there were low prevalence levels in some E and M countries.

  7. Conservation of myeloid surface antigens on primate granulocytes.

    Science.gov (United States)

    Letvin, N L; Todd, R F; Palley, L S; Schlossman, S F; Griffin, J D

    1983-02-01

    Monoclonal antibodies reactive with myeloid cell surface antigens were used to study evolutionary changes in granulocyte surface antigens from primate species. Certain of these granulocyte membrane antigens are conserved in phylogenetically distant species, indicating the potential functional importance of these structures. The degree of conservation of these antigens reflects the phylogenetic relationship between primate species. Furthermore, species of the same genus show similar patterns of binding to this panel of anti-human myeloid antibodies. This finding of conserved granulocyte surface antigens suggests that non-human primates may provide a model system for exploring uses of monoclonal antibodies in the treatment of human myeloid disorders.

  8. [Comparison of the clinical performance of the ECLusys HBsAg II assay with the Lumipulse f and HISCL 2000-i HBsAg screening assays].

    Science.gov (United States)

    Sugiura, Aya; Iwahara, Kunihiro; Suga, Yasuyuki; Uchiyama, Sachinori; Maekawa, Masato

    2012-02-01

    We compared the ECLusys HBsAgII (ECL HBsAg) assay to the Lumipulse Forte (LPf HBsAg) and HISCL (HIS HBsAg) assays. Measurement of dilution panels for which the WHO HBsAg international reference panel was the parent specimen revealed that the ECL and HIS assays enabled detection to a theoretical level of 0.04 IU/mL, whereas the LPf assay enabled detection to a level of 0.08 IU/mL. In a specificity test using high RF positive specimens (n = 33), pregnancy specimens (n = 35), cytomegalovirus antibody positive specimens (n = 36), and high M protein positive specimens (n = 21) that were confirmed negative for HBsAg by the LPf assay, negative results were obtained for all specimens on the HIS assay, but the ECL assay yielded a positive result for one of the high RF positive specimens. This individual was suggested on further testing to be an HBV carrier who was strongly positive for HBc antibody. In HBsAg mutants detection test, the detection rate was 92.3% with the ECL assay and 69.2% with the HIS assay. In a correlation test using routinely collected clinical specimens (n = 155), including positive stock specimens, aside from the one case where the LPf assay gave a negative result but both the ECL and HIS assays gave positive results, all of the results were consistent for all specimens. The above results confirmed that the ECL assay is both highly sensitive and specific, and also enables a high rate of HBsAg mutant detection.

  9. HBsAg level and hepatitis B viral load correlation with focus on pregnancy

    Science.gov (United States)

    Belopolskaya, Maria; Avrutin, Viktor; Firsov, Sergey; Yakovlev, Alexey

    2015-01-01

    Background Viral load measurement is necessary to estimate mother-to-child transmission risk for women with chronic hepatitis B (CHB), however, it is expensive. The present study aimed to investigate the relationship between HBsAg and hepatitis B virus (HBV) DNA levels, and to determine potential applications of HBsAg level monitoring for estimating viral load. Methods 85 patients with CHB (31 pregnant women, 26 non-pregnant women, 28 men) were included in the study. HBV DNA level was measured by real-time PCR, and HBsAg level by chemiluminescent immunoassay method. Dependency between viral load and HBsAg level was determined by Spearman correlation coefficient ρ. Results The correlation between HBsAg and HBV DNA levels was significant for all patients [ρ=0.3762 (P<0.0005; n=85)]. In the group of pregnant women, a low (unmeasurable) HBV DNA level led to a decrease in the Spearman coefficient ρ. In almost all cases a low level of the HBsAg corresponded to a low HBV DNA level. Only 2 patients had a low level of HBsAg and a relatively high viral load. By contrast, a high HBsAg level was observed in patients both with high and low viral load. Conclusions Correlation between HBsAg and HBV DNA levels is significant. In most cases, a low level of HBsAg indicates a low HBV DNA level, whereas a high HBsAg level does not always correspond to a high viral load. The measurement of HBV DNA level is necessary for pregnant women with a high HBsAg level. PMID:26127004

  10. Seroprevalence of Hepatitis B surface antigen, antibodies to the Hepatitis C virus, and human immunodeficiency virus in a hospital-based population in Jaipur, Rajasthan

    Directory of Open Access Journals (Sweden)

    Sood Smita

    2010-01-01

    Full Text Available Background: Hepatitis B, hepatitis C, and HIV infections are a serious global and public health problem. To assess the magnitude and dynamics of disease transmission and for its prevention and control, the study of its seroprevalence is important. A private hospital catering to the needs of a large population represents an important center for serological surveys. Available data, at Rajasthan state level, on the seroprevalence of these bloodborne pathogens is also very limited. Objective: A study was undertaken to estimate the seroprevalence of hepatitis B surface antigen (HBsAg and antibodies to hepatitis C (anti-HCV Ab and human immunodeficiency virus (anti-HIV Ab in both the sexes and different age groups in a hospital-based population in Jaipur, Rajasthan. Materials and Methods: Serum samples collected over a period of 14 months from patients attending OPDs and admitted to various IPDs of Fortis Escorts Hospital, Jaipur, were subjected within the hospital-based lab for the detection of HBsAg and anti-HCV Ab and anti-HIV Ab using rapid card tests. This was followed by further confirmation of all reactive samples by a microparticle enzyme immunoassay (Abbott AxSYM at Super Religare Laboratories (formerly SRL Ranbaxy Reference Lab, Mumbai. Results: The seroprevalence of HBsAg was found to be 0.87%, of anti-HCV Ab as 0.28%, and of anti-HIV Ab as 0.35%. Conclusion: The study throws light on the magnitude of viral transmission in the community in the state of Rajasthan and provides a reference for future studies.

  11. 21 CFR 660.1 - Antibody to Hepatitis B Surface Antigen.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 7 2010-04-01 2010-04-01 false Antibody to Hepatitis B Surface Antigen. 660.1... Hepatitis B Surface Antigen § 660.1 Antibody to Hepatitis B Surface Antigen. (a) Proper name and definition. The proper name of this product shall be Antibody to Hepatitis B Surface Antigen. The product is...

  12. Binding of hydrophobic antigens to surfaces

    DEFF Research Database (Denmark)

    2017-01-01

    A first aspect of the present invention is a method of detecting antibodies comprising the steps of: i) providing a first group of beads comprising a surface modified with C1-C10 alkyl groups comprising amine, ammonium, ether and/or hydroxyl groups, ii) contacting said first group of beads......-antigen-antibody conjugates, and v) detecting said bead-antigen-antibody conjugates. Further aspects include an antibody detection kit, a bead-antigen conjugate and a composition comprising at least two different groups of bead-antigen-conjugates....

  13. Cationic lipid-formulated DNA vaccine against hepatitis B virus: immunogenicity of MIDGE-Th1 vectors encoding small and large surface antigen in comparison to a licensed protein vaccine.

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    Anne Endmann

    Full Text Available Currently marketed vaccines against hepatitis B virus (HBV based on the small (S hepatitis B surface antigen (HBsAg fail to induce a protective immune response in about 10% of vaccinees. DNA vaccination and the inclusion of PreS1 and PreS2 domains of HBsAg have been reported to represent feasible strategies to improve the efficacy of HBV vaccines. Here, we evaluated the immunogenicity of SAINT-18-formulated MIDGE-Th1 vectors encoding the S or the large (L protein of HBsAg in mice and pigs. In both animal models, vectors encoding the secretion-competent S protein induced stronger humoral responses than vectors encoding the L protein, which was shown to be retained mainly intracellularly despite the presence of a heterologous secretion signal. In pigs, SAINT-18-formulated MIDGE-Th1 vectors encoding the S protein elicited an immune response of the same magnitude as the licensed protein vaccine Engerix-B, with S protein-specific antibody levels significantly higher than those considered protective in humans, and lasting for at least six months after the third immunization. Thus, our results provide not only the proof of concept for the SAINT-18-formulated MIDGE-Th1 vector approach but also confirm that with a cationic-lipid formulation, a DNA vaccine at a relatively low dose can elicit an immune response similar to a human dose of an aluminum hydroxide-adjuvanted protein vaccine in large animals.

  14. Low occurrence of HBsAg but high frequency of transient occult HBV infection in vaccinated and HBIG-administered infants born to HBsAg positive mothers.

    Science.gov (United States)

    Zhou, Shan; Li, Tingting; Allain, Jean-Pierre; Zhou, Bin; Zhang, Yuming; Zhong, Mei; Fu, Yongshui; Li, Chengyao

    2017-12-01

    The status of chronic and occult HBV infection (OBI) in neonatal hepatitis B vaccine and immunoglobulin (HBIG) vaccinated infants born to HBsAg+ mothers was investigated at a major hospital in China. Seventy-seven and 15 blood samples were collected in first or second follow-up detection from the vaccinated babies aged 3-36 months born to 43 HBsAg+ or plus 25 HBeAg+ mothers. HBV infection was analyzed between the paired baby and mother by serology and DNA analysis. Among 77 children born to 68 HBsAg+ mothers, 3.9% (3/77) were HBsAg+, and 36.4% (28/77) were HBV DNA+/HBsAg- (OBIs) by a single PCR, respectively. Thirteen of 28 HBV DNA+/HBsAg- samples were conformed by two PCRs or S sequence, which accounted for 16.9% (13/77) of children. Three HBsAg+ and six OBIs were genotyped in consistent with their mother's HBV strains. Of 77 babies' blood samples, anti-HBs reactivity varied slightly according to age groups, while passively transmitted anti-HBc reactivity declined from 100% high reactivity at age 3-5 months to mostly negative at age ≥12 months. Babies with apparent OBI had higher levels of anti-HBc and lower levels of anti-HBs than those without OBI but all eight OBI babies with second follow-up samples became HBV DNA negative beyond 1 year of age. The vaccinated infants born to HBsAg+ mothers presented the low rate of HBsAg occurrence as vaccination failure and high frequency of viral persistence in the form of transient OBIs since no evidence of active HBV infection occurred beyond 1 year of age. © 2017 Wiley Periodicals, Inc.

  15. Screening of HBsAg and anti HCV from tertiary care, private and public sector hospitals

    International Nuclear Information System (INIS)

    Khan, R.A.W.; Ahmed, W.; Alam, S.E.; Arif, A

    2011-01-01

    Objectives: To find out the frequency of hepatitis B surface antigen and hepatitis C antibodies in patients referred from a tertiary care public sector hospital, other public sector and private hospitals of Karachi. Settings and duration: Pakistan Medical Research Council's Specialized Research Centre for Gastroenterology and Hepatology, at Jinnah Postgraduate Medical Centre Karachi from January to December 2009. Patients and Methods: A cross sectional study was conducted where patients were referred from different departments of Jinnah Postgraduate Medical Centre (tertiary care public sector hospital), other public sector hospitals, private hospitals and clinics for the screening of hepatitis B and C virus infection. Three ml blood was collected from each patient, serum separated and tested for HBsAg and Anti HCV using Abbott Murex fourth Generation ELISA kits. Results: A total of 2965 cases were referred in a year. Overall sero prevalence of HBsAg and Anti-HCV was 5.9% and 12.8% respectively. HBsAg positivity in patient referred from public sector hospitals was 5.8%, those from private hospitals/clinics were 7.2%, and self-referred patients was 5.6%. Anti HCV positivity rates amongst these cases were 12.5%, 16.7% and 8.5% respectively. Co-infection of hepatitis B virus and hepatitis C virus was seen in 0.9, 2.5 and 1.4% cases respectively. Breakdown of viral positivity within different departments of Jinnah Postgraduate Medical Centre Karachi showed HBsAg positivity of 7.1% in Medical department, 5.2% in Surgical department, 5.0% in Gynaecology department, 6.6% in other departments of Jinnah Postgraduate Medical Centre while, only 1.7% were positive from Pakistan Railway, hospital Anti HCV positivity was maximally (20.3%) seen in medical department followed by 14% in other departments, 10.9% in surgical department, 7.9% in gynaecology and 5.1% in railway hospital. Co-infection of HBV and HCV was seen in 2% cases referred from medical department, while rest of the

  16. PENGAMATAN SERO—VIROLOGI BEBERAPA JENIS ANTIGEN VIRUS PADA SERUM TALIPUSAT BAYI DI RS. CIPTO MANGUNKUSUMO, JAKARTA

    Directory of Open Access Journals (Sweden)

    Djoko Yuwono

    2012-09-01

    Full Text Available Perinatal infection due to viral agents from mother to neonate is still a major cause of viral transmis­sion in developing countries. Several type of viruses which are known to be transmitted vertieally or perinatally from mother to neonates are: Hepatitis B virus, Herpes simplex, Rubella and Cytomegalovi­rus. In attempt to estimate the real problem of viral diseases which are vertically or perinatally transmis­sible among infants, a survey on sero-virology of several type viral antigens among neonates who were borned in Dr. Cipto Mangunkusumo hospital, was carried out. A total of 227 blood samples of umbillical cord were examined for the presence of their viral anti­gens such as: Hepatitis B surface antigen (HBsAg, Herpes simplex type 1 and type 2, and anti-rubella IgM as an indicator of early infection due to rubella virus in the fetus. The detection of antigens and anti-rubella IgM in the serum.were done by ELISA methode using reagents which are commercially available. The result of the study indicated that there was a possibility of perinatal infection due to related viruses, i.e.: 2.2%; 1.9% and 14.3% due to HBsAg; Herpes simplex type 1 and type 2 respectivelly, however none of the serum indicated seropositive IgM against rubella virus: infection.

  17. Association of social class in HBsAg and hepatocellular carcinoma

    International Nuclear Information System (INIS)

    Pervez, T.; Anwar, M. S.

    2001-01-01

    Objective: To find out the social class difference in relation to frequency of HBsAg and hepatocellular carcinoma in our population. Design: An analytical study. Place and Duration of Study: This study was conducted in Oncology Department, Services Hospital, Lahore from December 1997 to December 2000. Subjects and Methods: The HBsAg positive voluntary and apparently healthy blood donors were grouped into three, based on monthly income. Lower socioeconomic group and had monthly income less than 3,000 Pakistani rupees, middle socioeconomic group had monthly income between 3,000-10,000 rupees and upper socioeconomic group had income of more than 10,000 Pakistani rupees. On the same pattern patients suffering from hepatocellular carcinoma coming for treatment were also grouped. During this period, 1000 blood donors were screened for HBsAg and 95 biopsy proven liver cancer by causes were treated. Medical and demographic data of all subjects were recorded. HBsAg test was performed immuno-chromatographic technique using Daina Screen HBsAg kit manufactured by Dainabot Co. Ltd, Tokyo, Japan. Results: Patients from lower and middle social class had higher percentage (80% and 75%) of hepatocellular carcinoma as compared to higher social class (66.6%). In the healthy asymptomatic blood donors lower social class had higher (13.76%) HBsAg positively as compared to middle social class (11.25%) and higher social class (8.06%). Conclusion: Preventive measures should be taken in identifying and reducing factors predisposing high frequency of these conditions. (author)

  18. Radioimmunologic determination of hepatitis B antigen (HBsAG) in selected groups of persons and in special blood preparations

    Energy Technology Data Exchange (ETDEWEB)

    Lipsic, T; Geso, L [Clinic of Haematology and Blood Transfusion, Bratislava (Czechoslovakia)

    1978-06-30

    Presence of HBsAg was investigated by the RIA method in groups: exposed patients, blood donors, medical staff and different plasma preparations, namely: antihaemophilic cryoprotein (AHCp), Fibrinogen, I. Cohn's fraction and PPSB. 1789 samples of serum or converted material (plasma and its fractions) were investigated. In 405 cases AUSRIA-I method was used, the remaining 1384 cases were investigated by AUSRIA-II. Data are tabulated.

  19. The variability of hepatitis B envelope is associated with HBs antigen persistence in either chronic or acute HBV genotype A infection.

    Science.gov (United States)

    Eschlimann, Marine; Malvé, Brice; Velay, Aurélie; Fenaux, Honorine; Berger, Sibel; Frippiat, Jean-Pol; Zoulim, Fabien; Bensenane, Mouni; Bronowicki, Jean-Pierre; Goehringer, François; May, Thierry; Jeulin, Hélène; Schvoerer, Evelyne

    2017-09-01

    More than 240 million people are chronically infected by hepatitis B virus (HBV) worldwide. Envelope proteins play a crucial role in viral cellular entry and immune recognition. The loss of HBs antigen (HBsAg) correlated with a good clinical prognosis is rarely achieved with or without treatment (3-16%). HBV envelope variability was investigated according to HBsAg persistence. The cohort consisted of 15 HBV genotype A-infected patients divided into "resolvers", with HBsAg clearance, and "non-resolvers", with HBsAg persistence and in subgroups: acute (n=5, AHBV) or chronic infection (n=4, CHBV) and HBV/HIV coinfection (n=6, CHBV/HIV). HBV S and preS sequences were studied by direct and ultra-deep sequencing. Amino acid sequences were analyzed with bioinformatics for predicted antigenicity. In S gene, the complexity was lower in AHBV than in chronic-infected patients (p=0.046). Major mutations, detected using direct sequencing, were more frequent in AHBV developing chronicity (p=0.01) than in AHBV resolvers. In the Major Hydrophilic Region, more frequent mutations were observed in non-resolvers versus resolvers (p=0.047) and non-resolvers tended to have more haplotypes with a reduced predicted antigenicity (p=0.07). Most of the mutations in preS/S region were found rather in epitopic than in non-epitopic areas (p=0.025). Interestingly, the mutation sY161F found in 3/8 non-resolvers was associated with a decrease in predicted antigenicity (28%; AnTheProt). HBsAg persistence was correlated with mutations and deletions in areas playing a key role in immune recognition. These data suggest that variability in HBV envelope could favor immune escape in various clinical settings of HBV genotype A-infected patients. Copyright © 2017 Elsevier B.V. All rights reserved.

  20. Prevalence of HBsAg and anti-HBs among delivering women.

    Science.gov (United States)

    Sabău, M; Căpîlnă; Kiss, E

    1979-01-01

    A survey of 2,500 delivering women revealed a 7.6% incidence of past infection with hepatitis B virus (HBV) (HBsAg or anti-HBs). Only 5.9% of the anti-HBs-positive mothers had a possible history of parenteral exposure to hepatitis B and none of the 55 HBsAg carriers had such a history. The findings suggest that HBV is endemic and that it is probably spread in part by nonparenteral means. The high rates of HBsAg and anti-HBs point to the possible preventive value of routine screenings for this system among pregnant women.

  1. Evaluation of a solid-phase RIA technique and a solid-phase ELISA technique for demonstrating hepatitis-B surface antigen

    International Nuclear Information System (INIS)

    Vranckx, R.; Cole, J.; Peetermans, M.

    1978-01-01

    The sensitivities of a solid-phase radioimmunoassay (RIA), a solid-phase enzyme immunoassay (ELISA) and a haemagglutination test (RPHA) for the detection of the hepatitis-B surface antigen (HBsAg) were compared (1) by screening a panel of 300 sera (97 positives and 203 negatives), and (2) by titrating serial dilutions of 10 positive sera. Ninety-seven sera were positive by RIA, 95% were detected by ELISA and 81% were detected by RPHA. In the serial dilutions, the average end-points of the titrations were 0.005ng/ml for RIA, 0.01ng/ml for ELISA and 0.04 ng/ml for RPHA. It can be concluded that the sensitivity of the ELISA test is intermediate between that of the RIA and the RPHA. The ELISA and the RPHA tests seem to be a little more sensitive for the detection of subtype ay than for the detection of subtype ad. (author)

  2. Phosphine-free synthesis of high-quality reverse type-I ZnSe/CdSe core with CdS/CdxZn1 - xS/ZnS multishell nanocrystals and their application for detection of human hepatitis B surface antigen

    Science.gov (United States)

    Shen, Huaibin; Yuan, Hang; Niu, Jin Zhong; Xu, Shasha; Zhou, Changhua; Ma, Lan; Li, Lin Song

    2011-09-01

    Highly photoluminescent (PL) reverse type-I ZnSe/CdSe nanocrystals (NCs) and ZnSe/CdSe/CdS/CdxZn1 - xS/ZnS core/multishell NCs were successfully synthesized by a phosphine-free method. By this low-cost, 'green' synthesis route, more than 10 g of high-quality ZnSe/CdSe/CdS/CdxZn1 - xS/ZnS NCs were synthesized in a large scale synthesis. After the overgrowth of a CdS/CdxZn1 - xS/ZnS multishell on ZnSe/CdSe cores, the PL quantum yields (QYs) increased from 28% to 75% along with the stability improvement. An amphiphilic oligomer was used as a surface coating agent to conduct a phase transfer experiment, core/multishell NCs were dissolved in water by such surface modification and the QYs were still kept above 70%. The as-prepared water dispersible ZnSe/CdSe/CdS/CdxZn1 - xS/ZnS core/multishell NCs not only have high fluorescence QYs but also are extremely stable in various physiological conditions. Furthermore, a biosensor system (lateral flow immunoassay system, LFIA) for the detection of human hepatitis B surface antigen (HBsAg) was developed by using this water-soluble core/multishell NCs as a fluorescent label and a nitrocellulose filter membrane for lateral flow. The result showed that such ZnSe/CdSe/CdS/CdxZn1 - xS/ZnS core/multishell NCs were excellent fluorescent labels to detect HBsAg. The sensitivity of HBsAg detection could reach as high as 0.05 ng ml - 1.

  3. Physiological response of Pichia pastoris GS115 to methanol-induced high level production of the Hepatitis B surface antigen: catabolic adaptation, stress responses, and autophagic processes

    Science.gov (United States)

    2012-01-01

    Background Pichia pastoris is an established eukaryotic host for the production of recombinant proteins. Most often, protein production is under the control of the strong methanol-inducible aox1 promoter. However, detailed information about the physiological alterations in P. pastoris accompanying the shift from growth on glycerol to methanol-induced protein production under industrial relevant conditions is missing. Here, we provide an analysis of the physiological response of P. pastoris GS115 to methanol-induced high-level production of the Hepatitis B virus surface antigen (HBsAg). High product titers and the retention of the protein in the endoplasmic reticulum (ER) are supposedly of major impact on the host physiology. For a more detailed understanding of the cellular response to methanol-induced HBsAg production, the time-dependent changes in the yeast proteome and ultrastructural cell morphology were analyzed during the production process. Results The shift from growth on glycerol to growth and HBsAg production on methanol was accompanied by a drastic change in the yeast proteome. In particular, enzymes from the methanol dissimilation pathway started to dominate the proteome while enzymes from the methanol assimilation pathway, e.g. the transketolase DAS1, increased only moderately. The majority of methanol was metabolized via the energy generating dissimilatory pathway leading to a corresponding increase in mitochondrial size and numbers. The methanol-metabolism related generation of reactive oxygen species induced a pronounced oxidative stress response (e.g. strong increase of the peroxiredoxin PMP20). Moreover, the accumulation of HBsAg in the ER resulted in the induction of the unfolded protein response (e.g. strong increase of the ER-resident disulfide isomerase, PDI) and the ER associated degradation (ERAD) pathway (e.g. increase of two cytosolic chaperones and members of the AAA ATPase superfamily) indicating that potential degradation of HBsAg could

  4. Delayed clearance of serum HBsAg in compensated cirrhosis B

    DEFF Research Database (Denmark)

    Fattovich, G; Giustina, G; Sanchez-Tapias, J

    1998-01-01

    The aim of this study was to evaluate the incidence, prognostic factors and clinical significance of delayed clearance of serum HBsAg in compensated cirrhosis B.......The aim of this study was to evaluate the incidence, prognostic factors and clinical significance of delayed clearance of serum HBsAg in compensated cirrhosis B....

  5. Monoclonal Antibody Production against Human Spermatozoal Surface Antigens

    Directory of Open Access Journals (Sweden)

    M Jedi-Tehrani

    2005-10-01

    Full Text Available Introduction: As monoclonal antibodies are potential tools for characterization of soluble or cellular surface antigens, use of these proteins has always been considered in infertility and reproduction research. Therefore, in this study, monoclonal antibodies against human sperm surface antigens were produced. Material and Methods: To produce specific clones against human sperm surface antigens, proteins were extracted using solubilization methods. Balb/c mice were immunized intraperitoneally with the proteins using complete Freund’s adjuvant in the first injection and incomplete Adjuvant in the following booster injections. Hybridoma cells producing ASA were cloned by limiting dilution. Results: Five stable ASA producing hybridoma clones were achieved and their antibody isotypes were determined by ELISA. All the isotypes were of IgG class. Their cross reactivity with rat and mice spermatozoa was examined but they did not have any cross reactivity. Conclusion: The produced antibodies can be used in further studies to characterize and evaluate each of the antigens present on human sperm surface and determining their role in fertilization.

  6. A novel chromosome region maintenance 1-independent nuclear export signal of the large form of hepatitis delta antigen that is required for the viral assembly.

    Science.gov (United States)

    Lee, C H; Chang, S C; Wu, C H; Chang, M F

    2001-03-16

    Hepatitis delta virus (HDV) is a satellite virus of hepatitis B virus, as it requires hepatitis B virus for virion production and transmission. We have previously demonstrated that sequences within the C-terminal 19-amino acid domain flanking the isoprenylation motif of the large hepatitis delta antigen (HDAg-L) are important for virion assembly. In this study, site-directed mutagenesis and immunofluorescence staining demonstrated that in the absence of hepatitis B virus surface antigen (HBsAg), the wild-type HDAg-L was localized in the nuclei of transfected COS7 cells. Nevertheless, in the presence of HBsAg, the HDAg-L became both nuclei- and cytoplasm-distributed in about half of the cells. An HDAg-L mutant with a substitution of Pro-205 to alanine could neither form HDV-like particles nor shift the subcellular localization in the presence of HBsAg. In addition, nuclear trafficking of HDAg-L in heterokaryons indicated that HDAg-L is a nucleocytoplasmic shuttling protein. A proline-rich HDAg peptide spanning amino acid residues 198 to 210, designated NES(HDAg-L), can function as a nuclear export signal (NES) in Xenopus oocytes. Pro-205 is critical for the NES function. Furthermore, assembly of HDV is insensitive to leptomycin B, indicating that the NES(HDAg-L) directs nuclear export of HDAg-L to the cytoplasm via a chromosome region maintenance 1-independent pathway.

  7. sero-prevalence of hepatitis b surface antigen (hbsag)

    African Journals Online (AJOL)

    DR. AMINU

    of drugs, alcoholism, chemicals and environmental ... blood, serum, vaginal secretions and in saliva though in low concentrations (Lindsley et al., 1990). Although surrounded by a host cell derived envelope, HBV is remarkably stable to organic solvents. It is also heat and pH – resistant (Holling et al., 1995). Young children ...

  8. Low serum hyaluronic acid levels associated with spontaneous HBsAg clearance

    NARCIS (Netherlands)

    Harkisoen, S.; Arends, J. E.; van den Hoek, A.; van Erpecum, K. J.; Boland, G. J.; Hoepelman, A. I. M.

    2015-01-01

    Purpose The pathophysiological underlying mechanism of spontaneous HBsAg clearance in hepatitis B virus (HBV) infected patients is largely unknown. However, serum hyaluronic acid (sHA) plays a role in liver fibrosis progression and reversely could serve as a potential biomarker for HBsAg clearance.

  9. Anti-hepatitis B core antigen testing with detection and characterization of occult hepatitis B virus by an in-house nucleic acid testing among blood donors in Behrampur, Ganjam, Orissa in southeastern India: implications for transfusion

    Directory of Open Access Journals (Sweden)

    Panigrahi Rajesh

    2010-08-01

    Full Text Available Abstract Background Occult hepatitis B virus (HBV infection might transmit viremic units into the public blood supply if only hepatitis B surface antigen (HBsAg testing is used for donor screening. Our aim was to evaluate the prevalence of occult HBV infection among the HBsAg negative/antiHBc positive donations from a highly HIV prevalent region of India. Methods A total of 729 HBsAg negative donor units were included in this study. Surface gene and precore region were amplified by in house nucleic acid test (NAT for detection of occult HBV infection and surface gene was analyzed after direct sequencing. Results A total of 220 (30.1% HBsAg negative donors were antiHBc positive, of them 66 (30% were HBV DNA positive by NAT. HBV DNA positivity among 164 antiHBc only group, was 27.1% and among 40 antiHBs positive group was 30.0%. HBV/D (93.3% was predominant and prevalence of both HBV/C and HBV/A was 3.3%. Single or multiple amino acids substitutions were found in 95% samples. Conclusion Thus, a considerable number of HBV infected donors remain undiagnosed, if only HBsAg is used for screening. Addition of antiHBc testing for donor screening, although will lead to rejection of a large number of donor units, will definitely eliminate HBV infected donations and help in reducing HBV transmission with its potential consequences, especially among the immunocompromised population. The HBV genetic diversity found in this donor population are in accordance with other parts of India.

  10. Anti-hepatitis B core antigen testing with detection and characterization of occult hepatitis B virus by an in-house nucleic acid testing among blood donors in Behrampur, Ganjam, Orissa in southeastern India: implications for transfusion.

    Science.gov (United States)

    Panigrahi, Rajesh; Biswas, Avik; Datta, Sibnarayan; Banerjee, Arup; Chandra, Partha K; Mahapatra, Pradip K; Patnaik, Bharat; Chakrabarti, Sekhar; Chakravarty, Runu

    2010-08-27

    Occult hepatitis B virus (HBV) infection might transmit viremic units into the public blood supply if only hepatitis B surface antigen (HBsAg) testing is used for donor screening. Our aim was to evaluate the prevalence of occult HBV infection among the HBsAg negative/antiHBc positive donations from a highly HIV prevalent region of India. A total of 729 HBsAg negative donor units were included in this study. Surface gene and precore region were amplified by in house nucleic acid test (NAT) for detection of occult HBV infection and surface gene was analyzed after direct sequencing. A total of 220 (30.1%) HBsAg negative donors were antiHBc positive, of them 66 (30%) were HBV DNA positive by NAT. HBV DNA positivity among 164 antiHBc only group, was 27.1% and among 40 antiHBs positive group was 30.0%. HBV/D (93.3%) was predominant and prevalence of both HBV/C and HBV/A was 3.3%. Single or multiple amino acids substitutions were found in 95% samples. Thus, a considerable number of HBV infected donors remain undiagnosed, if only HBsAg is used for screening. Addition of antiHBc testing for donor screening, although will lead to rejection of a large number of donor units, will definitely eliminate HBV infected donations and help in reducing HBV transmission with its potential consequences, especially among the immunocompromised population. The HBV genetic diversity found in this donor population are in accordance with other parts of India.

  11. Transmission of hepatitis-B virus through salivary blood group antigens in saliva

    International Nuclear Information System (INIS)

    Meo, S.A.; Abdo, A.A.; Baksh, N.D.; Sanie, F.M.

    2010-01-01

    To determine an association between transmission of hepatitis B virus and secretor and non-secretor status of salivary blood group antigens. Study Design: Cross-sectional, analytical study. Place and Duration of Study: The Department of Physiology and Division of Hepatology, College of Medicine, King Khalid University Hospital, King Saud University, Riyadh, Kingdom of Saudi Arabia, from 2007 to 2009. Methodology: Eighty eight known patients, who were positive for Hepatitis B Surface Antigen [HBsAg] were recruited. Saliva was collected for investigating the secretor and non-secretor status by using blood typing kit number Kemtec Educational Science USA. Hepatitis B Surface antigen test was performed on Enzyme Linked Immunosorbent Assay technique. Polymerase chain reaction [PCR] on saliva was also carried out in High Performance Thermal Cycler-Palm- Cycler [Corbett Life Science, Sydney, Australia] and enzymatic amplification of extracted viral DNA was performed using primers covering the promoter of the core region of HBV. Results: Out of the 88 subjects, 61 belong to blood group O, 20 to A and 7 subjects to blood group B. Fifty subjects were secretors [salivary blood group antigens positive] and 38 subjects were non-secretors [salivary blood group antigens negative]. Among core gene positive 25 (69.4%) were secretors and 11 (30.6%) were non-secretors. However, in core gene negative 25 (48.1%) were secretors and 27 (51.9%) were non-secretors. Conclusion: The result shows an association [p=0.047] between secretor and non-secretors status of the salivary blood group antigens with core gene positive and core gene negative. (author)

  12. Identification and characterization of surface antigens in parasites, using radiolabelling techniques

    International Nuclear Information System (INIS)

    Ramasamy, R.

    1982-04-01

    Surface proteins of Schistosoma sp and Leishmania sp were studied using 125-Iodine as tracer. The surface proteins were labelled by the Lactoperoxidase method and the proteins then separated using SDS PAG electrophoresis and autoradiography. The possible immunogens were then separated using immunoprecipitation and Fluorescent Antibody techniques using sera from patients or from artificially immunized rabbits. Four common antigens were identified from the surfaces of male and female adult worms, cercariae and schistosomulae of S.mansoni. These antigens, which had molecular weights of 150,000, 78,000, 45,000, and 22,000 were also isolated from the surfaces of S.haematobium adults. The surface antigens on promastigotes of a Kenyan strain of Leishmania donovani were separated into three protein antigens with molecular weights of 66,000, 59,000 and 43,000 respectively. The 59,000 molecular weight antigen was a glycoprotein and was common to promastigotes of an American and Indian strain of L.donovani and to L.braziliensis mexicana. None of the isolated antigens have been shown to have a protective effect when vaccinated into mice, but the study illustrates the value of radionuclide tracers in the unravelling of the mosaic of antigens which parasites possess

  13. Effects of oxygen and ethanol on recombinant yeast fermentation for hepatitis B virus surface antigen production: modeling and simulation studies.

    Science.gov (United States)

    Shi, Y; Ryu, D D; Yuan, W K

    1993-01-05

    A model was formulated to examine the competitive growth of two phenotypes (Leu(+) and Leu(-)) and the product formation with recombinant Saccharomyces cerevisiae strain DBY-745, which contains the shuttle vector pYGH3-16-s with the foreign gene HBsAg (hepatitis B virus surface antigen) as well as experimental fedbatch fermentation data. The important state variables and the process parameters evaluated include (1) the ratio of the plasmid-free cell concentration to the plasmid-containing cell concentration (rho = X(-)X(+)), (2) the expression of human hepatitis B surface antigen g (CH), (3) the glucose consumption (S), (4) the ethanol production (/), (5) the change of working volume (V) in the fermentor, (6) the different specific growth rates of two phenotype cells, and (7) the plasmid loss frequency coefficient (alpha ). These variables and other parameters were carefully defined, their correlations were studied, and a mathematical model using a set of nonlinear ordinary differential equations (ODEs) for fed-batch fermentation was then obtained based on the theoretical considerations and the experimental results. The extended Kalman filter (EKF) methods was applied for the best estimate of these variables based on the experimentally observable variables: rhoV, and g (CH). Each of these variable was affected by random measuring errors under the different operating conditions. Simulation results presented for verification of the model agreed with our observations and provided useful information relevant to the operation and the control of the fedbatch recombinant yeast fermentation. The method of predicting an optimal profile of the cell growth was also demonstrated under the different dissolved oxygen concentrations.

  14. A new model mimicking persistent HBV e antigen-negative infection using covalently closed circular DNA in immunocompetent mice.

    Directory of Open Access Journals (Sweden)

    Lei Wang

    Full Text Available Despite the availability of an effective vaccine, hepatitis B virus (HBV infection remains a major health problem. HBV e antigen (HBeAg-negative strains have become prevalent. Previously, no animal model mimicked the clinical course of HBeAg-negative HBV infection. To establish an HBeAg-negative HBV infection model, the 3.2-kb full-length genome of HBeAg-negative HBV was cloned from a clinical sample and then circularized to form covalently closed circular (cccDNA. The resulting cccDNA was introduced into the liver of C57BL/6J mice through hydrodynamic injection. Persistence of the HBeAg-negative infection was monitored at predetermined time points using HBV-specific markers including HBV surface antigen (HBsAg, HBeAg, and HBV core antigen (HBcAg as well as DNA copies. Throughout the study, pAAV-HBV1.2 was used as a control. In mice injected with HBeAg-negative cccDNA, the HBV infection rate was 100% at the initial stage. HBsAg levels increased up to 1 week, at which point levels peaked and dropped quickly thereafter. In 60% of injected mice, HBsAg and HBcAg persisted for more than 10 weeks. High numbers of HBV DNA copies were detected in the serum and liver. Moreover, cccDNA persisted in the liver tissue of HBeAg-negative mice. In contrast to the pAAV-HBV 1.2 injected mice, no HBeAg was found in mice injected with HBeAg-negative HBV throughout the study period. These results demonstrate the first successful establishment of a model of HBeAg-negative HBV-persistent infection in immunocompetent mice. Compared to pAAV-HBV1.2-injected mice, the infection persistence and levels of serum virological and biochemical markers were approximately equal in the model mice. This model will be useful for mechanistic studies on HBeAg-negative HBV infection and will facilitate the evaluation of new antiviral drugs.

  15. The value of serum Hepatitis B surface antigen quantification in ...

    African Journals Online (AJOL)

    The value of serum Hepatitis B surface antigen quantification in determining viralactivity in chronic Hepatitis B virus infection. ... ofCHB andalso higher in hepatitis e antigen positive patients compared to hepatitis e antigen negative patients.

  16. Primary immunization-like response without hepatitis following transfusion of HBeAg-positive blood

    DEFF Research Database (Denmark)

    Gluud, C; Aldershvile, J; Kryger, P

    1983-01-01

    An accidental transfusion of hepatitis B surface antigen (HBsAg) and hepatitis B e antigen (HBeAg) positive whole blood was given to a 19-yr-old male, bleeding after tonsillectomy. Serum obtained from the patient before the transfusion revealed no hepatitis B antigens or antibodies. After...... the transfusion the patient became HBsAg-positive, cleared this antigen and developed antibodies to both HBsAg and HBeAg. The transfusion blood was positive for total antibody and IgM antibody to hepatitis B core antigen (HBcAg). The patient's blood became positive for these antibodies after the transfusion...

  17. Development of a Novel, Ultra-rapid Biosensor for the Qualitative Detection of Hepatitis B Virus-associated Antigens and Anti-HBV, Based on “Membrane-engineered” Fibroblast Cells with Virus-Specific Antibodies and Antigens

    Directory of Open Access Journals (Sweden)

    Antonios Perdikaris

    2009-03-01

    Full Text Available A novel miniature cell biosensor detection system for the detection of Hepatis B virus (HBV-associated antigens and anti-HBV is described. The biosensor is based on “membrane-engineered” Vero fibroblast cells immobilized in an alginate matrix. The membrane-engineering process involved the electroinsertion of anti-HBV specific antibodies (anti-HBs, anti-HBe or antigens (HBsAg in the membranes of the Vero cells. The attachment of a homologous antigen to the electroinserted antibody (or, respectively, of the antibody to the electroinserted antigen triggered specific changes to the cell membrane potential that were measured by appropriate microelectrodes, according to the principle of the Bioelectric Recognition Assay (BERA. The sensor was used for screening 133 clinical blood serum samples according to a double-blind protocol. Considerably higher sensor responses were observed against HBV-positive samples, compared with responses against negative samples or samples positive for heterologous hepatitis viruses such as Hepatitis C (HCV virus. Detection of anti-HBs antibodies was made possible by using a biosensor based on immobilized Vero cells bearing the respective antigen (HBsAg. The observed response was rapid (45 sec and quite reproducible. Fluorescence microscopy observations showed that attachment of HBV particles to cells membrane-engineered with anti-HBs was associated with a decrease of [Ca2+]cyt. The perspectives for using the novel biosensor as a qualitative, rapid screening, high throughput assay for HBV antigens and anti-HBs in clinical samples is discussed.

  18. Identification of Surface Exposed Elementary Body Antigens of ...

    African Journals Online (AJOL)

    This study sought to identify the surface exposed antigenic components of Cowdria ruminantium elementary body (EB) by biotin labeling, determine effect of reducing and non-reducing conditions and heat on the mobility of these antigens and their reactivity to antibodies from immunized animals by Western blotting.

  19. Concurrence of hepatitis B surface antibodies and surface antigen: implications for postvaccination control of health care workers

    NARCIS (Netherlands)

    Zaaijer, Hans L.; Lelie, P. N.; Vandenbroucke-Grauls, C. M. J. E.; Koot, M.

    2002-01-01

    Among 1081 persons testing positive for hepatitis B surface antigen, 106 (10%) tested positive for antibodies to surface antigen (anti-HBs) in the same blood sample. Thirty of these persons were studied in detail: seven tested positive for hepatitis B e-antigen, nine were apparently healthy blood

  20. Phosphine-free synthesis of high-quality reverse type-I ZnSe/CdSe core with CdS/Cd{sub x}Zn{sub 1-x}S/ZnS multishell nanocrystals and their application for detection of human hepatitis B surface antigen

    Energy Technology Data Exchange (ETDEWEB)

    Shen Huaibin; Niu Jin Zhong; Xu Shasha; Zhou Changhua; Li Linsong [Key Laboratory for Special Functional Materials, Henan University, Kaifeng 475004 (China); Yuan Hang; Ma Lan, E-mail: malan@sz.tsinghua.edu.cn, E-mail: lsli@henu.edu.cn [Life Science Division, Graduate School at Shenzhen, Tsinghua University, Shenzhen 518055 (China)

    2011-09-16

    Highly photoluminescent (PL) reverse type-I ZnSe/CdSe nanocrystals (NCs) and ZnSe/CdSe/CdS/Cd{sub x}Zn{sub 1-x}S/ZnS core/multishell NCs were successfully synthesized by a phosphine-free method. By this low-cost, 'green' synthesis route, more than 10 g of high-quality ZnSe/CdSe/CdS/Cd{sub x}Zn{sub 1-x}S/ZnS NCs were synthesized in a large scale synthesis. After the overgrowth of a CdS/Cd{sub x}Zn{sub 1-x}S/ZnS multishell on ZnSe/CdSe cores, the PL quantum yields (QYs) increased from 28% to 75% along with the stability improvement. An amphiphilic oligomer was used as a surface coating agent to conduct a phase transfer experiment, core/multishell NCs were dissolved in water by such surface modification and the QYs were still kept above 70%. The as-prepared water dispersible ZnSe/CdSe/CdS/Cd{sub x}Zn{sub 1-x}S/ZnS core/multishell NCs not only have high fluorescence QYs but also are extremely stable in various physiological conditions. Furthermore, a biosensor system (lateral flow immunoassay system, LFIA) for the detection of human hepatitis B surface antigen (HBsAg) was developed by using this water-soluble core/multishell NCs as a fluorescent label and a nitrocellulose filter membrane for lateral flow. The result showed that such ZnSe/CdSe/CdS/Cd{sub x}Zn{sub 1-x}S/ZnS core/multishell NCs were excellent fluorescent labels to detect HBsAg. The sensitivity of HBsAg detection could reach as high as 0.05 ng ml{sup -1}.

  1. Strains of Sarcocystis neurona exhibit differences in their surface antigens, including the absence of the major surface antigen SnSAG1.

    Science.gov (United States)

    Howe, Daniel K; Gaji, Rajshekhar Y; Marsh, Antoinette E; Patil, Bhagyashree A; Saville, William J; Lindsay, David S; Dubey, J P; Granstrom, David E

    2008-05-01

    A gene family of surface antigens is expressed by merozoites of Sarcocystis neurona, the primary cause of equine protozoal myeloencephalitis (EPM). These surface proteins, designated SnSAGs, are immunodominant and therefore excellent candidates for development of EPM diagnostics or vaccines. Prior work had identified an EPM isolate lacking the major surface antigen SnSAG1, thus suggesting there may be some diversity in the SnSAGs expressed by different S. neurona isolates. Therefore, a bioinformatic, molecular and immunological study was conducted to assess conservation of the SnSAGs. Examination of an expressed sequence tag (EST) database revealed several notable SnSAG polymorphisms. In particular, the EST information implied that the EPM strain SN4 lacked the major surface antigen SnSAG1. The absence of this surface antigen from the SN4 strain was confirmed by both Western blot and Southern blot. To evaluate SnSAG polymorphisms in the S. neurona population, 14 strains were examined by Western blots using monospecific polyclonal antibodies against the four described SnSAGs. The results of these analyses demonstrated that SnSAG2, SnSAG3, and SnSAG4 are present in all 14 S. neurona strains tested, although some variance in SnSAG4 was observed. Importantly, SnSAG1 was not detected in seven of the strains, which included isolates from four cases of EPM and a case of fatal meningoencephalitis in a sea otter. Genetic analyses by PCR using gene-specific primers confirmed the absence of the SnSAG1 locus in six of these seven strains. Collectively, the data indicated that there is heterogeneity in the surface antigen composition of different S. neurona isolates, which is an important consideration for development of serological tests and prospective vaccines for EPM. Furthermore, the diversity reported herein likely extends to other phenotypes, such as strain virulence, and may have implications for the phylogeny of the various Sarcocystis spp. that undergo sexual stages

  2. Pooled protein immunization for identification of cell surface antigens in Streptococcus sanguinis.

    Directory of Open Access Journals (Sweden)

    Xiuchun Ge

    2010-07-01

    Full Text Available Available bacterial genomes provide opportunities for screening vaccines by reverse vaccinology. Efficient identification of surface antigens is required to reduce time and animal cost in this technology. We developed an approach to identify surface antigens rapidly in Streptococcus sanguinis, a common infective endocarditis causative species.We applied bioinformatics for antigen prediction and pooled antigens for immunization. Forty-seven surface-exposed proteins including 28 lipoproteins and 19 cell wall-anchored proteins were chosen based on computer algorithms and comparative genomic analyses. Eight proteins among these candidates and 2 other proteins were pooled together to immunize rabbits. The antiserum reacted strongly with each protein and with S. sanguinis whole cells. Affinity chromatography was used to purify the antibodies to 9 of the antigen pool components. Competitive ELISA and FACS results indicated that these 9 proteins were exposed on S. sanguinis cell surfaces. The purified antibodies had demonstrable opsonic activity.The results indicate that immunization with pooled proteins, in combination with affinity purification, and comprehensive immunological assays may facilitate cell surface antigen identification to combat infectious diseases.

  3. Pooled protein immunization for identification of cell surface antigens in Streptococcus sanguinis.

    Science.gov (United States)

    Ge, Xiuchun; Kitten, Todd; Munro, Cindy L; Conrad, Daniel H; Xu, Ping

    2010-07-26

    Available bacterial genomes provide opportunities for screening vaccines by reverse vaccinology. Efficient identification of surface antigens is required to reduce time and animal cost in this technology. We developed an approach to identify surface antigens rapidly in Streptococcus sanguinis, a common infective endocarditis causative species. We applied bioinformatics for antigen prediction and pooled antigens for immunization. Forty-seven surface-exposed proteins including 28 lipoproteins and 19 cell wall-anchored proteins were chosen based on computer algorithms and comparative genomic analyses. Eight proteins among these candidates and 2 other proteins were pooled together to immunize rabbits. The antiserum reacted strongly with each protein and with S. sanguinis whole cells. Affinity chromatography was used to purify the antibodies to 9 of the antigen pool components. Competitive ELISA and FACS results indicated that these 9 proteins were exposed on S. sanguinis cell surfaces. The purified antibodies had demonstrable opsonic activity. The results indicate that immunization with pooled proteins, in combination with affinity purification, and comprehensive immunological assays may facilitate cell surface antigen identification to combat infectious diseases.

  4. Prevalence of hepatitis B virus infection in out-patient alcoholics

    DEFF Research Database (Denmark)

    Gluud, C; Gluud, B; Aldershvile, J

    1984-01-01

    Sera from 192 out-patient alcoholics attending a clinic for the treatment of alcoholism were tested for hepatitis B surface antigen (HBsAg) and for antibodies to HBsAg and to hepatitis B core antigen (HBcAg). Three sera (1.5%) were positive for HBsAg. Of the remaining 189 alcoholics, 29 (15%) were...... positive for one or both antibodies. This prevalence is not significantly different from that found in 137 hospitalized HBsAg-negative patients with alcoholic liver disease (35/137 [26%] were positive for one or both antibodies). However, the prevalence of hepatitis B antibodies in out-patient alcoholics...

  5. Neuronal surface antigen antibodies in limbic encephalitis

    Science.gov (United States)

    Graus, F; Saiz, A; Lai, M; Bruna, J; López, F; Sabater, L; Blanco, Y; Rey, M J.; Ribalta, T; Dalmau, J

    2008-01-01

    Objective: To report the frequency and type of antibodies against neuronal surface antigens (NSA-ab) in limbic encephalitis (LE). Methods: Analysis of clinical features, neuropathologic findings, and detection of NSA-ab using immunochemistry on rat tissue and neuronal cultures in a series of 45 patients with paraneoplastic (23) or idiopathic (22) LE. Results: NSA-ab were identified in 29 patients (64%; 12 paraneoplastic, 17 idiopathic). Thirteen patients had voltage-gated potassium channels (VGKC)-ab, 11 novel NSA (nNSA)-ab, and 5 NMDA receptor (NMDAR)-ab. nNSA-ab did not identify a common antigen and were more frequent in paraneoplastic than idiopathic LE (39% vs 9%; p = 0.03). When compared with VGKC-ab or NMDAR-ab, the nNSA associated more frequently with intraneuronal antibodies (11% vs 73%; p = 0.001). Of 12 patients (9 nNSA-ab, 2 VGKC-ab, 1 NMDAR-ab) with paraneoplastic LE and NSA-ab, concomitant intraneuronal antibodies occurred in 9 (75%). None of these 12 patients improved with immunotherapy. The autopsy of three of them showed neuronal loss, microgliosis, and cytotoxic T cell infiltrates in the hippocampus and amygdala. These findings were compatible with a T-cell mediated neuronal damage. In contrast, 13 of 17 (76%) patients with idiopathic LE and NSA-ab (8 VGKC-ab, 4 NMDAR-ab, 1 nNSA-ab) and 1 of 5 (20%) without antibodies had clinical improvement (p = 0.04). Conclusions: In paraneoplastic limbic encephalitis (LE), novel antibodies against neuronal surface antigens (nNSA-ab) occur frequently, coexist with antibodies against intracellular antigens, and these cases are refractory to immunotherapy. In idiopathic LE, the likelihood of improvement is significantly higher in patients with NSA-ab than in those without antibodies. GLOSSARY GAD = glutamic acid decarboxylase; LE = limbic encephalitis; NMDAR = N-methyl-D-aspartate receptor; NSA = neuronal surface antigens; nNSA = novel NSA; SCLC = small-cell lung cancer; VGKC = voltage-gated potassium channels

  6. Frequency of hepatitis B surface antigen and anti-hepatitis c antibodies in apparently healthy blood donors in northern areas

    International Nuclear Information System (INIS)

    Alam, M.; Naeem, M.A.

    2007-01-01

    To determine the frequency of HBsAg and anti HCV among the potential blood donors belonging to Northern areas.A total of 8949 apparently healthy blood donors, belonging to Northern areas were screened for HBsAg and anti-HCV by rapid method.Overall sero-positivity of HBsAg was 3.66% and anti-HCV 1.35%. The result indicates that frequency of HBsAg is more than anti-HCV in Northern areas. (author)

  7. Peg-interferon plus nucleotide analogue treatment versus no treatment in patients with chronic hepatitis B with a low viral load: a randomised controlled, open-label trial

    NARCIS (Netherlands)

    de Niet, Annikki; Jansen, Louis; Stelma, Femke; Willemse, Sophie B.; Kuiken, Sjoerd D.; Weijer, Sebastiaan; van Nieuwkerk, Carin M. J.; Zaaijer, Hans L.; Molenkamp, Richard; Takkenberg, R. Bart; Koot, Maarten; Verheij, Joanne; Beuers, Ulrich; Reesink, Hendrik W.

    2017-01-01

    Antiviral treatment is currently not recommended for patients with chronic hepatitis B with a low viral load. However, they might benefit from acquiring a functional cure (hepatitis B surface antigen [HBsAg] loss with or without formation of antibodies against hepatitis B surface antigen

  8. Dose-response association between hepatitis B surface antigen levels and liver cancer risk in Chinese men and women.

    Science.gov (United States)

    Yang, Yang; Gao, Jing; Li, Hong-Lan; Zheng, Wei; Yang, Gong; Zhang, Wei; Ma, Xiao; Tan, Yu-Ting; Rothman, Nathaniel; Gao, Yu-Tang; Chow, Wong-Ho; Shu, Xiao-Ou; Xiang, Yong-Bing

    2016-07-15

    We aimed at evaluating the risk of liver cancer in different levels of HBsAg among Chinese men and women. We carried out a nested case-control study including 363 cases and 3,511 controls in two population-based cohorts in Shanghai. Plasma samples collected at enrollment were quantified for HBsAg levels using the Architect QT assay. Conditional logistic regression was performed to estimate the odds ratios (ORs) and 95% confidence intervals (95% CIs) for liver cancer, with adjustment for potential confounders. HBsAg was detected in 6.29% of control subjects overall (7.02% in men and 4.98% in women). HBsAg levels were positively associated with liver cancer risk in a dose-response manner (ptrend  women. In men, the adjusted ORs increased from 7.27 (95% CI: 3.49-15.15) at the lowest detectable level of HBsAg (5-9 IU/ml) to 7.16 (95% CI: 3.21-15.96), 34.30 (95% CI: 16.94-69.44), and 47.33 (95% CI: 23.50-95.34) at the highest level of HBsAg (≥1,000 IU/ml) compared to those negative for HBsAg. The corresponding ORs were much lower for women, from 1.37 (95% CI: 0.25-7.47), 3.81 (95% CI: 1.09-13.28), 7.36 (95% CI: 2.41-22.46) and 16.86 (95% CI: 7.24-39.27), respectively. HBsAg quantification has potential to distinguish individuals at different risks of liver cancer. Men with the lowest detectable level of HBsAg should still pay attention to their liver cancer risks, but those with a higher level may be given a higher priority in future liver cancer surveillance program. © 2016 UICC.

  9. Humoral and cellular immune responses to modified hepatitis B ...

    African Journals Online (AJOL)

    Purpose: To evaluate the immunogenicity and types of immune response of a quality-controlled modified recombinant hepatitis B surface antigen (HBsAg) plasmid encoding HBsAg in mice. Methods: The characterized plasmid DNA was used in the immunization of Balb/c mice. Three groups of mice were intramuscularly ...

  10. Characterization of antigen association with accessory cells: specific removal of processed antigens from the cell surface by phospholipases

    International Nuclear Information System (INIS)

    Falo, L.D. Jr.; Haber, S.I.; Herrmann, S.; Benacerraf, B.; Rock, K.L.

    1987-01-01

    To characterize the basis for the cell surface association of processed antigen with the antigen-presenting cell (APC) the authors analyzed its sensitivity to enzymatic digestion. Antigen-exposed APC that are treated with phospholipase and then immediately fixed lose their ability to stimulate antigen-plus-Ia-specific T-T hybridomas. This effect is seen with highly purified phospholipase A 2 and phospholipase C. In addition it is observed with three distinct antigens - ovalbumin, bovine insulin, and poly(LGlu 56 LLys 35 LPhe 9 )[(GluLysPhe)/sub n/]. The effect of phospholipases is highly specific. Identically treated APC are equivalent to control in their ability to stimulate alloreactive hybridomas specific for precisely the same Ia molecule that is corecognized by antigen-plus-Ia-specific hybrids. Furthermore, the antigen-presenting function of enzyme-treated, fixed APC can be reconstituted by the addition of exogenous in vitro processed or processing independent antigens. In parallel studies 125 I-labeled avidin was shown to specifically bind to APC that were previously exposed and allowed to process biotin-insulin. Biotin-insulin-exposed APC that are pretreated with phospholipase bind significantly less 125 I-labeled avidin than do untreated, exposed APC. Identical enzyme treatment does not reduce the binding of avidin to a biotinylated antibody already bound to class II major histocompatibility complex molecules of APC. These studies demonstrate that phospholipase effectively removes processed cell surface antigen

  11. Seroprevalence of Human Immunodeficiency Virus, Hepatitis B ...

    African Journals Online (AJOL)

    surface antigen (HBsAg), syphilis and HCV from the antenatal records. The data were extracted by two trained assistants. Hepatitis B surface antigen and antibodies to HCV were determined using Clinotech diagnostic enzyme linked immunosorbent assay (ELISA) test kits (Clinotech Laboratories,. USA; batch/lot no. for ...

  12. Comparison of hepatitis B virus core-related antigen and hepatitis B surface antigen for predicting HBeAg seroconversion in chronic hepatitis B patients with pegylated interferon therapy.

    Science.gov (United States)

    Wang, Meng-Lan; Liao, Juan; Wei, Bing; Zhang, Dong-Mei; He, Ming; Tao, Ming-Chuan; Chen, En-Qiang; Tang, Hong

    2018-02-20

    Recent studies revealed that both quantitative hepatitis B surface antigen (qHBsAg) and hepatitis B core-related antigen (qHBcrAg) could serve as a good marker for predicting treatment response and indirectly reflecting intrahepatic cccDNA levels. This study aimed to compare the value of qHBsAg and qHBcrAg in predicting HBeAg seroconversion among patients undergoing PEG-IFN therapy. A total of 31 HBeAg-positive patients, who underwent PEG-IFN therapy for 12 months and follow-up for six months were retrospectively included in this study. The serum qHBsAg level was measured using Elecsys® HBsAg II Quant Assay and serum qHBcrAg level was measured using chemiluminescence enzyme immunoassay. During the 12-month treatment, the absolute levels of serum qHBsAg and qHBcrAg were both lower in patients with HBeAg seroconversion as compared to patients without HBeAg seroconversion, but only the difference in qHBcrAg was significant. During the 6-month follow-up period, both qHBsAg and qHBcrAg levels were rebounded significantly among patients without HBeAg seroconversion. Among patients with HBeAg seroconversion, no sustained significant decline of qHBsAg was observed, but serum qHBcrAg levels continued to decline significantly. The ROC curves analysis showed that both absolute qHBcrAg level and the extent of qHBcrAg decline at month 1 had better performance for the prediction of HBeAg seroconversion at month 6 after treatment, as compared to that of qHBsAg. Early on-treatment qHBcrAg may be a good biomarker for predicting off-treatment HBeAg seroconversion in patients receiving PEG-IFN therapy.

  13. Diversity and origin of hepatitis B virus in Dutch blood donors

    NARCIS (Netherlands)

    Koppelman, M. H. G. M.; Zaaijer, H. L.

    2004-01-01

    Two considerations led us to study the genetic diversity and origin of hepatitis B virus (HBV) in Dutch blood donors. Firstly, an HBV-infected Dutch blood donor was found negative by four assays used commonly for detection of HBV surface antigen (HBsAg). How variable is HBsAg among HBV infected

  14. The Lumipulse G HBsAg-Quant assay for screening and quantification of the hepatitis B surface antigen.

    Science.gov (United States)

    Yang, Ruifeng; Song, Guangjun; Guan, Wenli; Wang, Qian; Liu, Yan; Wei, Lai

    2016-02-01

    Qualitative HBsAg assay is used to screen HBV infection for decades. The utility of quantitative assay is also rejuvenated recently. We aimed to evaluate and compare the performance of a novel ultra-sensitive and quantitative assay, the Lumipulse assay, with the Architect and Elecsys assays. As screening methods, specificity was compared using 2043 consecutive clinical routine samples. As quantitative assays, precision and accuracy were assessed. Sera from 112 treatment-naïve chronic hepatitis B patients, four patients undergoing antiviral therapy and one patient with acute infection were tested to compare the correlations. Samples with concurrent HBsAg/anti-HBs were also quantified. The Lumipulse assay precisely quantified ultra-low level of HBsAg (0.004 IU/mL). It identified additional 0.98% (20/2043) clinical samples with trance amount of HBsAg. Three assays displayed excellent linear correlations irrespective of genotypes and S-gene mutations (R(2)>0.95, PLumipulse assay did not yield higher HBsAg concentrations in samples with concomitant anti-HBs. Compared with other assays, the Lumipulse assay is sensitive and specific for detecting HBsAg. The interpretation of the extremely low-level results, however, is challenging. Quantitative HBsAg results by different assays are highly correlated, but they should be interpreted interchangeably only after conversion to eliminate the biases. Copyright © 2015 Elsevier B.V. All rights reserved.

  15. Characterisation of surface antigens of Strongylus vulgaris of potential immunodiagnostic importance.

    Science.gov (United States)

    Nichol, C; Masterson, W J

    1987-08-01

    When antigens prepared by detergent washes of Strongylus vulgaris and Parascaris equorum were probed in an enzyme-linked immunosorbent assay test with horse sera from single species infections of S. vulgaris and P. equorum, a high degree of cross-reaction between the species was demonstrated. Western blot analysis of four common horse nematode species showed a large number of common antigens when probed with horse infection sera. Antisera raised in rabbits against the four species, including S. vulgaris, were also found to cross-react considerably. Rabbit anti-S. vulgaris sera were affinity adsorbed over a series of affinity chromatography columns, bound with cross-reactive surface antigens, to obtain S. vulgaris-specific antisera and thereby identify S. vulgaris-specific antigens by Western blotting. These studies revealed potentially specific antigens of apparent molecular weights of 100,000, 52,000, and 36,000. Of these bands, only the 52 kDa and 36 kDa appeared to be found on the surface as judged by 125I-labelling of intact worms by the Iodogen method, although neither protein was immunoprecipitated by horse infection sera. Finally, immunoprecipitation of in vitro translated proteins derived from larval S. vulgaris RNA suggests that two proteins may be parasite-derived. These findings are discussed both with respect to the surface of S. vulgaris and to the use of these species-specific antigens in immunodiagnosis.

  16. Evidence for glycosyl-phosphatidylinositol anchoring of Toxoplasma gondii major surface antigens

    International Nuclear Information System (INIS)

    Tomavo, S.; Schwarz, R.T.; Dubremetz, J.F.

    1989-01-01

    The four major surface antigens of Toxoplasma gondii tachyzoites (P43, P35, P30, and P22) were made water soluble by phosphatidylinositol-specific phospholipase C (PI-PLC). These antigens were biosynthetically labeled with 3 H-fatty acids, [ 3 H]ethanolamine, and [ 3 H]carbohydrates. Treatment of 3 H-fatty-acid-labeled parasite lysates with PI-PLC removed the radioactive label from these antigens. A cross-reacting determinant was exposed on these antigens after PI-PLC treatment

  17. Type B Hepatitis in Iran

    Directory of Open Access Journals (Sweden)

    M. Tabarestani

    1977-01-01

    Full Text Available Hepatitis B surface antigen CHBsAg was found in 1% of controls, 2.1% of professional blood donors, 2.0% of leprosy patients and 76.1% of acute hepatitis in Tehran and Mashhad, Iran. All HBsAg positive samples also possessed antibody to the hepatitis B core antigen and all were subtype ayw. Type B hepatitis and the HBsAg state aloe frequent in Iran, but most must be accounted for by u nonparenter- al" or "rnapparent'' parenteral exposure.

  18. Seroprevalence of hepatitis B virus infection among antenatal clinic ...

    African Journals Online (AJOL)

    Saharan Africa. The risk of vertical transmission increases if the mother is hepatitis B surface antigen (HBsAg) positive and more so when she is also hepatitis B envelope antigen (HBeAg) positive. Since 2000, the World Health Organization ...

  19. Ausab test - a radioimmunoassay in the solid phase for the detection of antibodies against HBsAg

    Energy Technology Data Exchange (ETDEWEB)

    Lange, W; Koehler, H; Apodaca, J [Bundesgesundheitsamt, Berlin (Germany, F.R.). Abt. fuer Virologie

    1974-01-01

    The suitability of a newly developed RIA (Ausab test, Abbott laboratories) for the detection of antibodies against the Hepatitis B (surface) antigen (HBsAg) has been tested on 1968 sera of blood donors. Reproducibility test and specificity test were included. During the examination the technique of the Ausab test was changed from the original one-step to the two-step procedure. With the one-step technique 431 of 1968 sera (21.9%) showed positive reactions. During the test problems concerning the differentiation between positive and negative results were encountered due to high unspecific binding of radioactivity. Positive sera were re-examined employing the two-step technique and only 77.4% of the previously positive reactions could be reproduced. 50 sera that were negative in the one-step test remained negative in the two-step test. Difficulties concerning nonspecific binding of radioactivity as observed with the one-step technique were not encountered with the two-step procedure. On 92 of the confirmed positive sera a specificity test was run and 90 (97.8%) proved to be specific. A calculated 16.5% of the blood donors in Berlin have to be considered as antibody carriers. Only 6 of the Ausab positive sera were found to give positive reactions in CEP. 3 sera that were initially positive in CEP could neither be confirmed in a repeated CEP nor in the Ausab test.

  20. Paired Expression Analysis of Tumor Cell Surface Antigens

    Directory of Open Access Journals (Sweden)

    Rimas J. Orentas

    2017-08-01

    Full Text Available Adoptive immunotherapy with antibody-based therapy or with T cells transduced to express chimeric antigen receptors (CARs is useful to the extent that the cell surface membrane protein being targeted is not expressed on normal tissues. The most successful CAR-based (anti-CD19 or antibody-based therapy (anti-CD20 in hematologic malignancies has the side effect of eliminating the normal B cell compartment. Targeting solid tumors may not provide a similar expendable marker. Beyond antibody to Her2/NEU and EGFR, very few antibody-based and no CAR-based therapies have seen broad clinical application for solid tumors. To expand the way in which the surfaceome of solid tumors can be analyzed, we created an algorithm that defines the pairwise relative overexpression of surface antigens. This enables the development of specific immunotherapies that require the expression of two discrete antigens on the surface of the tumor target. This dyad analysis was facilitated by employing the Hotelling’s T-squared test (Hotelling–Lawley multivariate analysis of variance for two independent variables in comparison to a third constant entity (i.e., gene expression levels in normal tissues. We also present a unique consensus scoring mechanism for identifying transcripts that encode cell surface proteins. The unique application of our bioinformatics processing pipeline and statistical tools allowed us to compare the expression of two membrane protein targets as a pair, and to propose a new strategy based on implementing immunotherapies that require both antigens to be expressed on the tumor cell surface to trigger therapeutic effector mechanisms. Specifically, we found that, for MYCN amplified neuroblastoma, pairwise expression of ACVR2B or anaplastic lymphoma kinase (ALK with GFRA3, GFRA2, Cadherin 24, or with one another provided the strongest hits. For MYCN, non-amplified stage 4 neuroblastoma, neurotrophic tyrosine kinase 1, or ALK paired with GFRA2, GFRA3, SSK

  1. Alkylglycerols modulate the proliferation and differentiation of non-specific agonist and specific antigen-stimulated splenic lymphocytes.

    Directory of Open Access Journals (Sweden)

    Linxi Qian

    Full Text Available Alkylglycerols (AKGs are ether-linked glycerols derived from shark liver oil and found in small amounts in human milk. Previous studies showed that oral AKGs administration significantly increased the immune response in mice. The aim of the present study was to investigate the in vitro immunomodulatory effect of AKGs on stimulating splenic lymphocyte responses. C57BL/6 mice were immunized with hepatitis B surface antigen (HBsAg. Splenic B cells were purified and stimulated with anti-BCR and anti-CD38. Meanwhile, splenic CD4+ T cells were purified and stimulated with anti-CD3 and anti-CD28. For antigen specific stimulation, the purified CD4+ T cells were cocultured with HBsAg -pulsed dendritic cells. The stimulated lymphocytes were treated with different concentrations of AKGs. The cell proliferation was assessed by [3H]-thymidine incorporation assay. The maturation of B cells was assessed by examining the germline (GL transcription of IgG (γ1 mRNA expression, and the surface expressions of CD80/CD86 markers were examined by flow cytometry analysis. Th1/Th2 polarity was assessed by T-BET (Th1/GATA-3 (Th2 flow cytometry assay and by characteristic cytokines ELISA assay (TNF-α and IFN-γ for Th1; IL-4 and IL-10 for Th2. It was found that AKGs significantly increased the BCR/CD38 -stimulated B cell proliferation. The T cell proliferation in response to CD3/CD28 or specific antigen stimulation was also increased by AKGs. The transcriptional level of IgG (γ1 and the expressions of CD80/CD86 molecules were markedly increased by AKGs in BCR/CD38 -stimulated B cells. Meanwhile, the results showed that AKGs increased the expression of T-BET transcriptional factor and the production of Th1 cytokines (TNF-α and IFN-γ upon CD3/CD28 stimulation; whereas, levels of Th2 cytokines (IL-4 and IL-10 were decreased by AKGs. Our study demonstrated that AKGs can modulate immune responses by boosting the proliferation and maturation of murine lymphocytes in vitro.

  2. Evaluation of HBsAg and anti-HBc assays in saliva and dried blood spot samples according HIV status.

    Science.gov (United States)

    Flores, Geane Lopes; Cruz, Helena Medina; Potsch, Denise Vigo; May, Silvia Beatriz; Brandão-Mello, Carlos Eduardo; Pires, Marcia Maria Amendola; Pilotto, Jose Henrique; Lewis-Ximenez, Lia Laura; Lampe, Elisabeth; Villar, Livia Melo

    2017-09-01

    Influence of HIV status in HBV markers detection in saliva and dried blood spots (DBS) was not well established. This study aims to evaluate the performance of optimized commercial immunoassay for identifying HBsAg and anti-HBc in saliva and DBS according HIV status. A sum of 535 individuals grouped as HIV + , HBV + , HIV/HBV + and HIV/HBV- were recruited where 347 and 188 were included for HBsAg and anti-HBc evaluation, respectively. Serum, DBS collected in Whatman 903 paper and saliva obtained using salivette device were analyzed using EIA. Increased sample volume and ROC curve analysis for cut off determination were used for DBS and saliva testing. HBsAg detection in saliva and DBS exhibited sensitivities of 80.9% and 85.6% and specificities of 86.8% and 96.3%. Sensitivity of anti-HBc in saliva and DBS were 82.4% and 76.9% and specificities in saliva and DBS were 96.9% and 91.7%. Low sensitivities were observed for HBsAg (62%) and anti-HBc (47%) detection in saliva of HIV/HBV+ individuals. OD values were also lower for HBsAg detection in DBS and saliva of HIV/HBV+ individuals compared to their serum samples. Statistical significance was found for sensitivities in HBsAg detection between saliva and DBS demonstrating high sensitivity for DBS specimens. In conclusion, HIV status or antiretroviral treatment appears to interfere in the performance of HBsAg and anti-HBc detection in DBS and saliva samples using the adapted commercial EIA. Copyright © 2017 Elsevier B.V. All rights reserved.

  3. HBsAg seroprevalence in students for college entrance examination from 2006 to 2014 in Qidong of Jiangsu Province

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    NI Zhengping

    2015-10-01

    Full Text Available ObjectiveTo investigate the HBsAg seroprevalence in the young generation in Qidong of Jiangsu Province, China. MethodsA total of 15 534 students for college entrance examination from 2006 to 2014 were randomly selected from three secondary schools in Qidong as student group. Some of them had hepatitis B vaccination at birth. A total of 1208 adults who had their routine checkups in our hospital from 2007 to 2013 were selected as adult group. It was confirmed that all of them did not have hepatitis B vaccination at birth. Serum HBsAg levels of the two groups were measured using enzyme-linked immunosorbent assay and the seroprevalence was analyzed. Comparison of data between the two groups was made by chi-square test. Results In the 9 years from 2007 to 2013, the seroprevalence rates of HBsAg in the student group were 4.2%(75/1794, 4.3%(77/1797, 4.4%(82/1858, 4.3%(82/1903, 3.4%(56/1627, 2.6%(46/1768, 1.6%(29/1778, 1.6%(27/1642, and 1.8%(24/1367, respectively. The mean HBsAg seroprevalence of the student group was 3.2%(498/15534, significantly lower compared with 7.1% (86/1208 of the adult group (χ2= 59.986, P<0.001. In both of the student group and the adult group, the males had a significantly higher HBsAg seroprevalence than the females (χ2=10.521, P=0.001; χ2=8.452, P=0.004 and the values were 3.7%(266/7236 vs 2.8%(229/8298 and 8.8%(66/750 vs 4.4%(20/458, respectively. Among male subjects, the HBsAg seroprevalence of the adult group was 2.4 times that of the student group; among female subjects, the HBsAg seroprevalence of the adult group was 1.6 times that of the student group. ConclusionIn the recent 9 years from 2006 to 2014, the HBsAg seroprevalence in students for college entrance examination declined continuously. The goal set by the World Health Organization Western Pacific Region in 2010 had been achieved ahead of the schedule that the HBsAg seroprevalence should be controlled below 2% in children aged less than 5.

  4. Method to conjugate polysaccharide antigens to surfaces for the detection of antibodies.

    Science.gov (United States)

    Boas, Ulrik; Lind, Peter; Riber, Ulla

    2014-11-15

    A new generic method for the conjugation of lipopolysaccharide (LPS)-derived polysaccharide antigens from gram-negative bacteria has been developed using Salmonella as a model. After removal of lipid A from the LPS by mild acidolysis, the polysaccharide antigen was conjugated to polystyrene microbeads modified with N-alkyl hydroxylamine and N-alkyl-O-methyl hydroxylamine surface groups by incubation of antigen and beads for 16 h at 40 °C without the need for coupling agents. The efficiency of the new method was evaluated by flow cytometry in model samples and serum samples containing antibodies against Salmonella typhimurium and Salmonella dublin. The presented method was compared with a similar method for conjugation of Salmonella polysaccharide antigens to surfaces. Here, the new method showed higher antigen coupling efficiency by detecting low concentrations of antibodies. Furthermore, the polysaccharide-conjugated beads showed preserved bioactivity after 1 year of use. Copyright © 2014 Elsevier Inc. All rights reserved.

  5. The Ausab test - a radioimmunoassay in the solid phase for the detection of antibodies against HBsAg

    International Nuclear Information System (INIS)

    Lange, W.; Koehler, H.; Apodaca, J.

    1974-01-01

    The suitability of a newly developed RIA (Ausab test, Abbott laboratories) for the detection of antibodies against the Hepatitis B (surface) antigen (HBsAg) has been tested on 1968 sera of blood donors. Reproducibility test and specificity test were included. During the examination the technique of the Ausab test was changed from the original one-step to the two-step procedure. With the one-step technique 431 of 1968 sera (21.9%) showed positive reactions. During the test problems concerning the differentiation between positive and negative results were encountered due to high unspecific binding of radioactivity. Positive sera were re-examined employing the two-step technique and only 77.4% of the previously positive reactions could be reproduced. 50 sera that were negative in the one-step test remained negative in the two-step test. Difficulties concerning nonspecific binding of radioactivity as observed with the one-step technique were not encountered with the two-step procedure. On 92 of the confirmed positive sera a specificity test was run and 90 (97.8%) proved to be specific. A calculated 16.5% of the blood donors in Berlin have to be considered as antibody carriers. Only 6 of the Ausab positive sera were found to give positive reactions in CEP. 3 sera that were initially positive in CEP could neither be confirmed in a repeated CEP nor in the Ausab test. (orig.) [de

  6. Sero-prevalence of hepatitis B surface antigen among primary ...

    African Journals Online (AJOL)

    of 2-7% in Southern and Eastern Europe to low rates of less than 2%, in .... Table 2. Distribution of HBsAg by Age and Gender amongst Primary School Pupils in the Hawal valley ... effective manner and the global assessment of hepatitis B. 13 ... settlement in the Middle Hawal Valley, Nigeria, Trans Roy. Soc Trop Med Hyg ...

  7. Frequency of anti-HCV, Hbsag and related risk factors in pregnant women at Nishtar Hospital, Multan

    International Nuclear Information System (INIS)

    Taseer, I.H.; Ishaq, F.; Hussain, L.; Safdar, S.; Mirbahar, A.M.; Faiz, S.A.

    2010-01-01

    Background: Viral hepatitis is a global issue. Among the hepatitis viruses hepatitis B and C are important in South Asia including Pakistan. There are various modes of transmission of these viruses. Vertical transmission is also gaining importance. Antepartum screening for HBV and HCV would help the infected women for appropriate antiviral therapy at appropriate time as well as for taking proper care of the newborns. The present study was designed to see the frequency of HBsAg and anti-HCV in pregnant women at Nishtar Hospital, Multan. Methods: This was a cross-sectional study carried out using non-probability purposive sampling technique. The period of the study was from June 2006 to August 2007. Five hundred (500) pregnant women attending outpatient department of Gynaecology and Obstetrics were included. Informed consent was taken. A specially designed proforma was filled in. Anti-HCV and HBsAg were tested by device method. Data were analyzed on SPSS-11. Results: Out of 500 pregnant women 35 (7.00%) were found to be anti-HCV positive and 23 (4.60%) were positive for HBsAg. Mean age was 26.7+-4.8 years. Majority of the patients 263 (52.60%) were in the age group 26-35 years. 138 (27.60%) women were nulliparous and 282 (56.40%) were para 1-4 and anti-HCV and HBsAg were common in this parity group. Only 80 (16.00%) women were para 5 or more. All anti-HCV and HBsAg positive women were house-wives. Most of them were belonging to rural areas having poor socio-economic status. Among 35 anti-HCV positive women, 20 (57.14%) had history of previous surgery, while 13 (37.14%) had history of multiple injections, 5 (14.28%) received blood transfusion, 4 (11.42%) had ear/nose piercing while tattooing was seen in only 2 (5.71%). Among 23 HBsAg positive women, 10 (43.47%) had history of previous surgery. History of multiple injections was present in 6 (26.08%) patients, 4 (17.39%) patients had history of blood transfusion, tattooing, ear/nose piercing, history of dental

  8. An investigation of clinical features of HBsAg and anti-HBs positive patients with chronic hepatitis B

    Directory of Open Access Journals (Sweden)

    SONG Jinyun

    2016-11-01

    Full Text Available ObjectiveTo investigate the phenomenon of coexistence of HBsAg and anti-HBs and its clinical features, as well as related causes. MethodsA total of 2260 persons who underwent physical examination in The Second Affiliated Hospital of Southeast University from February 2011 to February 2014 were enrolled, among whom 830 were diagnosed with chronic hepatitis B. Chemiluminescence microparticle immunoassay was used to screen out 188 patients with coexistence of HBsAg and anti-HBs, and these patients were divided into HBeAg positive group (101 patients and HBeAg negative group (87 patients. Another 200 patients with positive HBsAg and negative anti-HBs were enrolled as controls, among whom 80 were in the HBeAg-positive group and 120 were in the HBeAg-negative group. HBV serological markers, liver function, and viral load were measured and analyzed with reference to clinical manifestations. The chi-square test was used for comparison of categorical data between groups. ResultsThere were five patterns of HBV serological markers in patients with positive HBsAg and anti-HBs, among which positive HBsAg, anti-HBs, HBeAg, and anti-HBc and negative anti-HBe were the most common and accounted for 47.9% (90/188. The overall abnormal rate of liver function parameters was 69.1% (130/188, and the positive rate of HBV DNA was 56.9% (107/188. The two groups with positive HBeAg had a high level of HBV DNA replication, and there was no significant difference in the positive rate of HBV DNA between positive HBsAg and anti-HBs group and control group (P>0.05. In the groups with negative HBeAg, there was a significant difference in the proportion of patients with HBV DNA quantitation of >1×10^5 IU/ml between positive HBsAg and anti-HBs group and control group (P<0.05. The sequencing of the S region of HBV showed that among the 80 patients with positive HBsAg and anti-HBs, 27 had variations in this region, and the mutation rate reached 33.7%. The major variation

  9. Species specificity for HBsAg binding protein endonexin II

    NARCIS (Netherlands)

    deBruin, WCC; Leenders, WPJ; Moshage, H; vanHaelst, UJGM

    Background/Aims: Hepatitis B virus displays a distinct species and tissue tropism, Previously we have demonstrated that a human liver plasma membrane protein,vith a molecular weight of approximately 34 kiloDalton specifically binds to HBsAg. This protein was identified as endonexin II, a Ca2+

  10. Prediction of antigenic epitopes on protein surfaces by consensus scoring

    Directory of Open Access Journals (Sweden)

    Zhang Chi

    2009-09-01

    Full Text Available Abstract Background Prediction of antigenic epitopes on protein surfaces is important for vaccine design. Most existing epitope prediction methods focus on protein sequences to predict continuous epitopes linear in sequence. Only a few structure-based epitope prediction algorithms are available and they have not yet shown satisfying performance. Results We present a new antigen Epitope Prediction method, which uses ConsEnsus Scoring (EPCES from six different scoring functions - residue epitope propensity, conservation score, side-chain energy score, contact number, surface planarity score, and secondary structure composition. Applied to unbounded antigen structures from an independent test set, EPCES was able to predict antigenic eptitopes with 47.8% sensitivity, 69.5% specificity and an AUC value of 0.632. The performance of the method is statistically similar to other published methods. The AUC value of EPCES is slightly higher compared to the best results of existing algorithms by about 0.034. Conclusion Our work shows consensus scoring of multiple features has a better performance than any single term. The successful prediction is also due to the new score of residue epitope propensity based on atomic solvent accessibility.

  11. Human peripheral blood monocytes display surface antigens recognized by monoclonal antinuclear antibodies

    International Nuclear Information System (INIS)

    Holers, V.M.; Kotzin, B.L.

    1985-01-01

    The authors used monoclonal anti-nuclear autoantibodies and indirect immunofluorescence to examine normal human peripheral blood mononuclear leukocytes for the presence of cell surface nuclear antigens. Only one monoclonal anti-histone antibody (MH-2) was found to bind to freshly isolated PBL, staining approximately 10% of large cells. However, after cells were placed into culture for 16-24 h, a high percentage (up to 60%) of large-sized cells were recognized by an anti-DNA (BWD-1) and several different antihistone monoclonal antibodies (BWH-1, MH-1, and MH-2). These antibodies recognize separate antigenic determinants on chromatin and histones extracted from chromatin. The histone antigen-positive cells were viable, and the monoclonal antibodies could be shown to be binding to the cell surface and not to the nucleus. Using monoclonal antibodies specific for monocytes and T cells, and complement-mediated cytotoxicity, the cells bearing histone antigens were shown to be primarily monocytes. The appearance of histone and DNA antigen-positive cells was nearly completely inhibited by the addition of low concentrations of cycloheximide at initiation of the cultures. In contrast, little effect on the percentage of positive cells was detected if cells were exposed to high doses of gamma irradiation before culture. These data further support the existence of cell surface nuclear antigens on selected cell subsets, which may provide insight into the immunopathogenesis of systemic lupus erythematosus and related autoimmune diseases

  12. Efficacy of selective antenatal screening for hepatitis B among pregnant women in Denmark: is selective screening still an acceptable strategy in a low-endemicity country?

    DEFF Research Database (Denmark)

    Jensen, Lise; Heilmann, Carsten; Smith, Else

    2003-01-01

    The prevalence of hepatitis B virus (HBV) carriage in Denmark is unknown, but expected to be low (0.1%). This study aimed to evaluate the efficacy of selective antenatal screening for HBV infection and the epidemiology of HBV and hepatitis C virus (HCV) among pregnant women. 4098 women were...... included in the study. Blood tests were examined for hepatitis B surface antigen (HBsAg), anti-hepatitis B core antigen (HBc) and anti-HCV. Case records were studied to evaluate whether patients at risk for HBV infection had been tested. Among the 4098 women, 18 10.4%, 95% confidence interval (95% CI) 0.......3-0.71 were HBsAg positive. All had a risk factor for HBV infection. Only 13 (72%) were identified as HBsAg positive in the selective screening programme. 115 women (2.8%, 95% CI 2.3-3.4) were anti-HBc positive only. 95 (83%) were at risk for HBV. Only 72 of these (63%) were tested for HBsAg. The screening...

  13. Value of HBsAg level in dynamic monitoring of disease progression in patients with chronic HBV infection

    Directory of Open Access Journals (Sweden)

    BAO Teng

    2017-08-01

    Full Text Available ObjectiveTo investigate the clinical value of HBsAg level in dynamic monitoring of disease progression in patients with chronic HBV infection. MethodsA retrospective analysis was performed for the clinical data of 1107 patients with different clinical stages of chronic HBV infection who had not received antiviral therapy at the time of hospitalization in The Second Affiliated Hospital of Anhui Medical University from May 2011 to December 2015, and according to the disease status, they were divided into HBeAg-positive chronic hepatitis B (CHB group, HBeAg-negative CHB group, compensated liver cirrhosis group (LC-C group, decompensated liver cirrhosis group (LC-D group, and primary liver cancer (PLC group. These groups were compared in terms of HBsAg expression and the association between HBsAg and clinical features. An analysis of variance was used for comparison of continuous data between multiple groups, and the least significant difference t-test was used for further comparison between any two groups; the t-test was used for comparison of continuous data between two groups. The chi-square test was used for comparison of categorical data between these groups. Pearson correlation analysis was also performed. ResultsThere was a significant difference in serum HBsAg level between the HBeAg-positive CHB group, HBeAg-negative CHB group, LC-C group, LC-D group, and PLC group (F=100.45, P<0.001. The HBeAg-positive CHB group had significantly higher levels of HBsAg and HBV DNA than the HBeAg-negative CHB group (t= 16.67 an 16.22, both P<0.001. There were significant differences in HBsAg and HBV DNA levels between the HBeAg-positive CHB group, LC-C group, LC-D group, and PLC group (F= 42.92 and 27.38, both P<0.001, as well as between the HBeAg-negative CHB group, LC-C group, LC-D group, and PLC group (F=6.04 and 4.10, both P<0.05. HBV DNA level was significantly different across patients with different HBsAg levels (<1000 IU/ml, 1000-20 000 IU

  14. Results of HBsAg examination with immunoelectrophoresis and radioimmunoassay in VPR, Laotian PDR and Cuban R

    Energy Technology Data Exchange (ETDEWEB)

    Michal, L; Szilagyiova, M; Zahradny, V; Holan, J; Krajnak, V [Komenskeho Univ., Martin (Czechoslovakia). Lekarska Fakulta; Padurova, J [Okresna Hygienicka Stanica, Zilina (Czechoslovakia)

    1984-06-21

    The results are compared of examining 112 Vietnamese, 30 Laotian and 50 Cuban citizens for HBsAg using IEP and RIA methods. Of the examined persons with no liver disorders HBsAg was found in 23 (31.5%) of the Vietnamese and 1 (2.5%) of the Cubans using the RIA method and only in 4 (5.5%) of the Vietnamese using the IEP method. Of the examined persons with liver disorders RIA found HBsAg in 12 (30.8%) of the Vietnamese, 5 (71.4%) of the Laotians and 2 (20.0%) of the Cubans while with IEP only in 3 (7.7%) Vietnamese 2 (28.6%) Laotians and 1 (10.0%) of the Cubans examined.

  15. Results of HBsAg examination with immunoelectrophoresis a radioimmunoassay in VPR, Laotian PDR and Cuban R

    International Nuclear Information System (INIS)

    Michal, L.; Szilagyiova, M.; Zahradny, V.; Holan, J.; Krajnak, V.

    1984-01-01

    The results are compared of examining 112 Vietnamese, 30 Laotian and 50 Cuban citizens for HBsAg using IEP and RIA methods. Of the examined persons with no liver disorders HBsAg was found in 23 (31.5%) of the Vietnamese and 1 (2.5%) of the Cubans using the RIA method and only in 4 (5.5%) of the Vietnamese using the IEP method. Of the examined persons with liver disorders RIA found HBsAg in 12 (30.8%) of the Vietnamese, 5 (71.4%) of the Laotians and 2 (20.0%) of the Cubans while with IEP only in 3 (7.7%) Vietnamese 2 (28.6%) Laotians and 1 (10.0%) of the Cubans examined. (author)

  16. CELLISA: reporter cell-based immunization and screening of hybridomas specific for cell surface antigens.

    Science.gov (United States)

    Chen, Peter; Mesci, Aruz; Carlyle, James R

    2011-01-01

    Monoclonal antibodies (mAbs) specific for cell surface antigens are an invaluable tool to study immune receptor expression and function. Here, we outline a generalized reporter cell-based approach to the generation and high-throughput screening of mAbs specific for cell surface antigens. Termed CELLISA, this technology hinges upon the capture of hybridoma supernatants in mAb arrays that facilitate ligation of an antigen of interest displayed on BWZ reporter cells in the form of a CD3ζ-fusion chimeric antigen receptor (zCAR); in turn, specific mAb-mediated cross-linking of zCAR on BWZ cells results in the production of β-galactosidase enzyme (β-gal), which can be assayed colorimetrically. Importantly, the BWZ reporter cells bearing the zCAR of interest may be used for immunization as well as screening. In addition, serial immunizations employing additional zCAR- or native antigen-bearing cell lines can be used to increase the frequency of the desired antigen-specific hybridomas. Finally, the use of a cohort of epitope-tagged zCAR (e.g., zCAR(FLAG)) variants allows visualization of the cell surface antigen prior to immunization, and coimmunization using these variants can be used to enhance the immunogenicity of the target antigen. Employing the CELLISA strategy, we herein describe the generation of mAb directed against an uncharacterized natural killer cell receptor protein.

  17. Novel Pneumocystis Antigen Discovery Using Fungal Surface Proteomics

    OpenAIRE

    Zheng, Mingquan; Cai, Yang; Eddens, Taylor; Ricks, David M.; Kolls, Jay K.

    2014-01-01

    Pneumonia due to the fungus Pneumocystis jirovecii is a life-threatening infection that occurs in immunocompromised patients. The inability to culture the organism as well as the lack of an annotated genome has hindered antigen discovery that could be useful in developing novel vaccine- or antibody-based therapies as well as diagnostics for this infection. Here we report a novel method of surface proteomics analysis of Pneumocystis murina that reliably detected putative surface proteins that ...

  18. Sarcocystis neurona merozoites express a family of immunogenic surface antigens that are orthologues of the Toxoplasma gondii surface antigens (SAGs) and SAG-related sequences.

    Science.gov (United States)

    Howe, Daniel K; Gaji, Rajshekhar Y; Mroz-Barrett, Meaghan; Gubbels, Marc-Jan; Striepen, Boris; Stamper, Shelby

    2005-02-01

    Sarcocystis neurona is a member of the Apicomplexa that causes myelitis and encephalitis in horses but normally cycles between the opossum and small mammals. Analysis of an S. neurona expressed sequence tag (EST) database revealed four paralogous proteins that exhibit clear homology to the family of surface antigens (SAGs) and SAG-related sequences of Toxoplasma gondii. The primary peptide sequences of the S. neurona proteins are consistent with the two-domain structure that has been described for the T. gondii SAGs, and each was predicted to have an amino-terminal signal peptide and a carboxyl-terminal glycolipid anchor addition site, suggesting surface localization. All four proteins were confirmed to be membrane associated and displayed on the surface of S. neurona merozoites. Due to their surface localization and homology to T. gondii surface antigens, these S. neurona proteins were designated SnSAG1, SnSAG2, SnSAG3, and SnSAG4. Consistent with their homology, the SnSAGs elicited a robust immune response in infected and immunized animals, and their conserved structure further suggests that the SnSAGs similarly serve as adhesins for attachment to host cells. Whether the S. neurona SAG family is as extensive as the T. gondii SAG family remains unresolved, but it is probable that additional SnSAGs will be revealed as more S. neurona ESTs are generated. The existence of an SnSAG family in S. neurona indicates that expression of multiple related surface antigens is not unique to the ubiquitous organism T. gondii. Instead, the SAG gene family is a common trait that presumably has an essential, conserved function(s).

  19. Sarcocystis neurona Merozoites Express a Family of Immunogenic Surface Antigens That Are Orthologues of the Toxoplasma gondii Surface Antigens (SAGs) and SAG-Related Sequences†

    Science.gov (United States)

    Howe, Daniel K.; Gaji, Rajshekhar Y.; Mroz-Barrett, Meaghan; Gubbels, Marc-Jan; Striepen, Boris; Stamper, Shelby

    2005-01-01

    Sarcocystis neurona is a member of the Apicomplexa that causes myelitis and encephalitis in horses but normally cycles between the opossum and small mammals. Analysis of an S. neurona expressed sequence tag (EST) database revealed four paralogous proteins that exhibit clear homology to the family of surface antigens (SAGs) and SAG-related sequences of Toxoplasma gondii. The primary peptide sequences of the S. neurona proteins are consistent with the two-domain structure that has been described for the T. gondii SAGs, and each was predicted to have an amino-terminal signal peptide and a carboxyl-terminal glycolipid anchor addition site, suggesting surface localization. All four proteins were confirmed to be membrane associated and displayed on the surface of S. neurona merozoites. Due to their surface localization and homology to T. gondii surface antigens, these S. neurona proteins were designated SnSAG1, SnSAG2, SnSAG3, and SnSAG4. Consistent with their homology, the SnSAGs elicited a robust immune response in infected and immunized animals, and their conserved structure further suggests that the SnSAGs similarly serve as adhesins for attachment to host cells. Whether the S. neurona SAG family is as extensive as the T. gondii SAG family remains unresolved, but it is probable that additional SnSAGs will be revealed as more S. neurona ESTs are generated. The existence of an SnSAG family in S. neurona indicates that expression of multiple related surface antigens is not unique to the ubiquitous organism T. gondii. Instead, the SAG gene family is a common trait that presumably has an essential, conserved function(s). PMID:15664946

  20. Prevalence of Hepatitis B surface antigen among pregnant women ...

    African Journals Online (AJOL)

    Prevalence of Hepatitis B surface antigen among pregnant women attending antenatal ... Majigo Mtebe, Nyambura Moremi, Jeremiah Seni, Stephen E. Mshana. Abstract. In developing countries there is no routine screening of hepatitis B virus ...

  1. [Predictive study of HBsAg in different stages of neonatal venous blood on failure of blocking HBV mother to infant transmission].

    Science.gov (United States)

    Yi, Wei; Li, Ming-Hui; Hu, Yu-Hong; Liu, Feng; Zhang, Yang-Li; Liu, Xue-Jing; Hao, Hong-Xiao; Song, Shu-Jing; Liu, Ying; Li, Xing-Hong; Sun, Ji-Yun; Liu, Min; Cheng, Jun; Xie, Yao

    2011-10-01

    In this study, we discuss the predictive value of different content of HBsAg in different stages of neotal venous blood on failure of blocking mother to infant transmission of HBV. 150 infants born of chronically HBV infected mothers who were positive of both HBsAg and HBeAg and who also had a HBV DNA virus load above 10(5) copies/ml were enrolled. These infants were given hepatitis B virus immune globin (HBIG) 200 IU immediately after birth and were given hepatitis B vaccine 10 or 20 microg at brith, 1 month and 6 months after birth. HBV serological index of these infants were test at birth, 1 month and 7 months after birth respectively. Different content of HBsAg in different stages of neonatal venus blood were analyzed to predict the failure of blocking mother to infant transmission of HBV. 11 infants failed in blocking of HBV mother to infant transmission. The positive rate of HBsAg at birth, 1 month and 7 months after birth were 41.26%, 10.49% and 7.69% respectively, and were 97.90%, 65.73% and 13.29% of HBeAg. The positive predictive value of HBsAg > or = 0.05 and HBsAg > or = 1 IU/ml at birth were 18.64% and 70% respectively, and were 73.33% and 100% one month after birth. Infants with HBsAg > or = 1 IU/ml at birth should be suspicious of failure on blocking HBV mother-to-infant transmission and it should be more credible if the infant has HBsAg > or = 1 IU/ml one month after birth. How to improve the blocking rate of neonates who were positive of HBsAg at birth and one month after birth should be the focus of our future research.

  2. Hepatitis B Test

    Science.gov (United States)

    ... Links Patient Resources For Health Professionals Subscribe Search Hepatitis B Testing Send Us Your Feedback Choose Topic At ... Known As HBV Tests Hep B anti-HBs Hepatitis B Surface Antibody HBsAg Hepatitis B Surface Antigen HBeAg ...

  3. Hepatitis B Viral Markers in Surface Antigen Negative Blood Donors ...

    African Journals Online (AJOL)

    Of the 20 who were anti-HBc positive, seven had tattoo/traditional marks on their body and one had previous history of blood transfusion. Conclusion: This study has shown that some potential blood units containing HBV are being transfused to patients unknowingly by screening for HBsAg only. Screening for other markers ...

  4. Simultaneous detection of Hepatitis B surface antigen and its antibody by radioimmunoassay

    International Nuclear Information System (INIS)

    Crouzat-Reynes, Gerard; Perigois, Francois; Lecureuil, Michel; Lejeune, Bernard

    1981-01-01

    The authors describe an original radioimmunoassay which allows the simultaneous detection of hepatitis B surface antigen and its antibody in a biological sample. Antigen and antibody are indiscriminately detected in a first step and then distinguished in a second step using the same reagents [fr

  5. Adjuvant Activity of Poly-ε-caprolactone/Chitosan Nanoparticles Characterized by Mast Cell Activation and IFN-γ and IL-17 Production.

    Science.gov (United States)

    Jesus, Sandra; Soares, Edna; Borchard, Gerrit; Borges, Olga

    2018-01-02

    Polymeric nanoparticles (NPs) are extremely attractive vaccine adjuvants, able to promote antigen delivery and in some instances, exert intrinsic immunostimulatory properties that enhance antigen specific humoral and cellular immune responses. The poly-ε-caprolactone (PCL)/chitosan NPs were designed with the aim of being able to combine the properties of the 2 polymers in the preparation of an adjuvant for the hepatitis B surface antigen (HBsAg). This article reports important results of an in vitro mechanistic study and immunization studies with HBsAg associated with different concentrations of the nanoparticles. The results revealed that PCL/chitosan NPs promoted mast cell (MC) activation (β-hexosaminidase release) and that its adjuvant effect is not mediated by the TNF-α secretion. Moreover, we demonstrated that HBsAg loaded PCL/chitosan NPs, administered through the subcutaneous (SC) route, were able to induce higher specific antibody titers without increasing IgE when compared to a commercial vaccine, and that the IgG titers are nanoparticle-dose dependent. The results also revealed the NPs' capability to promote a cellular immune response against HBsAg, characterized by the production of IFN-γ and IL-17. These results demonstrated that PCL/chitosan NPs are a good hepatitis B antigen adjuvant, with direct influence on the intensity and type of the immune response generated.

  6. Antibody-mediated immunotherapy against chronic hepatitis B virus infection.

    Science.gov (United States)

    Gao, Ying; Zhang, Tian-Ying; Yuan, Quan; Xia, Ning-Shao

    2017-08-03

    The currently available drugs to treat hepatitis B virus (HBV) infection include interferons and nucleos(t)ide analogs, which can only induce disease remission and are inefficient for the functional cure of patients with chronic HBV infection (CHB). Since high titers of circulating hepatitis B surface antigen (HBsAg) may be essential to exhaust the host anti-HBV immune response and they cannot be significantly reduced by current drugs, new antiviral strategies aiming to suppress serum hepatitis B surface antigen (HBsAg) could help restore virus-specific immune responses and promote the eradication of the virus. As an alternative strategy, immunotherapy with HBsAg-specific antibodies has shown some direct HBsAg suppression effects in several preclinical and clinical trial studies. However, most described previously HBsAg-specific antibodies only had very short-term HBsAg suppression effects in CHB patients and animal models mimicking persistent HBV infection. More-potent antibodies with long-lasting HBsAg clearance effects are required for the development of the clinical application of antibody-mediated immunotherapy for CHB treatment. Our recent study described a novel mAb E6F6 that targets a unique epitope on HBsAg. It could durably suppress the levels of HBsAg and HBV DNA via Fcγ receptor-dependent phagocytosis in vivo. In this commentary, we summarize the current research progress, including the therapeutic roles and mechanisms of antibody-mediated HBV clearance as well as the epitope-determined therapeutic potency of the antibody. These insights may provide some clues and guidance to facilitate the development of therapeutic antibodies against persistent viral infection.

  7. Serologic tracers (HBsAg and HBsAc) of hepatitis B virus in expectant mothers of the Perinatal Maternal Institute; Marcadores serologicos (HBsAg y HBsAc) del virus de la hepatitis B en mujeres gestantes del Instituto Materno Perinatal

    Energy Technology Data Exchange (ETDEWEB)

    Garcia G, B M

    1997-07-01

    A study on hepatitis B tracers, (HBsAg and HBsAc), was conducted in women with different months of pregnancy at the Perinatal Maternal Institute in Lima, Peru. A total of 1010 mothers were studied during the period of January to October 1996, establishing by radioimmunoassay (RIA) whether they were positive or not. The results showed a prevalence rate of 1,6 for HBsAc and 1,3 for HBsAg for every 100,000 inhabitants. The incidence rate was 0,332 for HBsAc and 0,07 for HBsAg for every 100,000 inhabitants. This means that 21 expectant mothers are HBsAc positive and 5 are HBsAg positive. According to the investigations, there were different ways of transmission; promiscuity must be highlighted, as well as age -most of the mothers who were positive were between 20 and 25 years old- and origin. Most of them were immigrants from different places and live in shantytowns, which indicates that most of them have limited economic resources and have not received any orientation on family planning.

  8. The Ausab test - a radioimmunoassay in the solid phase for the detection of antibodies against HBsAg

    International Nuclear Information System (INIS)

    Lange, W.; Koehler, H.; Apodaca, J.

    1974-01-01

    The suitability of a newly developed RIA (Ausab test, Abbott Laboratories) for the detection of antibodies against the Hepatitis B (surface) antigen (HBsAg) has been tested on 1,968 sera of blood donors. Reproducibility test and specificity test were included. During the examination the technique of the Ausab test was changed from the original one-step to the two-step procedure. With the one-step technique 431 of 1,968 sera (21.9%) showed positive reactions. During the test problems concerning the differentiation between positive and negative results were encountered due to high unspecific binding of radioactivity. Positive sera were reexamined employing the two-step technique and only 77.4% of the previously positive reactions could be reproduced. 50 sera that were negative in the one-step test remained negative in the two-step test. Difficulties concerning nonspecific binding of radioactivity as observed with the one-step technique were not ecountered with the two-step procedure. On 92 of the confirmed positive sera a specificity test was run and 90 (97.8%) proved to be specific. A calculated 16.5% of the blood donors in Berlin have to be considered as antibody carriers. Only 6 of the Ausab positive sera were found to give positive reactions in CEP. 3 sera that were initially positive in CEP could neither be confirmed in a repeated CEP nor in the Ausab test. (orig.) [de

  9. Original Research Hepatitis B virus seroprevalence among ...

    African Journals Online (AJOL)

    genetic markers, and liver biopsy, amongst others.9,10 In. Malawi, screening for hepatitis B virus surface antigen. (HBsAg) in public hospitals .... produced in response to the core HBV antigen and persist for life, suggesting a past horizontal transmission in childhood and adulthood.21 Detection of HBV DNA could be useful.

  10. Detection of viral antigens by solid phase radioimmunoassay on polyethylene film

    Energy Technology Data Exchange (ETDEWEB)

    Prokudina, E N; Semenova, N P; Zhdanov, V M

    1986-04-01

    Polyethylene film, without any pretreatment, may serve as a solid phase (SP) for RIA. Viral antigens (HBsAg, and influenza virus) are detected by SP-RIA on the film with a sensitivity of about 2-3 ng/ml or 40-60 pg/assay. The use of polyethylene film allows one to record RIA autographically. The use of micro amounts of reagents and specimens tested is an added advantage. No special equipment is necessary, the method is inexpensive, easy to perform and may be used for mass screening. (Auth.). 7 refs.; 4 figs.

  11. Immunogenic Properties of Lactobacillus plantarum Producing Surface-Displayed Mycobacterium tuberculosis Antigens.

    Science.gov (United States)

    Kuczkowska, Katarzyna; Kleiveland, Charlotte R; Minic, Rajna; Moen, Lars F; Øverland, Lise; Tjåland, Rannei; Carlsen, Harald; Lea, Tor; Mathiesen, Geir; Eijsink, Vincent G H

    2017-01-15

    Tuberculosis (TB) remains among the most deadly diseases in the world. The only available vaccine against tuberculosis is the bacille Calmette-Guérin (BCG) vaccine, which does not ensure full protection in adults. There is a global urgency for the development of an effective vaccine for preventing disease transmission, and it requires novel approaches. We are exploring the use of lactic acid bacteria (LAB) as a vector for antigen delivery to mucosal sites. Here, we demonstrate the successful expression and surface display of a Mycobacterium tuberculosis fusion antigen (comprising Ag85B and ESAT-6, referred to as AgE6) on Lactobacillus plantarum The AgE6 fusion antigen was targeted to the bacterial surface using two different anchors, a lipoprotein anchor directing the protein to the cell membrane and a covalent cell wall anchor. AgE6-producing L. plantarum strains using each of the two anchors induced antigen-specific proliferative responses in lymphocytes purified from TB-positive donors. Similarly, both strains induced immune responses in mice after nasal or oral immunization. The impact of the anchoring strategies was reflected in dissimilarities in the immune responses generated by the two L. plantarum strains in vivo The present study comprises an initial step toward the development of L. plantarum as a vector for M. tuberculosis antigen delivery. This work presents the development of Lactobacillus plantarum as a candidate mucosal vaccine against tuberculosis. Tuberculosis remains one of the top infectious diseases worldwide, and the only available vaccine, bacille Calmette-Guérin (BCG), fails to protect adults and adolescents. Direct antigen delivery to mucosal sites is a promising strategy in tuberculosis vaccine development, and lactic acid bacteria potentially provide easy, safe, and low-cost delivery vehicles for mucosal immunization. We have engineered L. plantarum strains to produce a Mycobacterium tuberculosis fusion antigen and to anchor this

  12. Transmission of hepatitis B virus in clinical laboratory areas.

    Science.gov (United States)

    Lauer, J L; VanDrunen, N A; Washburn, J W; Balfour, H H

    1979-10-01

    The transmission of hepatitis B virus (HBV) in clinical laboratory areas was delineated by the use of hepatitis B surface antigen (HBsAg) as presumptive evidence for the presence of the infective agent. Twenty-six (34%) of 76 environmental surfaces sampled were positive for HBsAg. The outer surfaces of blood- and serum-specimen containers had HBsAg contamination rates of 55% (six of 11) and 44% (four of nine), respectively. Subsequent handling of pipetting aids, marking devices, and other items led to their contamination and further dissemination of HBsAg. An assay instrument for complete determinations of blood cell counts was observed to splatter and drip blood during its operation. The contamination rate for environmental surfaces associated with this instrument was 15%. The data indicate that transmission of HBV in the clinical laboratory is subtle and mainly via hand contact with contaminated items during the various steps of blood processing. These data support the concept that the portal of entry of HBV is through inapparent breaks in skin and mucous membranes.

  13. Liver Function In Patients With Homozygous Sickle Cell Disease ...

    African Journals Online (AJOL)

    Using the sensitive ELISA technique, 213 patients with sickle cell anemia (112 males and 101 females) aged 6 months to 18 years were screened for Hepatitis B infection using Hepatitis B surface antigen (HBsAg) and antibody to Hepatitis B core antigen. A biochemical evaluation of liver function was carried out on all ...

  14. Cell surface antigens of radiation leukemia virus-induced BALB/c leukemias defined by syngeneic cytotoxic T lymphocytes

    International Nuclear Information System (INIS)

    Kaneko, Yukio; Oettgen, H.F.; Obata, Yuichi; Nakayama, Eiichi.

    1989-01-01

    Two cell surface antigens of mouse leukemias were defined by BALB/c cytotoxic T lymphocytes (CTL) generated against syngeneic radiation leukemia virus (RadLV)-induced leukemia, BALBRV1 or BALBRVD. Hyperimmunization of BALB/c mice with irradiated leukemias followed by in vitro sensitization of primed spleen cells resulted in the generation of CTL with high killing activity. The specificity of CTL was examined by direct cytotoxicity assays and competitive inhibition assays. A shared cell surface antigen, designated as BALBRV1 antigen, was detected by BALB/c anti-BALBRV1 CTL. BALBRV1 antigen was expressed not only on RadLV-induced BALB/c leukemias except for BALBRVD, but also on spontaneous or X-ray-induced BALB/c leukemias, chemically-induced leukemias with the H-2 d haplotype and some chemically-induced BALB/c sarcomas. In contrast, a unique cell surface antigen, designated as BALBRVD antigen, was detected by BALB/c anti-BALBRVD CTL. BALBRVD antigen was expressed only on BALBRVD, but not on thirty-nine normal lymphoid or tumor cells. These two antigens could be distinguished from those previously defined on Friend, Moloney, Rauscher or Gross murine leukemia virus (MuLV) leukemias, or MuLV-related antigens. Both cytotoxic responses were blocked by antisera against H-2K d , but not H-2D d . The relationship of BALBRV1 antigen and BALBRVD antigen to endogenous MuLV is discussed with regard to the antigenic distribution on tumor cell lines. (author)

  15. Performance of hepatitis B assays on the Bayer ADVIA Centaur Immunoassay System.

    Science.gov (United States)

    van Helden, Josef; Denoyel, Gérard; Karwowska, Sylwia; Reamer, Randy; Schmalz, John; Wright, Ted; Preisel-Simmons, Barbara

    2004-01-01

    Bayer HealthCare LLC, Diagnostics Division, has developed several new assays on the ADVIA Centaur immunoassay system for the detection of markers of hepatitis B virus infection in human serum and plasma. This panel includes assays for: hepatitis B surface antigen (HBsAg), a confirmatory test method for HBsAg, antibodies to hepatitis B surface antigen (anti-HBs), IgM and IgG antibodies to hepatitis B core antigen (anti-HBc Total) and IgM antibodies to hepatitis B core antigen (anti-HBc IgM). These assays employ magnetic particle separation technology with direct chemiluminescence for optimal assay performance. All of the assays are fully automated, require sample volumes ranging from 15 microl to 100 microl (with the exception of the ADVIA Centaur HBsAg Confirmatory Assay, which requires 2 x 100 microl), and have throughputs of up to 240 tests per hour. The five ADVIA Centaur HBV assays were tested in extensive performance evaluations conducted at two sites in Europe. The performance evaluations, which included samples from HBV-infected individuals, blood donors, hospitalized/clinical patients, and HBV vaccinees (for Anti-HBs evaluation), generated performance data in support of obtaining the Communautés Européennes (CE) mark for European market distribution. The HBV performance evaluations resulted in an overall diagnostic specificity > 99%, i.e. 99.94% for the ADVIA Centaur HBsAg Assay, 100% for the ADVIA Centaur Anti-HBs Assay, 100% for the ADVIA Centaur HBc IgM Assay and 99.94% for the ADVIA Centaur HBc Total Assay. All of the ADVIA Centaur assays showed a very good diagnostic sensitivity on these populations with 100% for the ADVIA Centaur HBsAg Assay, 99.0% for the ADVIA Centaur Anti-HBs Assay, 98.53% for the ADVIA Centaur HBc IgM Assay and 100% for the ADVIA Centaur HBc Total Assay. The ADVIA Centaur HBsAg Confirmatory Test confirmed 100% of the positive HBsAg samples. Testing of interfering substances and potential cross-reacting samples for all ADVIA

  16. Extrahepatic Manifestations of Hepatitis B Virus Infection: Addison’s Disease and Myelofibrosis in a Patient with Persistent Hepatitis B Surface Antigenemia

    Directory of Open Access Journals (Sweden)

    François Somlo

    1993-01-01

    Full Text Available A 60-year-old white male patient was admitted to the hospital with acute abdominal pain, seemingly a self-limited ileus. He was found to be hepatitis B surface antigen (HBsAg-positive. Previous dental treatment was suspected to be the initial source of the infection with hepatitis B virus. Five months later he was re-admitted with a diagnosis of adrenal insufficiency (Addison’s disease which responded well to steroids. Four years later he developed fever and leucocytosis. A bone marrow biopsy revealed myelofibrosis. He had several episodes of pyrexia during his lifetime. After a 12-year period the patient suffered a fatal myocardial infarction. At autopsy the adrenal glands were reduced to scarred remnants and HBsAg was found to be present in the residual adrenocortical cells by immunoflouresence methods. Bone marrow at autopsy revealed myelosclerosis as well HBsAg (via immunofluoresence. Hepatitis B virus was therefore closely correlated with the development of Addison’s disease and myelofibrosis in this case.

  17. Coinfection of hepatic cell lines with human immunodeficiency virus and hepatitis B virus leads to an increase in intracellular hepatitis B surface antigen.

    Science.gov (United States)

    Iser, David M; Warner, Nadia; Revill, Peter A; Solomon, Ajantha; Wightman, Fiona; Saleh, Suha; Crane, Megan; Cameron, Paul U; Bowden, Scott; Nguyen, Tin; Pereira, Cândida F; Desmond, Paul V; Locarnini, Stephen A; Lewin, Sharon R

    2010-06-01

    Liver-related mortality is increased in the setting of HIV-hepatitis B virus (HBV) coinfection. However, interactions between HIV and HBV to explain this observation have not been described. We hypothesized that HIV infection of hepatocytes directly affects the life cycle of HBV. We infected human hepatic cell lines expressing HBV (Hep3B and AD38 cells) or not expressing HBV (Huh7, HepG2, and AD43 cells) with laboratory strains of HIV (NL4-3 and AD8), as well as a vesicular stomatitis virus (VSV)-pseudotyped HIV expressing enhanced green fluorescent protein (EGFP). Following HIV infection with NL4-3 or AD8 in hepatic cell lines, we observed a significant increase in HIV reverse transcriptase activity which was infectious. Despite no detection of surface CD4, CCR5, and CXCR4 by flow cytometry, AD8 infection of AD38 cells was inhibited by maraviroc and NL4-3 was inhibited by AMD3100, demonstrating that HIV enters AD38 hepatic cell lines via CCR5 or CXCR4. High-level infection of AD38 cells (50%) was achieved using VSV-pseudotyped HIV. Coinfection of the AD38 cell line with HIV did not alter the HBV DNA amount or species as determined by Southern blotting or nucleic acid signal amplification. However, coinfection with HIV was associated with a significant increase in intracellular HBsAg when measured by Western blotting, quantitative HBsAg, and fluorescence microscopy. We conclude that HIV infection of HBV-infected hepatic cell lines significantly increased intracellular HBsAg but not HBV DNA synthesis and that increased intrahepatic HBsAg secondary to direct infection by HIV may contribute to accelerated liver disease in HIV-HBV-coinfected individuals.

  18. Rapid and specific biotin labelling of the erythrocyte surface antigens of both cultured and ex-vivo Plasmodium parasites

    Directory of Open Access Journals (Sweden)

    Thompson Joanne

    2007-05-01

    Full Text Available Abstract Background Sensitive detection of parasite surface antigens expressed on erythrocyte membranes is necessary to further analyse the molecular pathology of malaria. This study describes a modified biotin labelling/osmotic lysis method which rapidly produces membrane extracts enriched for labelled surface antigens and also improves the efficiency of antigen recovery compared with traditional detergent extraction and surface radio-iodination. The method can also be used with ex-vivo parasites. Methods After surface labelling with biotin in the presence of the inhibitor furosemide, detergent extraction and osmotic lysis methods of enriching for the membrane fractions were compared to determine the efficiency of purification and recovery. Biotin-labelled proteins were identified on silver-stained SDS-polyacrylamide gels. Results Detergent extraction and osmotic lysis were compared for their capacity to purify biotin-labelled Plasmodium falciparum and Plasmodium chabaudi erythrocyte surface antigens. The pellet fraction formed after osmotic lysis of P. falciparum-infected erythrocytes is notably enriched in suface antigens, including PfEMP1, when compared to detergent extraction. There is also reduced co-extraction of host proteins such as spectrin and Band 3. Conclusion Biotinylation and osmotic lysis provides an improved method to label and purify parasitised erythrocyte surface antigen extracts from both in vitro and ex vivo Plasmodium parasite preparations.

  19. Seropositivity of HBsAg, anti-HCV and anti-HIV in preoperative patients

    Directory of Open Access Journals (Sweden)

    Berrin Karaayak Uzun

    2014-12-01

    Full Text Available Objective: The infections caused by human immunodeficiency virus (HIV, hepatitis B (HBV and C (HCV viruses pose a serious occupational risk for the healthcare workers especially those in emergency services, laboratories and surgery wards. Vaccination and establishment of the strict biosafety procedures are the main principles to prevent blood-borne infections in healthcare workers. Additionally, serological screening of the preoperative patients could decrease the risk for exposure. In this study, we aimed to determine the seroprevalence of HBsAg, anti-HCV, anti-HIV 1/2 in preoperative patients. Methods: Hospital automation records were evaluated retrospectively for 4.367 patients who were scheduled for surgery and scanned for anti-HIV 1/2, HBsAg and anti-HCV as preoperative procedures in the preparation period of operation between January 2012 and December 2012. Results: HBsAg positivity rate was found in 7.7% (n=336, anti-HCV positivity rate was found in 2.3% (n=101. A two (0.05% of five patients were positive for anti-HIV 1/2 was found positive verification test and the other three samples were accepted as false positive test results. Conclusion: All healthcare workers must be trained about occupational diseases and vaccinated against Hepatitis B. Universal precautions must be strictly followed particularly in the operating room. In addition, all patients should be considered as potential carriers regarded as a carrier of the potential for infection. J Clin Exp Invest 2013; 4 (4: 449-452

  20. The role of Plasmodium falciparum variant surface antigens in protective immunity and vaccine development

    DEFF Research Database (Denmark)

    Hviid, Lars

    2010-01-01

    There is substantial immuno-epidemiological evidence that the parasite-encoded, so-called variant surface antigens (VSAs) such as PfEMP1 on the surface of infected erythrocytes (IEs) are important-in some cases probably decisive-determinants of clinical outcome of P. falciparum malaria. The evide...... of VSAs, and how vaccines based on this type of antigens fit into the current global strategy to reduce, eliminate and eventually eradicate the burden of malaria....

  1. Serologic tracers (HBsAg and HBsAc) of hepatitis B virus in expectant mothers of the Perinatal Maternal Institute

    International Nuclear Information System (INIS)

    Garcia G, B.M.

    1997-01-01

    A study on hepatitis B tracers, (HBsAg and HBsAc), was conducted in women with different months of pregnancy at the Perinatal Maternal Institute in Lima, Peru. A total of 1010 mothers were studied during the period of January to October 1996, establishing by radioimmunoassay (RIA) whether they were positive or not. The results showed a prevalence rate of 1,6 for HBsAc and 1,3 for HBsAg for every 100,000 inhabitants. The incidence rate was 0,332 for HBsAc and 0,07 for HBsAg for every 100,000 inhabitants. This means that 21 expectant mothers are HBsAc positive and 5 are HBsAg positive. According to the investigations, there were different ways of transmission; promiscuity must be highlighted, as well as age -most of the mothers who were positive were between 20 and 25 years old- and origin. Most of them were immigrants from different places and live in shantytowns, which indicates that most of them have limited economic resources and have not received any orientation on family planning

  2. Mendelian and non-mendelian mutations affecting surface antigen expression in Paramecium tetraurelia

    International Nuclear Information System (INIS)

    Epstein, L.M.; Forney, J.D.

    1984-01-01

    A screening procedure was devised for the isolation of X-ray-induced mutations affecting the expression of the A immobilization antigen (i-antigen) in Paramecium tetraurelia. Two of the mutations isolated by this procedure proved to be in modifier genes. The two genes are unlinked to each other and unlinked to the structural A i-antigen gene. These are the first modifier genes identified in a Paramecium sp. that affect surface antigen expression. Another mutation was found to be a deletion of sequences just downstream from the A i-antigen gene. In cells carrying this mutation, the A i-antigen gene lies in close proximity to the end of a macronuclear chromosome. The expression of the A i-antigen is not affected in these cells, demonstrating that downstream sequences are not important for the regulation and expression of the A i-antigen gene. A stable cell line was also recovered which shows non-Mendelian inheritance of a macronuclear deletion of the A i-antigen gene. This mutant does not contain the gene in its macronucleus, but contains a complete copy of the gene in its micronucleus. In the cytoplasm of wild-type animals, the micronuclear gene is included in the developing macronucleus; in the cytoplasm of the mutant, the incorporation of the A i-antigen gene into the macronucleus is inhibited. This is the first evidence that a mechanism is available in ciliates to control the expression of a gene by regulating its incorporation into developing macronuclei

  3. Sequence analysis of sub-genotype D hepatitis B surface antigens isolated from Jeddah, Saudi Arabia

    Directory of Open Access Journals (Sweden)

    Sahar EL Hadad

    2018-05-01

    Full Text Available Little is known about the prevalence of HBV genotypes/sub-genotypes in Jeddah province, although the hepatitis B virus (HBV was identified as the most predominant type of hepatitis in Saudi Arabia. To characterize HBV genotypes/sub-genotypes, serum samples from 15 patients with chronic HBV were collected and subjected to HBsAg gene amplification and sequence analysis. Phylogenetic analysis of the HBsAg gene sequences revealed that 11 (48% isolates belonged to HBV/D while 4 (18% were associated with HBV/C. Notably, a HBV/D sub-genotype phylogenetic tree identified that eight current isolates (72% belonged to HBV/D1, whereas three isolates (28% appeared to be more closely related to HBV/D5, although they formed a novel cluster supported by a branch with 99% bootstrap value. Isolates belonging to D1 were grouped in one branch and seemed to be more closely related to various strains isolated from different countries. For further determination of whether the three current isolates belonged to HBV/D5 or represented a novel sub-genotype, HBV/DA, whole HBV genome sequences would be required. In the present study, we verified that HBV/D1 is the most prevalent HBV sub-genotype in Jeddah, and identified novel variant mutations suggesting that an additional sub-genotype designated HBV/DA should be proposed. Overall, the results of the present HBsAg sequence analyses provide us with insights regarding the nucleotide differences between the present HBsAg/D isolates identified in the populace of Jeddah, Saudi Arabia and those previously isolated worldwide. Additional studies with large numbers of subjects in other areas might lead to the discovery of the specific HBV strain genotypes or even additional new sub-genotypes that are circulating in Saudi Arabia. Keywords: Hepatitis B virus, HBV sub-genotypes, HBV/D, HBsAg, Viral isolates, Population studies

  4. Hepatitis B vaccination coverage and risk factors associated with incomplete vaccination of children born to hepatitis B surface antigen-positive mothers, Denmark, 2006 to 2010.

    Science.gov (United States)

    Kunoee, Asja; Nielsen, Jens; Cowan, Susan

    2016-01-01

    In Denmark, universal screening of pregnant women for hepatitis B has been in place since November 2005, with the first two years as a trial period with enhanced surveillance. It is unknown what the change to universal screening without enhanced surveillance has meant for vaccination coverage among children born to hepatitis B surface antigen (HBsAg)-positive mothers and what risk factors exist for incomplete vaccination. This retrospective cohort study included 699 children of mothers positive for HBsAg. Information on vaccination and risk factors was collected from central registers. In total, 93% (651/699) of the children were vaccinated within 48 hours of birth, with considerable variation between birthplaces. Only 64% (306/475) of the children had received all four vaccinations through their general practitioner (GP) at the age of two years, and 10% (47/475) of the children had received no hepatitis B vaccinations at all. Enhanced surveillance was correlated positively with coverage of birth vaccination but not with coverage at the GP. No or few prenatal examinations were a risk factor for incomplete vaccination at the GP. Maternity wards and GPs are encouraged to revise their vaccination procedures and routines for pregnant women, mothers with chronic HBV infection and their children.

  5. Genetic diversity and antigenicity variation of Babesia bovis merozoite surface antigen-1 (MSA-1) in Thailand.

    Science.gov (United States)

    Tattiyapong, Muncharee; Sivakumar, Thillaiampalam; Takemae, Hitoshi; Simking, Pacharathon; Jittapalapong, Sathaporn; Igarashi, Ikuo; Yokoyama, Naoaki

    2016-07-01

    Babesia bovis, an intraerythrocytic protozoan parasite, causes severe clinical disease in cattle worldwide. The genetic diversity of parasite antigens often results in different immune profiles in infected animals, hindering efforts to develop immune control methodologies against the B. bovis infection. In this study, we analyzed the genetic diversity of the merozoite surface antigen-1 (msa-1) gene using 162 B. bovis-positive blood DNA samples sourced from cattle populations reared in different geographical regions of Thailand. The identity scores shared among 93 msa-1 gene sequences isolated by PCR amplification were 43.5-100%, and the similarity values among the translated amino acid sequences were 42.8-100%. Of 23 total clades detected in our phylogenetic analysis, Thai msa-1 gene sequences occurred in 18 clades; seven among them were composed of sequences exclusively from Thailand. To investigate differential antigenicity of isolated MSA-1 proteins, we expressed and purified eight recombinant MSA-1 (rMSA-1) proteins, including an rMSA-1 from B. bovis Texas (T2Bo) strain and seven rMSA-1 proteins based on the Thai msa-1 sequences. When these antigens were analyzed in a western blot assay, anti-T2Bo cattle serum strongly reacted with the rMSA-1 from T2Bo, as well as with three other rMSA-1 proteins that shared 54.9-68.4% sequence similarity with T2Bo MSA-1. In contrast, no or weak reactivity was observed for the remaining rMSA-1 proteins, which shared low sequence similarity (35.0-39.7%) with T2Bo MSA-1. While demonstrating the high genetic diversity of the B. bovis msa-1 gene in Thailand, the present findings suggest that the genetic diversity results in antigenicity variations among the MSA-1 antigens of B. bovis in Thailand. Copyright © 2016 Elsevier B.V. All rights reserved.

  6. Treatment of Schistosoma mansoni with miltefosine in vitro enhances serological recognition of defined worm surface antigens.

    Directory of Open Access Journals (Sweden)

    Marwa H El-Faham

    2017-08-01

    Full Text Available Miltefosine, an anti-cancer drug that has been successfully repositioned for treatment of Leishmania infections, has recently also shown promising effects against Schistosoma spp targeting all life cycle stages of the parasite. The current study examined the effect of treating Schistosoma mansoni adult worms with miltefosine on exposure of worm surface antigens in vitro.In an indirect immunofluorescence assay, rabbit anti-S.mansoni adult worm homogenate and anti-S. mansoni infection antisera gave strong immunofluorescence of the S. mansoni adult worm surface after treatment with miltefosine, the latter antiserum having previously been shown to synergistically enhance the schistosomicidal activity of praziquantel. Rabbit antibodies that recognised surface antigens exposed on miltefosine-treated worms were recovered by elution off the worm surface in low pH buffer and were used in a western immunoblotting assay to identify antigenic targets in a homogenate extract of adult worms (SmWH. Four proteins reacting with the antibodies in immunoblots were purified and proteomic analysis (MS/MS combined with specific immunoblotting indicated they were the S. mansoni proteins: fructose-1,6 bisphosphate aldolase (SmFBPA, Sm22.6, alkaline phosphatase and malate dehydrogenase. These antibodies were also found to bind to the surface of 3-hour schistosomula and induce immune agglutination of the parasites, suggesting they may have a role in immune protection.This study reveals a novel mode of action of miltefosine as an anti-schistosome agent. The immune-dependent hypothesis we investigated has previously been lent credence with praziquantel (PZQ, whereby treatment unmasks parasite surface antigens not normally exposed to the host during infection. Antigens involved in this molecular mechanism could have potential as intervention targets and antibodies against these antigens may act to increase the drug's anti-parasite efficacy and be involved in the development

  7. Effect on HBs antigen clearance of addition of pegylated interferon alfa-2a to nucleos(t)ide analogue therapy versus nucleos(t)ide analogue therapy alone in patients with HBe antigen-negative chronic hepatitis B and sustained undetectable plasma hepatitis B virus DNA: a randomised, controlled, open-label trial.

    Science.gov (United States)

    Bourlière, Marc; Rabiega, Pascaline; Ganne-Carrie, Nathalie; Serfaty, Lawrence; Marcellin, Patrick; Barthe, Yoann; Thabut, Dominique; Guyader, Dominique; Hezode, Christophe; Picon, Magali; Causse, Xavier; Leroy, Vincent; Bronowicki, Jean Pierre; Carrieri, Patrizia; Riachi, Ghassan; Rosa, Isabelle; Attali, Pierre; Molina, Jean Michel; Bacq, Yannick; Tran, Albert; Grangé, Jean Didier; Zoulim, Fabien; Fontaine, Hélène; Alric, Laurent; Bertucci, Inga; Bouvier-Alias, Magali; Carrat, Fabrice

    2017-03-01

    Findings from uncontrolled studies suggest that addition of pegylated interferon in patients with HBe antigen (HBeAg)-negative chronic hepatitis B receiving nucleos(t)ide analogues with undetectable plasma hepatitis B virus (HBV) DNA might increase HBs antigen (HBsAg) clearance. We aimed to assess this strategy. In this randomised, controlled, open-label trial, we enrolled patients aged 18-75 years with HBeAg-negative chronic hepatitis B and documented negative HBV DNA while on stable nucleos(t)ide analogue regimens for at least 1 year from 30 hepatology tertiary care wards in France. Patients had to have an alanine aminotransferase concentration of less than or equal to five times the upper normal range, no hepatocellular carcinoma, and a serum α fetoprotein concentration of less than 50 ng/mL, normal dilated fundus oculi examination, and a negative pregnancy test in women. Patients with contraindications to pegylated interferon were not eligible. A centralised randomisation used computer-generated lists of random permuted blocks of four with stratification by HBsAg titres (sida et les hépatites virales (France Recherche Nord&sud Sida-vih Hepatites). Copyright © 2017 Elsevier Ltd. All rights reserved.

  8. Shedding of the immunodominant P20 surface antigen of Eimeria bovis sporozoites.

    OpenAIRE

    Speer, C A; Whitmire, W M

    1989-01-01

    P20 is an immunodominant surface antigen of Eimeria bovis sporozoites. As parasites underwent merogony within cultured bovine monocytes and Madin-Darby bovine kidney (MDBK) cells, P20 appeared to be shed gradually by meronts and was absent in type 1 and 2 first-generation merozoites. Meronts of E. bovis appeared to shed P20 into the parasitophorous vacuole of bovine monocytes, whereas MDBK cells evidently released P20 into the culture medium or destroyed its antigenic determinant.

  9. Radioimmunoassay for antibodies against surface membrane antigens using adhering cells

    Energy Technology Data Exchange (ETDEWEB)

    Tax, A; Manson, L A [Wistar Inst. of Anatomy and Biology, Philadelphia, Pa. (USA)

    1976-07-01

    A radioimmunoassay using cells adhering to plastic is described. In this assay, A-10 mammary carcinoma attached to the surface of plastic in microtiter plates were permitted to bind antibody and the bound antibody was detected with purified rabbit /sup 125/I-antimouse-Fab. The bound radioactive material was eluted with glycine-HCl buffer (pH 2.5), and the acid eluates were counted in a gamma counter. This assay can be used to detect cytolic or noncytolic antibody to cell surface antigens in studies with any tumor or normal cell that will adhere to a solid surface.

  10. Hepatitis B virus induces IL-23 production in antigen presenting cells and causes liver damage via the IL-23/IL-17 axis.

    Directory of Open Access Journals (Sweden)

    Qinghong Wang

    Full Text Available IL-23 regulates myriad processes in the innate and adaptive immune systems, and is a critical mediator of the proinflammatory effects exerted by Th17 cells in many diseases. In this study, we investigated whether and how hepatitis B virus (HBV causes liver damage directly through the IL-23 signaling pathway. In biopsied liver tissues from HBV-infected patients, expression of both IL-23 and IL-23R was remarkably elevated. In vivo observations also indicated that the main sources of IL-23 were myeloid dendritic cells (mDCs and macrophages. Analysis of in vitro differentiated immature DCs and macrophages isolated from healthy donors revealed that the HBV surface antigen (HBsAg efficiently induces IL-23 secretion in a mannose receptor (MR-dependent manner. Culture with an endosomal acidification inhibitor and the dynamin inhibitor showed that, upon binding to the MR, the HBsAg is taken up by mDCs and macrophages through an endocytosis mechanism. In contrast, although the HBV core antigen (HBcAg can also stimulate IL-23 secretion from mDCs, the process was MR- and endocytosis-independent. In addition, IL-23 was shown to be indispensible for HBsAg-stimulated differentiation of naïve CD4(+ T cells into Th17 cells, which were determined to be the primary source of IL-17 in HBV-infected livers. The cognate receptor, IL-17R, was found to exist on the hepatic stellate cells and mDCs, both of which might represent the potential target cells of IL-17 in hepatitis B disease. These data provide novel insights into a yet unrecognized mechanism of HBV-induced hepatitis, by which increases in IL-23 expression, through an MR/endocytosis-dependent or -independent manner, produce liver damage through the IL-23/IL-17 axis.

  11. Download this PDF file

    African Journals Online (AJOL)

    Methodology: 200 hepatitis B surface antigen (HBsAg) positive patients attending the Jos University. Teaching Hospital were enrolled in a cross-sectional study from June to November, 2010. A structured interviewer-administered questionnaire was used to obtain information from the participants regarding.

  12. Detection and Characterization of Autoantibodies to Neuronal Cell-Surface Antigens in the Central Nervous System

    Directory of Open Access Journals (Sweden)

    Marleen eVan Coevorden-Hameete

    2016-05-01

    Full Text Available Autoimmune encephalitis (AIE is a group of disorders in which autoantibodies directed at antigens located on the plasma membrane of neurons induce severe neurological symptoms. In contrast to classical paraneoplastic disorders, AIE patients respond well to immunotherapy. The detection of neuronal surface autoantibodies in patients’ serum or CSF therefore has serious consequences for the patients’ treatment and follow-up and requires the availability of sensitive and specific diagnostic tests. This mini-review provides a guideline for both diagnostic and research laboratories that work on the detection of known surface autoantibodies and/or the identification of novel surface antigens. We discuss the strengths and pitfalls of different techniques for anti-neuronal antibody detection: 1 Immunohistochemistry and immunofluorescence on rat/ primate brain sections, 2 Immunocytochemistry of living cultured hippocampal neurons, 3 Cell Based Assay (CBA. In addition, we discuss the use of immunoprecipitation and mass spectrometry analysis for the detection of novel neuronal surface antigens, which is a crucial step in further disease classification and the development of novel CBAs.

  13. A method for visualizing surface-exposed and internal PfEMP1 adhesion antigens in Plasmodium falciparum infected erythrocytes

    Directory of Open Access Journals (Sweden)

    Arnot David E

    2008-06-01

    Full Text Available Abstract Background The insertion of parasite antigens into the host erythrocyte membrane and the structure and distribution of Plasmodium falciparum adhesion receptors on that membrane are poorly understood. Laser scanning confocal microscopy (LSCM and a novel labelling and fixation method have been used to obtain high resolution immuno-fluorescent images of erythrocyte surface PfEMP1 and internal antigens which allow analysis of the accumulation of PfEMP1 on the erythrocyte membrane during asexual development. Methods A novel staining technique has been developed which permits distinction between erythrocyte surface PfEMP1 and intracellular PfEMP1, in parasites whose nuclear material is exceptionally well resolved. Primary antibody detection by fluorescence is carried out on the live parasitized erythrocyte. The surface labelled cells are then fixed using paraformaldehyde and permeabilized with a non-ionic detergent to permit access of antibodies to internal parasite antigens. Differentiation between surface and internal antigens is achieved using antibodies labelled with different fluorochromes and confocal microscopy Results Surface exposed PfEMP1 is first detectable by antibodies at the trophozoite stage of intracellular parasite development although the improved detection method indicates that there are differences between different laboratory isolates in the kinetics of accumulation of surface-exposed PfEMP1. Conclusion A sensitive method for labelling surface and internal PfEMP1 with up to three different fluorochromes has been developed for laser scanning confocal optical microscopy and the analysis of the developmental expression of malaria adhesion antigens.

  14. Detection of HBsAg and Anti HBc on donors of a blood bank by IRMA and ELISA methods

    International Nuclear Information System (INIS)

    Freire Martinez, D.Y.

    1985-10-01

    Comparative evaluation of two methods, Immunoradiometric Assay (IRMA) and Enzyme Immunoassay (ELISA), for detecting HBsAg and Anti HBc was made for determining which is the most advantageous and reliable. The study was made on 300 donors of the Hospital San Juan de Dios Blood Bank. In comparison with the reference method (IRMA), ELISA shows 91.67% of sensitivity. The Anti HBc detection by IRMA is more reliable than the HBsAg detection by IRMA and ELISA for determining the carrier state

  15. Identification of a surface antigen on Theileria parva sporozoites by monoclonal antibody.

    OpenAIRE

    Dobbelaere, D A; Shapiro, S Z; Webster, P

    1985-01-01

    A mouse monoclonal antibody (mAbD1) that neutralizes sporozoites of different stocks of the protozoan parasite Theileria parva has been used to localize and identify a sporozoite antigen. Protein A-colloidal gold was used to localize bound mAbD1 in immunoelectron microscopic studies. mAbD1 bound to sporozoite antigen, which was evenly spread over the surface of all sporozoites. Immune complexes were obtained by incubation of sporozoite suspensions with mAbD1 followed by Zwittergent 3-14 extra...

  16. Seroprevalence of HBsAg and its risk factors among pregnant ...

    African Journals Online (AJOL)

    Yemane Berhane

    The questionnaire included level of education, occupation, income, ethnicity, and history of dental and surgical procedure, tattooing, exposures to unsafe injection, history of caesarian section, abortion, liver disease, blood transfusion and ear piercing in jewelers shop. II. Serological detection of Hepatitis B surface antigen.

  17. Non-invasive optical detection of HBV based on serum surface-enhanced Raman spectroscopy

    Science.gov (United States)

    Zheng, Zuci; Wang, Qiwen; Weng, Cuncheng; Lin, Xueliang; Lin, Yao; Feng, Shangyuan

    2016-10-01

    An optical method of surface-enhanced Raman spectroscopy (SERS) was developed for non-invasive detection of hepatitis B surface virus (HBV). Hepatitis B virus surface antigen (HBsAg) is an established serological marker that is routinely used for the diagnosis of acute or chronic hepatitis B virus(HBV) infection. Utilizing SERS to analyze blood serum for detecting HBV has not been reported in previous literature. SERS measurements were performed on two groups of serum samples: one group for 50 HBV patients and the other group for 50 healthy volunteers. Blood serum samples are collected from healthy control subjects and patients diagnosed with HBV. Furthermore, principal components analysis (PCA) combined with linear discriminant analysis (LDA) were employed to differentiate HBV patients from healthy volunteer and achieved sensitivity of 80.0% and specificity of 74.0%. This exploratory work demonstrates that SERS serum analysis combined with PCA-LDA has tremendous potential for the non-invasive detection of HBV.

  18. CARbodies: Human Antibodies Against Cell Surface Tumor Antigens Selected From Repertoires Displayed on T Cell Chimeric Antigen Receptors

    Directory of Open Access Journals (Sweden)

    Vanesa Alonso-Camino

    2013-01-01

    Full Text Available A human single-chain variable fragment (scFv antibody library was expressed on the surface of human T cells after transduction with lentiviral vectors (LVs. The repertoire was fused to a first-generation T cell receptor ζ (TCRζ-based chimeric antigen receptor (CAR. We used this library to isolate antibodies termed CARbodies that recognize antigens expressed on the tumor cell surface in a proof-of-principle system. After three rounds of activation-selection there was a clear repertoire restriction, with the emergence dominant clones. The CARbodies were purified from bacterial cultures as soluble and active proteins. Furthermore, to validate its potential application for adoptive cell therapy, human T cells were transduced with a LV encoding a second-generation costimulatory CAR (CARv2 bearing the selected CARbodies. Transduced human primary T cells expressed significant levels of the CARbodies-based CARv2 fusion protein on the cell surface, and importantly could be specifically activated, after stimulation with tumor cells. This approach is a promising tool for the generation of antibodies fully adapted to the display format (CAR and the selection context (cell synapse, which could extend the scope of current adoptive cell therapy strategies with CAR-redirected T cells.

  19. Twenty-Year Evolution of Hepatitis B Virus and Human Immunodeficiency Virus Prevalence and Incidence in Voluntary Blood Donors in Côte d'Ivoire.

    Science.gov (United States)

    Seri, Benjamin; Minga, Albert; Gabillard, Delphine; Dembele, Bamori; Konate, Seidou; Le Carrou, Jérôme; Dohoun, Lambert; Abo, Yao; Karcher, Sophie; Coffie, Patrick; N'Dri-Yoman, Thérèse; Attia, Alain; Eholié, Serge P; Danel, Christine; Lacombe, Karine; Anglaret, Xavier; Boyd, Anders

    2018-04-01

    Hepatitis B virus (HBV) and human immunodeficiency virus (HIV) share common risk factors. The parallel description of their frequency over time may help capture their similarities and differences. Using data from the National Transfusion Center of Abidjan, we estimated the following over a 20-year period: (1) the prevalence of HIV and hepatitis B surface antigen (HBsAg) positivity at first contact; and (2) the incidence of HIV and HBsAg seroconversion in negative first-time blood donors. Between 1992 and 2012, 422319 donors (men [M] = 74%) provided 1063825 blood donations. For first-time donors, HIV prevalence decreased from 7.1% (M = 5.9%, women [W] =11.0%) in 1992-1994 to 1.1% (M = 0.8%, W = 2.0%) in 2010-2012. Prevalence of HBsAg positivity remained stable at 10.8% (M = 11.7%, W = 7.3%) in 1992-1994 to 11.1% (M = 12.5%, W = 7.1%) in 2010-2012. Among regular donors (N = 129256), the incidence of becoming HIV or HBsAg positive, respectively, decreased from 4.9 per 100 (M = 4.5, W = 8.6) and 7.3 per 100 person-years (M = 7.8, W = 2.3) in 1992-1994 to 0.07 (M = 0.06, W = 0.11) and 0.2 per 100 person-years (M = 0.2, W = 0.2) in 2010-2012. Human immunodeficiency virus prevalence and incidence decreased dramatically over time, whereas HBV prevalence remained stable. Incidence of HBsAg seroconversion, although decreasing, still reached unexpected levels, suggesting that the risk of HBV infection in adults may be higher than expected. Hepatitis B surface antigen-negative blood-donors should be offered HBV vaccination.

  20. The Effect of Superparamagnetic Iron Oxide Nanoparticle Surface Charge on Antigen Cross-Presentation

    Science.gov (United States)

    Mou, Yongbin; Xing, Yun; Ren, Hongyan; Cui, Zhihua; Zhang, Yu; Yu, Guangjie; Urba, Walter J.; Hu, Qingang; Hu, Hongming

    2017-01-01

    Magnetic nanoparticles (NPs) of superparamagnetic iron oxide (SPIO) have been explored for different kinds of applications in biomedicine, mechanics, and information. Here, we explored the synthetic SPIO NPs as an adjuvant on antigen cross-presentation ability by enhancing the intracellular delivery of antigens into antigen presenting cells (APCs). Particles with different chemical modifications and surface charges were used to study the mechanism of action of antigen delivery. Specifically, two types of magnetic NPs, γFe2O3/APTS (3-aminopropyltrimethoxysilane) NPs and γFe2O3/DMSA (meso-2, 3-Dimercaptosuccinic acid) NPs, with the same crystal structure, magnetic properties, and size distribution were prepared. Then, the promotion of T-cell activation via dendritic cells (DCs) was compared among different charged antigen coated NPs. Moreover, the activation of the autophagy, cytosolic delivery of the antigens, and antigen degradation mediated by the proteasome and lysosome were measured. Our results indicated that positive charged γFe2O3/APTS NPs, but not negative charged γFe2O3/DMSA NPs, enhanced the cross-presentation ability of DCs. Increased cross-presentation ability induced by γFe2O3/APTS NPs was associated with increased cytosolic antigen delivery. On the contrary, γFe2O3/DMSA NPs was associated with rapid autophagy. Overall, our results suggest that antigen delivered in cytoplasm induced by positive charged particles is beneficial for antigen cross-presentation and T-cell activation. NPs modified with different chemistries exhibit diverse biological properties and differ greatly in their adjuvant potentials. Thus, it should be carefully considered many different effects of NPs to design effective and safe adjuvants.

  1. Seroprevalence of hepatitis B and C in maintenance dialysis in a ...

    African Journals Online (AJOL)

    Additionally, a history suggestive of hepatitis in spouses was looked for and physical examination for tattoos and other scars was carried out. Laboratory investigations included urea, electrolytes and serum creatinine liver enzymes, hepatitis B surface antigen (HBsAg), immunoglobulin M anti-hepatitis B core antibody (IgM ...

  2. cDNA sequence analysis of a 29-kDa cysteine-rich surface antigen of pathogenic Entamoeba histolytica

    International Nuclear Information System (INIS)

    Torian, B.E.; Stroeher, V.L.; Stamm, W.E.; Flores, B.M.; Hagen, F.S.

    1990-01-01

    A λgt11 cDNA library was constructed from poly(U)-Spharose-selected Entamoeba histolytica trophozoite RNA in order to clone and identify surface antigens. The library was screened with rabbit polyclonal anti-E. histolytica serum. A 700-base-pair cDNA insert was isolated and the nucleotide sequence was determined. The deduced amino acid sequence of the cDNA revealed a cysteine-rich protein. DNA hybridizations showed that the gene was specific to E. histolytica since the cDNA probe reacted with DNA from four axenic strains of E. histolytica but did not react with DNA from Entamoeba invadens, Acanthamoeba castellanii, or Trichomonas vaginalis. The insert was subcloned into the expression vector pGEX-1 and the protein was expressed as a fusion with the C terminus of glutathione S-transferase. Purified fusion protein was used to generate 22 monoclonal antibodies (mAbs) and a mouse polyclonal antiserum specific for the E. histolytica portion of the fusion protein. A 29-kDa protein was identified as a surface antigen when mAbs were used to immunoprecipitate the antigen from metabolically 35 S-labeled live trophozoites. The surface location of the antigen was corroborated by mAb immunoprecipitation of a 29-kDa protein from surface- 125 I-labeled whole trophozoites as well as by the reaction of mAbs with live trophozoites in an indirect immunofluorescence assay performed at 4 degree C. Immunoblotting with mAbs demonstrated that the antigen was present on four axenic isolates tested. mAbs recognized epitopes on the 29-kDa native antigen on some but not all clinical isolates tested

  3. cDNA sequence analysis of a 29-kDa cysteine-rich surface antigen of pathogenic Entamoeba histolytica

    Energy Technology Data Exchange (ETDEWEB)

    Torian, B.E.; Stroeher, V.L.; Stamm, W.E. (Univ. of Washington, Seattle (USA)); Flores, B.M. (Louisiana State Univ. Medical Center, New Orleans (USA)); Hagen, F.S. (Zymogenetics Incorporated, Seattle, WA (USA))

    1990-08-01

    A {lambda}gt11 cDNA library was constructed from poly(U)-Spharose-selected Entamoeba histolytica trophozoite RNA in order to clone and identify surface antigens. The library was screened with rabbit polyclonal anti-E. histolytica serum. A 700-base-pair cDNA insert was isolated and the nucleotide sequence was determined. The deduced amino acid sequence of the cDNA revealed a cysteine-rich protein. DNA hybridizations showed that the gene was specific to E. histolytica since the cDNA probe reacted with DNA from four axenic strains of E. histolytica but did not react with DNA from Entamoeba invadens, Acanthamoeba castellanii, or Trichomonas vaginalis. The insert was subcloned into the expression vector pGEX-1 and the protein was expressed as a fusion with the C terminus of glutathione S-transferase. Purified fusion protein was used to generate 22 monoclonal antibodies (mAbs) and a mouse polyclonal antiserum specific for the E. histolytica portion of the fusion protein. A 29-kDa protein was identified as a surface antigen when mAbs were used to immunoprecipitate the antigen from metabolically {sup 35}S-labeled live trophozoites. The surface location of the antigen was corroborated by mAb immunoprecipitation of a 29-kDa protein from surface-{sup 125}I-labeled whole trophozoites as well as by the reaction of mAbs with live trophozoites in an indirect immunofluorescence assay performed at 4{degree}C. Immunoblotting with mAbs demonstrated that the antigen was present on four axenic isolates tested. mAbs recognized epitopes on the 29-kDa native antigen on some but not all clinical isolates tested.

  4. Transformation of tobacco plant (Nicotiana tabacum L. with the recombinant hepatitis B virus genes 35SHBsAg and 35SHBsAgER

    Directory of Open Access Journals (Sweden)

    Juliana Martins Ribeiro

    2010-03-01

    Full Text Available The recombinant surface antigen of hepatitis B virus (HBsAg, purified from transgenic plants, proved to be efficient when utilized for raising anti-HB antibodies for the prevention of hepatitis B. Because of the important role of the HBsAg antigen in hepatitis B prevention, the coding sequence of HBsAg antigen, with or without the addition of the carboxi-terminus sequence for protein retention in the endoplasmatic reticulum, was linked to cauliflower mosaic virus 35S promoter, tobacco mosaic virus leader sequence Ω, and the transcription terminator sequence. The aim of this work was to clone the chimeric gene 35SHBsAgER in the plant expression vector pGPTV/Kan/Asc. The resulting plasmid, called pG35SHBsAgER, and another plasmid produced previously in our laboratory called pG35SHBsAg, were transferred to Agrobacterium tumefaciens, and tobacco leaves, of the SR1 cultivar were used as explants for genetic transformation. Twenty-one fully regenerated plants were obtained (10 for the pG35SHBsAg construction and 11 for the pG35SHBsAgER construction. The genomic DNA of all plants was analyzed by PCR, and the presence of the transgene was confirmed in all plants.

  5. A radioimmunoassay for antibodies against surface membrane antigens using adhering cells

    International Nuclear Information System (INIS)

    Tax, A.; Manson, L.A.

    1976-01-01

    A radioimmunoassay using cells adhering to plastic is described. In this assay, A-10 mammary carcinoma attached to the surface of plastic in microtiter plates were permitted to bind antibody and the bound antibody was detected with purified rabbit 125 I-antimouse-Fab. The bound radioactive material was eluted with glycine-HCl buffer (pH 2.5), and the acid eluates were counted in a gamma counter. This assay can be used to detect cytolic or noncytolic antibody to cell surface antigens in studies with any tumor or normal cell that will adhere to a solid surface

  6. Prevalence, risk factors, and impact of isolated antibody to hepatitis B core antigen and occult hepatitis B virus infection in HIV-1-infected pregnant women.

    Science.gov (United States)

    Khamduang, Woottichai; Ngo-Giang-Huong, Nicole; Gaudy-Graffin, Catherine; Jourdain, Gonzague; Suwankornsakul, Weerapong; Jarupanich, Tapnarong; Chalermpolprapa, Veeradate; Nanta, Sirisak; Puarattana-Aroonkorn, Noossara; Tonmat, Sakchai; Lallemant, Marc; Goudeau, Alain; Sirirungsi, Wasna

    2013-06-01

    Prevalence and risk factors for isolated antibody to hepatitis B core antigen (anti-HBc) and occult hepatitis B virus (HBV) infection are not well known in human immunodeficiency virus type 1 (HIV-1)-infected pregnant women. It is unclear if women with occult infections are at risk of transmitting HBV to their infants. HIV-1-infected and HBV surface antigen (HBsAg)-negative pregnant women were tested for antibody to HBsAg (anti-HBs) and anti-HBc using enzyme immunoassay. Women with isolated anti-HBc were assessed for occult HBV infection, defined as HBV DNA levels >15 IU/mL, using the Abbott RealTime HBV DNA assay. Infants born to women with isolated anti-HBc and detectable HBV DNA were tested at 4 months of age for HBV DNA. Logistic regression analysis was used to identify factors associated with isolated anti-HBc and occult HBV infection. Among 1812 HIV-infected pregnant women, 1682 were HBsAg negative. Fourteen percent (95% confidence interval [CI], 12%-15%) of HBsAg-negative women had an isolated anti-HBc that was independently associated with low CD4 count, age >35 years, birth in northern Thailand, and positive anti-hepatitis C virus serology. Occult HBV infection was identified in 24% (95% CI, 18%-30%) of women with isolated anti-HBc, representing 2.6% (95% CI, 1.9%-3.5%) of HIV-1-infected pregnant women, and was inversely associated with HIV RNA levels. None of the women with isolated anti-HBc and occult HBV infection transmitted HBV to their infants. HIV-1-infected pregnant women with isolated anti-HBc and occult HBV infection have very low HBV DNA levels and are thus at very low risk to transmit HBV to their infants.

  7. Heterologous expression of carcinoembryonic antigen in Lactococcus lactis via LcsB-mediated surface displaying system for oral vaccine development.

    Science.gov (United States)

    Zhang, Xiaowei; Hu, Shumin; Du, Xue; Li, Tiejun; Han, Lanlan; Kong, Jian

    2016-12-01

    Carcinoembryonic antigen (CEA) is an attractive target for immunotherapy because it is expressed minimally in normal tissue, but is overexpressed in a wide variety of malignant epithelial tissues. Lactic acid bacteria (LABs), widely used in food processes, are attractive candidates for oral vaccination. Thus, we examined whether LABs could be used as a live vaccine vector to deliver CEA antigen. CEA was cloned into an Escherichia coli/Lactococcus lactis shuttle vector pSEC:LEISS under the control of a nisin promoter. For displaying the CEA on the cell surface of the L. lactis strain, the anchor motif LcsB from the S-layer protein of Lactobacillus crispatus was fused with CEA. Intracellular and cell surface expression of the CEA-LcsB fusion was confirmed by western blot analysis. Significantly higher levels of CEA-specific secretory immunoglobulin A in the sera of mice were observed upon oral administration of strain cultures containing the CEA-LcsB fused protein. In addition, the CEA-LcsB antigen group showed a higher spleen index compared to the CEA antigen alone or negative control, demonstrating that surface-displayed CEA antigen could induce a higher immune response. These results provided the first evidence for displaying CEA antigen on the cell surfaces of LABs as oral vaccines against cancer or infectious diseases. Copyright © 2014. Published by Elsevier B.V.

  8. Safety and immunogenicity of a combined hepatitis B virus-Haemophilus influenzae type B vaccine comprising a synthetic antigen in healthy adults.

    Science.gov (United States)

    Aguilar-Betancourt, Arístides; González-Delgado, Carlos Alberto; Cinza-Estévez, Z; Martínez-Cabrera, Jesus; Véliz-Ríos, Gloria; Alemán-Zaldívar, Regis; Alonso-Martínez, M I; Lago-Baños, M; Puble-Alvarez, N; Delahanty-Fernandez, A; Juvier-Madrazo, A I; Ortega-León, D; Olivera-Ruano, L; Correa-Fernández, A; Abreu-Reyes, D; Soto-Mestre, E; Pérez-Pérez, M V; Figueroa-Baile, N; Pérez, L Hernandez; Rodríguez-Silva, A; Martínez-Díaz, E; Guillén-Nieto, G E; Muzio-González, Verena L

    2008-01-01

    The combined HB-Hib vaccine candidate Hebervac HB-Hib (CIGB, La Habana), comprising recombinant HBsAg and tetanus toxoid conjugate synthetic PRP antigens has shown to be highly immunogenic in animal models. A phase I open, controlled, randomized clinical trial was carried out to assess the safety and immunogenicity profile of this bivalent vaccine in 25 healthy adults who were positive for antibody to HBsAg (anti-HBs). The trial was performed according to Good Clinical Practices and Guidelines. Volunteers were randomly allocated to receive the combined vaccine or simultaneous administration of HB vaccine Heberbiovac-HB and Hib vaccine QuimiHib (CIGB, La Habana). All individuals were intramuscularly immunized with a unique dose of 10 microg HBsAg plus 10 microg conjugated synthetic PRP. Adverse events were actively recorded after vaccine administration. Total anti-HBs and IgG anti-PRP antibody titers were evaluated using commercial ELISA kits at baseline and 30 days post-vaccination. The combined vaccine candidate was safe and well tolerated. The most common adverse reactions were local pain, febricula, fever and local erythema. These reactions were all mild in intensity and resolved without medical treatment. Adverse events were mostly reported during the first 6-72 hours post-vaccination. There were no serious adverse events during the study. No severe or unexpected events were either recorded during the trial. The combined vaccine elicited an anti-HBs and anti-PRP booster response in 100% of subjects at day 30 of the immunization schedule. Anti-HBs and anti-PRP antibody levels had at least a two-fold increase compared to baseline sera. Even more, anti-HBs antibody titer showed a four-fold increase in 100% of volunteers in the study group. The results indicate that the combined HB-Hib vaccine produces increased antibody levels in healthy adults who have previously been exposed to these two antigens. To our knowledge, this is the first demonstration of safety and

  9. A PILOT EXTERNAL QUALITY ASSURANCE STUDY OF TRANSFUSION SCREENING FOR HIV, HCV AND HBSAG IN TWELVE AFRICAN COUNTRIES

    Science.gov (United States)

    Bloch, Evan M; Shah, Avani; Kaidarova, Zhanna; Laperche, Syria; Lefrere, Jean-Jacques; van Hasselt, James; Zacharias, Peter; Murphy, Edward L

    2014-01-01

    Background and Objectives Serologic screening for the major transfusion transmissible viruses (TTV) is critical to blood safety and has been widely implemented. However, actual performance as measured by proficiency testing has not been well studied in Sub-Saharan Africa. Therefore, we conducted an external quality assessment of laboratories engaged in transfusion screening in the region. Materials and Methods Blinded test panels, each comprising 25 serum samples that were pedigreed for HIV, HBsAg, HCV and negative status, were sent to participating laboratories. The panels were tested using the laboratories’ routine donor screening methods and conditions. Sensitivity and specificity were calculated and multivariable analysis was used to compare performance against mode of testing, country and infrastructure. Results A total of 12 African countries and 44 laboratories participated in the study. The mean (range) sensitivities for HIV, HBsAg and HCV were 91.9% (14.3-100), 86.7% (42.9-100) and 90.1% (50-100), respectively. Mean specificities for HIV, HBsAg and HCV were 97.7%, 97% and 99.5% respectively. After adjusting for country and infrastructure, rapid tests had significantly lower sensitivity than enzyme immunoassays (EIA) for both HBsAg (p<0.0001) and HCV (p<0.05). Sensitivity also varied by country and selected infrastructure variables. Conclusion While specificity was high, sensitivity was more variable and deficient in a substantial number of testing laboratories. These findings underscore the importance of proficiency testing and quality control, particularly in Africa where TTV prevalence is high. PMID:25052195

  10. Mechanisms of Surface Antigenic Variation in the Human Pathogenic Fungus Pneumocystis jirovecii.

    Science.gov (United States)

    Schmid-Siegert, Emanuel; Richard, Sophie; Luraschi, Amanda; Mühlethaler, Konrad; Pagni, Marco; Hauser, Philippe M

    2017-11-07

    Microbial pathogens commonly escape the human immune system by varying surface proteins. We investigated the mechanisms used for that purpose by Pneumocystis jirovecii This uncultivable fungus is an obligate pulmonary pathogen that in immunocompromised individuals causes pneumonia, a major life-threatening infection. Long-read PacBio sequencing was used to assemble a core of subtelomeres of a single P. jirovecii strain from a bronchoalveolar lavage fluid specimen from a single patient. A total of 113 genes encoding surface proteins were identified, including 28 pseudogenes. These genes formed a subtelomeric gene superfamily, which included five families encoding adhesive glycosylphosphatidylinositol (GPI)-anchored glycoproteins and one family encoding excreted glycoproteins. Numerical analyses suggested that diversification of the glycoproteins relies on mosaic genes created by ectopic recombination and occurs only within each family. DNA motifs suggested that all genes are expressed independently, except those of the family encoding the most abundant surface glycoproteins, which are subject to mutually exclusive expression. PCR analyses showed that exchange of the expressed gene of the latter family occurs frequently, possibly favored by the location of the genes proximal to the telomere because this allows concomitant telomere exchange. Our observations suggest that (i) the P. jirovecii cell surface is made of a complex mixture of different surface proteins, with a majority of a single isoform of the most abundant glycoprotein, (ii) genetic mosaicism within each family ensures variation of the glycoproteins, and (iii) the strategy of the fungus consists of the continuous production of new subpopulations composed of cells that are antigenically different. IMPORTANCE Pneumocystis jirovecii is a fungus causing severe pneumonia in immunocompromised individuals. It is the second most frequent life-threatening invasive fungal infection. We have studied the mechanisms

  11. Geographical and temporal conservation of antibody recognition of Plasmodium falciparum variant surface antigens

    DEFF Research Database (Denmark)

    Nielsen, Morten A; Vestergaard, Lasse S; Lusingu, John

    2004-01-01

    The slow acquisition of protection against Plasmodium falciparum malaria probably reflects the extensive diversity of important antigens. The variant surface antigens (VSA) that mediate parasite adhesion to a range of host molecules are regarded as important targets of acquired protective immunity......, but their diversity makes them questionable vaccine candidates. We determined levels of VSA-specific immunoglobulin G (IgG) in human plasma collected at four geographically distant and epidemiologically distinct localities with specificity for VSA expressed by P. falciparum isolates from three African countries...

  12. In vivo activity of a mixture of two human monoclonal antibodies (anti-HBs) in a chronic hepatitis B virus carrier chimpanzee

    NARCIS (Netherlands)

    R. Heijtink; W. Paulij; P.A.C. van Bergen (Patrick); M.H. van Roosmalen (Mark); D. Rohm; B. Eichentopf (Bertram); E. Muchmore; A.D.M.E. Osterhaus (Albert); R.A. de Man (Robert)

    1999-01-01

    textabstractA 35-year-old female hepatitis B virus carrier chimpanzee was infused with one dose of a mixture of human monoclonal antibodies 9H9 and 4-7B (antibodies against hepatitis B virus surface antigen; HBsAg). Blood samples were taken before and up to 3 weeks

  13. Chronic Hepatitis B Infection: New insights in therapy and predictors of response

    NARCIS (Netherlands)

    P. Arends (Pauline)

    2014-01-01

    markdownabstract__Abstract__ The hepatitis B virus (HBV) was discovered by dr. Baruch Samuel Blumberg when he identified the ‘Australia antigen’ among an aboriginal in the 1960s. The ‘Australia antigen’ is nowadays known as the hepatitis B surface antigen (HBsAg). For his work dr. Blumberg was

  14. Hepatitis B screening bij zwangeren: een overzicht van 1991

    NARCIS (Netherlands)

    Loeber JG; Grosheide PM

    1992-01-01

    In October 1989 routine screening for hepatitis B surface antigen (HBsAg) in all regnant women was introduced in the Netherlands. In order to prevent hepatitis B infection in their offspring all infants of HBsAg-positive mothers receive passive active immunization. During 1991 about 75% of the

  15. Occult Hepatitis B Virus in Gezira State Sudan | Gasmelseed ...

    African Journals Online (AJOL)

    Background: Occult hepatitis B infection (OBI) is simply defined as serologically undetectable hepatitis B surface antigen (HBsAg-ve), despite the presence of circulating HBV DNA. Objective: The aim of this study was to determine the prevalence of occult HBV among Screened HBsAg subjects in Gezira State, Sudan.

  16. General seroprevalence of hepatitis and hepatitis B virus infections in population

    International Nuclear Information System (INIS)

    Khokar, N.; Gill, M.L.; Malik, G.J.

    2004-01-01

    Objective: To determine the prevalence of hepatitis C virus (HCV) and hepatitis B virus (HBV) infection by detection of anti-HCV and hepatitis B surface antigen (HbsAg) in general population of Pakistan. Materials and Methods: Sera of healthy adult individuals who presented for medical evaluation as a pre-employment criteria in the Gulf region were examined for presence of hepatitis B surface antigen and anti-HCV antibody. Alanine aminotransferase levels were also determined. Results: A total of 47,538 individuals were examined. Out of these, 2528 (5.31%) were positive for anti-HCV and 1221 (2.56%) individuals had positive HBsAg. Hepatitis B surface antigen and anti-HCV both were found in 92 (0.19%) individuals. Mean age of subjects, positive for HCV antibody was 44 years and 40.5 years for HBV. Ninety-four percent individuals were males and 6% were females. Alanine aminotransferase (ALT) was normal in 56% of subjects with positive HCV and 84% of individuals with HBV. Conclusion: This study which evaluated predominantly a healthy male population, showed a high seroprevalence of anti-HCV and average seroprevalence of hepatitis B virus infection. A large majority of these patients was young and had normal ALT. (author)

  17. Identification and characterization of Ixodes scapularis antigens that elicit tick immunity using yeast surface display.

    Directory of Open Access Journals (Sweden)

    Tim J Schuijt

    2011-01-01

    Full Text Available Repeated exposure of rabbits and other animals to ticks results in acquired resistance or immunity to subsequent tick bites and is partially elicited by antibodies directed against tick antigens. In this study we demonstrate the utility of a yeast surface display approach to identify tick salivary antigens that react with tick-immune serum. We constructed an Ixodes scapularis nymphal salivary gland yeast surface display library and screened the library with nymph-immune rabbit sera and identified five salivary antigens. Four of these proteins, designated P8, P19, P23 and P32, had a predicted signal sequence. We generated recombinant (r P8, P19 and P23 in a Drosophila expression system for functional and immunization studies. rP8 showed anti-complement activity and rP23 demonstrated anti-coagulant activity. Ixodes scapularis feeding was significantly impaired when nymphs were fed on rabbits immunized with a cocktail of rP8, rP19 and rP23, a hall mark of tick-immunity. These studies also suggest that these antigens may serve as potential vaccine candidates to thwart tick feeding.

  18. A Molecular-Level Account of the Antigenic Hantaviral Surface

    Directory of Open Access Journals (Sweden)

    Sai Li

    2016-05-01

    Full Text Available Hantaviruses, a geographically diverse group of zoonotic pathogens, initiate cell infection through the concerted action of Gn and Gc viral surface glycoproteins. Here, we describe the high-resolution crystal structure of the antigenic ectodomain of Gn from Puumala hantavirus (PUUV, a causative agent of hemorrhagic fever with renal syndrome. Fitting of PUUV Gn into an electron cryomicroscopy reconstruction of intact Gn-Gc spike complexes from the closely related but non-pathogenic Tula hantavirus localized Gn tetramers to the membrane-distal surface of the virion. The accuracy of the fitting was corroborated by epitope mapping and genetic analysis of available PUUV sequences. Interestingly, Gn exhibits greater non-synonymous sequence diversity than the less accessible Gc, supporting a role of the host humoral immune response in exerting selective pressure on the virus surface. The fold of PUUV Gn is likely to be widely conserved across hantaviruses.

  19. Twenty-Year Evolution of Hepatitis B Virus and Human Immunodeficiency Virus Prevalence and Incidence in Voluntary Blood Donors in Côte d’Ivoire

    Science.gov (United States)

    Seri, Benjamin; Minga, Albert; Gabillard, Delphine; Dembele, Bamori; Konate, Seidou; Le Carrou, Jérôme; Dohoun, Lambert; Abo, Yao; Karcher, Sophie; Coffie, Patrick; N’Dri-Yoman, Thérèse; Attia, Alain; Eholié, Serge P; Danel, Christine; Lacombe, Karine; Anglaret, Xavier; Boyd, Anders

    2018-01-01

    Abstract Background Hepatitis B virus (HBV) and human immunodeficiency virus (HIV) share common risk factors. The parallel description of their frequency over time may help capture their similarities and differences. Methods Using data from the National Transfusion Center of Abidjan, we estimated the following over a 20-year period: (1) the prevalence of HIV and hepatitis B surface antigen (HBsAg) positivity at first contact; and (2) the incidence of HIV and HBsAg seroconversion in negative first-time blood donors. Results Between 1992 and 2012, 422319 donors (men [M] = 74%) provided 1063825 blood donations. For first-time donors, HIV prevalence decreased from 7.1% (M = 5.9%, women [W] =11.0%) in 1992–1994 to 1.1% (M = 0.8%, W = 2.0%) in 2010–2012. Prevalence of HBsAg positivity remained stable at 10.8% (M = 11.7%, W = 7.3%) in 1992–1994 to 11.1% (M = 12.5%, W = 7.1%) in 2010–2012. Among regular donors (N = 129256), the incidence of becoming HIV or HBsAg positive, respectively, decreased from 4.9 per 100 (M = 4.5, W = 8.6) and 7.3 per 100 person-years (M = 7.8, W = 2.3) in 1992–1994 to 0.07 (M = 0.06, W = 0.11) and 0.2 per 100 person-years (M = 0.2, W = 0.2) in 2010–2012. Conclusions Human immunodeficiency virus prevalence and incidence decreased dramatically over time, whereas HBV prevalence remained stable. Incidence of HBsAg seroconversion, although decreasing, still reached unexpected levels, suggesting that the risk of HBV infection in adults may be higher than expected. Hepatitis B surface antigen-negative blood-donors should be offered HBV vaccination. PMID:29644251

  20. A Survey about Protective Effect of Echinococcus Granulosus Protoscolices Surface Antigens in Preventing Secondary Hydatid Cyst

    Directory of Open Access Journals (Sweden)

    H Yousofi

    2006-10-01

    Full Text Available ABSTRACT: Introduction & Objective: Hydatid cyst is located in human and some animal visceral organs such as liver and lung. The disease is considered as a medical, veterinary and economical problem in endemic area. When the hydatid cyst is ruptured, protoscolices from inside the cyst may spread out to other parts of the body and develops a new cyst named secondary hydatid cyst. In this research in an attempt to prevent secondary hydatid cyst, protective potential of protoscolices surface antigens extracted with different detergents has been investigated in animal model. Materials & Methods: In this experimental study, groups of Balb/c mice were immunized intra-peritoneally with protoscolices homogenate and three detergent (SDS, Tween and Triton x–100 extracted protoscolices surface antigens and alum as adjuvant. These mice were then boosted two times with the same antigens fortnightly. Control mice were simultaneously injected with alum alone. Two weeks following the last injection all the mice in cases and control groups were challenged with live protoscolices. Three months afterward all the mice in case and control groups were sacrificed and their peritoneal cavities were explored for hydatid cysts. Results: The mean of developed cyst number in mice injected with protoscolices homogenate was 3±2, while in control group the mean of developed cysts number was 5.8 ± 1.7 (p< 0.02. The mean of developed cyst number in mice injected with SDS, Tween and Triton x–100 extracted protoscolices surface antigens was 3, 3.6 and 3.4, respectively, while the mean of developed cyst number in control group was 5.8. Conclusion: The mean of cyst number in cases and control groups was different and this difference was statistically significant. Results of this investigation revealed that protoscolices homogenate antigens and some detergent extracted antigens are protective against secondary hydatid cyst infection

  1. Hepatitis B virus surface antigen (HBsAg)-positive and HBsAg-negative hepatitis B virus infection among mother-teenager pairs 13 years after neonatal hepatitis B virus vaccination.

    Science.gov (United States)

    Yao, Qing-Qing; Dong, Xiao-Lian; Wang, Xue-Cai; Ge, Sheng-Xiang; Hu, An-Qun; Liu, Hai-Yan; Wang, Yueping Alex; Yuan, Quan; Zheng, Ying-Jie

    2013-02-01

    It is unclear whether a mother who is negative for hepatitis B virus surface antigen (HBsAg) but positive for hepatitis B virus (HBV) is at potential risk for mother-to-child transmission of HBV. This study, using a paired mother-teenager population, aimed to assess whether maternal HBsAg-negative HBV infection ((hn)HBI) is a significant source of child HBV infection (HBI). A follow-up study with blood collection has been conducted on the 93 mother-teenager pairs from the initial 135 pregnant woman-newborn pairs 13 years after neonatal HBV vaccination. Serological and viral markers of HBV have been tested, and phylogenetic analysis of HBV isolates has been done. The HBI prevalence was 1.9% (1 (hn)HBI/53) for teenage children of non-HBI mothers, compared with 16.7% (1 (hn)HBI/6) for those of (hn)HBI mothers and 2.9% (1 HBsAg-positive HBV infection [(hp)HBI]/34) for those of (hp)HBI mothers. Similar viral sequences have been found in one pair of whom both the mother and teenager have had (hn)HBI. In comparison with the (hp)HBI cases, those with (hn)HBI had a lower level of HBV load and a higher proportion of genotype-C strains, which were accompanied by differentiated mutations (Q129R, K141E, and Y161N) of the "a" determinant of the HBV surface gene. Our findings suggest that mother-to-teenager transmission of (hn)HBI can occur among those in the neonatal HBV vaccination program.

  2. ORIGINAL ARTICLE

    African Journals Online (AJOL)

    User

    Blood transfusion necessitates screening of transmissible infectious pathogens such as hepatitis B virus (HBV) to curtail post transfusion risk of infection. The study re-examined this approach by evaluating the efficiency of solely testing for hepatitis B surface antigen (HbsAg) marker for blood transfusion, the efficacy of the ...

  3. A Clinical study of HBsAg and Anti-HBs in the serum of patients with various liver diseases

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Hak San; Kim, Jong Mann; Kim, Hwa Sook; Kim, Yul Ja; Lee, Hak Choong; Lee, Chong Suk [National Medical Center, Seoul (Korea, Republic of)

    1981-09-15

    Serum HBsAg and Anti-HBs obtained by radioimmunoassay were studied in 109 cases of various liver diseases who visited or were admitted to National Medical Center from December, 1980 to July, 1981. The results were as follows; 1) HBsAg was detected in 67.0% of total 109 cases; 71.9% of 32 cases with acute viral hepatitis, 71.4% of 14 cases with chronic hepatitis, 65.2% of 46 cases with liver cirrhosis and 58.8% of 17 cases with hepatoma. 2) Anti-HBs was detected in 32.1% of total 109 cases; 37.0% of 46 cases with liver cirrhosis, 29.4% of 17 cases with hepatoma, 28.6% of 14 cases with chronic hepatitis, 28.1% of 32 cases with acute viral hepatitis. 3) HBsAg or Anti-HBs, the markers of Hepatitis B virus was detected in 89.0% of total 109 cases; 93.6% of 32 cases with acute viral hepatitis, 89.1% of 46 cases with liver cirrhosis, 85.7% of 14 cases with chronic hepatitis and 82.4% of 17 cases with hepatoma, which strongly suggested that the various liver diseases were associated with hepatitis B virus infection.

  4. A Clinical study of HBsAg and Anti-HBs in the serum of patients with various liver diseases

    International Nuclear Information System (INIS)

    Kim, Hak San; Kim, Jong Mann; Kim, Hwa Sook; Kim, Yul Ja; Lee, Hak Choong; Lee, Chong Suk

    1981-01-01

    Serum HBsAg and Anti-HBs obtained by radioimmunoassay were studied in 109 cases of various liver diseases who visited or were admitted to National Medical Center from December, 1980 to July, 1981. The results were as follows; 1) HBsAg was detected in 67.0% of total 109 cases; 71.9% of 32 cases with acute viral hepatitis, 71.4% of 14 cases with chronic hepatitis, 65.2% of 46 cases with liver cirrhosis and 58.8% of 17 cases with hepatoma. 2) Anti-HBs was detected in 32.1% of total 109 cases; 37.0% of 46 cases with liver cirrhosis, 29.4% of 17 cases with hepatoma, 28.6% of 14 cases with chronic hepatitis, 28.1% of 32 cases with acute viral hepatitis. 3) HBsAg or Anti-HBs, the markers of Hepatitis B virus was detected in 89.0% of total 109 cases; 93.6% of 32 cases with acute viral hepatitis, 89.1% of 46 cases with liver cirrhosis, 85.7% of 14 cases with chronic hepatitis and 82.4% of 17 cases with hepatoma, which strongly suggested that the various liver diseases were associated with hepatitis B virus infection.

  5. Proteasomal targeting and minigene repetition improve cell-surface presentation of a transfected, modified melanoma tumour antigen

    DEFF Research Database (Denmark)

    Rasmussen, A B; Zocca, M-B; Bonefeld, C M

    2004-01-01

    Melanoma antigen recognized by T cell 1 (MART-1) is regarded as a candidate peptide for vaccination against malignant melanoma, and it is of importance to develop strategies to improve the vaccine-elicited T-cell activation towards MART-1. T-cell activation is, among other determinants, dependent...... on the density of specific major histocompatibility complex-peptide complexes on the surface of the antigen-presenting cell. In this study, we explored the cell-surface presentation of a substituted MART-1 peptide encoded by transfected minigenes. We investigated the potential of proteasomal targeting compared...... to non-proteasomal targeting of the epitope to increase its cell-surface presentation. Furthermore, we explored the potential of incorporating multiple minigenes instead of one to increase cell-surface presentation. We show that both proteasomal targeting and repetition of the minigene increase cell...

  6. Correlative Light-Electron Microscopy of Lipid-Encapsulated Fluorescent Nanodiamonds for Nanometric Localization of Cell Surface Antigens.

    Science.gov (United States)

    Hsieh, Feng-Jen; Chen, Yen-Wei; Huang, Yao-Kuan; Lee, Hsien-Ming; Lin, Chun-Hung; Chang, Huan-Cheng

    2018-02-06

    Containing an ensemble of nitrogen-vacancy centers in crystal matrices, fluorescent nanodiamonds (FNDs) are a new type of photostable markers that have found wide applications in light microscopy. The nanomaterial also has a dense carbon core, making it visible to electron microscopy. Here, we show that FNDs encapsulated in biotinylated lipids (bLs) are useful for subdiffraction imaging of antigens on cell surface with correlative light-electron microscopy (CLEM). The lipid encapsulation enables not only good dispersion of the particles in biological buffers but also high specific labeling of live cells. By employing the bL-encapsulated FNDs to target CD44 on HeLa cell surface through biotin-mediated immunostaining, we obtained the spatial distribution of these antigens by CLEM with a localization accuracy of ∼50 nm in routine operations. A comparative study with dual-color imaging, in which CD44 was labeled with FND and MICA/MICB was labeled with Alexa Fluor 488, demonstrated the superior performance of FNDs as fluorescent fiducial markers for CLEM of cell surface antigens.

  7. Spontaneous viral clearance, viral load, and genotype distribution of hepatitis C virus (HCV) in HIV-infected patients with anti-HCV antibodies in Europe

    DEFF Research Database (Denmark)

    Soriano, Vincent; Mocroft, Amanda; Rockstroh, Juergen

    2008-01-01

    BACKGROUND: Variables influencing serum hepatitis C virus (HCV) RNA levels and genotype distribution in individuals with human immunodeficiency virus (HIV) infection are not well known, nor are factors determining spontaneous clearance after exposure to HCV in this population. METHODS: All HCV...... for hepatitis B surface antigen (HBsAg) were more likely to have spontaneously cleared HCV than were those negative for HBsAg (43% vs. 21%; aOR, 2.91 [95% CI, 1.94-4.38]). Of patients with HCV viremia, 786 (53%) carried HCV genotype 1, and 53 (4%), 440 (29%), and 217 (15%) carried HCV genotype 2, 3, and 4...

  8. Genetic variation and significance of hepatitis B surface antigen

    Directory of Open Access Journals (Sweden)

    ZHANG Zhenhua

    2013-11-01

    Full Text Available Hepatitis B virus (HBV is prone to genetic variation because there is reverse transcription in the process of HBV replication. The gene mutation of hepatitis B surface antigen may affect clinical diagnosis of HBV infection, viral replication, and vaccine effect. The current research and existing problems are discussed from the following aspects: the mechanism and biological and clinical significance of S gene mutation. Most previous studies focused on S gene alone, so S gene should be considered as part of HBV DNA in the future research on S gene mutation.

  9. Antibodies to variable Plasmodium falciparum-infected erythrocyte surface antigens are associated with protection from novel malaria infections

    DEFF Research Database (Denmark)

    Giha, H A; Staalsoe, T; Dodoo, D

    2000-01-01

    is maintained at low densities. Here, we test the hypothesis that the presence or absence of antibodies against variant antigens on the surface of P. falciparum-infected erythrocytes protect individuals against some infectious challenges and render them susceptible to others. Plasma collected in Daraweesh...... susceptible and protected individuals. Together, the results indicate that pre-existing anti-PfEMP1 antibodies can reduce the risk of contracting clinical malaria when challenged by novel parasite clones expressing homologous, but not heterologous variable surface antigens. The results also confirm...

  10. Method to conjugate polysaccharide antigens to surfaces for the detection of antibodies

    DEFF Research Database (Denmark)

    Boas, Ulrik; Lind, Peter; Riber, Ulla

    2014-01-01

    microbeads modified with N-alkyl hydroxylamine and N-alkyl-O-methyl hydroxylamine surface groups by incubation of antigen and beads for 16 h at 40 oC without the need for coupling agents. The efficiency of the new method was evaluated by flow cytometry in model samples and serum samples containing antibodies...

  11. Factors Predicting HBsAg Seroclearance and Alanine Transaminase Elevation in HBeAg-Negative Hepatitis B Virus-Infected Patients with Persistently Normal Liver Function.

    Directory of Open Access Journals (Sweden)

    Tai-Long Chien

    Full Text Available A certain proportion of hepatitis B virus (HBV-infected patients with persistently normal alanine transaminase (ALT levels have significant fibrosis. Using liver stiffness measurements (Fibroscan® and laboratory data, including serum ALT, quantitative HBsAg (qHBsAg, and HBV DNA, we attempted to predict the natural histories of these patients.Non-cirrhotic HBeAg-negative chronic hepatitis B patients with persistently normal ALT were followed up prospectively with the end points of HBsAg seroclearance and ALT elevation above the upper limit of normal. The factors that were predictive of the end points were identified.A total of 235 patients with an average age of 48.1 +/- 10.7 years were followed up for 7 years. Eight patients (3.4% lost HBsAg, and 15 patients (6.4% experienced ALT elevation. The overall cumulative HBsAg seroclearances were 0.4%, 1.3% and 2.3% at years 1, 3 and 5, respectively. Regarding HBsAg seroclearance, the qHBsAg (< 30 IU/ml cutoff resulted in a hazard ratio (HR of 19.6 with a 95% confidence interval (CI of 2.2-166.7 (P = 0.008. The baseline ALT level (odd ratio (OR 1.075, 95% CI 1.020-1.132, P = 0.006 and a qHBsAg above 1000 IU/ml (3.7, 1.1-12.4, P = 0.032 were associated with ALT elevation. Limited to men, the baseline liver stiffness (1.6, 1.0-2.5, P = 0.031 and a qHBsAg above 1000 IU/ml (10.4, 2.1-52.4, P = 0.004 were factors that were independently associated with ALT elevation.A low qHBsAg level predicted HBsAg clearance. Baseline ALT and a qHBsAg above 1000 IU/ml were independent predictive factors for ALT elevation. Among the men, the independent predictive factors for ALT elevation were qHBsAg and liver stiffness.

  12. Hepatitis B, C and Human Immunodeficiency Virus (HIV) Co ...

    African Journals Online (AJOL)

    TNHJOURNALPH

    BACKGROUND. Nigeria which has one of the world's highest burden of children living with. Sickle cell anaemia is also endemic for hepatitis B, C and the Human immunodeficiency virus (HIV). This study set out to determine the prevalence of. Hepatitis B surface antigen (HBsAg), antibodies to Hepatitis C Virus (HCV) and.

  13. Seroprevalence and Risk Factors for Human Immunodeficiency ...

    African Journals Online (AJOL)

    This study sought to determine the seroprevalence of human immunodeficiency virus (HIV), hepatitis C virus (HCV), and hepatitis B surface antigen (HBsAg) among blood donors at Bolga-tanga Regional Hospital, Ghana by blood group type, sex and age and also determining the asso-ciation, if any, in the occurrence of the ...

  14. Research

    African Journals Online (AJOL)

    abp

    2013-09-10

    Sep 10, 2013 ... item questionnaire and collection of 2ml venous blood for hepatitis B surface antigens (HBsAg) and anti-HCV antibodies. .... Limitations: HBV DNA and HCV RNA by polymerase chain reaction were not done due ... Data Collection on Adverse Events of Anti-HIV drugs (D:A:D) .... blood donor group, Nigeria.

  15. Low prevalence of hepatitis B and C among tuberculosis patients in Duhok Province, Kurdistan: Are HBsAg and anti-HCV prerequisite screening parameters in tuberculosis control program?

    Science.gov (United States)

    Merza, Muayad A; Haji, Safer M; Alsharafani, Abid Mohialdeen Hasan; Muhammed, Shivan U

    2016-09-01

    Viral hepatitis, particularly hepatitis B virus (HBV) and hepatitis C virus (HCV), infections and tuberculosis (TB) are a global public health concern. Co-infection with HBV or HCV among TB patients may potentiate the risk of hepatotoxicity induced by anti-TB drugs. Hence, the aim of this study was to identify the prevalence of HBV and HCV among TB patients included in the Duhok National Tuberculosis Program (NTP). The Duhok NTP Center is a specialized institution in Duhok City, Iraq, concerned with management and follow-up of TB patients. A cross-sectional study was conducted at the center between June 2015 and May 2016. All documented TB patients were analyzed on the basis of socio-demographic and other characteristics. Thereafter, all patients underwent screening for hepatitis B surface antigen (HBsAg), anti-HCV, and anti-HIV using enzyme-linked immunosorbent assay (ELISA). The results obtained were analyzed by entering the data in binary format into a Microsoft Excel spreadsheet. A p value of Kurdistan, the negative history of injection drug use, and adherence to universal infection-control measures, including vaccination for HBV. Both history of dental intervention and belonging to a Syrian population were independent risk factors for HBV/TB co-infection. Copyright © 2016 Asian-African Society for Mycobacteriology. Published by Elsevier Ltd. All rights reserved.

  16. Flow cytometric analysis of cell-surface and intracellular antigens in leukemia diagnosis.

    Science.gov (United States)

    Knapp, W; Strobl, H; Majdic, O

    1994-12-15

    New technology allows highly sensitive flow cytometric detection and quantitative analysis of intracellular antigens in normal and malignant hemopoietic cells. With this technology, the earliest stages of myeloid and lymphoid differentiation can easily and reliably be identified using antibodies directed against (pro-)myeloperoxidase/MPO, CD22 and CD3 antigens, respectively. Particularly for the analysis of undifferentiated acute myeloblastic leukemia (AML) cells, the immunological demonstration of intracellular MPO or its enzymatically inactive proforms is highly relevant, since other myeloid marker molecules such as CD33, CD13, or CDw65 are either not restricted to the granulomonocytic lineage or appear later in differentiation. By combining MPO staining with staining for lactoferrin (LF), undifferentiated cells can be distinguished from the granulomonocytic maturation compartment in bone marrow, since LF is selectively expressed from the myelocyte stage of differentiation onward. The list of informative intracellular antigens to be used in leukemia cell analysis will certainly expand in the near future. One candidate, intracellular CD68, has already been tested by us, and results are presented. Also dealt within this article are surface marker molecules not (as yet) widely used in leukemia cell analysis but with the potential to provide important additional information. Among them are the surface structures CD15, CD15s, CDw65, CD79a (MB-1), CD79b (B29), CD87 (uPA-R), and CD117 (c-kit).

  17. Some problems associated with radiolabeling surface antigens on helminth parasites: a brief review

    Energy Technology Data Exchange (ETDEWEB)

    Hayunga, E.G. (Division of Tropical Public Health, Department of Preventive Medicine and Biometrics, Uniformed Services University of the Health Sciences, Bethesda, MD (USA)); Murrell, K.D. (Agricultural Research Service, Beltsville, MD (USA))

    1982-06-01

    Recent developments in technology have facilitated substantial advances in the characterization of surface antigens from a wide variety of both normal and neoplastic cells. However, the immunochemistry of parasites has lagged behind. Efforts to apply conventional radiolabeling methods to helminths have not always been successful. Experimental work with Schistosoma mansoni is reviewed to illustrate common problems encountered in surface labeling studies. These findings should provide insight for the future investigation of other helminth species.

  18. Some problems associated with radiolabeling surface antigens on helminth parasites: a brief review

    International Nuclear Information System (INIS)

    Hayunga, E.G.; Murrell, K.D.

    1982-01-01

    Recent developments in technology have facilitated substantial advances in the characterization of surface antigens from a wide variety of both normal and neoplastic cells. However, the immunochemistry of parasites has lagged behind. Efforts to apply conventional radiolabeling methods to helminths have not always been successful. Experimental work with Schistosoma mansoni is reviewed to illustrate common problems encountered in surface labeling studies. These findings should provide insight for the future investigation of other helminth species. (Auth.)

  19. A sensitive immunoradiometric assay for the detection of hepatitis B surface antigen

    International Nuclear Information System (INIS)

    Cameron, C.H.; Combridge, B.S.; Howell, D.R.; Barbara, J.A.J.

    1980-01-01

    A solid-phase immunoradiometric assay for hepatitis B surface antigen is described which has been in use since 1972. Initially it was used for reference laboratory work, but from 1974 it has also been used for screening blood and blood products. Methods for the production of reagents and their use in blood transfusion and reference work, are outlined. (Auth.)

  20. Author Details

    African Journals Online (AJOL)

    Serological Detection of Foot and Mouth Disease Virus (Fmdv) Sat 1 and Sat 2 Antibodies in Nigerian Cattle Abstract · Vol 5, No 3 (2009) - Articles Prevalence of Hepatitis B Surface Antigen (HBsAg) Amongst Alcohol Consumers at Bassa LGA, Plateau State, Nigeria Abstract · Vol 5, No 4 (2009) - Articles Seroprevalence of ...

  1. Purification and characterization of a major human Pneumocystis carinii surface antigen

    DEFF Research Database (Denmark)

    Lundgren, B; Lipschik, G Y; Kovacs, J A

    1991-01-01

    . To evaluate humoral immune responses to the human P. carinii protein, an enzyme-linked immunosorbent assay using purified protein was developed. Some, but not all, patients who subsequently developed P. carinii pneumonia demonstrated a serum antibody response to the surface antigen. Nearly all subjects...... without a history of P. carinii pneumonia had no detectable antibodies. Purified P. carinii proteins will greatly facilitate the investigation of host-P. carinii interactions....

  2. Posintro™-HBsAg, a modified ISCOM including HBsAg, induces strong cellular and humoral responses

    DEFF Research Database (Denmark)

    Schiött, Asa; Larsson, Kristina; Manniche, Søren

    2011-01-01

    HBsAg vaccine formulation, Posintro™-HBsAg, was compared to two commercial hepatitis B vaccines including aluminium or monophosphoryl lipid A (MPL) and the two adjuvant systems MF59 and QS21 in their efficiency to prime both cellular and humoral immune responses. The Posintro™-HBsAg induced...

  3. Inhibition effects of 125I-triplex forming oligonucleotide to hepatoma cells

    International Nuclear Information System (INIS)

    Lv Zhongwei; Hou Min; Cai Haidong; Yuan Xueyu; Yang Yuehua; Yuan Shidong; He Junmin

    2007-01-01

    Objective: Triplex forming oligonucleotide (TFO) has been reported as a new antigene strategy. The purpose of this study was to observe the inhibition effects of 125 I-TFO on hepatoma cells and to investigate the possibility of using 125 I-TFO as an antigene radiotherapy technique for hepatocellular carcinoma (HCC) related to HBV. Methods: TFO complementary to the initiator of S gene of HBV was synthesized and labeled with 125 I. HepG2.2.15 cells, in which HBV genome was integrated, were incubated with 125 I-TFO, TFO and 125 I respectively. After incubation, hepatitis B e antigen (HBeAg) and hepatitis B surface antigen (HBsAg) of each group were assayed with ELISA and the survival rate of cells in each group was determined with 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenylte-trazolium bromide (MTT) reduction assay. Results: 125 I-TFO showed a high stability with a radiolabeling rate of >93%. The radiochemical purity of labeled compound was 90.8%, 81.1% and 73.2% respectively after 12, 48 and 72 h at 37 degree C. The peak inhibition effect of 125 I-TFO on synthesizing HBsAg and HBeAg by HepG2.2.15 cells were found at 48 h after transfection, with significantly the highest inhibition rate of 45.2% for HBsAg and 74.5% for HBeAg expression among the three groups(P 125 I-TFO may inhibit the antigen expression of HBV and the growth of hepatocarcinoma cells, thus it may provide a new approach to develop gene-based radiotherapeutic pharmaceuticals for anti-HBV and HCC. (authors)

  4. ADCC-Mediated CD56DIM NK Cell Responses Are Associated with Early HBsAg Clearance in Acute HBV Infection.

    Science.gov (United States)

    Yu, Wen-Han; Cosgrove, Cormac; Berger, Christoph T; Cheney, Patrick C; Krykbaeva, Marina; Kim, Arthur Y; Lewis-Ximenez, Lia; Lauer, Georg M; Alter, Galit

    2018-01-01

    Hepatitis B virus (HBV) affects up to 400 million people worldwide and accounts for approximately one million deaths per year from liver pathologies. Current treatment regimens are effective in suppressing viremia but usually have to be taken indefinitely, warranting research into new therapeutic approaches. Acute HBV infection in adults almost universally results in resolution of viremia, with the exception of immunocompromised persons, suggesting that the immune response can functionally cure or even eradicate HBV infection. Because immunophenotypic and functional studies have implicated a role for Natural Killer (NK) cells in HBV clearance during acute infection, we hypothesized that a distinct NK-cell profile exists in acute HBV infection that could provide information for the mechanism of HBV clearance. Using multivariate flow cytometry, we evaluated the expression of key activating and inhibitory receptors on NK cells, and their ability to respond to classic target cell lines. Multivariate analysis revealed selective perturbation of the CD56 dim NK-cell subset during acute infection, displaying low levels of NKp46+, NKp30+, CD160+ and CD161+ cells. Intriguingly, the CD56 dim NK-cell profile predicted time to HBV surface antigen (HBsAg) clearance from the blood, and distinct NK-cell profiles predicted early (NKp30, CD94, CD161) and late clearance (KIR3DL1, CD158a, perforin, NKp46). Finally, functional analysis demonstrated that early and late clearance tracked with elevated degranulation (CD107a) or IFNγ production, respectively, in response to ADCC-mediated activation. The cytolytic CD56 dim NK-cell subset is selectively activated in acute HBV infection and displays distinct phenotypic and functional profiles associated with efficient and early control of HBV, implicating antibody-mediated cytolytic NK-cell responses in the early control and functional cure of HBV infection.

  5. Prevalence of hepatitis B virus in patients with diabetes mellitus: a comparative cross sectional study at Woldiya General Hospital, Ethiopia.

    Science.gov (United States)

    Mekonnen, Daniel; Gebre-Selassie, Solomon; Fantaw, Surafel; Hunegnaw, Andualem; Mihret, Adane

    2014-01-01

    The overall prevalence of HBV in Ethiopia varies from 4.7-16.8% for Hepatitis B surface antigen (HBsAg) and 70-76.38% for at least one marker positive. Patients suffering from type I Diabetes Mellitus (DM) incur high risk of infection with hepatotropic viruses because of frequent hospitalization and blood tests. A comparative cross sectional study was conducted at Woldiya General Hospital using 108 consented study populations from Diabetes and 108 non diabetes control groups during the period November 2010 - January 2011. VISITECT HBsAg rapid test kit and Humastat 80 chemistry analyzer were used. Multivariate logistic regression was used to see the association of HBV with clinical history of participants and Sociodemographic variables. All tests were two-sided with α-level of 0.05 and 80% power. Prevalence of HBsAg was equal between diabetic and non diabetic individuals, 3.7% indicating that there was no difference between the two groups. Only history of invasive procedures and chronic liver disease showed association with HBsAg seropositivity. In this study a positive relation was not indicated between HBV and Diabetes and the prevalence of HBsAg was equal between diabetic and non diabetic individuals.

  6. Small-angle neutron scattering study of recombinant yeast-derived human hepatitis B virus surface antigen vaccine particle

    Science.gov (United States)

    Sato, M.; Ito, Y.; Kameyama, K.; Imai, M.; Ishikawa, N.; Takagi, T.

    1995-02-01

    The overall and internal structure of recombinant yeast-derived human hepatitis B virus surface antigen vaccine particles was investigated by small-angle neutron scattering using the contrast variation method. The vaccine is a nearly spherical particle, and its contrast-matching point was determined to be at about 24% D 2O content, indicating that a large part of the vaccine particle is occupied by lipids and carbohydrates from the yeast. The Stuhrmann plot suggests that the surface antigens exist predominantly in the peripheral region of the particle, which is favorable to the induction of anti-virus antibodies.

  7. Protracted outbreak of severe delta hepatitis: experience in an isolated Amerindian population of the Upper Orinoco basin.

    Science.gov (United States)

    Torres, J R; Mondolfi, A

    1991-01-01

    In an investigation of a 21-year-old epidemic of severe hepatitis, 80 serum samples were studied from two isolated Yanomami Amerindian populations of the Upper Orinoco basin in Venezuela. Of the assayed samples, 30.6% were positive for hepatitis B surface antigen (HBsAg), 53.7% were considered to reflect immunity to infection with hepatitis B virus (HBV), and only 16.2% were believed to reflect susceptibility to HBV infection; 82.5% of the samples tested positive for any marker of HBV infection. Thirty-one (39.7%) of 78 samples were also positive for antibody to delta antigen, including 91.6% of those positive for HBsAg and 20.9% of those immune to HBV. Our findings provide evidence of a high prevalence of HBV infection in this population. Furthermore, the high prevalence of antibody to delta antigen strongly suggests that coinfections with HBV or superinfections with hepatitis delta virus (HDV) in HBV carriers may be an important factor in the occurrence of an unusually high number of cases of fulminant hepatitis and of chronic liver disease. Serum samples obtained at the beginning of the outbreak 13 years earlier from 36 selected cases in the same population revealed a high rate of HBV infection (96.5%). All six HBsAg carriers from whom enough serum remained to be assayed were positive for antibody to delta antigen. Our findings indicate that the outbreak coincided with the introduction of HDV into a population with an already-high prevalence of HBV infection.

  8. Immune-escape mutations and stop-codons in HBsAg develop in a large proportion of patients with chronic HBV infection exposed to anti-HBV drugs in Europe

    DEFF Research Database (Denmark)

    Colagrossi, Luna; Hermans, Lucas E; Salpini, Romina

    2018-01-01

    structure of HBV genome, some immune-escape mutations or stop-codons in HBsAg can derive from drug-resistance mutations in RT. This study is aimed at gaining insight in prevalence and characteristics of immune-associated escape mutations, and stop-codons in HBsAg in chronically HBV-infected patients...

  9. Isolated HBsAg positivity in a Mexican patient with newly diagnosed lupus nephritis

    Directory of Open Access Journals (Sweden)

    Guillermo Delgado-García

    2017-01-01

    Conclusions: Isolated HBsAg positivity may result from multiple causes, one of which is cross-reactivity. To the best of our knowledge, this is the first report of a false-positive reading using CMIA technique in an active lupus patient. It is reasonable to stress that lupus patients with a positive screening for HBV should undergo a confirmatory assay (such as genomic detection, since this diagnosis may have important therapeutic implications.

  10. Molecular cloning of cDNA for the human tumor-associated antigen CO-029 and identification of related transmembrane antigens

    International Nuclear Information System (INIS)

    Szala, S.; Kasai, Yasushi; Steplewski, Z.; Rodeck, U.; Koprowski, H.; Linnenbach, A.J.

    1990-01-01

    The human tumor-associated antigen CO-029 is a monoclonal antibody-defined cell surface glycoprotein of 27-34 kDa. By using the high-efficiency COS cell expression system, a full-length cDNA clone for CO-029 was isolated. When transiently expressed in COS cells, the cDNA clone directed the synthesis of an antigen reactive to monoclonal antibody CO-029 in mixed hemadsorption and immunoblot assays. Sequence analysis revealed that CO-029 belongs to a family of cell surface antigens that includes the melanoma-associated antigen ME491, the leukocyte cell surface antigen CD37, and the Sm23 antigen of the parasitic helminth Schistosoma mansoni. CO-029 and ME491 antigen expression and the effect of their corresponding monoclonal antibodies on cell growth were compared in human tumor cell lines of various histologic origins

  11. Delta antibody radioimmunoassay

    Energy Technology Data Exchange (ETDEWEB)

    Kselikova, M; Urbankova, J

    1985-11-15

    The principle and procedure are described of the radioimmunoassay of delta antibody (delta-Ab) using the ABBOTT ANTI-DELTA kit by Abbott Co. A description is given of the kit, the working procedure and the method of evaluation. The results are reported of the incidence of delta-Ab in sera of patients with viral hepatitis B, in haemophiliacs, carriers of the hepatitis B virus surface antigen (HBsAg) and blood donors. The presence was detected of delta-Ab in one HBsAg carrier. The necessity is emphasized of delta-Ab determinations in the blood of donors in view of the antibody transfer with blood and blood preparations.

  12. Prevalence and risk factors of hepatitis B and C virus infections in an impoverished urban community in Dhaka, Bangladesh

    Directory of Open Access Journals (Sweden)

    Salam Mohammed A

    2010-07-01

    Full Text Available Abstract Background Viral hepatitis is a serious global public health problem affecting billions of people globally, and both hepatitis B virus (HBV and hepatitis C virus (HCV infections are rapidly spreading in the developing countries including Bangladesh due to the lack of health education, poverty, illiteracy and lack of hepatitis B vaccination. Also there is lack of information on their prevalence among the general population. So, a population-based serological survey was conducted in Dhaka to determine the prevalence and risk factors of HBV and HCV infections. Methods Healthy individuals were selected for demographic and behavioural characteristics by stratified cluster sampling and blood tested for hepatitis B surface antigen (HBsAg, antibody to HBV core antigen (anti-HBc, and anti-HCV antibodies (anti-HCV. Results From June 2005-November 2006, 1997 participants were screened for HBsAg, anti-HBc and anti-HCV, 738 (37% were males with mean (SD age of 24 (14 years. HBV-seropositivity was documented in 582 (29% participants: 14 (0.7% were positive for HBsAg, 452 (22.6% for anti-HBc and 116 (5.8% for both HBsAg and anti-HBc. Four (0.2% participants were positive for anti-HCV, and another five (0.3% for both anti-HBc and anti-HCV. Ninety-six/246 (39% family members residing at same households with HBsAg positive participants were also HBV-seropositive [74 (30.1% for anti-HBc and 22 (8.9% for both HBsAg and anti-HBc], which was significantly higher among family members (39% than that of study participants (29% (OR 1.56; p Conclusions The results indicate intermediate level of endemicity of HBV infection in Dhaka community, with much higher prevalence among family members of HBsAg positive individuals but low prevalence of HCV infections, clearly indicating need for universal hepatitis B vaccination. The use of disposable needles for ear-nose-body piercing need to be promoted through public awareness programmes as a preventive strategy.

  13. A single point in protein trafficking by Plasmodium falciparum determines the expression of major antigens on the surface of infected erythrocytes targeted by human antibodies.

    Science.gov (United States)

    Chan, Jo-Anne; Howell, Katherine B; Langer, Christine; Maier, Alexander G; Hasang, Wina; Rogerson, Stephen J; Petter, Michaela; Chesson, Joanne; Stanisic, Danielle I; Duffy, Michael F; Cooke, Brian M; Siba, Peter M; Mueller, Ivo; Bull, Peter C; Marsh, Kevin; Fowkes, Freya J I; Beeson, James G

    2016-11-01

    Antibodies to blood-stage antigens of Plasmodium falciparum play a pivotal role in human immunity to malaria. During parasite development, multiple proteins are trafficked from the intracellular parasite to the surface of P. falciparum-infected erythrocytes (IEs). However, the relative importance of different proteins as targets of acquired antibodies, and key pathways involved in trafficking major antigens remain to be clearly defined. We quantified antibodies to surface antigens among children, adults, and pregnant women from different malaria-exposed regions. We quantified the importance of antigens as antibody targets using genetically engineered P. falciparum with modified surface antigen expression. Genetic deletion of the trafficking protein skeleton-binding protein-1 (SBP1), which is involved in trafficking the surface antigen PfEMP1, led to a dramatic reduction in antibody recognition of IEs and the ability of human antibodies to promote opsonic phagocytosis of IEs, a key mechanism of parasite clearance. The great majority of antibody epitopes on the IE surface were SBP1-dependent. This was demonstrated using parasite isolates with different genetic or phenotypic backgrounds, and among antibodies from children, adults, and pregnant women in different populations. Comparisons of antibody reactivity to parasite isolates with SBP1 deletion or inhibited PfEMP1 expression suggest that PfEMP1 is the dominant target of acquired human antibodies, and that other P. falciparum IE surface proteins are minor targets. These results establish SBP1 as part of a critical pathway for the trafficking of major surface antigens targeted by human immunity, and have key implications for vaccine development, and quantifying immunity in populations.

  14. [Comparative Study for Anti-Hepatitis B Surface Antigen Titers Based on Two Measurement Methods: Using Monoclonal Antibodies Isolated from Hepatitis B Vaccinated Recipients].

    Science.gov (United States)

    Oone, Kumiko; Kani, Satomi; Oohashi, Minoru; Shinkai, Noboru; Inoue, Takako; Wakimoto, Yukio; Tanaka, Yasuhito

    2015-08-01

    As anti-hepatitis B surface antigen (anti-HBs) titers vary depending on the measurement methods, we compared two different methods to measure anti-HBs titers in sera and HBs monoclonal antibodies. The sera from 182 HB virus-resolved patients who were negative for HBsAg but positive for antiHB core protein (HBc) and/or anti-HBs were obtained. The measurement of anti-HBs was compared using either Lumipulse G1200 or Architect i2000SR. Six different monoclonal antibody (mAbs) clones isolated from healthy individuals inoculated with hepatitis B vaccine Bimmugen (genotype C) were used. A statistically significant correlation in anti-HBs titers was found between the two methods tested (Y = 0.951X + 100.7, R = 0.813, p Lumipulse and 12 (6.6%) were opposite results. Measuring 2 mAbs with HBV neutralizing activity, the titers of the 116 antibody (1.0 μg/mL) were comparable (689.3 mIU/mL by Lumipulse and 440.7 mIU/mL by Architect), whereas those of the 478 antibody (1.0 μg/mL) were much lower by Architect than by Lumipulse (42.6 vs. 818.6 mIU/mL, respectively). Of four other mAbs without HBV neutralizing activity, equal titers were observed for one; two mAbs had less anti-HB titers by Architect; and one was below the cut-off index (Lumipulse, and the potential ability to detect the 478 antibody with neutralizing activity is low, indicating that Architect might underestimate anti-HBs titers. Future studies should standardize the anti-HBs titer measurement system.

  15. Prevention of Post Transfusion Hepatitis Employing Sensitive Assay for Hepatitis B Surface Antigen Screening(Topics in Transfusion Medicine 1990 : Autologous Transfusion and Post-Transfusion Hepatitis)

    OpenAIRE

    小島, 秀男; 大竹, 幸子; 富樫, 和枝; 石口, 重子; 山田, 恵子; 品田, 章二; Kojima, Hideo; Ohtake, Sachiko; Togashi, Kazue; Ishiguchi, Shigeko; Yamada, Keiko; Shinada, Shoji

    1990-01-01

    Post transfusion Hepatitis (PTH) is one of serious side effects and some times lead to fulminant hepatic failure in case transfused blood contain very low level (under the sensitivity of usual screening method) of hepatitis B virus (HBV). Redcross blood center and blood transfusion devision of our hospital have been employed reverse passive hemmaglutination method (RPHA) for HBsAg screening. Authors employed EIA for sensitive HBsAg test system and compared with RPHA method. Of 2,255 sera from...

  16. Antigen processing of glycoconjugate vaccines; the polysaccharide portion of the pneumococcal CRM(197) conjugate vaccine co-localizes with MHC II on the antigen processing cell surface.

    Science.gov (United States)

    Lai, Zengzu; Schreiber, John R

    2009-05-21

    Pneumococcal (Pn) polysaccharides (PS) are T-independent (TI) antigens and do not induce immunological memory or antibodies in infants. Conjugation of PnPS to the carrier protein CRM(197) induces PS-specific antibody in infants, and memory similar to T-dependent (Td) antigens. Conjugates have improved immunogenicity via antigen processing and presentation of carrier protein with MHC II and recruitment of T cell help, but the fate of the PS attached to the carrier is unknown. To determine the location of the PS component of PnPS-CRM(197) in the APC, we separately labeled PS and protein and tracked their location. The PS of types 14-CRM(197) and 19F-CRM(197) was specifically labeled by Alexa Fluor 594 hydrazide (red). The CRM(197) was separately labeled red in a reaction that did not label PS. Labeled antigens were incubated with APC which were fixed, permeabilized and incubated with anti-MHC II antibody labeled green by Alexa Fluor 488, followed by confocal microscopy. Labeled CRM(197) was presented on APC surface and co-localized with MHC II (yellow). Labeled unconjugated 14 or 19F PS did not go to the APC surface, but PS labeled 14-CRM(197) and 19F-CRM(197) was internalized and co-localized with MHC II. Monoclonal antibody to type 14 PS bound to intracellular type 14 PS and PS-CRM(197). Brefeldin A and chloroquine blocked both CRM(197) and PS labeled 14-CRM(197) and 19F-CRM(197) from co-localizing with MHC II. These data suggest that the PS component of the CRM(197) glycoconjugate enters the endosome, travels with CRM(197) peptides to the APC surface and co-localizes with MHC II.

  17. A novel therapeutic hepatitis B vaccine induces cellular and humoral immune responses and breaks tolerance in hepatitis B virus (HBV) transgenic mice.

    Science.gov (United States)

    Buchmann, Pascale; Dembek, Claudia; Kuklick, Larissa; Jäger, Clemens; Tedjokusumo, Raindy; von Freyend, Miriam John; Drebber, Uta; Janowicz, Zbigniew; Melber, Karl; Protzer, Ulrike

    2013-02-06

    Therapeutic vaccines are currently being developed for chronic hepatitis B and C. As an alternative to long-term antiviral treatment or to support only partially effective therapy, they should activate the patient's immune system effectively to fight and finally control the virus. A paradigm of therapeutic vaccination is the potent induction of T-cell responses against key viral antigens - besides activation of a humoral immune response. We have evaluated the potential of a novel vaccine formulation comprising particulate hepatitis B surface (HBsAg) and core antigen (HBcAg), and the saponin-based ISCOMATRIX™ adjuvant for its ability to stimulate T and B cell responses in C57BL/6 mice and its ability to break tolerance in syngeneic HBV transgenic (HBVtg) mice. In C57BL/6 mice, the vaccine induced multifunctional HBsAg- and HBcAg-specific CD8+ T cells detected by staining for IFNγ, TNFα and IL-2, as well as high antibody titers against both antigens. Vaccination of HBVtg animals induced potent HBsAg- and HBcAg-specific CD8+ T-cell responses in spleens and HBcAg-specific CD8+ T-cell responses in livers as well as anti-HBs seroconversion two weeks post injection. Vaccination further reduced HBcAg expression in livers of HBVtg mice without causing liver damage. In summary, this study demonstrates therapeutic efficacy of a novel vaccine formulation in a mouse model of immunotolerant, chronic HBV infection. Copyright © 2013 Elsevier Ltd. All rights reserved.

  18. Inhibition effects of {sup 125}I-triplex forming oligonucleotide to hepatoma cells

    Energy Technology Data Exchange (ETDEWEB)

    Zhongwei, Lv; Min, Hou; Haidong, Cai; Xueyu, Yuan; Yuehua, Yang; Shidong, Yuan [Department of Nuclear Medicine, 10th People' s Hospital, Tongji Univ., Shanghai (China); Junmin, He

    2007-08-15

    Objective: Triplex forming oligonucleotide (TFO) has been reported as a new antigene strategy. The purpose of this study was to observe the inhibition effects of {sup 125}I-TFO on hepatoma cells and to investigate the possibility of using {sup 125}I-TFO as an antigene radiotherapy technique for hepatocellular carcinoma (HCC) related to HBV. Methods: TFO complementary to the initiator of S gene of HBV was synthesized and labeled with {sup 125}I. HepG2.2.15 cells, in which HBV genome was integrated, were incubated with {sup 125}I-TFO, TFO and {sup 125}I respectively. After incubation, hepatitis B e antigen (HBeAg) and hepatitis B surface antigen (HBsAg) of each group were assayed with ELISA and the survival rate of cells in each group was determined with 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenylte-trazolium bromide (MTT) reduction assay. Results: {sup 125}I-TFO showed a high stability with a radiolabeling rate of >93%. The radiochemical purity of labeled compound was 90.8%, 81.1% and 73.2% respectively after 12, 48 and 72 h at 37 degree C. The peak inhibition effect of {sup 125}I-TFO on synthesizing HBsAg and HBeAg by HepG2.2.15 cells were found at 48 h after transfection, with significantly the highest inhibition rate of 45.2% for HBsAg and 74.5% for HBeAg expression among the three groups(P<0.01 ). As the transfection time prolonged its inhibition effects were stronger. Conclusion: {sup 125}I-TFO may inhibit the antigen expression of HBV and the growth of hepatocarcinoma cells, thus it may provide a new approach to develop gene-based radiotherapeutic pharmaceuticals for anti-HBV and HCC. (authors)

  19. Surface antigens contribute differently to the pathophysiological features in serotype K1 and K2 Klebsiella pneumoniae strains isolated from liver abscesses.

    Science.gov (United States)

    Yeh, Kuo-Ming; Chiu, Sheng-Kung; Lin, Chii-Lan; Huang, Li-Yueh; Tsai, Yu-Kuo; Chang, Jen-Chang; Lin, Jung-Chung; Chang, Feng-Yee; Siu, Leung-Kei

    2016-01-01

    The virulence role of surface antigens in a single serotype of Klebsiella pneumoniae strain have been studied, but little is known about whether their contribution will vary with serotype. To investigate the role of K and O antigen in hyper-virulent strains, we constructed O and K antigen deficient mutants from serotype K1 STL43 and K2 TSGH strains from patients with liver abscess, and characterized their virulence in according to the abscess formation and resistance to neutrophil phagocytosis, serum, and bacterial clearance in liver. Both of K1 and K2-antigen mutants lost their wildtype resistance to neutrophil phagocytosis and hepatic clearance, and failed to cause abscess formation. K2-antigen mutant became serum susceptible while K1-antigen mutant maintained its resistance to serum killing. The amount of glucuronic acid, indicating the amount of capsular polysaccharide (CPS, K antigen), was inversed proportional to the rate of phagocytosis. O-antigen mutant of serotype K1 strains had significantly more amount of CPS, and more resistant to neutrophil phagocytosis than its wildtype counterpart. O-antigen mutants of serotype K1 and K2 strains lost their wildtype serum resistance, and kept resistant to neutrophil phagocytosis. While both mutants lacked the same O1 antigen, O-antigen mutant of serotype K1 became susceptible to liver clearance and cause mild abscess formation, but its serotype K2 counterpart maintained these wildtype virulence. We conclude that the contribution of surface antigens to virulence of K. pneumoniae strains varies with serotypes.

  20. A meta-analysis of the antiviral activity of the HBV-specific immunotherapeutic TG1050 confirms its value over a wide range of HBsAg levels in a persistent HBV pre-clinical model.

    Science.gov (United States)

    Kratzer, Roland; Sansas, Benoît; Lélu, Karine; Evlachev, Alexei; Schmitt, Doris; Silvestre, Nathalie; Inchauspé, Geneviève; Martin, Perrine

    2018-02-01

    Pre-clinical models mimicking persistent hepatitis B virus (HBV) expression are seldom, do not capture all features of a human chronic infection and due to their complexity, are subject to variability. We report a meta-analysis of seven experiments performed with TG1050, an HBV-targeted immunotherapeutic, 1 in an HBV-persistent mouse model based on the transduction of mice by an adeno-associated virus coding for an infectious HBV genome (AAV-HBV). To mimic the clinical diversity seen in HBV chronically infected patients, AAV-HBV transduced mice displaying variable HBsAg levels were treated with TG1050. Overall mean percentages of responder mice, displaying decrease in important clinical parameters i.e. HBV-DNA (viremia) and HBsAg levels, were 52% and 51% in TG1050 treated mice, compared with 8% and 22%, respectively, in untreated mice. No significant impact of HBsAg level at baseline on response to TG1050 treatment was found. TG1050-treated mice displayed a significant shorter Time to Response (decline in viral parameters) with an Hazard Ratio (HR) of 8.3 for viremia and 2.6 for serum HBsAg. The mean predicted decrease for TG1050-treated mice was 0.5 log for viremia and 0.8 log for HBsAg, at the end of mice follow-up, compared to no decrease for viremia and 0.3 log HBsAg decrease for untreated mice. For mice receiving TG1050, a higher decline of circulating viremia and serum HBsAg level over time was detected by interaction term meta-analysis with a significant treatment effect (p = 0.002 and pHBV-persistent model mimicking clinical situations.

  1. Hepatitis B virus infections and risk factors among the general population in Anhui Province, China: an epidemiological study

    Directory of Open Access Journals (Sweden)

    Li Xiaoqing

    2012-04-01

    Full Text Available Abstract Background Hepatitis B is one of the most common infectious diseases in China. The aim of this study was to determine the prevalence of hepatitis B surface antigen (HBsAg among the general population and the risk factors associated with HBV infection in Anhui province, China. Methods A provincial serosurvey was conducted in four cities, and selected through stratified clustering sampling. Data on demographics, immunization history, medical history, family medical history, and life history were collected, along with serum tested for HBsAg. Completed surveys were analysed from 8,875 participants. Results Overall prevalence of HBsAg was 7.44%. Using multivariate analysis, older age was a risk factor for HBsAg infection among children younger than 15 years. Among adults 15-59 years old, the risk factors were male gender, a history of surgical operations, at least one HBsAg-positive family member, and non-vaccination. For adults older than 59 years, the risk factor was a blood transfusion history. Conclusions Though Anhui province has already reached the national goal of reducing HBsAg prevalence to less than 1% among children younger than 5 years, there are still several risk factors for HBsAg infection among the older population. Immunization programs should continue to focus on adults, and interventions should be taken to reduce risk factors associated with being infected with Hepatitis B.

  2. Reactivation of viral replication in anti-HBe positive chronic HBsAg carriers

    DEFF Research Database (Denmark)

    Krogsgaard, K; Aldershvile, J; Kryger, Peter

    1990-01-01

    Reactivation of hepatitis B virus replication was investigated in an unselected group of 44 HBV DNA negative, anti-HBe positive chronic HBsAg carriers. Twenty-five patients (54%) were intravenous drug addicts and 7 (16%) were male homosexuals. Sixteen patients had evidence of delta infection...... to an annual reactivation rate of 5%. Reactivation in four patients was detected by reversion to HBV DNA positivity only, whereas HBeAg/anti-HBe status remained unchanged. Two patients became both HBV DNA and HBeAg positive. None of the patients developed hepatitis-like symptoms and transaminase elevation...

  3. Hepatitis B Infection and Association with Other Sexually Transmitted Infections Among Men Who Have Sex with Men in Peru

    Science.gov (United States)

    Lama, Javier R.; Agurto, Hellen S.; Guanira, Juan V.; Ganoza, Carmela; Casapia, Martin; Ojeda, Nora; Ortiz, Abner; Zamalloa, Victoria; Suarez-Ognio, Luis; Cabezas, Cesar; Sanchez, Jose L.; Sanchez, Jorge

    2010-01-01

    To assess the epidemiology of hepatitis B virus (HBV) infection among men who have sex with men (MSM) in Peru, we evaluated the prevalence and associated risk factors for HBV serologic markers among participants of a HIV sentinel surveillance conducted in 2002–2003. The standardized prevalences for total antibodies to hepatitis B core antigen (anti-HBc) and hepatitis B surface antigen (HBsAg) were 20.2% and 2.8%, respectively. Individuals with human immunodeficiency virus (HIV-1) infection had significantly higher anti-HBc (44.3% versus 19.3%) and HBsAg (9.5% versus 2.3%) prevalences than uninfected men. Increasing age (adjusted odds ratio [AOR] = 1.06), versatile sexual role (AOR = 1.59), sex in exchange for money/gifts (AOR = 1.58), syphilis (AOR = 1.74), HIV-1 infection (AOR = 1.64), and herpes simplex virus type 2 (HSV-2, AOR = 2.77) infection were independently associated with anti-HBc positivity, whereas only HIV-1 infection (AOR = 3.51) and generalized lymph node enlargement (AOR = 3.72) were associated with HBsAg positivity. Pre-existing HBV infection is very common among Peruvian MSM and was correlated with sexual risk factors. MSM in Peru constitute a target population for further HBV preventive and treatment interventions. PMID:20595501

  4. A portion of the Pf155/RESA antigen of Plasmodium falciparum is accessible on the surface of infected erythrocytes

    International Nuclear Information System (INIS)

    Saul, A.; Maloy, W.L.; Howard, R.J.; Rock, E.P.

    1988-01-01

    An investigation of antigens accessible to lactoperoxidase-catalysed cell surface iodination on intact Plasmodium falciparum-infected red blood cells (RBC) has identified a 125 I-labelled antigen with an apparent size of about 155 kD. This labelled protein was specifically immunoprecipitated by the following antibodies: a rabbit antiserum and a mouse monoclonal antibody raised against a synthetic peptide comprising the 3',8-mer repeat EENVEHDA of the Pf155/RESA protein; a rabbit antiserum raised against a synthetic octapeptide comprising two copies of the 3',4-mer repeat EENV of the Pf155/RESA protein; and rabbit antisera against another synthetic peptide C(MYSNNNVED) 2 . The last antibody shows a strong reaction in asexual blood state parasites with the Pf155/RESA antigen. While this antigen has been described previously as a submembrane component of the outer membrane of infected RBC, this report shows that at least part of it is accessible to the surface of both ring and late trophozoite-infected erythrocytes. 21 refs., 4 figs

  5. Clinical and virological factors associated with hepatitis B virus reactivation in HBsAg-negative and anti-HBc antibodies-positive patients undergoing chemotherapy and/or autologous stem cell transplantation for cancer.

    Science.gov (United States)

    Borentain, P; Colson, P; Coso, D; Bories, E; Charbonnier, A; Stoppa, A M; Auran, T; Loundou, A; Motte, A; Ressiot, E; Norguet, E; Chabannon, C; Bouabdallah, R; Tamalet, C; Gérolami, R

    2010-11-01

    We studied clinical outcome and clinico-virological factors associated with hepatitis B virus reactivation (HBV-R) following cancer treatment in hepatitis B virus surface antigen (HBsAg)-negative/anti-hepatitis B core antibodies (anti-HBcAb)-positive patients. Between 11/2003 and 12/2005, HBV-R occurred in 7/84 HBsAg-negative/anti-HBcAb-positive patients treated for haematological or solid cancer. Virological factors including HBV genotype, core promoter, precore, and HBsAg genotypic and amino acid (aa) patterns were studied. Patients presenting with reactivation were men, had an hepatitis B virus surface antibody (HBsAb) titre 1 line of chemotherapy (CT) significantly more frequently than controls. All were treated for haematological cancer, 3/7 received haematopoietic stem cell transplantation (HSCT), and 4/7 received rituximab. Using multivariate analysis, receiving >1 line of CT was an independent risk factor for HBV-R. Fatal outcome occurred in 3/7 patients (despite lamivudine therapy in two), whereas 2/4 survivors had an HBsAg seroconversion. HBV-R involved non-A HBV genotypes and core promoter and/or precore HBV mutants in all cases. Mutations known to impair HBsAg antigenicity were detected in HBV DNA from all seven patients. HBV DNA could be retrospectively detected in two patients prior cancer treatment and despite HBsAg negativity. HBV-R is a concern in HBsAg-negative/anti-HBcAb-positive patients undergoing cancer therapy, especially in males presenting with haematological cancer, a low anti-HBsAb titre and more than one chemotherapeutic agent. HBV DNA testing is mandatory to improve diagnosis and management of HBV-R in these patients. The role of specific therapies such as rituximab or HSCT as well as of HBV aa variability deserves further studies. © 2009 Blackwell Publishing Ltd.

  6. Risk Factors for Hepatitis B virus Surface Antigen Positive Prevalence in the Most Migratory Province of Iran: A Matched Case- Control Study

    Directory of Open Access Journals (Sweden)

    Gh. Karimi

    2015-02-01

    Full Text Available Background and Objective: Hepatitis B Virus Infection is one of the most common infectious diseases and also among the world's top ten causes of this group diseases-related mortality, so that 500,000 to 1.2 million annually die due to the consequences of this infection such as chronic hepatitis, cirrhosis and hepatocellular carcinoma. This study was conducted to determine risk factors for HBsAg-positive prevalence in Alborz Province. Materials and Methods: A 1:1 matched case-control study, 213 of cases reported HBsAg positive to the Alborz University of Medical Sciences in 2013 as case group with 213 of family members of patients with hepatitis C who have serologic markers Anti- HCV negative and HBsAg negative as the control group, were compared in terms of demographic characteristics, History of high risk behaviors, Iatrogenic exposures, community exposures and history of liver disease. Statistical analysis using logistic regression was performed by SPSS software version 18. Results: Reported cases with a mean age of 37.6±15.5 years, was more relevant to marginalized, immigrants and male gender. Nationality, being married, low level of education, family history of HBsAg positive, history of non-intravenous drug abuse, alcohol consumption, history of prison, employment in high risk occupations, sharing of razor, injuries with contaminated sharp instruments and history of jaundice in mother were found to be independent risk factors for HBsAg positive prevalence (OR: 0.27, 3.61, 1.68, 18.04, 12.21, 2.9, 7.52, 2.47, 5.55, 21.48, 11.3, respectively. Conclusions: Unfavorable situation of the marginalized and the prisoners, imported illegal immigrants, especially Afghans can be extended to high-risk behaviors and the threat of a disease surveillance system. Screening and vaccination aforementioned groups, health promotion of the marginalized and raise public knowledge is necessary.

  7. Investigation concerning the determination of the hepatitis B surface antigen (HBsAG) by RIA

    International Nuclear Information System (INIS)

    Stute, R.

    1976-01-01

    The author searched for a method to shorten the time required for a RIA and to increase its sensitivity. This is possible by using herring plasma instead of serum, by increasing the reaction temperature, and by using a shaking water-bath. The detection limit could be lowered by three powers of ten by changing the environment. By shortening the RIA time, it is possible in blood donation to use the stored blood as early as 2-3 h after withdrawal without increasing the hepatitis risk. (AJ) [de

  8. Hepatitis B virus-specific miRNAs and Argonaute2 play a role in the viral life cycle.

    Directory of Open Access Journals (Sweden)

    C Nelson Hayes

    Full Text Available UNLABELLED: Disease-specific serum miRNA profiles may serve as biomarkers and might reveal potential new avenues for therapy. An HBV-specific serum miRNA profile associated with HBV surface antigen (HBsAg particles has recently been reported, and AGO2 and miRNAs have been shown to be stably associated with HBsAg in serum. We identified HBV-associated serum miRNAs using the Toray 3D array system in 10 healthy controls and 10 patients with chronic hepatitis B virus (HBV infection. 19 selected miRNAs were then measured by quantitative RT-PCR in 248 chronic HBV patients and 22 healthy controls. MiRNA expression in serum versus liver tissue was also compared using biopsy samples. To examine the role of AGO2 during the HBV life cycle, we analyzed intracellular co-localization of AGO2 and HBV core (HBcAg and surface (HBsAg antigens using immunocytochemistry and proximity ligation assays in stably transfected HepG2 cells. The effect of AGO2 ablation on viral replication was assessed using siRNA. Several miRNAs, including miR-122, miR-22, and miR-99a, were up-regulated at least 1.5 fold (P<2E-08 in serum of HBV-infected patients. AGO2 and HBcAg were found to physically interact and co-localize in the ER and other subcellular compartments. HBs was also found to co-localize with AGO2 and was detected in multiple subcellular compartments. Conversely, HBx localized non-specifically in the nucleus and cytoplasm, and no interaction between AGO2 and HBx was detected. SiRNA ablation of AGO2 suppressed production of HBV DNA and HBs antigen in the supernatant. CONCLUSION: These results suggest that AGO2 and HBV-specific miRNAs might play a role in the HBV life cycle.

  9. Novel Plasmodium falciparum malaria vaccines: evidence-based searching for variant surface antigens as candidates for vaccination against pregnancy-associated malaria

    DEFF Research Database (Denmark)

    Staalsoe, Trine; Jensen, Anja T R; Theander, Thor G

    2002-01-01

    Malaria vaccine development has traditionally concentrated on careful molecular, biochemical, and immunological characterisation of candidate antigens. In contrast, evidence of the importance of identified antigens in immunity to human infection and disease has generally been limited to statistic......Malaria vaccine development has traditionally concentrated on careful molecular, biochemical, and immunological characterisation of candidate antigens. In contrast, evidence of the importance of identified antigens in immunity to human infection and disease has generally been limited...... to statistically significant co-variation with protection rather than on demonstration of causal relationships. We have studied the relationship between variant surface antigen-specific antibodies and clinical protection from Plasmodium falciparum malaria in general, and from pregnancy-associated malaria (PAM......) in particular, to provide robust evidence of a causal link between the two in order to allow efficient and evidence-based identification of candidate antigens for malaria vaccine development....

  10. Bacteroides gingivalis antigens and bone resorbing activity in root surface fractions of periodontally involved teeth

    International Nuclear Information System (INIS)

    Patters, M.R.; Landsberg, R.L.; Johansson, L.-A.; Trummel, C.L.; Robertson, P.R.

    1982-01-01

    Bone resorbing activity and the presence of antigens of Bacteroides gingivalis were assessed in plaque, calculus, cementum, and dentin obtained from roots of teeth previously exposed to periodontitis. Each fraction was obtained by scaling the root surface. The fraction were extracted by stirring and sonication, and the soluble centrifuged, sterilized, dialyzed, and adjusted to equivalent protein concentrations. Cementum and dentin extracts from impacted teeth were prepared similarly and served as controls. Stimulation of bone resorption by each extract was assessed in organ cultures of fetal rat bones by measurement of release of previously-incorporated 45 Ca from the bone into the medium. In some groups of teeth, calculus and cementum were treated with acid prior to scaling. Citric acid washes were recovered and dialyzed. An enzyme-linked immunosorbent assay (ELISA) was used to assess the extracts for the presence of antigens reactive with an antiserum to B. gingivalis. Significant stimulation of bone resorption was found in all calculus and periodontally-involved cementum preparations. ELISA showed significant levels of B.gingivalis antigens in plaque, calculus, and cementum of periodontally-involved teeth, but not in involved dentin nor in cementum or dentin of impact teeth. Treatment with citric acid removed essentially all B.gingivalis antigens from cementum but not calculus. The results suggest that substances which stimulate bone resorption and substances which react with B. gingivalis antiserum are present in surface plaque, calculus, and cementum or periodontally-involved teeth. These substances are not present in cementum and dentin of impacted teeth nor in dentin of periodontally-involved teeth. Treatment by both scaling and citric demineralization will remove most of these substances from cementum of teeth previously exposed to periodontitis. (author)

  11. Bacteroides gingivalis antigens and bone resorbing activity in root surface fractions of periodontally involved teeth

    Energy Technology Data Exchange (ETDEWEB)

    Patters, M R; Landsberg, R L; Johansson, L A; Trummel, C L; Robertson, P R [Department of Periodontology, University of Connecticut, School of Dental Medicine, Farmington, Connecticut, U.S.A.

    1982-01-01

    Bone resorbing activity and the presence of antigens of Bacteroides gingivalis were assessed in plaque, calculus, cementum, and dentin obtained from roots of teeth previously exposed to periodontitis. Each fraction was obtained by scaling the root surface. The fraction were extracted by stirring and sonication, and the soluble centrifuged, sterilized, dialyzed, and adjusted to equivalent protein concentrations. Cementum and dentin extracts from impacted teeth were prepared similarly and served as controls. Stimulation of bone resorption by each extract was assessed in organ cultures of fetal rat bones by measurement of release of previously-incorporated /sup 45/Ca from the bone into the medium. In some groups of teeth, calculus and cementum were treated with acid prior to scaling. Citric acid washes were recovered and dialyzed. An enzyme-linked immunosorbent assay (ELISA) was used to assess the extracts for the presence of antigens reactive with an antiserum to B. gingivalis. Significant stimulation of bone resorption was found in all calculus and periodontally-involved cementum preparations. ELISA showed significant levels of B.gingivalis antigens in plaque, calculus, and cementum of periodontally-involved teeth, but not in involved dentin nor in cementum or dentin of impact teeth. Treatment with citric acid removed essentially all B.gingivalis antigens from cementum but not calculus. The results suggest that substances which stimulate bone resorption and substances which react with B. gingivalis antiserum are present in surface plaque, calculus, and cementum or periodontally-involved teeth. These substances are not present in cementum and dentin of impacted teeth nor in dentin of periodontally-involved teeth. Treatment by both scaling and citric demineralization will remove most of these substances from cementum of teeth previously exposed to periodontitis.

  12. A new technique to detect antibody-antigen reaction (biological interactions) on a localized surface plasmon resonance (LSPR) based nano ripple gold chip

    Energy Technology Data Exchange (ETDEWEB)

    Saleem, Iram, E-mail: iiram.qau@gmail.com [Department of Physics and Texas Center for Superconductivity, University of Houston, Houston, TX 77204 (United States); Widger, William, E-mail: widger@uh.edu [Department of Biology and Biochemistry and Texas Center for Superconductivity, University of Houston, Houston, TX 77204 (United States); Chu, Wei-Kan, E-mail: wkchu@uh.edu [Department of Physics and Texas Center for Superconductivity, University of Houston, Houston, TX 77204 (United States)

    2017-07-31

    Highlights: • The nano ripple LSPR chip has monolayer molecule-coating sensitivity and specific selectivity. • Gold nano-ripple sensing chip is a low cost, and a label-free method for detecting the antibody-antigen reaction. • The plasmonic resonance shift depends upon the concentration of the biomolecules attached on the surface of the nano ripple pattern. - Abstract: We demonstrate that the gold nano-ripple localized surface plasmon resonance (LSPR) chip is a low cost and a label-free method for detecting the presence of an antigen. A uniform stable layer of an antibody was coated on the surface of a nano-ripple gold pattern chip followed by the addition of different concentrations of the antigen. A red shift was observed in the LSPR spectral peak caused by the change in the local refractive index in the vicinity of the nanostructure. The LSPR chip was fabricated using oblique gas cluster ion beam (GCIB) irradiation. The plasmon-resonance intensity of the scattered light was measured by a simple optical spectroscope. The gold nano ripple chip shows monolayer scale sensitivity and high selectivity. The LSPR substrate was used to detect antibody-antigen reaction of rabbit X-DENTT antibody and DENTT blocking peptide (antigen).

  13. Identification and Characterization of Ixodes scapularis Antigens That Elicit Tick Immunity Using Yeast Surface Display

    NARCIS (Netherlands)

    Schuijt, T.J.; Narasimhan, S.; Daffre, S.; Deponte, K.; Hovius, J.W.R.; van 't Veer, C.; van der Poll, T.; Bakhtiari, K.; Meijers, J.C.M.; Boder, E.T.; van Dam, A.P.; Fikrig, E.

    2011-01-01

    Repeated exposure of rabbits and other animals to ticks results in acquired resistance or immunity to subsequent tick bites and is partially elicited by antibodies directed against tick antigens. In this study we demonstrate the utility of a yeast surface display approach to identify tick salivary

  14. Genomic Characterization of Variable Surface Antigens Reveals a Telomere Position Effect as a Prerequisite for RNA Interference-Mediated Silencing in Paramecium tetraurelia

    Science.gov (United States)

    Baranasic, Damir; Oppermann, Timo; Cheaib, Miriam; Cullum, John; Schmidt, Helmut

    2014-01-01

    ABSTRACT Antigenic or phenotypic variation is a widespread phenomenon of expression of variable surface protein coats on eukaryotic microbes. To clarify the mechanism behind mutually exclusive gene expression, we characterized the genetic properties of the surface antigen multigene family in the ciliate Paramecium tetraurelia and the epigenetic factors controlling expression and silencing. Genome analysis indicated that the multigene family consists of intrachromosomal and subtelomeric genes; both classes apparently derive from different gene duplication events: whole-genome and intrachromosomal duplication. Expression analysis provides evidence for telomere position effects, because only subtelomeric genes follow mutually exclusive transcription. Microarray analysis of cultures deficient in Rdr3, an RNA-dependent RNA polymerase, in comparison to serotype-pure wild-type cultures, shows cotranscription of a subset of subtelomeric genes, indicating that the telomere position effect is due to a selective occurrence of Rdr3-mediated silencing in subtelomeric regions. We present a model of surface antigen evolution by intrachromosomal gene duplication involving the maintenance of positive selection of structurally relevant regions. Further analysis of chromosome heterogeneity shows that alternative telomere addition regions clearly affect transcription of closely related genes. Consequently, chromosome fragmentation appears to be of crucial importance for surface antigen expression and evolution. Our data suggest that RNAi-mediated control of this genetic network by trans-acting RNAs allows rapid epigenetic adaptation by phenotypic variation in combination with long-term genetic adaptation by Darwinian evolution of antigen genes. PMID:25389173

  15. [Optimization of prokaryotic expression conditions of Leptospira interrogans trigeminy genus-specific protein antigen based on surface response analysis].

    Science.gov (United States)

    Wang, Jiang; Luo, Dongjiao; Sun, Aihua; Yan, Jie

    2008-07-01

    Lipoproteins LipL32 and LipL21 and transmembrane protein OMPL1 have been confirmed as the superficial genus-specific antigens of Leptospira interrogans, which can be used as antigens for developing a universal genetic engineering vaccine. In order to obtain high expression of an artificial fusion gene lipL32/1-lipL21-ompL1/2, we optimized prokaryotic expression conditions. We used surface response analysis based on the central composite design to optimize culture conditions of a new antigen protein by recombinant Escherichia coli DE3.The culture conditions included initial pH, induction start time, post-induction time, Isopropyl beta-D-thiogalactopyranoside (IPTG) concentration, and temperature. The maximal production of antigen protein was 37.78 mg/l. The optimal culture conditions for high recombinant fusion protein was determined: initial pH 7.9, induction start time 2.5 h, a post-induction time of 5.38 h, 0.20 mM IPTG, and a post-induction temperature of 31 degrees C. Surface response analysis based on CCD increased the target production. This statistical method reduced the number of experiments required for optimization and enabled rapid identification and integration of the key culture condition parameters for optimizing recombinant protein expression.

  16. Operating in a Yellow Nation; the frequency of hepatitis B and hepatitis C positive at a tertiary care teaching hospital

    International Nuclear Information System (INIS)

    Waheed, A.; Zafar-ul-Ahsan; Zaeem, F.A.; Shariff, M.M.; Qayyum, A.

    2010-01-01

    Objects contaminated with blood and other body fluids of patients suffering from hepatitis B and C are an occupational health hazard to the health care personnel and a source of nosocomial spread. This descriptive cross sectional study estimated the frequency of hepatitis B surface antigen (HBsAg) and anti hepatitis C antibody (Anti HCV) positive patients among those undergoing a urological procedure in a tertiary care teaching hospital. A sample size of 550 patients was estimated using Stat Calc for Epi Info. A cluster off 558 patients were included. Ninety five (17%) were positive for serum HBsAg and/or anti HCV by Elisa. Gender/sex, admission year, urological diagnosis did not predict statistically significant relationship with the positive status. Past surgical history was marginally significant. In conclusion, all patients undergoing a urological procedure should be checked for anti HCV and HBsAg. A solid policy outlining the preventive practices is needed to stop this high burden of hepatitis turning into public health disaster. (author)

  17. Twenty-year survey of the epidemiology of hepatitis B in Denmark: effect of immigration

    DEFF Research Database (Denmark)

    Gjørup, I E; Smith, E; Borgwardt, L

    2003-01-01

    Implementation of hepatitis B virus (HBV) vaccination is being considered in Denmark. Therefore, a 20 y survey on the epidemiology of HBV infection was performed. All notified cases of acute HBV infection in Denmark from 1982 to 2002 were reviewed retrospectively and all available data from 1970...... to 2001 on the prevalence of hepatitis B surface antigen (HBsAg) in different groups of the Danish population were studied. The notified annual incidence of acute HBV infection has declined from more than 200 cases to fewer than 50 cases in 2001. In the indigenous population there has been a similar...... decline in prevalence of HBsAg carriers, from 0.15 to 0.03%, but owing to immigration of new HBsAg carriers from developing countries the overall number of carriers has not changed. The small effect of immigration on the incidence of acute HBV infections as well as the decreasing prevalence of HBs...

  18. A molecular approach to immunoscintigraphy: A study of the T-antigen conformation on the surface of tumors

    International Nuclear Information System (INIS)

    Noujaim, A.; Selvaraj, S.; Suresh, M.R.; Turner, C.; McLean, G.; Willans, D.; Longenecker, B.M.; Haines, D.M.

    1987-01-01

    The role of glycoconjugates in tumor cell differentiation has been well documented. We have examined the expression of the two anomers of the Thomsen-Friedenreich antigen on the surface of human, canine and murine tumor cell membranes both in vitro and in vivo. This has been accomplished through the synthesis of the disaccharide terminal residues in both α and β configuration. Both entities were used to generate murine monoclonal antibodies which recognized the carbohydrate determinants. The determination of fine specificities of these antibodies was effected by means of cellular uptake, immunohistopathology and immunoscintigraphy. Examination of pathological specimens of human and canine tumor tissue indicated that the expressed antigen was in the β configuration. More than 89% of all human carcinomas tested expressed the antigen in the above anomeric form. The combination of synthetic antigens and monoclonal antibodies raised specifically against them provide us with invaluable tools for the study of tumor marker expression in humans and their respective animal tumor models. (orig.) [de

  19. Leukemia-associated antigens in man.

    Science.gov (United States)

    Brown, G; Capellaro, D; Greaves, M

    1975-12-01

    Rabbit antisera raised against acute lymphoblastic leukemia (ALL) cells were used to distinguish ALL from other leukemias, to identify rare leukemia cells in the bone marrow of patients in remission, and to define human leukemia-associated antigens. Antibody binding was studied with the use of immunofluorescence reagents and the analytic capacity of the Fluorescence Activated Cell Sorter-1 (FACS-1). The results indicated that most non-T-cell ALL have three leukemia-associated antigens on their surface which are absent from normal lymphoid cells: 1) an antigen shared with myelocytes, myeloblastic leukemia cells, and fetal liver (hematopoietic) cells; 2) an antigen shared with a subset of intermediate normoblasts in normal bone marrow and fetal liver; and 3) an antigen found thus far only on non-T-cell ALL and in some acute undifferentiated leukemias, which we therefore regard as a strong candidate for a leukemia-specific antigen. These antigens are absent from a subgroup of ALL patients in which the lymphoblasta express T-cell surface markers. Preliminary studies on the bone marrow samples of patients in remission indicated that rare leukemia cells were present in some samples. The implications of these findings with respect to the heterogeneity and cell origin(s) of ALL, its diagnosis, and its potential monitoring during treatment were discussed.

  20. Use of radio-immuno-inhibition assay for the study of the y, d and w determinants of hepatitis B surface antigen

    Energy Technology Data Exchange (ETDEWEB)

    Donea-Debroise, B; Brocteur, J; Andre, A; Remacle, M B [Liege Univ. (Belgium)

    1979-01-01

    A radioimmunoassay determination of the HBs antigen subtypes is discussed, this simple but effective technique was used in association with the use of the Austria II kit (Abbott Laboratories). This method consists of an inhibition reaction of the Austria II test, by previous incubation of the antigen to be subtyped with a monospecific antibody. With this method we were able to distinguish the y and the d antigens as well as the w1, w3, w4 determinants of hepatitis B surface antigen. We have included a frequency table of the various HBs subtypes found among donor and patient populations in Liege.

  1. A simple assay for the detection of antibodies to endocrine islet cell surface antigens

    International Nuclear Information System (INIS)

    Contreas, G.; Madsen, O.D.; Vissing, H.; Lernmark, Aa.

    1986-01-01

    A simple and sensitive immunoradiometric assay for the detection of islet cell surface antibodies (CIRMA) has been developed. Live, transformed islet cells derived from a liver metastasis of a transplantable islet cell tumor were grown in removable microtiter wells and incubated with antibody. Cell-bound antibodies were quantitated using 125 I-labelled second antibodies. The assay was used to detect islet cell antibodies present in sera from non-diabetic and diabetic BB rats and proved to be particularly effective for screening hybridoma supernatants in order to identify monoclonal antibodies recognizing islet cell surface antigens. (Auth.)

  2. The herpes virus Fc receptor gE-gI mediates antibody bipolar bridging to clear viral antigens from the cell surface.

    Directory of Open Access Journals (Sweden)

    Blaise Ndjamen

    2014-03-01

    Full Text Available The Herpes Simplex Virus 1 (HSV-1 glycoprotein gE-gI is a transmembrane Fc receptor found on the surface of infected cells and virions that binds human immunoglobulin G (hIgG. gE-gI can also participate in antibody bipolar bridging (ABB, a process by which the antigen-binding fragments (Fabs of the IgG bind a viral antigen while the Fc binds to gE-gI. IgG Fc binds gE-gI at basic, but not acidic, pH, suggesting that IgG bound at extracellular pH by cell surface gE-gI would dissociate and be degraded in acidic endosomes/lysosomes if endocytosed. The fate of viral antigens associated with gE-gI-bound IgG had been unknown: they could remain at the cell surface or be endocytosed with IgG. Here, we developed an in vitro model system for ABB and investigated the trafficking of ABB complexes using 4-D confocal fluorescence imaging of ABB complexes with transferrin or epidermal growth factor, well-characterized intracellular trafficking markers. Our data showed that cells expressing gE-gI and the viral antigen HSV-1 gD endocytosed anti-gD IgG and gD in a gE-gI-dependent process, resulting in lysosomal localization. These results suggest that gE-gI can mediate clearance of infected cell surfaces of anti-viral host IgG and viral antigens to evade IgG-mediated responses, representing a general mechanism for viral Fc receptors in immune evasion and viral pathogenesis.

  3. Immunological demonstration of intestinal absorption and digestion of protein macromolecules in the trout (Salmo gairdneri).

    Science.gov (United States)

    Georgopoulou, U; Sire, M F; Vernier, J M

    1986-01-01

    An immunofluorescence technique using antibodies against the Fc and Fab fragments of human IgG (IgGH) was used to study the absorption of proteins by the intestinal epithelial cells of rainbow trout after oral or anal administration. Cellular absorption of a high molecular weight protein, hepatitis-B surface antigen (HBsAg), was also studied by using two monoclonal antibodies, one specific for the confirmation of the antigen (implying disulfide bridges), and the other that reacts with the constituent polypeptides. Both absorbed IgGH and HBsAg were seen to be segregated in the apical vacuolar system, a characteristic feature of intestinal epithelial cells. The same antibodies were used with an everted sac technique in conjunction with immunofluorescence, to show the intravacuolar degradation of IgGH and HBsAg following absorption. By using an antibody against cathepsin D, it was possible to demonstrate, by immunofluorescence, the localization of this enzyme in the same vacuolar system. After coupling the antibody to peroxidase or to the protein A/colloidalgold complex, the ultrastructural antigenic sites of cathepsin D could be seen to be localized in the interior of the vacuoles. The vacuolar localization of a cathepsin B activity was determined by incubating sections of intestinal mucosa, or isolated epithelial cells, with a specific synthetic substrate (Z-Ala-Arg-Arg-methoxynaphthylamide). The supranuclear hyaloplasmic vacuoles of intestinal epithelial cells may be considered to be phagolysosomes that assure the degradation of absorbed proteins. This function may be of fundamental importance in the in the nutritional processes of this species.

  4. Postvaccination seroconversion against the surface antigen of Hepatitis B virus, in nursing students

    Directory of Open Access Journals (Sweden)

    Gladys Amanda Mera-Urbano

    2013-09-01

    Full Text Available Objective: To determine the status of seroconversion after vaccination against the surface antigen of hepatitis B virus in nursing students, University of Cauca. Methods: Cross sectional study in students of V and VI semester. The sample was taken from 37 students, 15 of V and 22 of VI semester. The instrument used was a survey that included 11 questions of multiple selections. Records for weight, height and laboratory results were collected; blood samples for antibody titers were performed with informed consent. The data were tabulated and analyzed using SPSS, version 17.0. Results: 89.2% of students had levels of antibodies to the surface antigen. This value was greater than 10 mUI/ml, considered by the scientific community as a protector value of Hepatitis B. 10.8% of had lesser values. Regarding vaccination scheme, 24% had a dose, 19% two, 48% three and 8% had a one dose. The population with 3 doses and reinforcement seroconverted by 100%. Conclusion: This study demonstrated failings in the scheme of vaccination of the students of nursing and that 10.8 % presented lower values than 10 mIU/ml. It is necessary to apply the institutional rules with more strength as a preventive measure for hepatitis B.

  5. Infección oculta por el virus de la hepatitis B en hijos de madres positivas al HBsAg

    Directory of Open Access Journals (Sweden)

    Marité Bello-Corredor

    2016-04-01

    Full Text Available La infección oculta por el virus de la hepatitis B (IOB, se caracteriza por la presencia en suero o plasma del genoma viral (ADN-VHB y anticuerpos contra la proteína de la cápside (anti-HBc en ausencia del antígeno de superficie (HBsAg, marcador que tradicionalmente se emplea para identificar la presencia del virus. Con el objetivo de caracterizar la presencia de IOB en hijos de madres positivas al HBsAg, se estudiaron 291 muestras séricas de niños con la condición de ser HBsAg (- y anticuerpos anti-HBsAg (anti-HBs menores de 50 UI/L, conservadas en la seroteca del Laboratorio de Referencia Nacional de Hepatitis Virales. Se realizaron ensayos para determinar la exposición al virus (anti-HBc, a los sueros anti-HBc (+ se les realizó Reacción en Cadena de la Polimerasa en Tiempo Real (RCP-TR para determinar y cuantificar el ADN-VHB. La prevalencia de exposición al VHB (anti-HBc fue 16,8% (49/291. El ADN viral se cuantificó en el 14% (6/43 de los casos anti-HBc (+, observándose cargas virales que oscilaban entre 2,15 x 101 hasta 3,42 x 101 UI/mL. La prevalencia de la IOB para el total de los pacientes analizados fue 2,1% (6/291, considerada relativamente baja. No se encontró asociación significativa entre las variables sociodemográficas analizadas tales como: edad, sexo y provincia de procedencia. La IOB está presente en hijos de madres positivas al HBsAg, a pesar de la profilaxis contra la hepatitis B. Por lo tanto, se requiere de pesquisajes adecuados para detectar dicha entidad. Las implicaciones clínicas y epidemiológicas de la misma, requieren de un estrecho monitoreo y atención de estos pacientes. Este estudio se realiza por primera vez en Cuba y aporta conocimientos útiles para el diagnóstico, prevención y control de esta enfermedad en niños.

  6. Antigen processing and remodeling of the endosomal pathway: requirements for antigen cross-presentation.

    Science.gov (United States)

    Compeer, Ewoud Bernardus; Flinsenberg, Thijs Willem Hendrik; van der Grein, Susanna Geertje; Boes, Marianne

    2012-01-01

    Cross-presentation of endocytosed antigen as peptide/class I major histocompatibility complex complexes plays a central role in the elicitation of CD8(+) T cell clones that mediate anti-viral and anti-tumor immune responses. While it has been clear that there are specific subsets of professional antigen presenting cells capable of antigen cross-presentation, identification of mechanisms involved is still ongoing. Especially amongst dendritic cells (DC), there are specialized subsets that are highly proficient at antigen cross-presentation. We here present a focused survey on the cell biological processes in the endosomal pathway that support antigen cross-presentation. This review highlights DC-intrinsic mechanisms that facilitate the cross-presentation of endocytosed antigen, including receptor-mediated uptake, maturation-induced endosomal sorting of membrane proteins, dynamic remodeling of endosomal structures and cell surface-directed endosomal trafficking. We will conclude with the description of pathogen-induced deviation of endosomal processing, and discuss how immune evasion strategies pertaining endosomal trafficking may preclude antigen cross-presentation.

  7. Antigen processing and remodeling of the endosomal pathway: requirements for antigen cross-presentation.

    Directory of Open Access Journals (Sweden)

    Ewoud Bernardus Compeer

    2012-03-01

    Full Text Available The cross-presentation of endocytosed antigen as peptide/class I MHC complexes plays a central role in the elicitation of CD8+ T cell clones that mediate anti-viral and anti-tumor immune responses. While it has been clear that there are specific subsets of professional antigen presenting cells (APC capable of antigen cross-presentation, description of mechanisms involved is still ongoing. Especially amongst dendritic cells (DC, there are specialized subsets that are highly proficient at antigen cross-presentation. We here present a focused survey on the cell biological processes in the endosomal pathway that support antigen cross-presentation. This review highlight DC-intrinsic mechanisms that facilitate the cross-presentation of endocytosed antigen, including receptor-mediated uptake, recycling and maturation including the sorting of membrane proteins, dynamic remodeling of endosomal structures and cell-surface directed endosomal trafficking. We will conclude with description of pathogen-induced deviation of endosomal processing, and discuss how immune evasion strategies pertaining endosomal trafficking may preclude antigen cross-presentation.

  8. Immunophenotyping of Waldenstroms macroglobulinemia cell lines reveals distinct patterns of surface antigen expression: potential biological and therapeutic implications.

    Directory of Open Access Journals (Sweden)

    Aneel Paulus

    Full Text Available Waldenströms macroglobulinemia (WM is a subtype of Non-Hodgkin's lymphoma in which the tumor cell population is markedly heterogeneous, consisting of immunoglobulin-M secreting B-lymphocytes, plasmacytoid lymphocytes and plasma cells. Due to rarity of disease and scarcity of reliable preclinical models, many facets of WM molecular and phenotypic architecture remain incompletely understood. Currently, there are 3 human WM cell lines that are routinely used in experimental studies, namely, BCWM.1, MWCL-1 and RPCI-WM1. During establishment of RPCI-WM1, we observed loss of the CD19 and CD20 antigens, which are typically present on WM cells. Intrigued by this observation and in an effort to better define the immunophenotypic makeup of this cell line, we conducted a more comprehensive analysis for the presence or absence of other cell surface antigens that are present on the RPCI-WM1 model, as well as those on the two other WM cell lines, BCWM.1 and MWCL-1. We examined expression of 65 extracellular and 4 intracellular antigens, comprising B-cell, plasma cell, T-cell, NK-cell, myeloid and hematopoietic stem cell surface markers by flow cytometry analysis. RPCI-WM1 cells demonstrated decreased expression of CD19, CD20, and CD23 with enhanced expression of CD28, CD38 and CD184, antigens that were differentially expressed on BCWM.1 and MWCL-1 cells. Due to increased expression of CD184/CXCR4 and CD38, RPCI-WM1 represents a valuable model in which to study the effects anti-CXCR4 or anti-CD38 targeted therapies that are actively being developed for treatment of hematologic cancers. Overall, differences in surface antigen expression across the 3 cell lines may reflect the tumor clone population predominant in the index patients, from whom the cell lines were developed. Our analysis defines the utility of the most commonly employed WM cell lines as based on their immunophenotype profiles, highlighting unique differences that can be further studied for

  9. [Hepatitis B prevalence among women in child-bearing age in Shandong Province, China, 2014].

    Science.gov (United States)

    Zhang, L; Liu, J Y; Lyu, J J; Yan, B Y; Feng, Y; Wu, W L; Song, L Z; Xu, A Q

    2017-06-06

    Objective: To know the prevalence of hepatitis B virus (HBV) among women in child-bearing age in Shandong Province, China, providing references to the improvement of HBV control strategy. Methods: The participants were randomly selected by two-stage sampling method from 12 counties which were representative for the whole province. Firstly two townships were selected from each county by probability proportional to size sampling (PPS) method. Then participants aged 1-4 years, 5-14 years, 15-29 years and 30-59 years were selected by stratified random sampling method. The women in child-bearing age (20-49 years) were involved in this study. Questionnaire survey and 5 ml blood collection were conducted among all participants. Blood samples were detected for hepatitis B surface antigen (HBsAg), antibody against HBsAg (anti-HBs) and antibody against hepatitis B core antigen (anti-HBc). Those who were positive for HBsAg were further detected for hepatitis e antigen (HBeAg), antibody against HBeAg (anti-HBe) and the load of HBV DNA. The basic information of the participants including age, gender, occupation, nationality and residence place were collected. The prevalence of HBV infection indicators after weight adjustment were calculated and compared between participants with different demographic characteristics. Results: A total of 1 151 women in child-bearing age were involved in this study. Twenty-seven participants were positive for HBsAg and the prevalence rate was 2.10% (95 % CI: 0.97%-3.23%). Five participants were positive for both HBsAg and HBeAg and the prevalence rate was 0.36% (95 % CI: 0-0.84%). There were 567 and 291 participants who were positive for anti-HBs and anti-HBc respectively and the corresponding prevalence rates were 47.72% (95 %CI: 41.68%-53.75%) and 24.40% (95 % CI: 18.50%-30.30%). The number of participants susceptible for HBV was 527 and the percentage of HBV susceptible women was 47.55% (95 % CI: 41.63%-53.47%). Conclusion: HBV infection among

  10. Hepatitis B virus surface antigen and anti-hepatitis C virus rapid tests underestimate hepatitis prevalence among HIV-infected patients

    DEFF Research Database (Denmark)

    Hønge, Bo Langhoff; Jespersen, S; Medina, C

    2014-01-01

    . RESULTS: Two rapid tests were used in Guinea-Bissau: HBsAg Strip Ref 2034 (VEDA.LAB, Alençon, France; sensitivity 62.3%; specificity 99.2%) and HEPA-SCAN (Bhat Bio-Tech, Bangalore, India; sensitivity 57.1%; specificity 99.7%). In the two tests the ability to obtain the correct outcome depended...

  11. Prevalence of hepatitis B virus and hepatitis C virus among blood donors at a tertiary care hospital in India: a five-year study.

    Science.gov (United States)

    Meena, Monika; Jindal, Tarun; Hazarika, Anjali

    2011-01-01

    Hepatitis B virus (HBV) and hepatitis C virus (HCV) are important transfusion-transmissible infections. This study was performed to assess the prevalence of HBV and HCV seropositivity among blood donors at a tertiary care hospital-based blood bank in India. The blood donation records over 5 years (2005-2009) were reviewed, retrospectively, for the prevalence and yearly trends of HBV and HCV seropositivity. A total of 94,716 donations were received. The overall number of HBV-seropositive donations was 1353 and that for HCV was 537, with the prevalence rates of 1.43% for hepatitis B surface antigen (HBsAg) and 0.57% for HCV. The seropositivity rate was higher in the replacement donors compared to the voluntary donors. The annual rates showed decreasing trends in case of HBsAg, but in case of HCV, there was a linear increase. Our study raises serious concerns regarding the HBV and HCV prevalence in our country. Although HBV showed decreasing trends, it cannot be relied upon because the donors were screened only for HBsAg. HCV is clearly on the rise. Stringent measures need to be taken on urgent basis including dissemination of information, strict screening of blood, inclusion of antibody to hepatitis B core antigen and other sensitive markers to the screening protocol, and better donor recruitment. © 2010 American Association of Blood Banks.

  12. Ultraviolet radiation (UVR) induces cell-surface Ro/SSA antigen expression by human keratinocytes in vitro: a possible mechanism for the UVR induction of cutaneous lupus lesions

    International Nuclear Information System (INIS)

    Jones, S.K.

    1992-01-01

    Antinuclear antibodies are useful markers of connective tissue disease. In this study, UVB but not UVA induced the expression of Ro/SSA antigen on keratinocyte surfaces in vitro. This expression was also found with the extractable nuclear antigens RnP and Sm, but not with single or double-stranded DNA. The expression was prevented by blocking protein synthesis, suggesting that it was an active process. The results suggest that UVB exposure may result in the expression of Ro/SSA antigen on the surfaces of basal keratinocytes in vivo. This antigen could then bind circulating antibody leading to the cutaneous lesions in neonatal and subacute cutaneous lupus erythematosus. (Author)

  13. The use of radio-immuno-inhibition assay for the study of the y, d and w determinants of hepatitis B surface antigen

    International Nuclear Information System (INIS)

    Donea-Debroise, B.; Brocteur, J.; Andre, A.; Remacle, M.B.

    1979-01-01

    A radioimmunoassay determination of the HBs antigen subtypes is discussed, this simple but effective technique was used in association with the use of the Austria II kit (Abbott Laboratories). This method consists of an inhibition reaction of the Austria II test, by previous incubation of the antigen to be subtyped with a monospecific antibody. With this method we were able to distinguish the y and the d antigens as well as the w1, w3, w4 determinants of hepatitis B surface antigen. We have included a frequency table of the various HBs subtypes found among donor and patient populations in Liege

  14. Assessment of immunomodulatory activity of aqueous extract of Calamus rotang

    Directory of Open Access Journals (Sweden)

    Amit Gupta

    2017-04-01

    Full Text Available Objective: There are a number of medicinal plant products which has been used to treat various immunological diseases. Out of these medicinal plants, Calamus rotang has shown several medicinal properties including anti-viral, anti-diabetic, anti-inflammatory effects. Normally, the roots of C. rotang are used in various ailments to cure piles, burning sensation, cough, leprosy and bleeding disorder and also it was used in the treatment of inflammation. In the present study, our group were investigated the immunomodulatory activity of aqueous extract of C. rotang root in human whole blood and peripheral blood mononuclear cells (PBMC using hepatitis B vaccine (HBsAg as an antigen. Materials and Methods: Variable doses of root aqueous extract (0.5 – 30 mg/ml, 100 µl was administered to human whole blood and PBMC using hepatitis B vaccine containing surface antigen (HBsAg; 20 µg/ml, 10 µl as specific antigen in order to estimate the total blood counts in human whole blood and nitric oxide production and CD14 FITC surface marker from human PBMC. Results: Overall, the results showed that roots aqueous extract of C. rotang showed remarkable increase in the number of blood counts in human whole blood at lower doses (0.5 mg/ml. In addition, root aqueous extract of C. rotang also showed the same pattern in case of nitric oxide production and estimation of CD14 FITC surface marker in human PBMC. Conclusion: Altogether, the results suggest that root aqueous extract of C. rotang showed immunomodulatory activity.

  15. Management of hepatitis B reactivation in patients receiving cancer chemotherapy

    OpenAIRE

    Huang, Yi-Wen; Chung, Raymond T.

    2012-01-01

    Hepatitis B virus (HBV) reactivation is well documented in previously resolved or inactive HBV carriers who receive cancer chemotherapy. The consequences of HBV reactivation range from self-limited conditions to fulminant hepatic failure and death. HBV reactivation also leads to premature termination of chemotherapy or delay in treatment schedules. This review summarizes current knowledge of management of HBV reactivation in patients receiving cancer chemotherapy. HBV surface antigen (HBsAg) ...

  16. T cell--associated immunoregulation and antiviral effect of oxymatrine in hydrodynamic injection HBV mouse model.

    Science.gov (United States)

    Sang, Xiuxiu; Wang, Ruilin; Han, Yanzhong; Zhang, Cong'en; Shen, Honghui; Yang, Zhirui; Xiong, Yin; Liu, Huimin; Liu, Shijing; Li, Ruisheng; Yang, Ruichuang; Wang, Jiabo; Wang, Xuejun; Bai, Zhaofang; Xiao, Xiaohe

    2017-05-01

    Although oxymatrine (OMT) has been shown to directly inhibit the replication of hepatitis B virus (HBV) in vitro , limited research has been done with this drug in vivo . In the present study, the antiviral effect of OMT was investigated in an immunocompetent mouse model of chronic HBV infection. The infection was achieved by tail vein injection of a large volume of DNA solution. OMT (2.2, 6.7 and 20 mg/kg) was administered by daily intraperitoneal injection for 6 weeks. The efficacy of OMT was evaluated by the levels of HBV DNA, hepatitis B surface antigen (HBsAg), hepatitis B e antigen (HBeAg) and hepatitis B core antigen (HBcAg). The immunoregulatory activity of OMT was evaluated by serum ELISA and flow cytometry. Results shows that OMT at 20 mg/kg inhibited HBV replication, and it was more efficient than entecavir (ETV) in the elimination of serum HBsAg and intrahepatic HBcAg. In addition, OMT accelerated the production of interferon- γ (IFN- γ ) in a dose-dependent manner in CD4 + T cells. Our findings demonstrate the beneficial effects of OMT on the enhancement of immunological function and in the control of HBV antigens. The findings suggest this drug to be a good antiviral therapeutic candidate for the treatment of HBV infection.

  17. Correlation between HBsAg, prothrombin time activity, and indocyanine green retention rate at 15 minutes in patients with HBeAg-positive chronic HBV infection

    Directory of Open Access Journals (Sweden)

    FAN Wenhai

    2016-11-01

    Full Text Available ObjectiveTo investigate the correlation between HBsAg, prothrombin time activity (PTA, and indocyanine green retention rate at 15 minutes (ICG R15 in patients with HBeAg-positive chronic HBV infection. MethodsA total of 92 patients with HBeAg-positive chronic HBV infection who were admitted to The First Hospital of Lanzhou University from December 2015 to April 2016 were enrolled and divided into chronic hepatitis B (CHB group (24 patients, compensated liver cirrhosis group (38 patients, and decompensated liver cirrhosis group (30 patients. Serum HBsAg quantitation, PTA test, and liver reserve function test (ICG R15 were performed for all patients. The chi-square test was used for comparison of categorical data between groups, an analysis of variance was used for comparison of continuous data between multiple groups, and a Pearson correlation analysis was also performed. ResultsThere were significant differences between the three groups in serum HBsAg quantitation (3.82±0.43 log10IU/ml vs 2.88±0.36 log10IU/ml vs 2.60±0.27 log10IU/ml, F=25.19, P<0.001, ICG R15 (7.51%±3.10% vs 9.57%±8.18% vs 24.13%±14.28%, F=24.00, P=0.001, and PTA (8100%±1762% vs 83.08%±9.64% vs 62.32%±16.90%, F=13.42, P=0.009. The correlation analysis showed that PTA was negatively correlated with ICG R15 in all three groups (r=-0.948, -0.602, and -0.735, all P<0.01. In the compensated liver cirrhosis group and decompensated liver cirrhosis group, HBsAg was positively correlated with PTA (r=0.410 and 0.473, both P<0.05 and negatively correlated with ICG R15 (r=-0.427 and -0.768, P<0.01. ConclusionIn HBeAg positive patients, there are certain correlations between HBsAg, PTA, and ICG R15, which, to a certain degree, reflects the liver reserve function in patients with chronic HBV infection.

  18. Expression and immunological characterisation of Eimeria tenella glycosylphosphatidylinositol-anchored surface antigen-5

    Science.gov (United States)

    Ho, Sue-Kim; Nathan, Sheila; Wan, Kiew-Lian

    2016-11-01

    Eimeria tenella is the most pathogenic of the Eimeria species that infect chickens and causes huge economic losses to the poultry industry. The glycosylphosphatidylinositol-anchored surface antigen-5 (SAG5) found on the surface of the parasite has been shown to activate the chicken's immune system. In this study, recombinant SAG5 was expressed, purified and used to investigate the immune-inducing characteristics of the molecule. Chickens were immunized with purified recombinant SAG5 and sera were subjected to Enzyme-linked Immunosorbant Assay (ELISA). Results indicated that specific antibodies against rSAG5 were produced, with IgG detected at a higher level compared to IgA and IgM. Information on the immunological responses elicited by SAG5 provides essential knowledge that will contribute towards the effort to develop more effective strategies against coccidiosis.

  19. Surface co-expression of two different PfEMP1 antigens on single Plasmodium falciparum-infected erythrocytes facilitates binding to ICAM1 and PECAM1

    DEFF Research Database (Denmark)

    Joergensen, Louise; Bengtsson, Dominique C; Bengtsson, Anja

    2010-01-01

    The Plasmodium falciparum erythrocyte membrane protein 1 (PfEMP1) antigens play a major role in cytoadhesion of infected erythrocytes (IE), antigenic variation, and immunity to malaria. The current consensus on control of variant surface antigen expression is that only one PfEMP1 encoded by one var...

  20. Reactivation of Hepatitis B Virus in Hematopoietic Stem Cell Transplant Recipients in Japan: Efficacy of Nucleos(tide Analogues for Prevention and Treatment

    Directory of Open Access Journals (Sweden)

    Shingo Nakamoto

    2014-11-01

    Full Text Available We retrospectively reviewed 413 recipients with hematologic malignancies who underwent hematopoietic stem cell transplantation (HSCT between June 1986 and March 2013. Recipients with antibody to hepatitis B core antigen (anti-HBc and/or to hepatitis B surface antigen (anti-HBs were regarded as experiencing previous hepatitis B virus (HBV infection. Clinical data of these recipients were reviewed from medical records. We defined ≥1 log IU/mL increase in serum HBV DNA from nadir as HBV reactivation in hepatitis B surface antigen (HBsAg-positive recipients, and also defined ≥1 log IU/mL increase or re-appearance of HBV DNA and/or HBsAg as HBV reactivation in HBsAg-negative recipients. In 5 HBsAg-positive recipients, 2 recipients initially not administered with nucleos(tide analogues (NUCs experienced HBV reactivation, but finally all 5 were successfully controlled with NUCs. HBV reactivation was observed in 11 (2.7% of 408 HBsAg-negative recipients; 8 of these were treated with NUCs, and fortunately none developed acute liver failure. In 5 (6.0% of 83 anti-HBc and/or anti-HBs-positive recipients, HBV reactivation occurred. None of 157 (0% recipients without HBsAg, anti-HBs or anti-HBc experienced HBV reactivation. In HSCT recipients, HBV reactivation is a common event in HBsAg-positive recipients, or in HBsAg-negative recipients with anti-HBc and/or anti-HBs. Further attention should be paid to HSCT recipients with previous exposure to HBV.

  1. [HCV and HBV seropositivity in university students of the State of Nuevo Leòn, Mexico].

    Science.gov (United States)

    Flores-Castañeda, M S; García-Méndez, B L; Tijerina-Menchaca, R

    1996-01-01

    Viral hepatitis is a contagious disease. Patients infected with hepatitis B virus (HBV) or hepatitis C virus (HCV), may be either chronically symptomatic or asymptomatic, and suffer cirrhosis and high risk of hepatic carcinoma. Asymptomatic carriers of HBV surface antigen (HBs-Ag) or with anti-HCV antibodies are potentially infectious, and therefore a risk to public health. This work seeks to establish the frequency of seropositivity for HBs-Ag and anti-HCV antibodies in a population of 774 newly accepted students of the Medical School of the Autonomous University of Nuevo Leon, whose average age was 18 years. Second generation ELISA test were used to screen for HBs-Ag and anti-HCV antibodies. HBs-Ag was confirmed by a neutralization test and anti-HCV antibodies were confirmed by a RIBA test. Three sera were positive for HBs-Ag by ELISA and only one serum (0.13% of analyzed samples) was confirmed by the neutralization technique. On the other hand 12 sera were positive for anti-HCV antibodies by ELISA, and eight of these were confirmed by RIBA (1.03% of the analyzed samples). Intensive reactivity bands were found in two sera, and weak reactivity bands were found in six sera. ELISA screening for anti-HCV antibodies showed 0.5% of false positives. This study shows that the frequency of anti-HCV antibodies is 7.95% times higher than that found for HBs-Ag. All seropositive patients were asymptomatic and potentially infective. This demonstrates the need to routinely screen for HBs-Ag and anti-HCV antibodies to establish the prevalence of these diseases in our area.

  2. A comparative epidemiological study of hepatitis B and hepatitis D virus infections in Yanomami and Piaroa Amerindians of Amazonas State, Venezuela.

    Science.gov (United States)

    Duarte, María Carolina; Cardona, Nathalia; Poblete, Fresia; González, Kenia; García, Mayila; Pacheco, Milian; Botto, Carlos; Pujol, Flor H; Williams, John R

    2010-08-01

    To report the prevalences of hepatitis B (HBV) and hepatitis D (HDV) infections in remote and more accessible Yanomami and Piaroa Venezuelan Amazonian Amerindian populations; to estimate incidence per susceptible. Clinico-epidemiological evaluation was carried out in 9 Piaroa villages. Blood samples were tested for HBV core antibody (anti-HBc), surface antigen (HBsAg) and HDV antibody (anti-HDV). Results were analysed using logistic regression, and estimates made of HBV forces of infection (FOI). Prevalences and FOI were also estimated for 4 Yanomami villages. Mean Piaroa anti-HBc and HBsAg prevalences were 27.4% and 5.1%, respectively (up to 53% and 19% in the remote Autana region). Mean Yanomami anti-HBc and HBsAg prevalences were, respectively, 58.0% (range 43-70%) and 14.3% (31% in the village with highest HBsAg). No significant difference was found between sexes, with age and maternal HBsAg the only risk factors for HBV identified in multivariate regression of Piaroa data. Only 4 Piaroa and 2 Yanomami individuals were anti-HDV positive. Piaroa HBV prevalences were generally higher in remote villages than in less remote ones, with prevalences in Yanomami villages even higher. Anti-HBc prevalence was 47% in one Yanomami village with a history of HBV vaccination but no HBsAg cases were identified, suggestive of previously cleared or possibly transient infection or vaccine escape. Despite a past history of HDV epidemic outbreaks and HBsAg levels in some villages appearing sufficient to facilitate HDV transmission, anti-HDV prevalence was low; it remains to be established why no recent outbreaks have been reported.

  3. Simultaneous identification of Trypanosoma cruzi surface and internal antigens reactive to different immunoglobulin classes (radio-immunoblotting)

    International Nuclear Information System (INIS)

    Stolf, A.M.S.; Umezawa, E.S.; Zingales, B.

    1990-01-01

    A radioactive Western blotting technique was developed by which the reactivity of Immunoglobulins (IGs) from different classes to both membrane radiolabelled and internal parasite antigens is simultaneously identified. The method includes radioiodination of parasites, polypeptide fractionation by SDS-PAGE, Western-blot transfer and autoradiography of the immunoblots developed with anti-Igs conjugates labelled with enzymes. The analysis is then performed by the comparison of common bands on the autoradiograms and the respective substrate stained nitrocellulose blots. This technique was used to analyse. T.cruzi trypomastigote surface labelled antigens reactive to IgM, IgA and IgC specific antibodies. A different pattern of reactivity with acute Chagas disease patients sera was thus obtained. (author)

  4. Changing trends of hepatitis b seromarkers amongst pakistani population: a laboratory-based review

    International Nuclear Information System (INIS)

    Zafar, A.; Khan, E.; Khan, M.S.; Moiz, B.; Jafri, W.

    2013-01-01

    Objective: To study the changing trends of hepatitis B markers tested at Aga Khan University Hospital clinical laboratory according to the internationally recognised classification of hepatitis B profile. Methods: The retrospective study involved analysis of laboratory records of hepatitis B profiles of all patients collected from January 2001 to December 2008 at the Aga Khan University Hospital's clinical laboratory. Patients with complete profile tested were categorised according to the Centre for Diseases Control classification of hepatitis B profile. SPSS 16 was used for statistical analysis. Results: A total of 185,825 patients had serological markers for hepatitis B tested. Mean-age of reactive hepatitis B surface antigen (HBsAg) patients was 30+-12.5 years. HBsAg reactivity was significantly higher in males than females (34% vs 12%; p <0.0001). HBsAg showed a slight decline in the percentage reactivity during the 8-year study period, while a gradual increase in hepatitis B surface antibody (HBsAb) reactivity was observed. Of the total, 23% patients belonged to the 'susceptible to infection' category; 39% patients were classified as 'chronically-ill'; 12% patients were categorised as 'immune due to hepatitis B vaccination'. 3% patients were classed as 'acutely infected'. Overall, samples received from Peshawar, Quetta and Larkana showed very high reactivity rates. Conclusion: The study substantiated the general perception that levels of HBsAg is showing a decreasing trend, while levels of HBsAb are increasing perhaps due to better vaccination of population. (author)

  5. Radioimmunoassays of hidden viral antigens

    International Nuclear Information System (INIS)

    Neurath, A.R.; Strick, N.; Baker, L.; Krugman, S.

    1982-01-01

    Antigens corresponding to infectious agents may be present in biological specimens only in a cryptic form bound to antibodies and, thus, may elude detection. We describe a solid-phase technique for separation of antigens from antibodies. Immune complexes are precipitated from serum by polyethylene glycol, dissociated with NaSCN, and adsorbed onto nitrocellulose or polystyrene supports. Antigens remain topographically separated from antibodies after removal of NaSCN and can be detected with radiolabeled antibodies. Genomes from viruses immobilized on nitrocellulose can be identified by nucleic acid hybridization. Nanogram quantities of sequestered hepatitis B surface and core antigens and picogram amounts of hepatitis B virus DNA were detected. Antibody-bound adenovirus, herpesvirus, and measles virus antigens were discerned by the procedure

  6. In Vitro Variant Surface Antigen Expression in Plasmodium falciparum Parasites from a Semi-Immune Individual Is Not Correlated with Var Gene Transcription

    Science.gov (United States)

    Tschan, Serena; Flötenmeyer, Matthias; Koch, Iris; Berger, Jürgen; Kremsner, Peter; Frank, Matthias

    2016-01-01

    Plasmodium falciparum erythrocyte membrane protein 1 (PfEMP1) is considered to be the main variant surface antigen (VSA) of Plasmodium falciparum and is mainly localized on electron-dense knobs in the membrane of the infected erythrocyte. Switches in PfEMP1 expression provide the basis for antigenic variation and are thought to be critical for parasite persistence during chronic infections. Recently, strain transcending anti-PfEMP1 immunity has been shown to develop early in life, challenging the role of PfEMP1 in antigenic variation during chronic infections. In this work we investigate how P. falciparum achieves persistence during a chronic asymptomatic infection. The infected individual (MOA) was parasitemic for 42 days and multilocus var gene genotyping showed persistence of the same parasite population throughout the infection. Parasites from the beginning of the infection were adapted to tissue culture and cloned by limiting dilution. Flow cytometry using convalescent serum detected a variable surface recognition signal on isogenic clonal parasites. Quantitative real-time PCR with a field isolate specific var gene primer set showed that the surface recognition signal was not correlated with transcription of individual var genes. Strain transcending anti-PfEMP1 immunity of the convalescent serum was demonstrated with CD36 selected and PfEMP1 knock-down NF54 clones. In contrast, knock-down of PfEMP1 did not have an effect on the antibody recognition signal in MOA clones. Trypsinisation of the membrane surface proteins abolished the surface recognition signal and immune electron microscopy revealed that antibodies from the convalescent serum bound to membrane areas without knobs and with knobs. Together the data indicate that PfEMP1 is not the main variable surface antigen during a chronic infection and suggest a role for trypsin sensitive non-PfEMP1 VSAs for parasite persistence in chronic infections. PMID:27907004

  7. Differential presentation of endogenous and exogenous hepatitis B surface antigens influences priming of CD8(+) T cells in an epitope-specific manner.

    Science.gov (United States)

    Riedl, Petra; Reiser, Michael; Stifter, Katja; Krieger, Jana; Schirmbeck, Reinhold

    2014-07-01

    Little is known about whether presentation of endogenous and exogenous hepatitis B virus (HBV) surface antigens on APCs targeted by vaccination and/or virus-harboring hepatocytes influences de novo priming of CD8(+) T cells. We showed that surface antigen-expressing transfectants exclusively display a K(b) /S190 epitope, whereas cells pulsed with recombinant surface particles (rSPs) exclusively present a K(b) /S208 epitope to CD8(+) T cells. The differential presentation of these epitopes largely reflects the selective, but not exclusive, priming of K(b) /S190- and K(b) /S208-specific T cells in C57BL/6 mice by endogenous/DNA- or exogenous/protein-based vaccines, respectively. Silencing the K(b) /S190 epitope (K(b) /S190V194F ) in antigen-expressing vectors rescued the presentation of the K(b) /S208 epitope in stable transfectants and significantly enhanced priming of K(b) /S208-specific T cells in C57BL/6 mice. A K(b) /S190-mediated immunodominance operating in surface antigen-expressing cells, but not in rSP-pulsed cells, led to an efficient suppression in the presentation of the K(b) /S208 epitope and a consequent decrease in the priming of K(b) /S208-specific T cells. This K(b) /S190-mediated immunodominance also operated in 1.4HBV-S(mut) transgenic (tg) hepatocytes selectively expressing endogenous surface antigens and allowed priming of K(b) /S208- but not K(b) /S190-specific T cells in 1.4HBV-S(mut) tg mice. However, IFN-γ(+) K(b) /S208-specific T cells could not inhibit HBV replication in the liver of 1.4HBV-S(mut) tg mice. These results have practical implications for the design of T-cell-stimulating therapeutic vaccines. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  8. Naturally occurring mutations in large surface genes related to occult infection of hepatitis B virus genotype C.

    Directory of Open Access Journals (Sweden)

    Hong Kim

    Full Text Available Molecular mechanisms related to occult hepatitis B virus (HBV infection, particularly those based on genotype C infection, have rarely been determined thus far in the ongoing efforts to determine infection mechanisms. Therefore, we aim to elucidate the mutation patterns in the surface open reading frame (S ORF underlying occult infections of HBV genotype C in the present study. Nested PCRs were applied to 624 HBV surface antigen (HBsAg negative Korean subjects. Cloning and sequencing of the S ORF gene was applied to 41 occult cases and 40 control chronic carriers. Forty-one (6.6% of the 624 Korean adults with HBsAg-negative serostatus were found to be positive for DNA according to nested PCR tests. Mutation frequencies in the three regions labeled here as preS1, preS2, and S were significantly higher in the occult subjects compared to the carriers in all cases. A total of two types of deletions, preS1 deletions in the start codon and preS2 deletions as well as nine types of point mutations were significantly implicated in the occult infection cases. Mutations within the "a" determinant region in HBsAg were found more frequently in the occult subjects than in the carriers. Mutations leading to premature termination of S ORF were found in 16 occult subjects (39.0% but only in one subject from among the carriers (2.5%. In conclusion, our data suggest that preS deletions, the premature termination of S ORF, and "a" determinant mutations are associated with occult infections of HBV genotype C among a HBsAg-negative population. The novel mutation patterns related to occult infection introduced in the present study can help to broaden our understanding of HBV occult infections.

  9. Leishmania-specific surface antigens show sub-genus sequence variation and immune recognition.

    Directory of Open Access Journals (Sweden)

    Daniel P Depledge

    2010-09-01

    Full Text Available A family of hydrophilic acylated surface (HASP proteins, containing extensive and variant amino acid repeats, is expressed at the plasma membrane in infective extracellular (metacyclic and intracellular (amastigote stages of Old World Leishmania species. While HASPs are antigenic in the host and can induce protective immune responses, the biological functions of these Leishmania-specific proteins remain unresolved. Previous genome analysis has suggested that parasites of the sub-genus Leishmania (Viannia have lost HASP genes from their genomes.We have used molecular and cellular methods to analyse HASP expression in New World Leishmania mexicana complex species and show that, unlike in L. major, these proteins are expressed predominantly following differentiation into amastigotes within macrophages. Further genome analysis has revealed that the L. (Viannia species, L. (V. braziliensis, does express HASP-like proteins of low amino acid similarity but with similar biochemical characteristics, from genes present on a region of chromosome 23 that is syntenic with the HASP/SHERP locus in Old World Leishmania species and the L. (L. mexicana complex. A related gene is also present in Leptomonas seymouri and this may represent the ancestral copy of these Leishmania-genus specific sequences. The L. braziliensis HASP-like proteins (named the orthologous (o HASPs are predominantly expressed on the plasma membrane in amastigotes and are recognised by immune sera taken from 4 out of 6 leishmaniasis patients tested in an endemic region of Brazil. Analysis of the repetitive domains of the oHASPs has shown considerable genetic variation in parasite isolates taken from the same patients, suggesting that antigenic change may play a role in immune recognition of this protein family.These findings confirm that antigenic hydrophilic acylated proteins are expressed from genes in the same chromosomal region in species across the genus Leishmania. These proteins are

  10. Protamine-based nanoparticles as new antigen delivery systems.

    Science.gov (United States)

    González-Aramundiz, José Vicente; Peleteiro Olmedo, Mercedes; González-Fernández, África; Alonso Fernández, María José; Csaba, Noemi Stefánia

    2015-11-01

    The use of biodegradable nanoparticles as antigen delivery vehicles is an attractive approach to overcome the problems associated with the use of Alum-based classical adjuvants. Herein we report, the design and development of protamine-based nanoparticles as novel antigen delivery systems, using recombinant hepatitis B surface antigen as a model viral antigen. The nanoparticles, composed of protamine and a polysaccharide (hyaluronic acid or alginate), were obtained using a mild ionic cross-linking technique. The size and surface charge of the nanoparticles could be modulated by adjusting the ratio of the components. Prototypes with optimal physicochemical characteristics and satisfactory colloidal stability were selected for the assessment of their antigen loading capacity, antigen stability during storage and in vitro and in vivo proof-of-concept studies. In vitro studies showed that antigen-loaded nanoparticles induced the secretion of cytokines by macrophages more efficiently than the antigen in solution, thus indicating a potential adjuvant effect of the nanoparticles. Finally, in vivo studies showed the capacity of these systems to trigger efficient immune responses against the hepatitis B antigen following intramuscular administration, suggesting the potential interest of protamine-polysaccharide nanoparticles as antigen delivery systems. Copyright © 2015 Elsevier B.V. All rights reserved.

  11. Epidemiology of hepatitis B and hepatitis C virus infections in pregnant women in Sana’a, Yemen

    Science.gov (United States)

    2013-01-01

    Background Screening for Hepatitis B and C during pregnancy may help to decide on appropriate antiviral therapy and the institution of steps to minimize vertical transmission to the newborn infants. Methods A cross-sectional study was conducted during November–December 2011 to investigate the seroprevalence and associated risk factors for markers of HBV (hepatitis B surface antigen; HBsAg) and anti-HCV antibody among pregnant women at the Al-Thawra hospital in Sana’a, Yemen. Structured questionnaires were used to obtain sociodemographic obstetrics and medical data and sera were tested for HBsAg and anti-HCV. Results Of the 400 pregnant women enrolled in the study, HBsAg and anti-HCV were detected in 43 (10.8%; 95% CI: 8.0–14.0%) and 34 (8.5%, 95% CI: 6.0–11.5%) women, respectively. None of the women were co-infected with HBV and HCV. Multivariate analysis showed that circumcision was significantly associated with HBsAg seropositivity (OR = 3.3, 95% CI: 1.1–10.2; p = 0.03), low parity (primigravidae and secundigravidae) and education below secondary level were significantly associated with anti- HCV seropositivity (OR = 3.3, 95% CI: 1.1–10.2; p = 0.03). No other sociodemographic or clinical characteristics (age, residence, history of home delivery, miscarriage, dental manipulation, surgery, and blood transfusion) were significantly associated with HBsAg or anti-HCV seropositivity. Conclusion The results of this study suggest that HBsAg and anti-HCV have high prevalence among pregnant women. PMID:23758990

  12. Anti-pre-S responses and viral clearance in chronic hepatitis B virus infection.

    Science.gov (United States)

    Budkowska, A; Dubreuil, P; Poynard, T; Marcellin, P; Loriot, M A; Maillard, P; Pillot, J

    1992-01-01

    Serial sera were collected prospectively during the clinical course of 13 HBsAg carriers with chronic liver disease and analyzed for ALT levels, pre-S1 and pre-S2 antigens and corresponding antibodies and other serological hepatitis B virus markers. In five patients, anti-pre-S1 and anti-pre-S2 antibodies became detectable in multiple serum samples, whereas in eight patients anti-pre-S was never detected or only appeared transiently during the follow-up. The first pattern was associated with normalization of ALT levels and undetectable pre-S antigens and viral DNA by the polymerase chain reaction assay at final follow-up. HBsAg clearance occurred in two of the five patients. The second pattern was one of persistence of HBsAg and pre-S antigens, associated with the presence of serum HBV DNA detectable by spot hybridization or polymerase chain reaction regardless of clinical outcome. These findings demonstrate the occurrence of anti-pre-S antibodies in chronic hepatitis B virus-induced liver disease and associate anti-pre-S appearance with the clearance of hepatitis B virus from serum.

  13. Surface gene variants of hepatitis B Virus in Saudi Patients.

    Science.gov (United States)

    Al-Qudari, Ahmed Y; Amer, Haitham M; Abdo, Ayman A; Hussain, Zahid; Al-Hamoudi, Waleed; Alswat, Khalid; Almajhdi, Fahad N

    2016-01-01

    Hepatitis B virus (HBV) continues to be one of the most important viral pathogens in humans. Surface (S) protein is the major HBV antigen that mediates virus attachment and entry and determines the virus subtype. Mutations in S gene, particularly in the "a" determinant, can influence virus detection by ELISA and may generate escape mutants. Since no records have documented the S gene mutations in HBV strains circulating in Saudi Arabia, the current study was designed to study sequence variation of S gene in strains circulating in Saudi Arabia and its correlation with clinical and risk factors. A total of 123 HBV-infected patients were recruited for this study. Clinical and biochemical parameters, serological markers, and viral load were determined in all patients. The entire S gene sequence of samples with viral load exceeding 2000 IU/mL was retrieved and exploited in sequence and phylogenetic analysis. A total of 48 mutations (21 unique) were recorded in viral strains in Saudi Arabia, among which 24 (11 unique) changed their respective amino acids. Two amino acid changes were recorded in "a" determinant, including F130L and S135F with no evidence of the vaccine escape mutant G145R in any of the samples. No specific relationship was recognized between the mutation/amino acid change record of HBsAg in strains in Saudi Arabia and clinical or laboratory data. Phylogenetic analysis categorized HBV viral strains in Saudi Arabia as members of subgenotypes D1 and D3. The present report is the first that describes mutation analysis of HBsAg in strains in Saudi Arabia on both nucleotide and amino acid levels. Different substitutions, particularly in major hydrophilic region, may have a potential influence on disease diagnosis, vaccination strategy, and antiviral chemotherapy.

  14. Improved humoral and cellular immune response against the gp120 V3 loop of HIV-1 following genetic immunization with a chimeric DNA vaccine encoding the V3 inserted into the hepatites B surface antigen

    DEFF Research Database (Denmark)

    Fomsgaard, A.; Nielsen, H.V.; Bryder, K.

    1998-01-01

    response and a uniform strong anti-HBs CTL response already 1 week p.i. in all mice. DNA vaccination with the chimeric MN V2/HBsAg plasmid elicited humoral responses against both viruses within 3-6 weeks which peaked at 6-12 weeks and remained stable for at least 25 weeks. In addition, specific CTL...... responses were induced in all mice against both MN V3 and HBsAg already within the first 3 weeks, lasting at least 11 weeks. Thus, HBsAg acts as a `genetic vaccine adjuvant' augmenting and accelerating the cellular and humoral immune response against the inserted MN V3 loop. Such chimeric HIV-HbsAg plasmid...

  15. Improved humoral and cellular immune responses against the gp120 V3 loop of HIV-1 following genetic immunization with a chimeric DNA vaccine encoding the V3 inserted into the hepatitis B surface antigen

    DEFF Research Database (Denmark)

    Fomsgaard, A; Nielsen, H V; Bryder, K

    1998-01-01

    response and a uniform strong anti-HBs CTL response already 1 week p.i. in all mice. DNA vaccination with the chimeric MN V3/HBsAg plasmid elicited humoral responses against both viruses within 3-6 weeks which peaked at 6-12 weeks and remained stable for at least 25 weeks. In addition, specific CTL...... responses were induced in all mice against both MN V3 and HBsAg already within the first 3 weeks, lasting at least 11 weeks. Thus, HBsAg acts as a 'genetic vaccine adjuvant' augmenting and accelerating the cellular and humoral immune response against the inserted MN V3 loop. Such chimeric HIV-HBsAg plasmid...

  16. Development of hen antihepatitis B antigen IgY-based conjugate for ELISA assay

    Directory of Open Access Journals (Sweden)

    Najat Muayed Nafea

    2015-01-01

    Conclusions: This study showed that laying hens can be used as an alternative source for production of polyclonal antibodies against HBsAg and anti-HBs IgY could be labeled with HRP enzyme and could subsequently be used successfully as secondary antibody in ELISA for detection of HBsAg in the patients sera.

  17. Enzyme-linked immunosorbent assays for detection of equine antibodies specific to Sarcocystis neurona surface antigens.

    Science.gov (United States)

    Hoane, Jessica S; Morrow, Jennifer K; Saville, William J; Dubey, J P; Granstrom, David E; Howe, Daniel K

    2005-09-01

    Sarcocystis neurona is the primary causative agent of equine protozoal myeloencephalitis (EPM), a common neurologic disease of horses in the Americas. We have developed a set of enzyme-linked immunosorbent assays (ELISAs) based on the four major surface antigens of S. neurona (SnSAGs) to analyze the equine antibody response to S. neurona. The SnSAG ELISAs were optimized and standardized with a sample set of 36 equine sera that had been characterized by Western blotting against total S. neurona parasite antigen, the current gold standard for S. neurona serology. The recombinant SnSAG2 (rSnSAG2) ELISA showed the highest sensitivity and specificity at 95.5% and 92.9%, respectively. In contrast, only 68.2% sensitivity and 71.4% specificity were achieved with the rSnSAG1 ELISA, indicating that this antigen may not be a reliable serological marker for analyzing antibodies against S. neurona in horses. Importantly, the ELISA antigens did not show cross-reactivity with antisera to Sarcocystis fayeri or Neospora hughesi, two other equine parasites. The accuracy and reliability exhibited by the SnSAG ELISAs suggest that these assays will be valuable tools for examining the equine immune response against S. neurona infection, which may help in understanding the pathobiology of this accidental parasite-host interaction. Moreover, with modification and further investigation, the SnSAG ELISAs have potential for use as immunodiagnostic tests to aid in the identification of horses affected by EPM.

  18. Comparison of two solid-phase radioimmunoassay systems and a reverse passive haemagglutination test for the detection of hepatitis B surface antigen

    International Nuclear Information System (INIS)

    Hui, Z.; Coulepis, A.G.; Gust, I.D.

    1982-01-01

    The sensitivity and specificity of two commercially available radioimmunosay tests (Austria II-125, Abbott Laboratories; and International CIS, Commissariat Alenergie Atomique-Oris Laboratoire des Produits Biomedicaux) and a reverse passive haemagglutination test (Hepatest, Wellcome) for detection of hepatitis B surface antigen were evaluated using the Australian hepatitis B reference panel of 25 sera, and a panel of 257 sera collected from patients with acute hepatitis B, chronic carriers of hepatitis B surface antigen and two populations in which hepatitis B virus infection is known to be endemic. The three techniques were found to be generally comparable in sensitivity and specificity. The advantages and disadvantages of each method are discussed

  19. The Relationship between Serum Bilirubin and Elevated Fibrotic Indices among HBV Carriers: A Cross-Sectional Study of a Chinese Population

    Directory of Open Access Journals (Sweden)

    Min Du

    2016-12-01

    Full Text Available The study probed the association between bilirubin and hepatitis B virus (HBV infection and progression. A cross-sectional analysis of 28,500 middle aged and elderly Chinese participants was performed to analyze the differences of bilirubin in terms of hepatitis B surface antigen (HBsAg positive or negative and the correlation between bilirubin and severity of hepatic fibrosis estimated by non-invasive indices. Bilirubin was significantly higher in the HBsAg (+ group than the HBsAg (− group. Higher bilirubin levels were consistently associated with elevated liver fibrosis indices among HBsAg carriers. Compared with quartile 1 of total bilirubin (TBil, the multivariable-adjusted ORs (95% CIs for elevated fibrosis indices of quartile 4 were 2.24 (95% CIs, 1.57–3.21 estimated by fibrosis 4 score (FIB-4 and 2.22 (95% CIs, 1.60–3.08 estimated by aspartate transaminase to platelet ratio index (APRI. In addition, direct bilirubin (DBil had a stronger association with elevated liver fibrosis indices than did indirect bilirubin (IBil. Furthermore, the relationship between DBil and elevated fibrosis indices was more robust among participants who were female, overweight or had central fat distribution. These findings suggested that bilirubin levels, especially DBil, were independently associated with an increased risk of increased fibrosis indices.

  20. Serologic and molecular characteristics of hepatitis B virus among school children in East Java, Indonesia.

    Science.gov (United States)

    Utsumi, Takako; Yano, Yoshihiko; Lusida, Maria Inge; Amin, Mochamad; Soetjipto; Hotta, Hak; Hayashi, Yoshitake

    2010-07-01

    Universal childhood hepatitis B vaccination was introduced in Indonesia in 1997; by 2008, coverage was estimated to be 78%. This study aimed to investigate the serologic status and virologic characteristics of hepatitis B virus (HBV) among the children in East Java. A total of 229 healthy children born during 1994-1999 were enrolled in this study. Overall, 3.1% were positive for hepatitis B surface antigen (HBsAg) and 23.6% were positive for antibody to HBsAg (anti-HBs). HBV DNA was detected in 5 of 222 HBsAg-negative carriers, which were suggested to be cases of occult HBV infection. A single amino substitution (T126I) in the S region was frequently found. HBV infection remains endemic, and the prevalence of anti-HBs remains insufficient among children in East Java, Indonesia.

  1. Virosomes for antigen and DNA delivery

    NARCIS (Netherlands)

    Daemen, T; de Mare, A; Bungener, L; de Jonge, J; Huckriede, A; Wilschut, J

    2005-01-01

    Specific targeting and delivery as well as the display of antigens on the surface of professional antigen-presenting cells (APCs) are key issues in the design and development of new-generation vaccines aimed at the induction of both humoral and cell-mediated immunity. Prophylactic vaccination

  2. Hepatitis B core antigen antibody as an indicator of a low grade carrier state for hepatitis B virus in a Saudi Arabian blood donor population.

    Science.gov (United States)

    Bernvil, S S; Andrews, V; Kuhns, M C; McNamara, A L

    1997-03-01

    Blood donor screening for anti-hepatitis B core antigen (anti-HBc) was introduced as a surrogate marker of non-A, non-B hepatitis prior to the availability of a specific test for hepatitis C. In areas endemic for hepatitis B virus (HBV), such as Saudi Arabia, earlier studies indicated that up to 30% of blood donors might disqualify if screened for anti-HBc. The issue was readdressed in a study of 6035 consecutive first-time Saudi national blood donors in an attempt to identify a subgroup of anti-HBc positive donors who might be at high risk of being low grade carriers of HBV. An isolated anti-HBc of high titer in a donor with a low or absent anti-hepatitis B surface antigen (anti-HBsAg) was taken as an indicator of increased risk of a low grade carrier state. Using this algorithm, an additional 125 (2%) donors would disqualify. HBsAg immune complex assays and polymerase chain reaction of donor samples with an isolated anti-HBc identified two donors with immune complexes and two donors with HBV DNA. All four donor samples expressed over 90% neutralization in the anti-HBc supplementary testing, indicating high titer anti-HBc. These findings seem to support the suggested policy of donor exclusion based on the anti-HBc and anti-HBsAg serology as a means to eliminate low grade carriers of HBV in endemic areas without jeopardizing the blood supply.

  3. Natural selection promotes antigenic evolvability.

    Science.gov (United States)

    Graves, Christopher J; Ros, Vera I D; Stevenson, Brian; Sniegowski, Paul D; Brisson, Dustin

    2013-01-01

    The hypothesis that evolvability - the capacity to evolve by natural selection - is itself the object of natural selection is highly intriguing but remains controversial due in large part to a paucity of direct experimental evidence. The antigenic variation mechanisms of microbial pathogens provide an experimentally tractable system to test whether natural selection has favored mechanisms that increase evolvability. Many antigenic variation systems consist of paralogous unexpressed 'cassettes' that recombine into an expression site to rapidly alter the expressed protein. Importantly, the magnitude of antigenic change is a function of the genetic diversity among the unexpressed cassettes. Thus, evidence that selection favors among-cassette diversity is direct evidence that natural selection promotes antigenic evolvability. We used the Lyme disease bacterium, Borrelia burgdorferi, as a model to test the prediction that natural selection favors amino acid diversity among unexpressed vls cassettes and thereby promotes evolvability in a primary surface antigen, VlsE. The hypothesis that diversity among vls cassettes is favored by natural selection was supported in each B. burgdorferi strain analyzed using both classical (dN/dS ratios) and Bayesian population genetic analyses of genetic sequence data. This hypothesis was also supported by the conservation of highly mutable tandem-repeat structures across B. burgdorferi strains despite a near complete absence of sequence conservation. Diversification among vls cassettes due to natural selection and mutable repeat structures promotes long-term antigenic evolvability of VlsE. These findings provide a direct demonstration that molecular mechanisms that enhance evolvability of surface antigens are an evolutionary adaptation. The molecular evolutionary processes identified here can serve as a model for the evolution of antigenic evolvability in many pathogens which utilize similar strategies to establish chronic infections.

  4. Natural selection promotes antigenic evolvability.

    Directory of Open Access Journals (Sweden)

    Christopher J Graves

    Full Text Available The hypothesis that evolvability - the capacity to evolve by natural selection - is itself the object of natural selection is highly intriguing but remains controversial due in large part to a paucity of direct experimental evidence. The antigenic variation mechanisms of microbial pathogens provide an experimentally tractable system to test whether natural selection has favored mechanisms that increase evolvability. Many antigenic variation systems consist of paralogous unexpressed 'cassettes' that recombine into an expression site to rapidly alter the expressed protein. Importantly, the magnitude of antigenic change is a function of the genetic diversity among the unexpressed cassettes. Thus, evidence that selection favors among-cassette diversity is direct evidence that natural selection promotes antigenic evolvability. We used the Lyme disease bacterium, Borrelia burgdorferi, as a model to test the prediction that natural selection favors amino acid diversity among unexpressed vls cassettes and thereby promotes evolvability in a primary surface antigen, VlsE. The hypothesis that diversity among vls cassettes is favored by natural selection was supported in each B. burgdorferi strain analyzed using both classical (dN/dS ratios and Bayesian population genetic analyses of genetic sequence data. This hypothesis was also supported by the conservation of highly mutable tandem-repeat structures across B. burgdorferi strains despite a near complete absence of sequence conservation. Diversification among vls cassettes due to natural selection and mutable repeat structures promotes long-term antigenic evolvability of VlsE. These findings provide a direct demonstration that molecular mechanisms that enhance evolvability of surface antigens are an evolutionary adaptation. The molecular evolutionary processes identified here can serve as a model for the evolution of antigenic evolvability in many pathogens which utilize similar strategies to establish

  5. IgM response to a human Pneumocystis carinii surface antigen in HIV-infected patients with pulmonary symptoms

    DEFF Research Database (Denmark)

    Lundgren, Bettina; Kovacs, J A; Mathiesen, Lars Reinhardt

    1993-01-01

    We have developed an ELISA to detect IgM antibodies to a major human Pneumocystis carinii surface antigen (gp95), and investigated the IgM response in 128 HIV-infected patients who underwent bronchoscopy for evaluation of pulmonary symptoms. Only 5 (4%) patients had IgM antibodies to P. carinii g...

  6. Comparison between two population-based hepatitis B serosurveys with an 8-year interval in Shandong Province, China.

    Science.gov (United States)

    Liu, Jiaye; Lv, Jingjing; Yan, Bingyu; Feng, Yi; Song, Lizhi; Xu, Aiqiang; Zhang, Li; Yan, Yongping

    2017-08-01

    Tremendous progress has been made in hepatitis B virus (HBV) prevention and control in the last 30 years in China, but it continues to be a major public health problem. The most recently reported population-based seroepidemiological survey on HBV in Shandong Province in China was published in 2006, and an updated baseline for HBV prevalence was badly needed in the province to identify the change in HBV epidemiology in the last decade. Two population-based cross-sectional serosurveys were performed among the population aged 1-59 years in the same sample areas in Shandong Province, China in 2006 and 2014, respectively. Data on demographic characteristics were collected. A blood sample was obtained from each person and was tested for hepatitis B surface antigen (HBsAg), antibody against HBsAg (anti-HBs), and antibody against hepatitis B core antigen (anti-HBc). Overall, the prevalence rates of HBsAg, anti-HBs, and anti-HBc were 3.39% (95% confidence interval (CI) 2.51-4.26), 44.96% (95% CI 41.34-48.57), and 24.45% (95% CI 22.19-26.71), respectively, among the population aged 1-59 years in the 2006 serovsurvey; the corresponding prevalence rates were 2.49% (95% CI 1.81-3.17), 48.27% (95% CI 45.63-50.92), and 22.56% (95% CI 20.14-24.97), respectively, in 2014. The prevalence rates of HBsAg and anti-HBc were lower in 2014 than in 2006. Conversely, the prevalence of anti-HBs showed an increase. However, none of these differences were statistically significant (all p>0.05). The prevalence of HBsAg showed an increase among persons aged 20-24 years in 2014 (3.83%) compared with 2006 (2.98%) (t=0.45, p=0.67). Among all occupation groups, the prevalence of HBsAg was lower in 2014 than in 2006, while the prevalence of anti-HBc showed moderate increases in students and farmers (all p>0.05). The prevalence of HBsAg decreased more obviously in urban areas (65.49%) than rural areas (7.07%) from 2006 to 2014. The epidemiology of HBV infection has changed in Shandong Province, China

  7. Differing results of direct and indirect solid phase radioimmunoassay for HBsAg in acute hepatitis

    International Nuclear Information System (INIS)

    Strohm, W.D.; Legler, K.; Gerlich, W.; Stamm, B.; Zimmer, S.; Biotest-Serum-Institut G.m.b.H., Frankfurt am Main; Goettingen Univ.

    1978-01-01

    In 54 patients suffering from active viral hepatitis the indirect solid phase radioimmunoassay (ind-SPRIA) for HBsAg was positive in 9 cases the direct solid phase radioimmunoassay (d-SPRIA) being negative. In 2 further cases ind-SPRIA was positive during several weeks but d-SPRIA only once. AntiHBc could be detected in 9 of these patients. In 7 patients the usual decrease of the transaminase activity was followed by a second elavation with prolongation of the disease. The unknown factor detected by ind-SPRIA suggests a special of acute hepatitis. (orig.) [de

  8. Differing results of direct and indirect solid phase radioimmunoassay for HBsAg in acute hepatitis

    Energy Technology Data Exchange (ETDEWEB)

    Strohm, W D; Legler, K; Gerlich, W; Stamm, B; Zimmer, S [Frankfurt Univ. (Germany, F.R.). Abt. fuer Gastroenterologie; Biotest-Serum-Institut G.m.b.H., Frankfurt am Main (Germany, F.R.); Goettingen Univ. (Germany, F.R.). Hygiene-Institut)

    1978-09-01

    In 54 patients suffering from active viral hepatitis the indirect solid phase radioimmunoassay (ind-SPRIA) for HBsAg was positive in 9 cases the direct solid phase radioimmunoassay (d-SPRIA) being negative. In 2 further cases ind-SPRIA was positive during several weeks but d-SPRIA only once. AntiHBc could be detected in 9 of these patients. In 7 patients the usual decrease of the transaminase activity was followed by a second elavation with prolongation of the disease. The unknown factor detected by ind-SPRIA suggests a special of acute hepatitis.

  9. Targeted case finding for hepatitis B using dry blood spot testing in the British-Chinese and South Asian populations of the North-East of England.

    Science.gov (United States)

    McPherson, S; Valappil, M; Moses, S E; Eltringham, G; Miller, C; Baxter, K; Chan, A; Shafiq, K; Saeed, A; Qureshi, R; Hudson, M; Bassendine, M F

    2013-09-01

    Chronic infection with the hepatitis B virus (HBV) is a frequent cause of cirrhosis and liver cancer. Targeted HBV screening is recommended by the Centre for Disease Control (CDC) and Prevention for subjects born in countries with >2% HBV prevalence. However, there are no UK guidelines. Here, we applied the (CDC) recommendations to the British-Chinese and British-South Asian community of North-East (NE) England. British-Chinese and South Asian subjects were invited to attend for HBV education and screening sessions held in community centres. Hepatitis B surface antigen (HBsAg) and hepatitis B core total antibody (HBcAb) were tested with dry blood spot tests. South Asians were also tested for hepatitis C antibody (HCVAb). A total of 1126 subjects (606 Chinese and 520 South Asian) were screened. Sixty-two (5.5%) were HBsAg positive. Ten of these reported a previous diagnosis of HBV. The prevalence of HBsAg positivity was 4.6% when previously diagnosed individuals were excluded. The HBsAg prevalence was significantly higher in the Chinese subjects compared with South Asians (8.7% VS. 1.7% P < 0.001). In Chinese subjects, HBsAg positivity was highest in subjects born in Vietnam (17.4%), followed by China (11%), Hong Kong (7.8%) and the UK (6.7%). Subjects from Pakistan had the highest HBsAg and HCV Ab prevalence in the South Asians (3.1% and 1.8%, respectively). Ten percentage of HBsAg positive patients who had follow-up assessment had active disease requiring antiviral treatment. Undiagnosed HBV infection was above the 2% threshold for screening suggested by the CDC in the British-Chinese and Pakistani community of NE England, which provides evidence for a UK HBV-targeted screening programme. © 2013 John Wiley & Sons Ltd.

  10. Antigen Loss Variants: Catching Hold of Escaping Foes.

    Science.gov (United States)

    Vyas, Maulik; Müller, Rolf; Pogge von Strandmann, Elke

    2017-01-01

    Since mid-1990s, the field of cancer immunotherapy has seen steady growth and selected immunotherapies are now a routine and preferred therapeutic option of certain malignancies. Both active and passive cancer immunotherapies exploit the fact that tumor cells express specific antigens on the cell surface, thereby mounting an immune response specifically against malignant cells. It is well established that cancer cells typically lose surface antigens following natural or therapy-induced selective pressure and these antigen-loss variants are often the population that causes therapy-resistant relapse. CD19 and CD20 antigen loss in acute lymphocytic leukemia and chronic lymphocytic leukemia, respectively, and lineage switching in leukemia associated with mixed lineage leukemia (MLL) gene rearrangements are well-documented evidences in this regard. Although increasing number of novel immunotherapies are being developed, majority of these do not address the control of antigen loss variants. Here, we review the occurrence of antigen loss variants in leukemia and discuss the therapeutic strategies to tackle the same. We also present an approach of dual-targeting immunoligand effectively retargeting NK cells against antigen loss variants in MLL-associated leukemia. Novel immunotherapies simultaneously targeting more than one tumor antigen certainly hold promise to completely eradicate tumor and prevent therapy-resistant relapses.

  11. Facts on the fragmentation of antigens in presenting cells, on the association of antigen fragments with MHC molecules in cell-free systems, and speculation on the cell biology of antigen processing

    DEFF Research Database (Denmark)

    Werdelin, O; Mouritsen, S; Petersen, B L

    1988-01-01

    The processing of a protein antigen is a multi-step event taking place in antigen-presenting cells. Processing is a prerequisite for the recognition of most antigens by T lymphocytes. The antigen is ingested by endocytosis, transported to an acid cellular compartment and subjected to proteolytic...... fragmentation. Some of the antigen fragments bind to MHC class II molecules and are transported to the surface of the antigen-presenting cell where the actual presentation to T lymphocytes occurs. The nature of the processed antigen, how and where it is derived and subsequently becomes associated with MHC...... molecules are the questions discussed in this review. To us, the entire concept of processing has appeal not only because it explains some hitherto well-established, but poorly understood, phenomena such as the fact that T lymphocytes focus their attention entirely upon antigens on other cells. It has...

  12. Antigenic variation and the genetics and epigenetics of the PfEMP1 erythrocyte surface antigens in Plasmodium falciparum malaria

    DEFF Research Database (Denmark)

    Arnot, David E; Jensen, Anja T R

    2011-01-01

    . Sterile immunity is not achieved and chronic parasitization of apparently healthy adults is the norm. In this article, we analyse the best understood malaria "antigenic variation" system, that based on Plasmodium falciparum's PfEMP1-type cytoadhesion antigens, and critically review recent literature...

  13. Induction of protective immunity to Theileria annulata using two major merozoite surface antigens presented by different delivery systems

    NARCIS (Netherlands)

    C. D'Oliveira; A. Feenstra; H.W. Vos (Helma); A.D.M.E. Osterhaus (Albert); B.R. Shiels; A.W.C.A. Cornelissen; F. Jongejan

    1997-01-01

    textabstractAllelic forms (Tams1-1 and Tams1-2) of the major merozoite surface antigen gene of Theileria annulata have recently been expressed in Escherichia coli and in Salmonella typhimurium aroA vaccine strain SL3261. To test the potential of subunit vaccines against T. annulata infection, we

  14. Identification of a novel dendritic cell surface antigen defined by carbohydrate specific CD24 antibody cross-reactivity.

    Science.gov (United States)

    Williams, L A; McLellan, A D; Summers, K L; Sorg, R V; Fearnley, D B; Hart, D N

    1996-01-01

    Dendritic cells (DC) are characterized as leucocytes that lack mature lineage specific markers and stimulate naive T-lymphocyte proliferation in vitro and in vivo. The mouse heat stable antigen (HSA) participates in T lymphocyte co-stimulation and is expressed by DC isolated from thymus, skin and spleen. The human HSA homologue, CD24, is predominantly expressed by B lymphocytes and granulocytes, but its expression on DC has not been studied in detail. CD24 clearly participates in B-lymphocyte signalling but co-stimulatory activity for T lymphocytes has not yet been described. We have examined the expression of CD24 on human peripheral blood DC populations isolated directly or following in vitro culture. The CD24 antigen was absent from blood DC however, cross-reactive sialylated carbohydrate epitopes were detected on DC with some CD24 monoclonal antibodies (mAb). These CD24 mAb define a protein surface antigen, which is expressed by an immature or resting subpopulation of peripheral blood DC and is down-regulated following activation differentiation in vitro. PMID:8911149

  15. A label-free electrochemical immunosensor based on the novel signal amplification system of AuPdCu ternary nanoparticles functionalized polymer nanospheres.

    Science.gov (United States)

    Yan, Qin; Yang, Yuying; Tan, Zhaoling; Liu, Qing; Liu, Hui; Wang, Ping; Chen, Lei; Zhang, Daopeng; Li, Yueyun; Dong, Yunhui

    2018-04-30

    A sensitive label-free electrochemical immunosensor was designed using a novel signal amplification system for quantitative detecting hepatitis B surface antigen (HBsAg). Nitrogen-doped graphene quantum dots (N-GQDs) supported surfactant-free AuPdCu ternary nanoparticles (AuPdCu/N-GQDs), which featured with good conductivity and excellent catalytic properties for the reduction of hydrogen peroxide (H 2 O 2 ), was synthesized by a simple and benign hydrothermal procedure. At the same time, the electroactive polymer nanospheres (PS) was synthesized by infinite coordination polymers of ferrocenedicarboxylic acid, which could play as carrier and electronic mediator to load AuPdCu/N-GQDs. The PS not only improved the ability to load antibodies because of the good biocompatibility, but also accelerated electron transport of the electrode interface attribute to plentiful ferrocene unit. Thus, the prepared AuPdCu/N-GQDs@PS has abilities of good biocompatibility, catalytic activity and electrical conductivity to be applied as transducing materials to amplify electrochemical signal in detection of HBsAg. Under optimal conditions, the fabricated immunosensor exhibited high sensitivity and stability in the detection of HBsAg. A linear relationship between current signals and the concentrations of HBsAg was obtained in the range from 10fg/mL to 50ng/mL and the detection limit of HBsAg was 3.3fg/mL (signal-to-noise ratio of 3). Moreover, the designed immunosensor with excellent selectivity, reproducibility and stability shows excellent performance in detection of human serum samples. Furthermore, this label-free electrochemical immunosensor has promising application in clinical diagnosis of HBsAg. Copyright © 2017 Elsevier B.V. All rights reserved.

  16. An investigation of an outbreak of viral hepatitis B in Modasa town, Gujarat, India

    Directory of Open Access Journals (Sweden)

    Disha A Patel

    2012-01-01

    Full Text Available Background: Most outbreaks of viral hepatitis in India are caused by hepatitis E. Recently in the year 2009, Modasa town of Sabarkantha district in Gujarat witnessed the outbreak of hepatitis B. Purpose: An attempt was made to study the outbreak clinically and serologically, to estimate the seropositivity of hepatitis B Virus among the cases and their contacts and to know the seroprevalence of hepatitis B envelope antigen (HBeAg and IgM antibody against hepatitis B core antigen (IgM HBcAb out of all the Hepatitis B surface Antigen (HBsAg positive ones. Materials and Methods: Eight hundred and fifty-six (856 cases and 1145 contacts were evaluated for hepatitis B markers namely HBsAg, HBeAg and IgM HBcAb by enzyme-linked immuno Sorbent Assay (ELISA test. Results: This outbreak of viral hepatitis B in Modasa, Gujarat was most likely due to unsafe injection practices. Evidence in support of this was collected by Government authorities. Most of the patients and approximately 40% of the surveyed population gave history of injections in last 1.5-6 months. Total 664/856 (77.57% cases and 20/1145 (1.75% contacts were found to be positive for HBsAg. 53.41% of the positive cases and 52.93% of the positive contacts were HBeAg-positive and thus in a highly infectious stage. Conclusions: Inadequately sterilized needles and syringes are an important cause of transmission of hepatitis B in India. Our data reflects the high positivity rate of a hepatitis B outbreak due to such unethical practices. There is a need to strengthen the routine surveillance system, and to organise a health education campaign targeting all health care workers including private practitioners, especially those working in rural areas, as well as the public at large, to take all possible measures to prevent this often fatal infection.

  17. Evaluation of two reverse passive haemagglutination techniques and a solid-phase radioimmunoassay for detection of hepatitis B surface antigen

    Energy Technology Data Exchange (ETDEWEB)

    Zhuang, H [Beijing Medical College (China); Coulepis, A G; Gust, I D [Fairfield Hospital for Communicable Diseases, Melbourne (Australia)

    1972-08-01

    The sensitivity and specificity of two commercially available reverse passive haemagglutination tests (Hepatest and Raphadex B) for the detection of hepatitis B surface antigen, were compared with the most widely used radioimmunoassay (Ausria II-125). A selected group of 282 sera were tested: these included the Australian hepatitis B reference panel, and a batch of 257 sera collected from patients with acute hepatitis B, chronic carriers of hepatitis B surface antigen and two populations in which hepatitis B virus infection is known to be endemic. The two reverse passive haemagglutination techniques were of comparable sensitivity but slightly less sensitive than radioimmunoassay. While radioimmunoassay still remains the test of choice for blood transfusion services, the reverse passive haemagglutination techniques are of great value for smaller laboratories and for field studies because of their longer shelf life, the absence of radioactive reagents and the lack of need to acquire a gammacounter.

  18. Efficacy of combined hepatitis B immunoglobulin and hepatitis B vaccine in blocking father-infant transmission of hepatitis B viral infection.

    Science.gov (United States)

    Cao, L-H; Liu, Z-M; Zhao, P-L; Sun, S-C; Xu, D-B; Shao, M-H; Zhang, J-D

    2015-05-04

    The aim of this study was to examine the efficacy of combined immunization of hepatitis B immunoglobulin (HBIG) and hepatitis B vaccine (HBVac) in blocking father-infant transmission of hepatitis B virus (HBV). Newborns positive at birth for blood HBV sur-face antigen (HBsAg) and/or HBV DNA were selected and immunized with HBIG combination HBVac. At 7 months, HBV markers and HBV DNA of each neonate were measured using electrochemiluminescence with the Cobas-e-411 Automatic Electrochemiluminescence Immuno-assay Analyzer and fluorescence quantitative polymerase chain reaction. Among all 7-month-old subjects, the negative conversion rates of HBV DNA and HBsAg were 48/61 (78.7%) and 19/41 (46.3%), respectively. Therefore, this study demonstrated that prompt combination injection of HBIG and HBVac can protect some of the HBV DNA- and/ or HBsAg-positive newborns from HBV.

  19. STUDIES IN DYNAMICS OF APOPTOSIS-RELATED SURFACE ANTIGEN (CD95 EXPRESSION ON NEUTROPHILS FROM CERVICAL AND VAGINAL SECRETIONS IN WOMEN WITH CHLAMIDIA INFECTION

    Directory of Open Access Journals (Sweden)

    O. A. Giesinger

    2010-01-01

    Full Text Available CD95 (Fas/APO-1 antigen expression was studied on the surface of neutrophil granulocytes from cervical secretions. Sixty-five female patients with established Chlamydia infection were found to have an increased CD95+ antigen expression following basic therapy. CD95+ receptors on neutrophils in the patients with Chlamydia infection have been shown to return to normal levels following a combined magnetic laser treatment.

  20. Applications of human hepatitis B virus preS domain in bio- and nanotechnology.

    Science.gov (United States)

    Toita, Riki; Kawano, Takahito; Kang, Jeong-Hun; Murata, Masaharu

    2015-06-28

    Human hepatitis B virus (HBV) is a member of the family Hepadnaviridae, and causes acute and chronic infections of the liver. The hepatitis B surface antigen (HBsAg) contains the large (L), middle (M), and small (S) surface proteins. The L protein consists of the S protein, preS1, and preS2. In HBsAg, the preS domain (preS1 + preS2) plays a key role in the infection of hepatocytic cells by HBV and has several immunogenic epitopes. Based on these characteristics of preS, several preS-based diagnostic and therapeutic materials and systems have been developed. PreS1-specific monoclonal antibodies (e.g., MA18/7 and KR127) can be used to inhibit HBV infection. A myristoylated preS1 peptide (amino acids 2-48) also inhibits the attachment of HBV to HepaRG cells, primary human hepatocytes, and primary tupaia hepatocytes. Antibodies and antigens related to the components of HBsAg, preS (preS1 + preS2), or preS1 can be available as diagnostic markers of acute and chronic HBV infections. Hepatocyte-targeting delivery systems for therapeutic molecules (drugs, genes, or proteins) are very important for increasing the clinical efficacy of these molecules and in reducing their adverse effects on other organs. The selective delivery of diagnostic molecules to target hepatocytic cells can also improve the efficiency of diagnosis. In addition to the full-length HBV vector, preS (preS1 + preS2), preS1, and preS1-derived fragments can be useful in hepatocyte-specific targeting. In this review, we discuss the literature concerning the applications of the HBV preS domain in bio- and nanotechnology.

  1. Antigenic evaluation of a recombinant baculovirus-expressed Sarcocystis neurona SAG1 antigen.

    Science.gov (United States)

    Gupta, G D; Lakritz, J; Saville, W J; Livingston, R S; Dubey, J P; Middleton, J R; Marsh, A E

    2004-10-01

    Sarcocystis neurona is the primary parasite associated with equine protozoal myeloencephalitis (EPM). This is a commonly diagnosed neurological disorder in the Americas that infects the central nervous system of horses. Current serologic assays utilize culture-derived parasites as antigen. This method requires large numbers of parasites to be grown in culture, which is labor intensive and time consuming. Also, a culture-derived whole-parasite preparation contains conserved antigens that could cross-react with antibodies against other Sarcocystis species and members of Sarcocystidae such as Neospora spp., Hammondia spp., and Toxoplasma gondii. Therefore, there is a need to develop an improved method for the detection of S. neurona-specific antibodies. The sera of infected horses react strongly to surface antigen 1 (SnSAG1), an approximately 29-kDa protein, in immunoblot analysis, suggesting that it is an immunodominant antigen. The SnSAG1 gene of S. neurona was cloned, and recombinant S. neurona SAG1 protein (rSnSAG1-Bac) was expressed with the use of a baculovirus system. By immunoblot analysis, the rSnSAG1-Bac antigen detected antibodies to S. neurona from naturally infected and experimentally inoculated equids, cats, rabbit, mice, and skunk. This is the first report of a baculovirus-expressed recombinant S. neurona antigen being used to detect anti-S. neurona antibodies in a variety of host species.

  2. Routine screening of blood donations at Qingdao central blood bank, China, for hepatitis B virus (HBV) DNA with a real-time, multiplex nucleic acid test for HBV, hepatitis C virus, and human immunodeficiency virus Types 1 and 2.

    Science.gov (United States)

    Yang, Zhongsi; Xu, Lei; Liu, Li; Feng, Qiuxia; Zhang, Longmu; Ma, Weijuan; Saldanha, John; Wang, Mingmin; Zhao, Lin

    2013-10-01

    The Roche cobas TaqScreen MPX test was used to evaluate the rate of hepatitis B surface antigen (HBsAg)-negative donations that were hepatitis B virus (HBV) DNA reactive from June 2010 to January 2011 in Qingdao, China. HBsAg-negative samples from 65,800 voluntary blood donors were tested with the cobas TaqScreen MPX test in pools of 6 on the Roche cobas s 201 blood screening platform. Samples positive for HBV DNA and negative for HBsAg were quantitated with the Roche COBAS AmpliPrep/COBAS TaqMan HBV test. In addition, serologic tests for HBsAg, hepatitis B surface antibody, anti-hepatitis B core antigen (anti-HBc), anti-hepatitis B e antigen (anti-HBe), and hepatitis B e antigen (HBe) were done using the Roche electrochemiluminescence immunoassay. A total of 80 nucleic acid amplification technology (NAT) test-reactive pools were identified and 59 pools (74%) resolved to a reactive sample. All samples were HBV DNA reactive and the viral load in each sample was quantitated. The viral loads of the samples ranged from less than 20 to 34,600 IU/mL; 13 samples (22%) had viral loads of more than 20 IU/mL, 27 samples (45.8%) had viral loads of less than 20 IU/mL, and 19 samples (32.2%) had undetectable viral loads. Of the 59 NAT-reactive samples, 40 (67.8%) were anti-HBc positive. Fifteen of the 59 samples could not be confirmed as NAT reactive either by an alternative NAT test or by serology. The HBV NAT yield in blood donors in Qingdao is 0.06% (38/65,800). This study confirmed the value of NAT for interdicting HBV-positive donations and preventing transfusion-transmitted HBV infections. © 2013 American Association of Blood Banks.

  3. Splenic B cells and antigen-specific B cells process anti-Ig in a similar manner

    International Nuclear Information System (INIS)

    Myers, C.D.; Vitetta, E.S.

    1989-01-01

    B lymphocytes can process and present antigen to T cells. However, the fate of native antigen after its binding to specific B cells, i.e., the intracellular events involved in the processing and recycling of the antigenic fragments to the cell surface for antigen presentation, are not well understood. In the present study, we demonstrate that murine B cells degrade anti-Ig molecules bound to their surface and release acid soluble fragments into the supernatant. We also demonstrate that the kinetics of this process are identical for anti-mu, anti-delta, and anti-light chain antibodies, indicating that both surface IgM and surface IgD are equally effective in binding antigen and directing its processing. We also describe the effects of azide, chloroquine, and irradiation on this process. To extend these studies to the processing of specifically bound antigen, we demonstrate that highly purified trinitrophenyl antigen-binding cells degrade anti-Ig molecules with the same kinetics as unpurified splenic B cells. Thus, this purified population provides a suitable model system for the analysis of antigen degradation by antigen-specific cells

  4. A solid phase radio immunoassay on hydrophobic membrane filters: detection of antibodies to gonocal surface antigens

    International Nuclear Information System (INIS)

    Lambden, P.R.; Watt, P.J.

    1978-01-01

    A solid phase radioimmunoassay (SPRIA) has been developed for detection of IgG antibodies to gonococcal outer membrane components. Gonococcal antigens was immobilised on a solid support by covalent coupling to CNBr-activated Sepharose in the presence of the detergent Triton X-100. Binding of specific antibody to the Sepharose-antigen complex was detected using radiolabelled Protein A as the antiglobulin. Protein A was labelled by radioacetylation with tritiated acetic anhydride, yielding a product of high specific activity and high stability. No detectable loss of activity was observed over a ten month period. The entire assay was performed on Mitex teflon hydrophobic membrane filters which held the Sepharose beads and aqueous supernatant as a discrete drop of liquid. The supernatants and incubation were easily and rapidly removed from the beads by suction on a specially-designed manifold system. This procedure removed the need for repeated and time-consuming centrifugations. Titres were obtained graphically from double log plots of cpm bound versus antiserum dilution by extrapolation of the straight line to a point corresponding to twice the control level of radioactivity binding. The assay proved to be a very reliable and simple procedure for the detection of IgG antibodies to gonococcal surface antigens. (Auth.)

  5. Limited antigenic variation in the Trypanosoma cruzi candidate vaccine antigen TSA-1.

    Science.gov (United States)

    Knight, J M; Zingales, B; Bottazzi, M E; Hotez, P; Zhan, B

    2014-12-01

    Chagas disease (American trypanosomiasis caused by Trypanosoma cruzi) is one of the most important neglected tropical diseases in the Western Hemisphere. The toxicities and limited efficacies of current antitrypanosomal drugs have prompted a search for alternative technologies such as a therapeutic vaccine comprised of T. cruzi antigens, including a recombinant antigen encoding the N-terminal 65 kDa portion of Trypomastigote surface antigen-1 (TSA-1). With at least six known genetically distinct T. cruzi lineages, variability between the different lineages poses a unique challenge for the development of broadly effective therapeutic vaccine. The variability across the major lineages in the current vaccine candidate antigen TSA-1 has not previously been addressed. To assess the variation in TSA-1, we cloned and sequenced TSA-1 from several different T. cruzi strains representing three of the most clinically relevant lineages. Analysis of the different alleles showed limited variation in TSA-1 across the different strains and fit with the current theory for the evolution of the different lineages. Additionally, minimal variation in known antigenic epitopes for the HLA-A 02 allele suggests that interlineage variation in TSA-1 would not impair the range and efficacy of a vaccine containing TSA-1. © 2014 John Wiley & Sons Ltd.

  6. A radioimmunoassay for human antibody specific for microbial antigens

    International Nuclear Information System (INIS)

    Tew, J.G.; Burmeister, J.; Greene, E.J.; Pflaumer, S.K.; Goldstein, J.

    1977-01-01

    A simple and sensitive method for detecting and quantitating antibody specific or microbial antigens is described. Bacterial, fungal, parasitic or viral antigens attached to bromoacetyl cellulose or the intact cells themselves were added to a series of two-fold dilutions of human serum. After a short incubation period, which allowed human antibody to attach to the antigens, the complex was thoroughly washed and carbon-14 labeled anti-human light chain antibody was added to each dilution. The resulting complex was washed, collected on a filter pad, placed in a scintillation vial and radioassayed. The relationship between radioactivity bound and -log 2 of the serum dilution was linear. The endpoint for each assay and a confidence interval was calculated by doing inverse prediction from simple linear regression. Results obtained using this assay indicated the presence of antibody in a pool of normal human sera specific for herpes virus and for both cell surface and intracellular antigens of Streptococcus mutans, Naegleria fowleri and Cryptococcus neoformans. In general the dominant response was against the intracellular antigens rather than cell surface antigens

  7. Evaluation of Hepatitis B Infection Prevalence in Institutionalized Intellectually Disabled Children

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    Foad Davoodbeglou

    2016-04-01

    Full Text Available Background: Hepatitis B virus (HBV infection causes chronic infection in human population, with high mortality. One of the high risk communities is mentally retarded children, who are institutionalized. Special conditions in these centers predispose children for HBV infection and transmission to healthy people. In this study our objective was to determine the prevalence of HBV infection among institutionalized mentally retarded children and study its associated risk factors.Materials and Methods: In this study, 250 mentally retarded children (younger than 14 years old were included. They were living in 5 nursing institutions, located in different parts of Tehran. Hepatitis B surface antigen (HBsAg was measured in the sera of these patients by ELISA method.Results: Among 250 children, 20 children (8% were HBsAg positive. HBV infection in girls was more than boys (11% to 5.6%. Among the types of mental retardation, children with cerebral palsy had the highest positive result for HBsAg. The most HBV infection (28.5% was seen in children with longest duration of being institutionalized (10 to 11 years. Vaccinated children were more HBsAg positive (8.7% than non-vaccinated children (5.3%. However, no significant relationship was observed between any of these factors and HBsAg positivity.Conclusion: Despite improvement of people’s health condition and implementation of HBV vaccination, the prevalence of HBV infection is increased in institutionalized mentally retarded children, which highlights the need for active measures to reduce this infection among this high risk population

  8. Development of a second generation monoclonal immunoradiometric assay. Increased sensitivity leads to enhanced detection of hepatitis B viral infection

    Energy Technology Data Exchange (ETDEWEB)

    Takahashi, H; Wands, J R; Kameda, H

    1988-09-13

    The authors have developed and employed a second generation monoclonal immunoradiometric assay (M2-IRMA) using antibodies of high affinity for epitopes that reside on hepatitis B surface antigen (HBsAg). This assay is capable of detecting as little as 15 pg/ml of HBsAg in serum. Improvements in sensitivity over a first generation immunoradiometric assay (MI-IRMA) was achieved by increasing the sample volume and time of incubation, and subjecting the reaction to a mechanical rotary device. 164 subjects with chronic hepatitis, 105 with cirrhosis, 67 with hepatocellular carcinoma, six with acute hepatitis A, seven with acute hepatitis B, 167 chronic carriers of hepatitis B virus (HBV) and 235 healthy individuals from Japan were studied and the results of the M2-IRMA were compared to a conventional polyclonal radioimmunoassay (P-RIA). By using a more sensitive assay design (M2-IRMA), a significant number of additional cases of HBV infection heretofore unsuspected in the etiology of chronic liver disease were identified. It is concluded that improvement in assay sensitivity for HBsAg is important in the serologic diagnosis of HBV in patients with chronic hepatitis, cirrhosis and hepatocellular carcinoma. 14 refs.; 6 figs.; 6 tabs.

  9. Decline and changing profile of hepatitis delta among injection drug users in Spain.

    Science.gov (United States)

    Aguilera, Antonio; Trastoy, Rocio; Barreiro, Pablo; Costa, José Javier; de Mendoza, Carmen; Peña, Jose M; Soriano, Vicente

    2018-01-01

    Roughly 15 million people worldwide have hepatitis delta, the most severe form of chronic viral hepatitis that often leads to cirrhosis and liver cancer. Injection drug users (IDUs) are the largest HDV reservoir. Their resurgence in North America and Europe may represent a new opportunity for HDV to spread more widely. We examined all consecutive active IDUs seen for the first time and enrolled in detoxification programmes at two clinics in Spain during two periods (1993-1996 and 2011-2014, respectively). Serum markers of HIV, HBV and HDV infection were tested. A total of 209 IDUs were examined in the first period. Mean age was 27-years-old. All had markers of past or current HBV infection. The rate of HIV-antibody (Ab), hepatitis B surface antigen (HBsAg) and HDV-Ab was as follows: 122 (58.4%), 73 (34.9%) and 62 (29.7%), respectively. Serum HDV-Ab was recognized in 53.4% of HBsAg+ and 16.9% of HBsAg- patients (Pforeign immigrants. It may reflect the benefit of universal HBV vaccination as well as the success of needle exchange programmes in Spain.

  10. Characterization of SeseC_01411 as a surface protective antigen of Streptococcus equi ssp. zooepidemicus.

    Science.gov (United States)

    Xie, Honglin; Wei, Zigong; Ma, Chunquan; Li, Shun; Liu, Xiaohong; Fu, Qiang

    2018-06-01

    Streptococcus equi ssp. zooepidemicus (Streptococcus zooepidemicus, SEZ) is a commensal bacterium related to opportunistic infections of many species, including humans, dogs, cats, and pigs. SeseC_01411 has been proven to be immunogenic. However, its protective efficacy remained to be evaluated. In the present study, the purified recombinant SeseC_01411 could elicit a strong humoral antibody response and protect against lethal challenge with virulent SEZ in mice. Our finding confirmed that SeseC_01411 distributes on the surface of SEZ. In addition, the hyperimmune sera against SeseC_01411 could efficiently kill the bacteria in the phagocytosis test. The present study identified the immunogenic protein, SeseC_01411, as a novel surface protective antigen of SEZ. Copyright © 2018 Elsevier Ltd. All rights reserved.

  11. The relationship between HBcrAg and HBV reinfection in HBV related post-liver transplantation patients.

    Science.gov (United States)

    Urabe, Ayako; Imamura, Michio; Tsuge, Masataka; Kan, Hiromi; Fujino, Hatsue; Fukuhara, Takayuki; Masaki, Keiichi; Kobayashi, Tomoki; Ono, Atsushi; Nakahara, Takashi; Kawaoka, Tomokazu; Hiramatsu, Akira; Kawakami, Yoshiiku; Aikata, Hiroshi; Hayes, Clair Nelson; Maki, Noboru; Ohdan, Hideaki; Chayama, Kazuaki

    2017-03-01

    Post-transplant hepatitis B virus (HBV) reinfection is one of the major problems facing patients who undergo HBV-related liver transplantation (LT). We analyzed the clinical impact of serum hepatitis B core-related antigen (HBcrAg) on HBV reinfection in post-LT patients with HBV-related liver diseases. Serum hepatitis B surface antigen (HBsAg), HBV DNA, and HBcrAg were measured over time in 32 post-LT patients. Twenty-one out of 32 patients had HCC at LT. The effects of HBcrAg, hepatocellular carcinoma (HCC) recurrence, and HBs gene mutation on HBV reinfection and withdrawal from hepatitis B immune globulin (HBIG) were analyzed. Sixteen out of 32 patients (50 %) were positive for HBcrAg even though only six patients were thought to have experienced HBV reinfection based on reappearance of either HBV DNA or HBsAg during a median follow-up time of 75 months. Three of these six patients who became re-infected with HBV experienced HCC recurrence after LT. The HBV DNA reappearance rate was significantly higher in patients with HCC recurrence after LT (p HBV re-infected patients without HCC recurrence had HBs gene mutations G145R and G145A, respectively. Anti-HBs antibody development rate by HB vaccination was similar between HBcrAg-positive and negative patients (p = 0.325). HBV reinfection is more common than is usually considered based on conventional measurement of HBsAg and HBV DNA. HCC recurrence and mutations in the HBV S gene were associated with HBV reinfection after LT.

  12. Establishment of a common acute lymphoblastic leukemia cell line (LC4-1) and effects of phorbol myristate acetate (PMA) on the surface antigen expression of the cell line.

    Science.gov (United States)

    Yoshimura, T; Mayumi, M; Yorifuji, T; Kim, K M; Heike, T; Miyanomae, T; Shinomiya, K; Mikawa, H

    1987-09-01

    A common acute lymphoblastic leukemia (ALL) cell line, designated LC4-1, was established from peripheral blood mononuclear cells of a patient with acute non-T-cell ALL. LC4-1 cells were characteristically positive for Ia, B4, and common ALL antigens (CALLA), but negative for B2, Tac, T3, T4, T8, T11, and M1 antigens and E-rosette formation. Approximately 30% of LC4-1 cells expressed detectable amounts of B1 antigens. LC4-1 cells expressed neither Epstein-Barr-virus-associated nuclear antigen (EBNA), cytoplasmic immunoglobulins (cIg) nor surface immunoglobulins (sIg). Gene rearrangements had already occurred in LC4-1 in the D-J region of immunoglobulin heavy chain genes, but not in T-cell receptor (beta-chain) genes, suggesting that LC4-1 is a progenitor cell line of B-cell lineage earlier than pre-B-cells. The expression of cell surface antigens of LC4-1 was changed by treatment with 4-phorbol 12-myristate 13-acetate (PMA) (0.1 ng/ml) for 2 days. Before treatment with PMA, about 98% of LC4-1 cells were positive for B4, CALLA, and Ia. However, following treatment they lost CALLA expression without any change in expression of Ia and B4. There was no change in B1-positive population. The change in surface antigens on LC4-1 cells seems to be due to differentiation induced in the cells by PMA. These results support the hypothesis that CALLA is a differentiation antigen and suggest one possible differentiation pathway for pre-B-cells.

  13. The SnSAG merozoite surface antigens of Sarcocystis neurona are expressed differentially during the bradyzoite and sporozoite life cycle stages.

    Science.gov (United States)

    Gautam, A; Dubey, J P; Saville, W J; Howe, D K

    2011-12-29

    Sarcocystis neurona is a two-host coccidian parasite whose complex life cycle progresses through multiple developmental stages differing at morphological and molecular levels. The S. neurona merozoite surface is covered by multiple, related glycosylphosphatidylinositol-linked proteins, which are orthologous to the surface antigen (SAG)/SAG1-related sequence (SRS) gene family of Toxoplasma gondii. Expression of the SAG/SRS proteins in T. gondii and another related parasite Neospora caninum is life-cycle stage specific and seems necessary for parasite transmission and persistence of infection. In the present study, the expression of S. neurona merozoite surface antigens (SnSAGs) was evaluated in the sporozoite and bradyzoite stages. Western blot analysis was used to compare SnSAG expression in merozoites versus sporozoites, while immunocytochemistry was performed to examine expression of the SnSAGs in merozoites versus bradyzoites. These analyses revealed that SnSAG2, SnSAG3 and SnSAG4 are expressed in sporozoites, while SnSAG5 was appeared to be downregulated in this life cycle stage. In S. neurona bradyzoites, it was found that SnSAG2, SnSAG3, SnSAG4 and SnSAG5 were either absent or expression was greatly reduced. As shown for T. gondii, stage-specific expression of the SnSAGs may be important for the parasite to progress through its developmental stages and complete its life cycle successfully. Thus, it is possible that the SAG switching mechanism by these parasites could be exploited as a point of intervention. As well, the alterations in surface antigen expression during different life cycle stages may need to be considered when designing prospective approaches for protective vaccination. Copyright © 2011 Elsevier B.V. All rights reserved.

  14. Activity of nucleic acid polymers in rodent models of HBV infection.

    Science.gov (United States)

    Schöneweis, Katrin; Motter, Neil; Roppert, Pia L; Lu, Mengji; Wang, Baoju; Roehl, Ingo; Glebe, Dieter; Yang, Dongliang; Morrey, John D; Roggendorf, Michael; Vaillant, Andrew

    2018-01-01

    Nucleic acid polymers (NAPs) block the release of HBsAg from infected hepatocytes. These compounds have been previously shown to have the unique ability to eliminate serum surface antigen in DHBV-infected Pekin ducks and achieve multilog reduction of HBsAg or HBsAg loss in patients with chronic HBV infection and HBV/HDV coinfection. In ducks and humans, the blockage of HBsAg release by NAPs occurs by the selective targeting of the assembly and/or secretion of subviral particles (SVPs). The clinically active NAP species REP 2055 and REP 2139 were investigated in other relevant animal models of HBV infection including woodchucks chronically infected with WHV, HBV transgenic mice and HBV infected SCID-Hu mice. The liver accumulation of REP 2139 in woodchucks following subcutaneous administration was examined and was found to be similar to that observed in mice and ducks. However, in woodchucks, NAP treatment was associated with only mild (36-79% relative to baseline) reductions in WHsAg (4/10 animals) after 3-5 weeks of treatment without changes in serum WHV DNA. In HBV infected SCID-Hu mice, REP 2055 treatment was not associated with any reduction of HBsAg, HBeAg or HBV DNA in the serum after 28 days of treatment. In HBV transgenic mice, no reductions in serum HBsAg were observed with REP 2139 with up to 12 weeks of treatment. In conclusion, the antiviral effects of NAPs in DHBV infected ducks and patients with chronic HBV infection were weak or absent in woodchuck and mouse models despite similar liver accumulation of NAPs in all these species, suggesting that the mechanisms of SVP assembly and or secretion present in rodent models differs from that in DHBV and chronic HBV infections. Copyright © 2017 The Authors. Published by Elsevier B.V. All rights reserved.

  15. The prevalence of hepatitis B virus infection markers and socio-demographic risk factors in HIV-infected patients in Southern Brazil

    Directory of Open Access Journals (Sweden)

    Saulo Martins

    2014-10-01

    Full Text Available Introduction Hepatitis B virus (HBV and human immunodeficiency virus (HIV infections are two of the world's most important infectious diseases. Our objective was to determine the hepatitis B surface antigen (HBsAg and hepatitis B core antibody (anti-HBc prevalences among adult HIV-infected patients and identify the associations between socio-demographic variables and these HBV infection markers. Methods This study was performed from October 2012 to March 2013. Three hundred HIV-seropositive patients were monitored by the Clinical Analysis Laboratory of Professor Polydoro Ernani de São Thiago University Hospital, Santa Catarina, Brazil. The blood tests included HBsAg, anti-HBc immunoglobulin M (IgM and total anti-HBc. Patients reported their HIV viral loads and CD4+ T-cell counts using a questionnaire designed to collect sociodemographic data. Results The mean patient age was 44.6 years, the mean CD4 T-cell count was 525/mm3, the mean time since beginning antiretroviral therapy was 7.6 years, and the mean time since HIV diagnosis was 9.6 years. The overall prevalences of HBsAg and total anti-HBc were 2.3% and 29.3%, respectively. Among the individuals analyzed, 0.3% were positive for HBsAg, 27.3% were positive for total anti-HBc, and 2.0% were positive either for HBsAg or total anti-HBc and were classified as chronically HBV-infected. Furthermore, 70.3% of the patients were classified as never having been infected. Male gender, age >40 years and Caucasian ethnicity were associated with an anti-HBc positive test. Conclusions The results showed an intermediate prevalence of HBsAg among the studied patients. Moreover, the associations between the anti-HBc marker and socio-demographic factors suggest a need for HBV immunization among these HIV-positive individuals, who are likely to have HIV/HBV coinfection.

  16. Hepatitis B virus core antigen determines viral persistence in a C57BL/6 mouse model.

    Science.gov (United States)

    Lin, Yi-Jiun; Huang, Li-Rung; Yang, Hung-Chih; Tzeng, Horng-Tay; Hsu, Ping-Ning; Wu, Hui-Lin; Chen, Pei-Jer; Chen, Ding-Shinn

    2010-05-18

    We recently developed a mouse model of hepatitis B virus (HBV) persistence, in which a single i.v. hydrodynamic injection of HBV DNA to C57BL/6 mice allows HBV replication and induces a partial immune response, so that about 20-30% of the mice carry HBV for more than 6 months. The model was used to identify the viral antigen crucial for HBV persistence. We knocked out individual HBV genes by introducing a premature termination codon to the HBV core, HBeAg, HBx, and polymerase ORFs. The specific-gene-deficient HBV mutants were hydrodynamically injected into mice and the HBV profiles of the mice were monitored. About 90% of the mice that received the HBcAg-mutated HBV plasmid exhibited high levels of hepatitis B surface antigenemia and maintained HBsAg expression for more than 6 months after injection. To map the region of HBcAg essential for viral clearance, we constructed a set of serial HBcAg deletion mutants for hydrodynamic injection. We localized the essential region of HBcAg to the carboxyl terminus, specifically to the 10 terminal amino acids (HBcAg176-185). The majority of mice receiving this HBV mutant DNA did not elicit a proper HBcAg-specific IFN-gamma response and expressed HBV virions for 6 months. These results indicate that the immune response triggered in mice by HBcAg during exposure to HBV is important in determining HBV persistence.

  17. HDV Seroprevalence in HBsAg Positive Patients

    International Nuclear Information System (INIS)

    Abbasi, A.; Bhutto, A. R.; Mahmood, K.; Butt, N.

    2014-01-01

    Objective: To find out the frequency of HDV seroprevalence and the demographic characteristics or HBsAg-HDV positive patients. Study Design: Cross-sectional analytical study. Place and Duration of Study: Jinnah Postgraduate Medical Centre and Civil Hospital, Medical Unit-III, Karachi, from March 2007 to April 2011. Methodology: Patients with positive HBsAg were included in the study. Those having co-infection with HCV or HIV, autoimmune hepatitis, alcoholic hepatitis, Wilson's disease and haemochromatosis were excluded. After detailed history and physical examination all the patients underwent laboratory workup including complete blood count, liver function test, viral profile (HAV, HCV, HIV and anti-HDV) and prothrombin time. While in selected patients, HBc (core) antibodies, ultrasound abdomen, serum iron profile, ANA and liver biopsy were also carried out whenever needed to establish a clinical stage of liver disease. Results: There were 374 patients with 266 (71.1%) males and 108 (28.9%) females with overall mean age of 31.64 +- 8.66 years. Overall frequency of anti-HDV antibodies positivity was found in 28.1% (n = 105) patients. HDV seropositivity was slightly more prevalent in males as compared to females (28.57% vs. 26.57%). HDV seropositivity frequency was significantly higher in patients who presented with acute hepatitis/hepatic failure as compared to other clinical diagnoses (p = 0.027) and in those sub-sets of patients who had raised ALT levels (p = 0.012). Conclusion: There was a high frequency of HDV seropositivity in the studied population particularly in males with acute hepatitis or hepatic failure, having raised ALT levels. The emphasis should be on preventive measures taken by other countries to reduce the prevalence of these treatment challenging infections. (author)

  18. Alpha-fetoprotein and hepatitis B virus infection in chronic liver disease

    International Nuclear Information System (INIS)

    Solina, A.

    1987-01-01

    Among 177 patients with chronic non-malignant liver disease, the prevalence of raised levels of alpha-fetoprotein (AFP) was 11.2 percent. A close association between the severity of the liver disease and AFP concentrations was observed. The most frequent pattern of hepatitis B virus (HBV) infection in these patients was the presence of antibodies to hepatitis B surface antigen (anti-HBs) and hepatitis B core antigen (anti-HBc), whilst only 5 cases were positive for hepatitis B surface antigen (HBsAg). Sixty seven patients, 18 of whom with high AFP, were longitudinally studied over a period ranging from 1 to 6 years. The evaluation of AFP was transient in 6 cases and persistent in 12 cases. The patients in the former group had high activity of liver disease and none of them developed primary liver cell cancer during the follow-up. In contrast, only two patients in the latter group had high activity, and 3 developed PLC. Active HBV replication was significantly more frequent among those with transient elevation of AFP, whereas anti-HBs and anti-HBc positive cases were significantly more frequent among those with persistent elevation of AFP. It is concluded that the severity of the liver disease is the major factor of elevation of AFP. Transiently raised levels of AFP are not related with PLC, whereas persistently high levels represent a premalignant condition. At variance with data obtained in areas with high prevalence of PLC, HBsAg seems not to be related with persistent elevation of AFP. The high rate positive for anti-HBs and anti-HBc in this group remains to be clarified

  19. Antigen presentation by hapten-specific B lymphocytes. II. Specificity and properties of antigen-presenting B lymphocytes, and function of immunoglobulin receptors

    International Nuclear Information System (INIS)

    Abbas, A.K.; Haber, S.; Rock, K.L.

    1985-01-01

    Studies were designed to examine the ability of hapten-binding murine B lymphocytes to present hapten-protein conjugates to protein antigen-specific, Ia-restricted T cell hybridomas. BALB/c B cells specific for TNP or FITC presented hapten-modified proteins (TNP-G1 phi, TNP-OVA, or FITC-OVA) to the relevant T cell hybridomas at concentrations below 0.1 microgram/ml. Effective presentation of the same antigens by B lymphocyte-depleted splenocytes, and of unmodified proteins by either hapten-binding B cells or Ig spleen cells, required about 10(3)-to 10(4)-fold higher concentrations of antigen. The use of two different haptens and two carrier proteins showed that this extremely efficient presentation of antigen was highly specific, with hapten specificity being a property of the B cells and carrier specificity of the responding T cells. The presentation of hapten-proteins by hapten-binding B lymphocytes was radiosensitive and was not affected by the depletion of plastic-adherent cells, suggesting that conventional APCs (macrophages or dendritic cells) are not required in this phenomenon. Antigen-pulsing and antibody-blocking experiments showed that this hapten-specific antigen presentation required initial binding of antigen to surface Ig receptors. Moreover, linked recognition of hapten and carrier determinants was required, but these recognition events could be temporally separated. Finally, an antigen-processing step was found to be necessary, and this step was disrupted by ionizing radiation. These data suggest a role for B cell surface Ig in providing a specific high-affinity receptor to allow efficient uptake or focusing of antigen for its subsequent processing and presentation to T lymphocytes

  20. Characterization of Antigen-Specific B Cells Using Nominal Antigen-Coated Flow-Beads

    Science.gov (United States)

    Akl, Ahmed; Lepetit, Maud; Crochette, Romain; Giral, Magali; Lepourry, Julie; Pallier, Annaick; Castagnet, Stéphanie; Dugast, Emilie; Guillot-Gueguen, Cécile; Jacq-Foucher, Marylène; Saulquin, Xavier; Cesbron, Anne; Laplaud, David; Nicot, Arnaud; Brouard, Sophie; Soulillou, Jean-Paul

    2013-01-01

    In order to characterize the reactivity of B cells against nominal antigens, a method based on the coupling of antigens onto the surface of fluorescent core polystyrene beads was developed. We first demonstrate that murine B cells with a human MOG-specific BCR are able to interact with MOG-coated beads and do not recognize beads coated with human albumin or pp65. B cells purified from human healthy volunteer blood or immunized individuals were tested for their ability to interact with various nominal antigens, including viral, vaccine, self and alloantigens, chosen for their usefulness in studying a variety of pathological processes. A substantial amount of B cells binding self-antigen MOG-coated beads can be detected in normal blood. Furthermore, greater frequencies of B cell against anti-Tetanic Toxin or anti-EBNA1 were observed in primed individuals. This method can reveal increased frequencies of anti-HLA committed B cells in patients with circulating anti-HLA antibodies compared to unsensitized patients and normal individuals. Of interest, those specific CD19 cells were preferentially identified within CD27−IgD+ (i-e naïve) subset. These observations suggest that a broad range of medical situations could benefit from a tool that allows the detection, the quantification and the characterization of antigen-specific blood B cells. PMID:24386360

  1. Antibodies to variant antigens on the surfaces of infected erythrocytes are associated with protection from malaria in Ghanaian children

    DEFF Research Database (Denmark)

    Dodoo, D; Staalsoe, T; Giha, H

    2001-01-01

    Plasmodium falciparum erythrocyte membrane protein 1 (PfEMP1) is a variant antigen expressed on the surface of infected erythrocytes. Each parasite genome contains about 40 PfEMP1 genes, but only 1 PfEMP1 gene is expressed at a given time. PfEMP1 serves as a parasite-sequestering ligand to endoth...

  2. Surface antigens and potential virulence factors from parasites detected by comparative genomics of perfect amino acid repeats

    Directory of Open Access Journals (Sweden)

    Adler Joël

    2007-12-01

    Full Text Available Abstract Background Many parasitic organisms, eukaryotes as well as bacteria, possess surface antigens with amino acid repeats. Making up the interface between host and pathogen such repetitive proteins may be virulence factors involved in immune evasion or cytoadherence. They find immunological applications in serodiagnostics and vaccine development. Here we use proteins which contain perfect repeats as a basis for comparative genomics between parasitic and free-living organisms. Results We have developed Reptile http://reptile.unibe.ch, a program for proteome-wide probabilistic description of perfect repeats in proteins. Parasite proteomes exhibited a large variance regarding the proportion of repeat-containing proteins. Interestingly, there was a good correlation between the percentage of highly repetitive proteins and mean protein length in parasite proteomes, but not at all in the proteomes of free-living eukaryotes. Reptile combined with programs for the prediction of transmembrane domains and GPI-anchoring resulted in an effective tool for in silico identification of potential surface antigens and virulence factors from parasites. Conclusion Systemic surveys for perfect amino acid repeats allowed basic comparisons between free-living and parasitic organisms that were directly applicable to predict proteins of serological and parasitological importance. An on-line tool is available at http://genomics.unibe.ch/dora.

  3. DNA secondary structures are associated with recombination in major Plasmodium falciparum variable surface antigen gene families

    DEFF Research Database (Denmark)

    Sander, Adam F.; Lavstsen, Thomas; Rask, Thomas Salhøj

    2014-01-01

    falciparum-erythrocyte membrane protein 1 class on the infected erythrocyte surface. Recombination clearly generates var diversity, but the nature and control of the genetic exchanges involved remain unclear. By experimental and bioinformatic identification of recombination events and genome...... of recombination during DNA replication in P. falciparum sexual stages, and that these DSS-regulated genetic exchanges generate functional and diverse P. falciparum adhesion antigens. DSS-induced recombination may represent a common mechanism for optimizing the evolvability of virulence gene families in pathogens....

  4. Effects of pregnancy and intensity of Plasmodium falciparum transmission on immunoglobulin G subclass responses to variant surface antigens

    DEFF Research Database (Denmark)

    Megnekou, Rosette; Staalsoe, Trine; Taylor, Diane W

    2005-01-01

    Placenta-sequestering Plasmodium falciparum involved in the pathogenesis of pregnancy-associated malaria (PAM) in otherwise clinically immune women expresses particular variant surface antigens (VSA(PAM)) on the surface of infected erythrocytes that differ from VSA found in parasitized nonpregnant...... individuals (non-PAM type VSA). We studied levels of immunoglobulin G (IgG) and IgG subclasses with specificity for VSA(PAM) and for non-PAM type VSA in pregnant and nonpregnant women from two sites with different endemicities in Cameroon. We found that VSA(PAM)-specific responses depended on the pregnancy......(PAM)-specific immunity to pregnancy-associated malaria....

  5. A novel merozoite surface antigen of Plasmodium falciparum (MSP-3 identified by cellular-antibody cooperative mechanism antigenicity and biological activity of antibodies

    Directory of Open Access Journals (Sweden)

    Claude Oeuvray

    1994-01-01

    Full Text Available We report the identification of a 48kDa antigen targeted by antibodies which inhibit Plasmodium falciparum in vitro growth by cooperation with blood monocytes in an ADCI assay correlated to the naturally acquired protection. This protein is located on the surface of the merozoite stage of P. falciparum, and is detectable in all isolates tested. Epidemiological studies demonstrated that peptides derived from the amino acid sequence of MSP-3 contain potent B and T-cell epitopes recognized by a majority of individuals living in endemic areas. Moreover human antibodies either purified on the recombinant protein, or on the synthetic peptide MSP-3b, as well as antibodies raised in mice, were all found to promote parasite killing mediated by monocytes.

  6. Studies on the surface antigenicity and susceptibility to antibody-dependent killing of developing schistosomula using sera from chronically infected mice and mice vaccinated with irradiated cercariae

    International Nuclear Information System (INIS)

    Bickle, Q.D.; Ford, M.J.

    1982-01-01

    Changes in the surface antigenicity and susceptibility to in vitro killing during development of schistosomula of Schistosoma mansoni were studied using serum from chronically infected mice (CIS) and from mice vaccinated with highly irradiated (20 krad) cercariae (VS). Binding of these sera was quantitated by counting the number of P388D 1 cells (a transformed, macrophage-like cell of mouse origin, bearing Fc receptors for IgG) binding to the parasite surface. Compared with schistosomula derived in vitro by mechanical transformation (MS), schistosomula recovered 3 hr after skin penetration in vitro (SS) showed a significant loss in surface binding of CIS. Schistosomula recovered 3 hr after skin penetration in vivo (SRS) showed even less binding, and this trend continued such that parasites recovered from the lungs 5 days after infection (LS) showed only minimal binding, and 10-day-old worms from the portal system showed no significant binding. In contrast, VS, which bound significantly less well to MS than CIS, showed enhanced binding to SS, and in the face of their declining antigenicity with respect to CIS, 3- to 24-hr SRS maintained this raised level of antigenicity. Although there appeared to be a decline in binding of VS thereafter, LS remained antigenic, still binding as many cells as MS did despite the fact that they also expressed host antigens detected usng antisera raised against mouse RBC. In spite of this persistence of VS binding up to the lung stage, resistance to eosinophil-mediated killing in vitro had developed by 48 hr post-infection, and LS were totally resistant to both eosinophil- and C-mediated killing

  7. Recent advances in understanding and diagnosing hepatitis B virus infection [version 1; referees: 2 approved

    Directory of Open Access Journals (Sweden)

    Slim Fourati

    2016-09-01

    Full Text Available Hepatitis B virus (HBV infects approximately 240 million individuals worldwide. Recent advances in the virology, immunopathogenesis, and diagnosis of HBV infection are summarized in this review article. The identification of a hepatocyte-specific cellular receptor for HBV, the sodium taurocholate co-transporting polypeptide (NTCP, made it possible to develop reliable cell culture systems and better understand the early steps of the viral lifecycle. Viral and host factors involved in covalently closed circular DNA synthesis, stability, and transcriptional regulation have also been identified and provide potential targets for new drugs. Based on recent evidence showing trained immunity in immune-tolerant patients, the immune tolerance and immune clearance phases have been renamed the non-inflammatory and inflammatory phases, respectively. New diagnostic and monitoring tools are now available, including rapid diagnostic tests for hepatitis B surface antigen (HBsAg detection, HBsAg quantification assays, anti-HBc antibody quantification assays, an HBV core-related antigen (HBcrAg quantification test, new HBV DNA detection and quantification assays, and an HBV RNA quantification test. Their clinical utility is under study. Finally, new antiviral and immune modulation approaches are in the preclinical or early clinical developmental stages, with the goal to achieve functional cure or ideally (if possible eradication of HBV infection.

  8. Serum ALT levels as a surrogate marker for serum HBV DNA levels in HBeAg-negative pregnant women.

    Science.gov (United States)

    Sangfelt, Per; Von Sydow, Madeleine; Uhnoo, Ingrid; Weiland, Ola; Lindh, Gudrun; Fischler, Björn; Lindgren, Susanne; Reichard, Olle

    2004-01-01

    In Stockholm, Sweden, the majority of pregnant women positive for hepatitis B surface antigen (HBsAg) are hepatitis Be antigen (HBeAg) negative. Newborns to HBeAg positive mothers receive vaccination and hepatitis B immunoglobulin (HBIg). Newborns to HBeAg negative mothers receive vaccine and HBIg only if the mothers have elevated ALT levels. The aim of this study was to retrospectively evaluate ALT levels as a surrogate marker for HBV DNA levels in HBeAg negative carrier mothers. Altogether 8947 pregnant women were screened for HBV markers from 1999 to 2001 at the Virology Department, Karolinska Hospital. Among mothers screened 192 tested positive for HBsAg (2.2%). 13 of these samples could not be retrieved. Of the remaining 179 sera, 8 (4%) tested positive for HBeAg and 171 (95.5%) were HBeAg negative. Among the HBeAg negative mothers, 9 had HBV DNA levels > 10(5) copies/ml, and of these 7 had normal ALT levels indicating low sensitivity of an elevated ALT level as a surrogate marker for high HBV DNA level. Furthermore, no correlation was found between ALT and HBV DNA levels. Hence, it is concluded that the use of ALT as a surrogate marker for high viral replication in HBeAg negative mothers could be questioned.

  9. Analysis of IgG with specificity for variant surface antigens expressed by placental Plasmodium falciparum isolates

    Directory of Open Access Journals (Sweden)

    Kremsner Peter G

    2004-07-01

    Full Text Available Abstract Background Pregnancy-associated malaria (PAM is caused by Plasmodium falciparum-infected erythrocytes that can sequester in placental intervillous space by expressing particular variant surface antigens (VSA that can mediate adhesion to chondroitin sulfate A (CSA in vitro. IgG antibodies with specificity for the VSA expressed by these parasites (VSAPAM are associated with protection from maternal anaemia, prematurity and low birth weight, which is the greatest risk factor for death in the first month of life. Methods In this study, the development of anti-VSAPAM antibodies in a group of 151 women who presented to the maternity ward of Albert Schweitzer Hospital in Lambaréné, Gabon for delivery was analysed using flow cytometry assays. Plasma samples from placenta infected primiparous women were also investigated for their capacity to inhibit parasite binding to CSA in vitro. Results In the study cohort, primiparous as well as secundiparous women had the greatest risk of infection at delivery as well as during pregnancy. Primiparous women with infected placentas at delivery showed higher levels of VSAPAM-specific IgG compared to women who had no malaria infections at delivery. Placental isolates of Gabonese and Senegalese origin tested on plasma samples from Gabon showed parity dependency and gender specificity patterns. There was a significant correlation of plasma reactivity as measured by flow cytometry between different placental isolates. In the plasma of infected primiparous women, VSAPAM-specific IgG measured by flow cytometry could be correlated with anti-adhesion antibodies measured by the inhibition of CSA binding. Conclusion Recognition of placental parasites shows a parity- and sex- dependent pattern, like that previously observed in laboratory strains selected to bind to CSA. Placental infections at delivery in primiparous women appear to be sufficient to induce functional antibodies which can both recognize the surface of

  10. Effectiveness of HBV vaccination in infants and prediction of HBV prevalence trend under new vaccination plan: findings of a large-scale investigation.

    Directory of Open Access Journals (Sweden)

    Shi-gui Yang

    Full Text Available BACKGROUND: Hepatitis B virus (HBV infection remains a severe public health problem. Investigating its prevalence and trends is essential to prevention. METHODS: To evaluate the effectiveness of HBV vaccination under the 1992 Intervention Program for infants and predicted HBV prevalence trends under the 2011 Program for all ages. We conducted a community-based investigation of 761,544 residents of 12 counties in Zhejiang Province selected according to their location, population density, and economic development. The HBV prevalence trends were predicted by a time-shifting approach. HBV surface antigen (HBsAg and alanine amino transferase (ALT were determined. RESULTS: Of the 761,544 persons screened for HBsAg, 54,132 were positive (adjusted carrier rate 6.13%; 9,455 had both elevated ALT and a positive HBsAg test (standardized rate 1.18%. The standardized HBsAg carrier rate for persons aged ≤20 years was 1.51%. Key factors influencing HBV infection were sex, age, family history, drinking, smoking, employment as a migrant worker, and occupation. With the vaccination program implemented in 2011, we predict that by 2020, the HBsAg carrier rate will be 5.27% and that for individuals aged ≤34 years will reach the 2% upper limit of low prevalence according to the WHO criteria, with a standardized rate of 1.86%. CONCLUSIONS: The national HBV vaccination program for infants implemented in 1992 has greatly reduced the prevalence of HBV infection. The 2011 program is likely to reduce HBV infection in Zhejiang Province to a low moderate prevalence, and perinatal transmission is expected to be controlled by 2020.

  11. Alpha-fetoprotein still is a valuable diagnostic and prognosis predicting biomarker in hepatitis B virus infection-related hepatocellular carcinoma.

    Science.gov (United States)

    Yao, Mingjie; Zhao, Jingmin; Lu, Fengmin

    2016-01-26

    Use of serum alpha-fetoprotein (AFP) in clinical practices has been challenged in recent years, due to the lack of specificity and sensitivity. Here we conducted a retrospective study to evaluate the diagnostic and prognostic value of serum AFP among hepatocellular carcinoma (HCC) patients with their pathogenic features taken into consideration. The cohort for this study comprised 318 cases of hepatitis and 731 cases of cirrhosis, as well as 796 HCC patients. Using 11.62ng/mL as a cut-off value, the positive rate of AFP test among serum hepatitis B surface antigen (HBsAg) positive HCC patients was significantly higher than that in those HBsAg negative HCC patients (79.55% vs 56.49%, P < 0.000). Similarly, the median serum AFP level in HCC patients with serum HBsAg positive was significantly higher than that in those HBsAg negative HCC patients (423.89ng/ml vs 40.82ng/ml, P < 0.000). In addition, Kaplan-Meier curve analysis revealed that lower preoperative AFP level implicated a much higher overall survival rate. Of note, such prognosis predicting value was only seen in those chronic HBV infection-related HCC patients, but not among the HCC patients etiologically irrelevant to HBV infection. We believe that serum AFP is of diagnosis and prognostic predicting value for HCC with chronic HBV infection, and strongly suggest use of serum AFP as a biomarker in China and other HBV infection endemic area like Southeast Asia.

  12. Identification of a peptide binding protein that plays a role in antigen presentation

    International Nuclear Information System (INIS)

    Lakey, E.K.; Margoliash, E.; Pierce, S.K.

    1987-01-01

    The helper T-cell response to globular proteins appears, in general, to require intracellular processing of the antigen, such that a peptide fragment containing the T-cell antigenic determinant is released and transported to and held on the surface of an Ia-expressing, antigen-presenting cell. However, the molecular details underlying these phenomena are largely unknown. The means by which antigenic peptides are anchored on the antigen-presenting cell surface was investigated. A cell surface protein is identified that was isolated by it ability to bind to a 24-amino acid peptide fragment of pigeon cytochrome c, residues 81-104, containing the major antigenic determinant for B10.A mouse T cells. This peptide binding protein, purified from [ 35 S]methionine-labeled cells, appears as two discrete bands of ≅72 and 74 kDa after NaDodSO 4 /PAGE. The protein can be eluted from the peptide affinity column with equivalent concentrations of either the antigenic pigeon cytochrome c peptide or the corresponding nonantigenic peptide of mouse cytochrome c. However, it does not bind to the native cytochromes c, either of pigeon or mouse, and thus the protein appears to recognize some structure available only in the free peptides. This protein plays a role in antigen presentation. Its expression is not major histocompatibility complex-restricted in that the blocking activity of the antisera can be absorbed on spleen cells from mice of different haplotypes. This peptide binding protein can be isolated from a variety of cell types, including B cells, T cells, and fibroblasts. The anchoring of processed peptides on the cell surface by such a protein may play a role in antigen presentation

  13. Plasmodium falciparum parasites expressing pregnancy-specific variant surface antigens adhere strongly to the choriocarcinoma cell line BeWo

    DEFF Research Database (Denmark)

    Haase, Rikke N; Megnekou, Rosette; Lundquist, Maja

    2006-01-01

    Placenta-sequestering Plasmodium falciparum parasites causing pregnancy-associated malaria express pregnancy-specific variant surface antigens (VSA(PAM)). We report here that VSA(PAM)-expressing patient isolates adhere strongly to the choriocarcinoma cell line BeWo and that the BeWo line can...... be used to efficiently select for VSA(PAM) expression in vitro....

  14. Immunization and chemical conjugation of Bm95 obtained from Pichia pastoris enhances the immune response against vaccinal protein and Neisseria meningitidis capsular polysaccharide

    Directory of Open Access Journals (Sweden)

    Rodriguez-Valle M

    2014-03-01

    Full Text Available Manuel Rodriguez-Valle,1 Leonardo Canan-Hadden,2 Olivia Niebla2 1Animal Biotechnology Division, 2Analytical Division, Centre for Genetic Engineering and Biotechnology, Havana, Cuba Abstract: The ectoparasite Rhipicephalus (Boophilus microplus causes severe economic losses to the cattle industry in tropical and subtropical regions, and transmits endoparasites, such as Babesia bovis. The glycoprotein Bm95 is homologous to Bm86, a surface membrane protein of gut epithelial cells in R. microplus, and has been shown to efficiently control this ectoparasite in regions of the Americas. The immunostimulant properties of Bm86 have already been demonstrated after its coinjection with hepatitis B surface antigen (HBsAg and the infectious bovine rhinotracheitis virus. This study evaluated the carrier and immunostimulant properties of Bm95 using low immunogenic Neisseria meningitidis capsular C polysaccharide (Men CpS and HBsAg. We produced two polysaccharide-Bm95 conjugates by carbodiimide (MenCpSBm-c and reductive amination (MenCpSBm-ra methods. These conjugates were characterized and evaluated in mice. Antibody titers against Men CpS were significantly higher in mice immunized with MenCpSBm-ra (2,350±250, P<0.01 than in those immunized with MenCpSBm-c (250±75 or Men CpS (570±104. The study data indicate effective immunological memory after booster inoculation in mice immunized with MenCpSBm-ra. Additionally, significant humoral immunity against HBsAg was documented in mice coimmunized via the intranasal route with recombinant Bm95 (11,400±345 and HBsAg (128,000±250 compared with mice immunized only with HBsAg (400±40 or Bm95 (5,461±150, P<0.01. In conclusion, the immunostimulatory properties of recombinant Bm95 make it a useful element for developing safer conjugated vaccines against bacterial pathogens and for evaluation against ticks and tick-borne diseases in the context of a polyvalent veterinary vaccine. Keywords: glycoconjugate, Bm86

  15. Fusion protein of tapasin and hepatitis B core antigen 18‑27 enhances T helper cell type 1/2 cytokine ratio and antiviral immunity by inhibiting suppressors of cytokine signaling family members 1/3 in hepatitis B virus transgenic mice.

    Science.gov (United States)

    Tang, Yuyan; Chen, Xiaohua; Zhang, Yi; Tang, Zhenghao; Zhuo, Meng; Li, Dan; Wang, Peng; Zang, Guoqing; Yu, Yongsheng

    2014-04-01

    Persistent hepatitis B virus (HBV) infection is characterized by a weak adaptive immune response, which is considered to be due to an imbalance of T helper cell types 1 and 2 (Th1/Th2). Suppressors of cytokine signaling (SOCS) family members, particularly SOCS1 and SOCS3, have been demonstrated to be important in the regulation of T cell differentiation. Previous studies by our group showed that the expressed and purified fusion protein of cytoplasmic transduction peptide (CTP) and HBV core antigen 18‑27 (HBcAg18‑27)‑tapasin was able to enter the cytoplasm of bone marrow‑derived dendritic cells (BMDCs), promoting the maturation of BMDCs and efficiently enhancing T cell immune responses in vitro. In the present study, HBcAg‑specific immune responses induced by CTP‑HBcAg18‑27‑tapasin in HBV were assessed in transgenic mice, and SOCS1 and SOCS3 were identified as negative regulators of this response. The Th1/Th2 cytokine ratio was analyzed by ELISA. The expression of T cell‑specific T‑box transcription factor (T‑bet) and GATA‑binding protein 3 (GATA‑3), SOCS1 and SOCS3 were detected by real‑time quantitative polymerase chain reaction and western blot analysis. The results demonstrated that CTP‑HBcAg18‑27‑tapasin significantly increased the Th1/Th2 cytokine ratio in HBV transgenic mice. CTP‑HBcAg18‑27‑tapasin immunization more efficiently suppressed the expression of serum hepatitis B surface antigen (HBsAg), HBV DNA as well as liver HBsAg and HBcAg in HBV transgenic mice. Furthermore, CTP‑HBcAg18‑27‑tapasin promotes T‑bet but reduces GATA‑3 expression. In addition, the expression of SOCS1 and SOCS3 was significantly downregulated in the CTP‑HBcAg18‑27‑tapasin group compared with the control groups. In conclusion, the present study demonstrated that CTP‑HBcAg18‑27‑tapasin enhanced the Th1/Th2 cytokine ratio and antiviral immunity by suppressing SOCS1/3 in HBV transgenic mice.

  16. Well-known surface and extracellular antigens of pathogenic microorganisms among the immunodominant proteins of the infectious microalgae Prototheca zopfii.

    Science.gov (United States)

    Irrgang, Alexandra; Murugaiyan, Jayaseelan; Weise, Christoph; Azab, Walid; Roesler, Uwe

    2015-01-01

    Microalgae of the genus Prototheca (P.) are associated with rare but severe infections (protothecosis) and represent a potential zoonotic risk. Genotype (GT) 2 of P. zopfii has been established as pathogenic agent for humans, dogs, and cattle, whereas GT1 is considered to be non-pathogenic. Since pathogenesis is poorly understood, the aim of this study was to determine immunogenic proteins and potential virulence factors of P. zopfii GT2. Therefore, 2D western blot analyses with sera and isolates of two dogs naturally infected with P. zopfii GT2 have been performed. Cross-reactivity was determined by including the type strains of P. zopfii GT2, P. zopfii GT1, and P. blaschkeae, a close relative of P. zopfii, which is known to cause subclinical forms of bovine mastitis. The sera showed a high strain-, genotype-, and species-cross-reactivity. A total of 198 immunogenic proteins have been analyzed via MALDI-TOF MS. The majority of the 86 identified proteins are intracellularly located (e.g., malate dehydrogenase, oxidoreductase, 3-dehydroquinate synthase) but some antigens and potential virulence factors, known from other pathogens, have been found (e.g., phosphomannomutase, triosephosphate isomerase). One genotype-specific antigen could be identified as heat shock protein 70 (Hsp70), a well-known antigen of eukaryotic pathogens with immunological importance when located extracellularly. Both sera were reactive to glyceraldehyde-3-phosphate-dehydrogenase of all investigated strains. This house-keeping enzyme is found to be located on the surface of several pathogens as virulence factor. Flow-cytometric analysis revealed its presence on the surface of P. blaschkeae.

  17. RESEARCH OF ANTIGEN AND ANTIBODIES FROM RETROVIRUSES, CMV AND HBV AMONG PRISONERS OF THE PENITENTIARY COMPLEX OF THE REGION OF CAMPINAS, SP, BRAZIL

    Directory of Open Access Journals (Sweden)

    Neusa Maria OSTI

    1998-07-01

    Full Text Available Some viruses of the families Retroviridae, such as Human T Lymphotropic Virus (HTLV; Herpesviridae as the Cytomegalovirus (CMV and Hepadnaviridae such as the Hepatitis B Virus (HBV are liable to be co-transmitted with the Human Immunodeficiency Virus (HIV. Since prisoners are exposed to several and important risk factors involved in the transmission of HIV and the above mentioned viruses, male inmates from the penitentiary complex of Campinas, SP, Brazil, including HIV + and HIV - ones, were examined for the presence of HTLV-I and/or II antibodies; IgG and IgM anti-CMV antibodies, and the research of the superficial hepatitis B antigen (HBsAg. The presence of anti-HTLV-I and/or II was determined by the Western Blot (WB technique, whereas IgG and IgM anti-CMV and the search of HBsAg were carried out by the Microparticle Enzyme Immunoassay (MEIA-Abbott Lab.With regard to anti-HTLV-I and/or II, 58.3% (14/24-Number of positive reactions/number of sera examined were reactive among the anti-HIV positive sera. Conversely, only 12.5% (3/24 among the HIV- negative sera showed positive reactions to HTLV-I and/or II antibodies. When looking for IgG anti-CMV percentages of 97.7% (43/44 and 95% (38/40 were obtained for anti-HIV positive and negative sera, respectively. As to IgM anti-CMV antibodies 11.36% (5/44 and 2.5% (1/40 of reactive sera were found for anti-HIV positive and negative, respectively. The HBsAg was found in 12.8% (5/39 of the sera which were anti-HIV positive.Alguns vírus das famílias Retroviridae, tais como, o Vírus do Linfoma Humano de Células T ( HTLV; Herpesviridae, tais como o Vírus Citomegálico (CMV e da Hepatite B (HBV podem ser co-transmitidos com o Vírus da Imunodeficiência Adquirida (HIV. Uma vez que prisioneiros estão expostos a diversos fatores de risco envolvidos na transmissão do HIV e dos vírus acima mencionados, prisioneiros do sexo masculino do Complexo Penitenciário de Campinas, SP, Brasil, incluindo aqueles

  18. Early childhood transmission of hepatitis B prior to the first hepatitis B vaccine dose is rare among babies born to HIV-infected and non-HIV infected mothers in Gulu, Uganda.

    Science.gov (United States)

    Seremba, E; Van Geertruyden, J P; Ssenyonga, R; Opio, C K; Kaducu, J M; Sempa, J B; Colebunders, R; Ocama, P

    2017-05-19

    Hepatitis B (HBV) in sub-Saharan Africa is believed to be horizontally acquired. However, because of the high HBV prevalence in northern Uganda, no hepatitis B vaccination at birth and no access to HBV immunoglobulin, we hypothesize that vertical transmission also could also play an important role. We therefore investigated the incidence of HBV among babies presenting for their first HBV vaccine dose in Gulu, Uganda. We recruited mothers and their babies (at least 6-week old) presenting for their postnatal care and first HBV vaccine dose respectively. Socio-demographic and risk factors for HBV transmission were recorded. Mothers were tested for Hepatitis B core antibody (anti-HBc-IgG) and hepatitis B surface antigen (HBsAg). HBsAg-positive sera were tested for hepatitis B e antigen (HBeAg) and HBV viral load (HBVDNA). Babies were tested for HBsAg at presentation and at the last immunization visit. A sample of HBsAg-negative babies were tested for HBVDNA. Incident HBV infection was defined by either a positive HBsAg or HBVDNA test. Chi-square or fisher's exact tests were utilized to investigate associations and t-tests or Wilcoxon rank-sum test for continuous differences. We recruited 612 mothers, median age 23years (IQR 20-28). 53 (8.7%) were HBsAg-positive and 339 (61.5%) were anti-HBc-IgG-positive. Ten (18.9%) of the HBsAg-positive mothers were HBeAg-positive. Median HBVDNA levels of HBV-infected mothers was 5.7log (IQR 4.6-7.0) IU/mL with 9 (17.6%) having levels≥10 5 IU/mL. Eighty (13.3%) mothers were HIV-infected of whom 9 (11.5%) were co-infected with HBV. No baby tested HBsAg or HBVDNA positive. Vertical transmission does not seem to contribute substantially to the high HBV endemicity in northern Uganda. The current practice of administering the first HBV vaccine to babies in Uganda at six weeks of age may be adequate in control of HBV transmission. Copyright © 2017 Elsevier Ltd. All rights reserved.

  19. An MHC-restricted antibody-based chimeric antigen receptor requires TCR-like affinity to maintain antigen specificity

    Directory of Open Access Journals (Sweden)

    Marcela V Maus

    2016-01-01

    Full Text Available Chimeric antigen receptors (CARs are synthetic receptors that usually redirect T cells to surface antigens independent of human leukocyte antigen (HLA. Here, we investigated a T cell receptor-like CAR based on an antibody that recognizes HLA-A*0201 presenting a peptide epitope derived from the cancer-testis antigen NY-ESO-1. We hypothesized that this CAR would efficiently redirect transduced T cells in an HLA-restricted, antigen-specific manner. However, we found that despite the specificity of the soluble Fab, the same antibody in the form of a CAR caused moderate lysis of HLA-A2 expressing targets independent of antigen owing to T cell avidity. We hypothesized that lowering the affinity of the CAR for HLA-A2 would improve its specificity. We undertook a rational approach of mutating residues that, in the crystal structure, were predicted to stabilize binding to HLA-A2. We found that one mutation (DN lowered the affinity of the Fab to T cell receptor-range and restored the epitope specificity of the CAR. DN CAR T cells lysed native tumor targets in vitro, and, in a xenogeneic mouse model implanted with two human melanoma lines (A2+/NYESO+ and A2+/NYESO−, DN CAR T cells specifically migrated to, and delayed progression of, only the HLA-A2+/NY-ESO-1+ melanoma. Thus, although maintaining MHC-restricted antigen specificity required T cell receptor-like affinity that decreased potency, there is exciting potential for CARs to expand their repertoire to include a broad range of intracellular antigens.

  20. Curcumin inhibits hepatitis B virus infection by down-regulating cccDNA-bound histone acetylation.

    Science.gov (United States)

    Wei, Zhi-Qiang; Zhang, Yong-Hong; Ke, Chang-Zheng; Chen, Hong-Xia; Ren, Pan; He, Yu-Lin; Hu, Pei; Ma, De-Qiang; Luo, Jie; Meng, Zhong-Ji

    2017-09-14

    To investigate the potential effect of curcumin on hepatitis B virus (HBV) covalently closed circular DNA (cccDNA) and the underlying mechanism. A HepG2.2.15 cell line stably transfected with HBV was treated with curcumin, and HBV surface antigen (HBsAg) and e antigen (HBeAg) expression levels were assessed by ELISA. Intracellular HBV DNA replication intermediates and cccDNA were detected by Southern blot and real-time PCR, respectively. The acetylation levels of histones H3 and H4 were measured by Western blot. H3/H4-bound cccDNA was detected by chromatin immunoprecipitation (ChIP) assays. The deacetylase inhibitors trichostatin A and sodium butyrate were used to study the mechanism of action for curcumin. Additionally, short interfering RNAs (siRNAs) targeting HBV were tested along with curcumin. Curcumin treatment led to time- and dose-dependent reductions in HBsAg and HBeAg expression and significant reductions in intracellular HBV DNA replication intermediates and HBV cccDNA. After treatment with 20 μmol/L curcumin for 2 d, HBsAg and cccDNA levels in HepG2.2.15 cells were reduced by up to 57.7% ( P curcumin, accompanied by reductions in H3- and H4-bound cccDNA. Furthermore, the deacetylase inhibitors trichostatin A and sodium butyrate could block the effects of curcumin. Additionally, transfection of siRNAs targeting HBV enhanced the inhibitory effects of curcumin. Curcumin inhibits HBV gene replication via down-regulation of cccDNA-bound histone acetylation and has the potential to be developed as a cccDNA-targeting antiviral agent for hepatitis B.

  1. HIV, HCV, HBV and syphilis rate of positive donations among blood donations in Mali: lower rates among volunteer blood donors.

    Science.gov (United States)

    Diarra, A; Kouriba, B; Baby, M; Murphy, E; Lefrere, J-J

    2009-01-01

    Good data on background seroprevalence of major transfusion transmitted infections is lacking in Mali. We gathered data on the rate of positive donations of human immunodeficiency virus (HIV), hepatitis C virus (HCV), hepatitis B virus (HBV) and syphilis among blood donations in Mali for calendar year 2007. Donations with repeatedly reactive results on screening enzyme immunoassay (EIA) were considered to be seropositive. Rate of positive donations per blood unit collected was 2.6% for HIV, 3.3% for HCV, 13.9% for hepatitis B surface antigen (HBsAg) and 0.3% for syphilis. For HIV, HBsAg and syphilis, rate of positive donations was significantly (pdonations from replacement donors than those from volunteer donors, while HCV rate of positive donations was similar in the two groups. Rate of positive donations was also significantly (p<0.0001) lower in blood units from regular than from first-time donors. These data reinforce WHO recommendations for increasing the number of regular, volunteer blood donors in Africa.

  2. Clinicopathological study on the primary hepatoma of the atomic bomb survivors

    Energy Technology Data Exchange (ETDEWEB)

    Satoh, T; Takahara, O; Takahashi, N; Matsuo, K; Tsunoo, S [Nagasaki Atomic Bomb Hospital (Japan)

    1978-09-01

    Fifty-eight cases autopsied during 10 years from 1968 to 1977 were divided into (A) a non-exposed group, (B) a group exposed within 2 km of the center of explosion, and (C) a group exposed over 2 km from the center of explosion or a group who entered Nagasaki city after the explosion, and clinicopathological study on them was made in detail. These three groups were studied as to incidences according to age and sex, prognosis, histological types and hepatic lesion complicated by hepatoma in survival cases for more than one year, histological diagnosis, gross types, histological types, degree of atypia, hepatic lesion at sites not injured with hepatoma, and the detection rate of B-type virus hepatitis surface antigen (HBs-Ag). Pathohistologically, ordinary hematoxylin-eosin staining, van Gieson staining, silvering staining, iron staining were performed, and aldehyde-fuchsine staining was also performed HBs-Ag detection in a part of cases for.

  3. Production of vaccines for treatment of infectious diseases by transgenic plants

    Directory of Open Access Journals (Sweden)

    Kristina LEDL

    2016-04-01

    Full Text Available Since the first pathogen antigen was expressed in transgenic plants with the aim of producing edible vaccine in early 1990s, transgenic plants have become a well-established expression system for production of alternative vaccines against various human and animal infectious diseases. The main focus of plant expression systems in the last five years has been on improving expression of well-studied antigens such as porcine reproductive and respiratory syndrome (PRRSV, bovine viral diarrhea disease virus (BVDV, footh and mouth disease virus (FMDV, hepatitis B surface antigen (HBsAg, rabies G protein, rotavirus, Newcastle disease virus (NDV, Norwalk virus capsid protein (NVCP, avian influenza virus H5N1, Escherichia coli heat-labile enterotoxin subunit B (LT-B, cholera toxin B (CT-B, human immunodeficiency virus (HIV, artherosclerosis, ebola and anthrax. Significant increases in expression have been obtained using improved expression vectors, different plant species and transformation methods.

  4. An integrated electrochemical device based on immunochromatographic test strip and enzyme labels for sensitive detection of disease-related biomarkers

    Energy Technology Data Exchange (ETDEWEB)

    Zou, Zhexiang; Wang, Jun; Wang, Hua; Li, Yao Q.; Lin, Yuehe

    2012-05-30

    A novel electrochemical biosensing device that integrates an immunochromatographic test strip and a screen-printed electrode (SPE) connected to a portable electrochemical analyzer was presented for rapid, sensitive, and quantitative detection of disease-related biomarker in human blood samples. The principle of the sensor is based on sandwich immunoreactions between a biomarker and a pair of its antibodies on the test strip, followed by highly sensitive square-wave voltammetry (SWV) detection. Horseradish peroxidase (HRP) was used as a signal reporter for electrochemical readout. Hepatitis B surface antigen (HBsAg) was employed as a model protein biomarker to demonstrate the analytical performance of the sensor in this study. Some critical parameters governing the performance of the sensor were investigated in detail. The sensor was further utilized to detect HBsAg in human plasma with an average recovery of 91.3%. In comparison, a colorimetric immunochromatographic test strip assay (ITSA) was also conducted. The result shows that the SWV detection in the electrochemical sensor is much more sensitive for the quantitative determination of HBsAg than the colorimetric detection, indicating that such a sensor is a promising platform for rapid and sensitive point-of-care testing/screening of disease-related biomarkers in a large population

  5. Genetic engineering of chimeric antigen receptors using lamprey derived variable lymphocyte receptors

    Directory of Open Access Journals (Sweden)

    Robert Moot

    2016-01-01

    Full Text Available Chimeric antigen receptors (CARs are used to redirect effector cell specificity to selected cell surface antigens. Using CARs, antitumor activity can be initiated in patients with no prior tumor specific immunity. Although CARs have shown promising clinical results, the technology remains limited by the availability of specific cognate cell target antigens. To increase the repertoire of targetable tumor cell antigens we utilized the immune system of the sea lamprey to generate directed variable lymphocyte receptors (VLRs. VLRs serve as membrane bound and soluble immune effectors analogous but not homologous to immunoglobulins. They have a fundamentally different structure than immunoglobulin (Ig-based antibodies while still demonstrating high degrees of specificity and affinity. To test the functionality of VLRs as the antigen recognition domain of CARs, two VLR-CARs were created. One contained a VLR specific for a murine B cell leukemia and the other contained a VLR specific for the human T cell surface antigen, CD5. The CAR design consisted of the VLR sequence, myc-epitope tag, CD28 transmembrane domain, and intracellular CD3ζ signaling domain. We demonstrate proof of concept, including gene transfer, biosynthesis, cell surface localization, and effector cell activation for multiple VLR-CAR designs. Therefore, VLRs provide an alternative means of CAR-based cancer recognition.

  6. Peg-interferon plus nucleotide analogue treatment versus no treatment in patients with chronic hepatitis B with a low viral load: a randomised controlled, open-label trial.

    Science.gov (United States)

    de Niet, Annikki; Jansen, Louis; Stelma, Femke; Willemse, Sophie B; Kuiken, Sjoerd D; Weijer, Sebastiaan; van Nieuwkerk, Carin M J; Zaaijer, Hans L; Molenkamp, Richard; Takkenberg, R Bart; Koot, Maarten; Verheij, Joanne; Beuers, Ulrich; Reesink, Hendrik W

    2017-08-01

    Antiviral treatment is currently not recommended for patients with chronic hepatitis B with a low viral load. However, they might benefit from acquiring a functional cure (hepatitis B surface antigen [HBsAg] loss with or without formation of antibodies against hepatitis B surface antigen [anti-HBs]). We assessed HBsAg loss during peg-interferon-alfa-2a (peg-IFN) and nucleotide analogue combination therapy in patients with chronic hepatitis B with a low viral load. In this randomised controlled, open-label trial, patients were enrolled from the Academic Medical Center (AMC), Amsterdam, Netherlands. Eligible patients were HBsAg positive and hepatitis B e antigen (HBeAg) negative for more than 6 months, could be treatment naive or treatment experienced, and had alanine aminotransferase (ALT) concentrations less than 5 × upper limit of normal (ULN). Participants were randomly assigned (1:1:1) by a computerised randomisation programme (ALEA Randomisation Service) to receive peg-IFN 180 μg/week plus adefovir 10 mg/day, peg-IFN 180 μg/week plus tenofovir disoproxil fumarate 245 mg/day, or no treatment for 48 weeks. The primary endpoint was the proportion of patients with serum HBsAg loss among those who received at least one dose of study drug or had at least one study visit (modified intention-to-treat population [mITT]). All patients have finished the initial study of 72 weeks and will be observed for up to 5 years of follow-up. This study is registered with ClinicalTrials.gov, number NCT00973219. Between Aug 4, 2009, and Oct 17, 2013, 167 patients were screened for enrolment, of whom 151 were randomly assigned (52 to peg-IFN plus adefovir, 51 to peg-IFN plus tenofovir, and 48 to no treatment). 46 participants in the peg-IFN plus adefovir group, 45 in the peg-IFN plus tenofovir group, and 43 in the no treatment group began treatment or observation and were included in the mITT population. At week 72, two (4%) patients in the peg-IFN plus adefovir group and two (4

  7. Radioimmunoassay for hepatitis B core antigen

    International Nuclear Information System (INIS)

    Sagnelli, E.; Pereira, C.; Triolo, G.; Vernace, S.; Paronetto, F.

    1982-01-01

    Serum hepatitis B core antigen (HBcAg) is an important marker of hepatitis B virus replication. We describe an easy, sensitive radioimmunoassay for determination of HBcAg in detergent-treated serum pellets containing Dane particles. Components of a commercial kit for anticore determination are used, and HBcAG is measured by competitive inhibition of binding of 125 I-labeled antibodies to HBcAg with HBcAg-coated beads. We assayed for HBcAG in the sera of 49 patients with hepatitis B surface antigen (HBsAg)-positive chronic hepatitis, 50 patients with HBsAg-negative chronic hepatitis, and 30 healthy volunteers. HBcAg was detected in 41% of patients with HBsAg-positive chronic hepatitis but not in patients with HBsAg-negative chronic hepatitis. Hepatitis Be antigen (an antigen closely associated with the core of Dane particles) determined in the same sera by radioimmunoassay, was not detected in 50% of HBcAg-positive sera

  8. [Relationship between HBeAg from HBsAg positive mothers and regulatory T cells in neonates and its influence on HBV intrauterine transmission].

    Science.gov (United States)

    Hao, H Y; Yang, Z Q; Xu, X X; Wang, X F; Wang, B; Shi, X H; Fu, Z D; Wang, B; Wang, S P

    2017-10-10

    Objective: To explore the relationship between HBeAg in HBsAg positive mothers and CD(4)(+)CD(25)(+) Foxp3 (+)regulatory T cells (Treg) in newborns, as well as how they would influence the increasing risk on HBV intrauterine transmission. Methods: We collected information on general demographic characteristics and delivery on 270 HBsAg positive mothers and their newborns from the Third People's Hospital of Taiyuan. Fluorescence quantitative polymerase chain reaction (FQ-PCR) and chemiluminescence immunoassay (CLIA) were used to detect HBV DNA and HBV serological markers in peripheral blood from both mothers and neonates. The expression of Treg and other immune cells in peripheral blood of neonates were detected with flow cytometry (FCM). Results: Maternal HBeAg positive rates were associated with an increased risk of intrauterine transmission ( OR =4.08, 95 %CI : 1.89-8.82). Rates of Treg in newborns born to HBsAg-positive mothers were higher than that of the negative group ( Z =2.29, P =0.022). Each pair of the subjects was assigned to five different groups according to the HBeAg titers of mothers. Frequencies of both Treg and HBeAg in newborns and HBV DNA in mothers between the above said 5 groups showed similar trends of changing patterns and the differences between groups were statistically significant(χ(2)=18.73, P mother's HBeAg titers were positively related to the percentage of Treg in their newborns ( r(s) =0.19, P =0.039). In addition, the frequencies of Treg were negatively correlated with pDC and CD(4)(+) T cell in their newborns ( r(s) =-0.21, P =0.017; r(s) =-0.23, P =0.009). Conclusion: HBeAg from HBsAg positive mothers might have inhibited the function of neonatal DC cells and T cells to reduce the immune response to HBV by up-regulating the proportion of Treg and finally increased the risk of HBV intrauterine transmission.

  9. Well-known surface and extracellular antigens of pathogenic microorganisms among the immunodominant proteins of the infectious microalgae Prototheca zopfii

    Directory of Open Access Journals (Sweden)

    Alexandra eIrrgang

    2015-09-01

    Full Text Available Microalgae of the genus Prototheca (P. are associated with rare but severe infections (protothecosis and represent a potential zoonotic risk. Genotype (GT 2 of P. zopfii has been established as pathogenic agent for humans, dogs and cattle, whereas GT1 is considered to be non-pathogenic. Since pathogenesis is poorly understood, the aim of this study was to determine immunogenic proteins and potential virulence factors of P. zopfii GT2. Therefore, 2D western blot analyses with sera and isolates of two dogs naturally infected with P. zopfii GT2 have been performed. Cross-reactivity was determined by including the type strains of P. zopfii GT2, P. zopfii GT1 and P. blaschkeae, a close relative of P. zopfii, which is known to cause subclinical forms of bovine mastitis. The sera showed a high strain-, genotype-, and species-cross-reactivity. A total of 198 immunogenic proteins have been analysed via MALDI- TOF MS. The majority of the 86 identified proteins are intracellularly located (e.g. malate dehydrogenase, oxidoreductase, 3-dehydroquinate synthase but some antigens and potential virulence factors, known from other pathogens, have been found (e.g. phosphomannomutase, triosephosphate isomerase. One genotype-specific antigen could be identified as heat shock protein 70 (Hsp70, a well-known antigen of eukaryotic pathogens with immunological importance when located extracellularly. Both sera were reactive to glyceraldehyde-3-phosphate-dehydrogenase of all investigated strains. This house-keeping enzyme is found to be located on the surface of several pathogens as virulence factor. Flow-cytometric analysis revealed its presence on the surface of P. blaschkeae.

  10. Temporal expression and localization patterns of variant surface antigens in clinical Plasmodium falciparum isolates during erythrocyte schizogony.

    Directory of Open Access Journals (Sweden)

    Anna Bachmann

    Full Text Available Avoidance of antibody-mediated immune recognition allows parasites to establish chronic infections and enhances opportunities for transmission. The human malaria parasite Plasmodium falciparum possesses a number of multi-copy gene families, including var, rif, stevor and pfmc-2tm, which encode variant antigens believed to be expressed on the surfaces of infected erythrocytes. However, most studies of these antigens are based on in vitro analyses of culture-adapted isolates, most commonly the laboratory strain 3D7, and thus may not be representative of the unique challenges encountered by P. falciparum in the human host. To investigate the expression of the var, rif-A, rif-B, stevor and pfmc-2tm family genes under conditions that mimic more closely the natural course of infection, ex vivo clinical P. falciparum isolates were analyzed using a novel quantitative real-time PCR approach. Expression patterns in the clinical isolates at various time points during the first intraerythrocytic developmental cycle in vitro were compared to those of strain 3D7. In the clinical isolates, in contrast to strain 3D7, there was a peak of expression of the multi-copy gene families rif-A, stevor and pfmc-2tm at the young ring stage, in addition to the already known expression peak in trophozoites. Furthermore, most of the variant surface antigen families were overexpressed in the clinical isolates relative to 3D7, with the exception of the pfmc-2tm family, expression of which was higher in 3D7 parasites. Immunofluorescence analyses performed in parallel revealed two stage-dependent localization patterns of RIFIN, STEVOR and PfMC-2TM. Proteins were exported into the infected erythrocyte at the young trophozoite stage, whereas they remained inside the parasite membrane during schizont stage and were subsequently observed in different compartments in the merozoite. These results reveal a complex pattern of expression of P. falciparum multi-copy gene families during

  11. Infection with hepatitis B and hepatitis C virus as risk factors for hepatocarcinoma in Peru: Study of cases and control; Infeccion con virus de la hepatitis B y hepatitis C como factores de riesgo para hepatocarcinoma en el Peru: estudio de casos y controles

    Energy Technology Data Exchange (ETDEWEB)

    Ruiz, E; Celis, J; Pizarro, R; Montalbeti, J; Urbano, R [Instituto de Enfermedades Neoplasicas, Lima (Peru); Almonte, M [Centro de Investigacion en Cancer Maes Heller, Lima (Peru)

    1998-09-01

    To investigate whether past exposure to Hepatitis B virus (HBV) and Hepatitis C Virus (HCV) were risk factors for the development of Hepatocellular Carcinoma (HCC) in Peru, a case-control study of 136 patients with HCC and 136 age-matched and sex-matched control subjects was performed. Past exposure to HBV and HCV were assessed respectively by antibody to hepatitis B core antigen (Anti-HBc) and HbsAg and Anti-HCV. Of the HCC cases, 63,2% were positive for HbsAg and 0,73% for anti-HCV. Of the control patients, 4,4% were positive to HbsAg and 0,73% to anti-HCV. The mean age of patients with HCC negative for HbsAg was significantly greater than that of patients HCC positive for HbsAg (35,4 versus 29,4 years, p less than 0,001). The HbsAg patients are 36,26 times more prone to developing HCC than those with HbsAg negative (95% confidence interval: 15.31-90.7). Infection with HCV does not pose a risk for the development of HCC (RR 1, 95% confidence interval: 0.062-16.152). A causal relation between HBV infection in children HCC was observed. These results indicate that HbsAg carriage is a risk factor for HCC in Peru. The importance of vertical or perinatal transmission of HBV and the prophylactic role of passive immunization plus vaccination during childhood is emphasized as well as the selective vaccination of high risk groups. (authors)

  12. Infection with hepatitis B and hepatitis C virus as risk factors for hepatocarcinoma in Peru: Study of cases and control

    International Nuclear Information System (INIS)

    Ruiz, E.; Celis, J.; Pizarro, R.; Montalbeti, J.; Urbano, R.; Almonte, M.

    1998-01-01

    To investigate whether past exposure to Hepatitis B virus (HBV) and Hepatitis C Virus (HCV) were risk factors for the development of Hepatocellular Carcinoma (HCC) in Peru, a case-control study of 136 patients with HCC and 136 age-matched and sex-matched control subjects was performed. Past exposure to HBV and HCV were assessed respectively by antibody to hepatitis B core antigen (Anti-HBc) and HbsAg and Anti-HCV. Of the HCC cases, 63,2% were positive for HbsAg and 0,73% for anti-HCV. Of the control patients, 4,4% were positive to HbsAg and 0,73% to anti-HCV. The mean age of patients with HCC negative for HbsAg was significantly greater than that of patients HCC positive for HbsAg (35,4 versus 29,4 years, p less than 0,001). The HbsAg patients are 36,26 times more prone to developing HCC than those with HbsAg negative (95% confidence interval: 15.31-90.7). Infection with HCV does not pose a risk for the development of HCC (RR 1, 95% confidence interval: 0.062-16.152). A causal relation between HBV infection in children HCC was observed. These results indicate that HbsAg carriage is a risk factor for HCC in Peru. The importance of vertical or perinatal transmission of HBV and the prophylactic role of passive immunization plus vaccination during childhood is emphasized as well as the selective vaccination of high risk groups. (authors)

  13. The Leishmania promastigote surface antigen-2 (PSA-2) is specifically recognised by Th1 cells in humans with naturally acquired immunity to L. major

    DEFF Research Database (Denmark)

    Kemp, M; Handman, E; Kemp, K

    1998-01-01

    The promastigote surface antigen-2 (PSA-2) is a Leishmania parasite antigen, which can induce Th1-mediated protection against murine leishmaniasis when used as a vaccine. To evaluate PSA-2 as a human vaccine candidate the specific T-cell response to PSA-2 was characterised in individuals immune...... to cutaneous leishmaniasis. Peripheral blood mononuclear cells from Sudanese individuals with a past history of self-healing cutaneous leishmaniasis proliferated vigorously in response to PSA-2 isolated from Leishmania major, whereas the antigen did not activate cells from presumably unexposed Danes....... Peripheral blood mononuclear cells from individuals with previous L. major infection had varying proliferative responses to PSA-2 derived from L. donovani promastigotes. Peripheral blood mononuclear cells activated by PSA-2 from L. major produced high amounts of interferon-gamma and tumour necrosis factor...

  14. SnSAG5 is an alternative surface antigen of Sarcocystis neurona strains that is mutually exclusive to SnSAG1.

    Science.gov (United States)

    Crowdus, Carolyn A; Marsh, Antoinette E; Saville, Willliam J; Lindsay, David S; Dubey, J P; Granstrom, David E; Howe, Daniel K

    2008-11-25

    Sarcocystis neurona is an obligate intracellular parasite that causes equine protozoal myeloencephalitis (EPM). Previous work has identified a gene family of paralogous surface antigens in S. neurona called SnSAGs. These surface proteins are immunogenic in their host animals, and are therefore candidate molecules for development of diagnostics and vaccines. However, SnSAG diversity exists in strains of S. neurona, including the absence of the major surface antigen gene SnSAG1. Instead, sequence for an alternative SnSAG has been revealed in two of the SnSAG1-deficient strains. Herein, we present data characterizing this new surface protein, which we have designated SnSAG5. The results indicated that the protein encoded by the SnSAG5 sequence is indeed a surface-associated molecule that has characteristics consistent with the other SAGs identified in S. neurona and related parasites. Importantly, Western blot analyses of a collection of S. neurona strains demonstrated that 6 of 13 parasite isolates express SnSAG5 as a dominant surface protein instead of SnSAG1. Conversely, SnSAG5 was not detected in SnSAG1-positive strains. One strain, which was isolated from the brain of a sea otter, did not express either SnSAG1 or SnSAG5. Genetic analysis with SnSAG5-specific primers confirmed the presence of the SnSAG5 gene in Western blot-positive strains, while also suggesting the presence of a novel SnSAG sequence in the SnSAG1-deficient, SnSAG5-deficient otter isolate. The findings provide further indication of S. neurona strain diversity, which has implications for diagnostic testing and development of vaccines against EPM as well as the population biology of Sarcocystis cycling in the opossum definitive host.

  15. Prevalence of chronic hepatitis B virus infection and infrastructure for its diagnosis in Madagascar: implication for the WHO's elimination strategy.

    Science.gov (United States)

    Andriamandimby, Soa Fy; Olive, Marie-Marie; Shimakawa, Yusuke; Rakotomanana, Fanjasoa; Razanajatovo, Iony Manitra; Andrianinarivomanana, Tsarasoa Malala; Ravalohery, Jean-Pierre; Andriamamonjy, Seta; Rogier, Christophe; Héraud, Jean-Michel

    2017-08-04

    WHO developed a global strategy to eliminate hepatitis B by 2030 and set target to treat 80% of people with chronic hepatitis B virus (HBV) infection eligible for antiviral treatment. As a first step to achieve this goal, it is essential to conduct a situation analysis that is fundamental to designing national hepatitis plans. We therefore estimated the prevalence of chronic HBV infection, and described the existing infrastructure for HBV diagnosis in Madagascar. We conducted a stratified multi-stage serosurvey of hepatitis B surface antigen (HBsAg) in adults aged ≥18 years using 28 sentinel surveillance sites located throughout the country. We obtained the list of facilities performing HBV testing from the Ministry of Health, and contacted the person responsible at each facility. A total of 1778 adults were recruited from the 28 study areas. The overall weighted seroprevalence of HBsAg was 6.9% (95% CI: 5.6-8.6). Populations with a low socio-economic status and those living in rural areas had a significantly higher seroprevalence of HBsAg. The ratio of facilities equipped to perform HBsAg tests per 100,000 inhabitants was 1.02 in the capital city of Antananarivo and 0.21 outside the capital. There were no facilities with the capacity to perform HBV DNA testing or transient elastography to measure liver fibrosis. There are only five hepatologists in Madagascar. Madagascar has a high-intermediate level of endemicity for HBV infection with a severely limited capacity for its diagnosis and treatment. Higher HBsAg prevalence in rural or underprivileged populations underlines the importance of a public health approach to decentralize the management of chronic HBV carriers in Madagascar by using simple and low-cost diagnostic tools.

  16. Prevalence of hepatitis B and C infection in persons living with HIV enrolled in care in Rwanda.

    Science.gov (United States)

    Umutesi, Justine; Simmons, Bryony; Makuza, Jean D; Dushimiyimana, Donatha; Mbituyumuremyi, Aimable; Uwimana, Jean Marie; Ford, Nathan; Mills, Edward J; Nsanzimana, Sabin

    2017-05-02

    Hepatitis B (HBV) and C (HCV) are important causes of morbidity and mortality in people living with human immunodeficiency virus (HIV). The burden of these co-infections in sub-Saharan Africa is still unclear. We estimated the prevalence of the hepatitis B surface antigen (HBsAg) and hepatitis C antibody (HCVAb) among HIV-infected individuals in Rwanda and identified factors associated with infection. Between January 2016 and June 2016, we performed systematic screening for HBsAg and HCVAb among HIV-positive individuals enrolled at public and private HIV facilities across Rwanda. Results were analyzed to determine marker prevalence and variability by demographic factors. Overall, among 117,258 individuals tested, the prevalence of HBsAg and HCVAb was 4.3% (95% confidence interval [CI] (4.2-4.4) and 4.6% (95% CI 4.5-4.7) respectively; 182 (0.2%) HIV+ individuals were co-infected with HBsAg and HCVAb. Prevalence was higher in males (HBsAg, 5.4% [5.1-5.6] vs. 3.7% [3.5-3.8]; HCVAb, 5.0% [4.8-5.2] vs. 4.4% [4.3-4.6]) and increased with age; HCVAb prevalence was significantly higher in people aged ≥65 years (17.8% [16.4-19.2]). Prevalence varied geographically. HBV and HCV co-infections are common among HIV-infected individuals in Rwanda. It is important that viral hepatitis prevention and treatment activities are scaled-up to control further transmission and reduce the burden in this population. Particular efforts should be made to conduct targeted screening of males and the older population. Further assessment is required to determine rates of HBV and HCV chronicity among HIV-infected individuals and identify effective strategies to link individuals to care and treatment.

  17. Molecular analysis of Toxoplasma gondii Surface Antigen 1 (SAG1) gene cloned from Toxoplasma gondii DNA isolated from Javanese acute toxoplasmosis

    Science.gov (United States)

    Haryati, Sri; Agung Prasetyo, Afiono; Sari, Yulia; Dharmawan, Ruben

    2018-05-01

    Toxoplasma gondii Surface Antigen 1 (SAG1) is often used as a diagnostic tool due to its immunodominant-specific as antigen. However, data of the Toxoplasma gondii SAG1 protein from Indonesian isolate is limited. To study the protein, genomic DNA was isolated from a Javanese acute toxoplasmosis blood samples patient. A complete coding sequence of Toxoplasma gondii SAG1 was cloned and inserted into an Escherichia coli expression plasmid and sequenced. The sequencing results were subjected to bioinformatics analysis. The Toxoplasma gondii SAG1 complete coding sequences were successfully cloned. Physicochemical analysis revealed the 336 aa of SAG1 had 34.7 kDa of weight. The isoelectric point and aliphatic index were 8.4 and 78.4, respectively. The N-terminal methionine half-life in Escherichia coli was more than 10 hours. The antigenicity, secondary structure, and identification of the HLA binding motifs also had been discussed. The results of this study would contribute information about Toxoplasma gondii SAG1 and benefits for further works willing to develop diagnostic and therapeutic strategies against the parasite.

  18. Determinants of variant surface antigen antibody response in severe Plasmodium falciparum malaria in an area of low and unstable malaria transmission

    DEFF Research Database (Denmark)

    A-Elgadir, T M E; Theander, T G; Elghazali, G

    2006-01-01

    The variant surface antigens (VSA) of infected erythrocytes are important pathogenic markers, a set of variants (VSA(SM)), were assumed to be associated with severe malaria (SM), while SM constitutes clinically diverse forms, such as, severe malarial anemia (SMA) and cerebral malaria (CM). This s...

  19. Performance evaluation of LUMIPULSE G1200 autoimmunoanalyzer for the detection of serum hepatitis B virus markers.

    Science.gov (United States)

    Choi, Seung Jun; Park, Yongjung; Lee, Eun Young; Kim, Sinyoung; Kim, Hyon-Suk

    2013-05-01

    We evaluated recently introduced automated immunoassay analyzer LUMIPULSE G1200 (Fujirebio, Inc., Tokyo, Japan) for detecting serologic hepatitis B virus (HBV) markers by comparison with the results by ARCHITECT i4000SR (Abbott, Abbott Park, IL). Precision performance was evaluated over 20 days. HBV surface antigen (HBsAg), HBV e antigen (HBeAg), antibodies to HBV core antigen (anti-HBc), antibodies to HBeAg (anti-HBe), and antibodies to HBsAg (anti-HBs) in a total of 1,000 serum samples were assessed by the two analyzers. Discrepant results were retested by COBAS e411 (Roche Diagnostics, Mannheim, Germany). LUMIPULSE showed excellent precision performance of total imprecision less than 3.5% coefficient of variation. The qualitative results between the two analyzers were agreed with each other in 92.0-99.8% of the specimens according to the different HBV markers. The degrees of reactions for HBeAg were moderately correlated between the two analyzers (r = 0.60), and those of other HBV markers were well correlated (r = 0.80 or greater). However, there were 183 discrepancies among 1,000 cases, and most of them showed degree of reaction around the cutoff values. LUMIPULSE G1200 showed well-concordant results with ARCITHECT for hepatitis B serologic tests. However, results near the cutoff values would need to be retested with other immunoassay or molecular methods, when the serological profiles of HBV markers are unusual or are not correlated to the clinical conditions of the patient, due to discrepancies between the immunoassay analyzers. © 2013 Wiley Periodicals, Inc.

  20. Strong Antibody Responses Induced by Protein Antigens Conjugated onto the Surface of Lecithin-Based Nanoparticles

    Science.gov (United States)

    Sloat, Brian R.; Sandoval, Michael A.; Hau, Andrew M.; He, Yongqun; Cui, Zhengrong

    2009-01-01

    An accumulation of research over the years has demonstrated the utility of nanoparticles as antigen carriers with adjuvant activity. Herein we defined the adjuvanticity of a novel lecithin-based nanoparticle engineered from emulsions. The nanoparticles were spheres of around 200 nm. Model protein antigens, bovine serum albumin (BSA) or Bacillus anthracis protective antigen (PA) protein, were covalently conjugated onto the nanoparticles. Mice immunized with the BSA-conjugated nanoparticles developed strong anti-BSA antibody responses comparable to that induced by BSA adjuvanted with incomplete Freund's adjuvant and 6.5-fold stronger than that induced by BSA adsorbed onto aluminum hydroxide. Immunization of mice with the PA-conjugated nanoparticles elicited a quick, strong, and durable anti-PA antibody response that afforded protection of the mice against a lethal dose of anthrax lethal toxin challenge. The potent adjuvanticity of the nanoparticles was likely due to their ability to move the antigens into local draining lymph nodes, to enhance the uptake of the antigens by antigen-presenting cells (APCs), and to activate APCs. This novel nanoparticle system has the potential to serve as a universal protein-based vaccine carrier capable of inducing strong immune responses. PMID:19729045

  1. Reduction of T-Helper Cell Responses to Recall Antigen Mediated by Codelivery with Peptidoglycan via the Intestinal Nanomineral-Antigen Pathway.

    Science.gov (United States)

    Hewitt, Rachel E; Robertson, Jack; Haas, Carolin T; Pele, Laetitia C; Powell, Jonathan J

    2017-01-01

    Naturally occurring intestinal nanomineral particles constituently form in the mammalian gut and trap luminal protein and microbial components. These cargo loaded nanominerals are actively scavenged by M cells of intestinal immune follicles, such as Peyer's patches and are passed to antigen-presenting cells. Using peripheral blood mononuclear cell populations as an in vitro model of nanomineral uptake and antigen presentation, we show that monocytes avidly phagocytose nanomineral particles bearing antigen and peptidoglycan (PGN), and that the presence of PGN within particles downregulates their cell surface MHC class II and upregulates programmed death receptor ligand 1. Nanomineral delivery of antigen suppresses antigen-specific CD4 + T cell responses, an effect that is enhanced in the presence of PGN. Blocking the interleukin-10 receptor restores CD4 + T cell responses to antigen codelivered with PGN in nanomineral form. Using human intestinal specimens, we have shown that the in vivo nanomineral pathway operates in an interleukin-10 rich environment. Consequently, the delivery of a dual antigen-PGN cargo by endogenous nanomineral in vivo is likely to be important in the establishment of intestinal tolerance, while their synthetic mimetics present a potential delivery system for therapeutic applications targeting the modulation of Peyer's patch T cell responses.

  2. Clinical patterns associated with the concurrent detection of anti-HBs and HBV DNA.

    Science.gov (United States)

    Anastasiou, Olympia E; Widera, Marek; Korth, Johannes; Kefalakes, Helenie; Katsounas, Antonios; Hilgard, Gudrun; Gerken, Guido; Canbay, Ali; Ciesek, Sandra; Verheyen, Jens

    2018-02-01

    Simultaneous detection of anti-HBs and HBV DNA is a rare serological combination and has been described in acute and chronic HBV infection. To scrutinize viral and clinical patterns associated with concurrent detection of anti-HBs and HBV DNA. Simultaneous detection of anti-HBs and HBV DNA was observed in 64/1444 (4.4%) patients treated for HBV infection at the University Hospital of Essen from 2006 to 2016 (8 with acute, 20 with reactivated, and 36 chronic HBV infection). Clinical data and laboratory parameters were analyzed. Regions of the small hepatitis B surface antigen (SHB) and the reverse transcriptase (RT) were sequenced using next generation sequencing (NGS). Among the 64 patients with detectable HBV DNA and anti-HBs, 17 were HBsAg negative (HBsAg[-]), and two had acute liver failure. Patients with acute HBV infection had fewer genotype specific amino acid substitutions in the SHB region than patients with reactivated HBV infection (4 [4.5] vs 9 [16.25], P = 0.043). However, we could observe a significantly higher number of mutations in the a-determinant region when comparing chronically infected patients to patients with acute infection (0 [1] vs 1 [1], P = 0.044). The ratio of nonsynonymous to synonymous mutations (Ka/Ks) was on average >1 for the SHB region and 1) in the SHB region indicates that anti-HBs might have exerted selection pressure on the HBsAg. In three cases the diagnosis of acute HBV infection would have been at least delayed by only focusing on HBsAg testing. © 2017 Wiley Periodicals, Inc.

  3. Circulating Gut-Homing (α4β7+) Plasmablast Responses against Shigella Surface Protein Antigens among Hospitalized Patients with Diarrhea.

    Science.gov (United States)

    Sinha, Anuradha; Dey, Ayan; Saletti, Giulietta; Samanta, Pradip; Chakraborty, Partha Sarathi; Bhattacharya, M K; Ghosh, Santanu; Ramamurthy, T; Kim, Jae-Ouk; Yang, Jae Seung; Kim, Dong Wook; Czerkinsky, Cecil; Nandy, Ranjan K

    2016-07-01

    Developing countries are burdened with Shigella diarrhea. Understanding mucosal immune responses associated with natural Shigella infection is important to identify potential correlates of protection and, as such, to design effective vaccines. We performed a comparative analysis of circulating mucosal plasmablasts producing specific antibodies against highly conserved invasive plasmid antigens (IpaC, IpaD20, and IpaD120) and two recently identified surface protein antigens, pan-Shigella surface protein antigen 1 (PSSP1) and PSSP2, common to all virulent Shigella strains. We examined blood and stool specimens from 37 diarrheal patients admitted to the Infectious Diseases & Beliaghata General Hospital, Kolkata, India. The etiological agent of diarrhea was investigated in stool specimens by microbiological methods and real-time PCR. Gut-homing (α4β7 (+)) antibody-secreting cells (ASCs) were isolated from patient blood by means of combined magnetic cell sorting and two-color enzyme-linked immunosorbent spot (ELISPOT) assay. Overall, 57% (21 of 37) and 65% (24 of 37) of the patients were positive for Shigella infection by microbiological and real-time PCR assays, respectively. The frequency of α4β7 (+) IgG ASC responders against Ipas was higher than that observed against PSSP1 or PSSP2, regardless of the Shigella serotype isolated from these patients. Thus, α4β7 (+) ASC responses to Ipas may be considered an indirect marker of Shigella infection. The apparent weakness of ASC responses to PSSP1 is consistent with the lack of cross-protection induced by natural Shigella infection. The finding that ASC responses to IpaD develop in patients with recent-onset shigellosis indicates that such responses may not be protective or may wane too rapidly and/or be of insufficient magnitude. Copyright © 2016, American Society for Microbiology. All Rights Reserved.

  4. The prevalence of hepatitis B virus E antigen among Ghanaian ...

    African Journals Online (AJOL)

    We studied the prevalence of hepatitis B virus 'e' antigen (HBeAg) among individuals determined to be hepatitis B virus (HBV) surface antigen- positive and analyzed the gender/age category associated with more active HBV infection and whether alteration in the levels of alanine aminotransferase could be associated with ...

  5. Stop codons in the hepatitis B surface proteins are enriched during antiviral therapy and are associated with host cell apoptosis

    International Nuclear Information System (INIS)

    Colledge, Danielle; Soppe, Sally; Yuen, Lilly; Selleck, Lucy; Walsh, Renae; Locarnini, Stephen; Warner, Nadia

    2017-01-01

    Premature stop codons in the hepatitis B virus (HBV) surface protein can be associated with nucleos(t)ide analogue resistance due to overlap of the HBV surface and polymerase genes. The aim of this study was to determine the effect of the replication of three common surface stop codon variants on the hepatocyte. Cell lines were transfected with infectious HBV clones encoding surface stop codons rtM204I/sW196*, rtA181T/sW172*, rtV191I/sW182*, and a panel of substitutions in the surface proteins. HBsAg was measured by Western blotting. Proliferation and apoptosis were measured using flow cytometry. All three surface stop codon variants were defective in HBsAg secretion. Cells transfected with these variants were less proliferative and had higher levels of apoptosis than those transfected with variants that did not encode surface stop codons. The most cytopathic variant was rtM204I/sW196*. Replication of HBV encoding surface stop codons was toxic to the cell and promoted apoptosis, exacerbating disease progression. - Highlights: •Under normal circumstances, HBV replication is not cytopathic. •Premature stop codons in the HBV surface protein can be selected and enriched during nucleos(t)ide analogue therapy. •Replication of these variants can be cytopathic to the cell and promote apoptosis. •Inadequate antiviral therapy may actually promote disease progression.

  6. Stop codons in the hepatitis B surface proteins are enriched during antiviral therapy and are associated with host cell apoptosis

    Energy Technology Data Exchange (ETDEWEB)

    Colledge, Danielle; Soppe, Sally; Yuen, Lilly; Selleck, Lucy; Walsh, Renae; Locarnini, Stephen, E-mail: stephen.locarnini@mh.org.au; Warner, Nadia

    2017-01-15

    Premature stop codons in the hepatitis B virus (HBV) surface protein can be associated with nucleos(t)ide analogue resistance due to overlap of the HBV surface and polymerase genes. The aim of this study was to determine the effect of the replication of three common surface stop codon variants on the hepatocyte. Cell lines were transfected with infectious HBV clones encoding surface stop codons rtM204I/sW196*, rtA181T/sW172*, rtV191I/sW182*, and a panel of substitutions in the surface proteins. HBsAg was measured by Western blotting. Proliferation and apoptosis were measured using flow cytometry. All three surface stop codon variants were defective in HBsAg secretion. Cells transfected with these variants were less proliferative and had higher levels of apoptosis than those transfected with variants that did not encode surface stop codons. The most cytopathic variant was rtM204I/sW196*. Replication of HBV encoding surface stop codons was toxic to the cell and promoted apoptosis, exacerbating disease progression. - Highlights: •Under normal circumstances, HBV replication is not cytopathic. •Premature stop codons in the HBV surface protein can be selected and enriched during nucleos(t)ide analogue therapy. •Replication of these variants can be cytopathic to the cell and promote apoptosis. •Inadequate antiviral therapy may actually promote disease progression.

  7. Sero‑prevalence of Hepatitis B Virus Infection and its Risk factors ...

    African Journals Online (AJOL)

    with the exception of Morocco and Tunisia, which have intermediate endemicity. ... tested for hepatitis B e antigen (HBeAg) using ELISA kits (Orgenics, Israel). A pretested ..... Table 3: Prevalence of HBsAg in relation to sociodemographic.

  8. An immobilization antigen gene of the fish-parasitic protozoan Ichthyophthirius multifiliis strain ARS-6

    Science.gov (United States)

    Ichthyophthirius multifiliis (Ich) is a severe fish parasite that causes ‘white spot’ disease in many freshwater fish and leads to high mortality. The antigens on the parasite surface are involved in the antibody-mediated immobilization and hence designated as immobilization antigens (i-antigens). ...

  9. Flow Cytometric Analysis of T, B, and NK Cells Antigens in Patients with Mycosis Fungoides

    Directory of Open Access Journals (Sweden)

    Serkan Yazıcı

    2015-01-01

    Full Text Available We retrospectively analyzed the clinicopathological correlation and prognostic value of cell surface antigens expressed by peripheral blood mononuclear cells in patients with mycosis fungoides (MF. 121 consecutive MF patients were included in this study. All patients had peripheral blood flow cytometry as part of their first visit. TNMB and histopathological staging of the cases were retrospectively performed in accordance with International Society for Cutaneous Lymphomas/European Organization of Research and Treatment of Cancer (ISCL/EORTC criteria at the time of flow cytometry sampling. To determine prognostic value of cell surface antigens, cases were divided into two groups as stable and progressive disease. 17 flow cytometric analyses of 17 parapsoriasis (PP and 11 analyses of 11 benign erythrodermic patients were included as control groups. Fluorescent labeled monoclonal antibodies were used to detect cell surface antigens: T cells (CD3+, CD4+, CD8+, TCRαβ+, TCRγδ+, CD7+, CD4+CD7+, CD4+CD7−, and CD71+, B cells (HLA-DR+, CD19+, and HLA-DR+CD19+, NKT cells (CD3+CD16+CD56+, and NK cells (CD3−CD16+CD56+. The mean value of all cell surface antigens was not statistically significant between parapsoriasis and MF groups. Along with an increase in cases of MF stage statistically significant difference was found between the mean values of cell surface antigens. Flow cytometric analysis of peripheral blood cell surface antigens in patients with mycosis fungoides may contribute to predicting disease stage and progression.

  10. Low prevalence of liver disease but regional differences in HBV treatment characteristics mark HIV/HBV co-infection in a South African HIV clinical trial.

    Directory of Open Access Journals (Sweden)

    Prudence Ive

    Full Text Available Hepatitis B virus (HBV infection is endemic in South Africa however, there is limited data on the degree of liver disease and geographic variation in HIV/HBV coinfected individuals. In this study, we analysed data from the CIPRA-SA 'Safeguard the household study' in order to assess baseline HBV characteristics in HIV/HBV co-infection participants prior to antiretroviral therapy (ART initiation.812 participants from two South African townships Soweto and Masiphumelele were enrolled in a randomized trial of ART (CIPRA-SA. Participants were tested for hepatitis B surface antigen (HBsAg, hepatitis B e antigen (HBeAg, and HBV DNA. FIB-4 scores were calculated at baseline.Forty-eight (5.9% were HBsAg positive, of whom 28 (58.3% were HBeAg positive. Of those with HBV, 29.8% had an HBV DNA<2000 IU/ml and ALT<40 IU/ml ; 83.0% had a FIB-4 score <1.45, consistent with absent or minimal liver disease. HBV prevalence was 8.5% in Masiphumelele compared to 3.8% in Soweto (relative risk 2.3; 95% CI: 1.3-4.0. More participants in Masiphumelele had HBeAg-negative disease (58% vs. 12%, p = 0.002 and HBV DNA levels ≤2000 IU/ml, (43% vs. 6% p<0.007.One third of HIV/HBV co-infected subjects had low HBV DNA levels and ALT while the majority had indicators of only mild liver disease. There were substantial regional differences in HBsAg and HbeAg prevalence in HIV/HBV co-infection between two regions in South Africa. This study highlights the absence of severe liver disease and the marked regional differences in HIV/HBV co-infection in South Africa and will inform treatment decisions in these populations.

  11. Longitudinal evaluation of humoral immune response and merozoite surface antigen diversity in calves naturally infected with Babesia bovis, in São Paulo, Brazil.

    Science.gov (United States)

    Matos, Carlos António; Gonçalves, Luiz Ricardo; Alvarez, Dasiel Obregón; Freschi, Carla Roberta; Silva, Jenevaldo Barbosa da; Val-Moraes, Silvana Pompeia; Mendes, Natalia Serra; André, Marcos Rogério; Machado, Rosangela Zacarias

    2017-01-01

    Babesiosis is an economically important infectious disease affecting cattle worldwide. In order to longitudinally evaluate the humoral immune response against Babesia bovis and the merozoite surface antigen diversity of B. bovis among naturally infected calves in Taiaçu, Brazil, serum and DNA samples from 15 calves were obtained quarterly, from their birth to 12 months of age. Anti-B. bovis IgG antibodies were detected by means of the indirect fluorescent antibody test (IFAT) and enzyme-linked immunosorbent assay (ELISA). The polymerase chain reaction (PCR) was used to investigate the genetic diversity of B. bovis, based on the genes that encode merozoite surface antigens (MSA-1, MSA-2b and MSA-2c). The serological results demonstrated that up to six months of age, all the calves developed active immunity against B. bovis. Among the 75 DNA samples evaluated, 2, 4 and 5 sequences of the genes msa-1, msa-2b and msa-2c were obtained. The present study demonstrated that the msa-1 and msa-2b genes sequences amplified from blood DNA of calves positive to B. bovis from Taiaçu were genetically distinct, and that msa-2c was conserved. All animals were serologically positive to ELISA and IFAT, which used full repertoire of parasite antigens in despite of the genetic diversity of MSAs.

  12. The neural cell adhesion molecule L1 is distinct from the N-CAM related group of surface antigens BSP-2 and D2

    DEFF Research Database (Denmark)

    Faissner, A; Kruse, J; Goridis, C

    1984-01-01

    The neural cell adhesion molecule L1 and the group of N-CAM related molecules, BSP-2 and D2 antigen, are immunochemically distinct molecular species. The two groups of surface molecules are also functionally distinct entities, since inhibition of Ca2+-independent adhesion among early post-natal m...

  13. Preparation of miniantibodies to Azospirillum brasilense Sp245 surface antigens and their use for bacterial detection.

    Science.gov (United States)

    Dykman, Lev A; Staroverov, Sergei A; Guliy, Olga I; Ignatov, Oleg V; Fomin, Alexander S; Vidyasheva, Irina V; Karavaeva, Olga A; Bunin, Viktor D; Burygin, Gennady L

    2012-01-01

    This article reports the first preparation of miniantibodies to Azospirillum brasilense Sp245 surface antigens by using a combinatorial phage library of sheep antibodies. The prepared phage antibodies were used for the first time for lipopolysaccharide and flagellin detection by dot assay, electro-optical analysis of cell suspensions, and transmission electron microscopy. Interaction of A. brasilense Sp245 with antilipopolysaccharide and antiflagellin phage-displayed miniantibodies caused the magnitude of the electro-optical signal to change considerably. The electro-optical results were in good agreement with the electron microscopic data. This is the first reported possibility of employing phage-displayed miniantibodies in bacterial detection aided by electro-optical analysis of cell suspensions.

  14. Effect of radiation on the expression of tumor-associated antigens of human lung adenocarcinoma cells

    International Nuclear Information System (INIS)

    Hareyama, Masato

    1988-01-01

    We studied the effects of irradiation on the expression of a tumor-associated antigen (YH206 antigen) of cultured human lung adenocarcinoma A549 cells by using enzyme-linked immunosorbent assay (ELISA) and flow cytometry. YH206 antigen is preferentially expressed on adenocarcinoma cells. Irradiation of A549 cells remarkably increased the expression of YH206 antigen on the cell surface and the level of the antigen in the culture supernatant as well as in the cell lysate, whereas it significantly affected the expression of HLA (MHC-class I) antigen on the same cells. The expression of HLA antigen on the cell was also increased after treatment of the cells with interferon-γ. In an additional experiment, cells were stained simultaneously for surface antigens (fluorescein coupled antibodies) and for DNA content (propidium iodide), and then dual parameter measurements were performed by flow cytometry to analyse the relationship between antigen levels and the cell cycle. YH206 antigen and HLA antigen increased more in the S and G 2 /M phases of the cell cycle than in G 0 /G 1 . The expression of YH206 antigen was enhanced in the S and G 2 /M phases by irradiation, whereas the expression of HLA antigen was enhanced in each phase of the cell cycle with irradiation or IFN. These results suggest that irradiation plays a key role in the change of the expression of certain tumor-associated antigens. (author)

  15. Faktor Risiko Hepatitis B Pada Tenaga Kesehatan Kota Pekanbaru

    Directory of Open Access Journals (Sweden)

    Rina Amtarina

    2014-10-01

    Full Text Available Hepatitis B is still the one of serious public health problem in the world including Indonesia. Transmission of hepatitis B virus (HBV is strongly associated with use of contaminated blood products. For many people infected with HBV, risk factors of transmission are unknown. We examined risk factors for acquiring HBV in health care worker. This research was done by retrospective to blood participants who tested positive for HBs antibody or HBs antigen, using a questionnaire.participants divided into 2 groups. Had/having exposed to VHB with ati-HBs Positive HBsag negative or HBsag positive, anti-HBs negative and never had exposed to VHB with HBsag and anti-HBs negative. Positive anti- HBs were identified in 32 (29.1% of 110 participants. Positive HBs antigen anti-HBs negative was identified in 1 (0.9% of 110 participants. In questionnaire analysis, significant risk factors for HBV infection among HBs antibody - positive participants were tooth extraction in 29 (90.6%, and needle stick injuries in 18 (56.2% of 32 participants. Only 3 (9.3% of 32 participants with HBs antibody - positive had history of post infected HBV for several years ago. In 1 participant with HBs antigen - positive, significant risk factors were needle stick injuries, acupuncture, tooth extraction, and contact infected person. The most significant risk factors for transmission of hepatitis B in health care worker in Pekanbaru city are tooth extraction and needle stick injuries.

  16. Viral hepatitis B- an overview

    African Journals Online (AJOL)

    1994-08-08

    Aug 8, 1994 ... of HBsAg.'o This excess HBsAg can be used to provide ... bound to aluminium hydroxide and thus do not produce detectable ..... formation of immune complexes or to other poorly ..... Australia-antigen-associated hepatitis.

  17. Reduction of T-Helper Cell Responses to Recall Antigen Mediated by Codelivery with Peptidoglycan via the Intestinal Nanomineral–Antigen Pathway

    Science.gov (United States)

    Hewitt, Rachel E.; Robertson, Jack; Haas, Carolin T.; Pele, Laetitia C.; Powell, Jonathan J.

    2017-01-01

    Naturally occurring intestinal nanomineral particles constituently form in the mammalian gut and trap luminal protein and microbial components. These cargo loaded nanominerals are actively scavenged by M cells of intestinal immune follicles, such as Peyer’s patches and are passed to antigen-presenting cells. Using peripheral blood mononuclear cell populations as an in vitro model of nanomineral uptake and antigen presentation, we show that monocytes avidly phagocytose nanomineral particles bearing antigen and peptidoglycan (PGN), and that the presence of PGN within particles downregulates their cell surface MHC class II and upregulates programmed death receptor ligand 1. Nanomineral delivery of antigen suppresses antigen-specific CD4+ T cell responses, an effect that is enhanced in the presence of PGN. Blocking the interleukin-10 receptor restores CD4+ T cell responses to antigen codelivered with PGN in nanomineral form. Using human intestinal specimens, we have shown that the in vivo nanomineral pathway operates in an interleukin-10 rich environment. Consequently, the delivery of a dual antigen–PGN cargo by endogenous nanomineral in vivo is likely to be important in the establishment of intestinal tolerance, while their synthetic mimetics present a potential delivery system for therapeutic applications targeting the modulation of Peyer’s patch T cell responses. PMID:28367148

  18. Carcinoma-associated antigens

    International Nuclear Information System (INIS)

    Bartorelli, A.; Accinni, R.

    1981-01-01

    This invention relates to novel antigens associated with breast carcinoma, anti-sera specific to said antigens, 125 I-labeled forms of said antigens and methods of detecting said antigens in serum or plasma. The invention also relates to a diagnostic kit containing standardised antigens or antisera or marked forms thereof for the detection of said antigens in human blood, serum or plasma. (author)

  19. Immunity to tumour antigens.

    Science.gov (United States)

    Li, Geng; Ali, Selman A; McArdle, Stephanie E B; Mian, Shahid; Ahmad, Murrium; Miles, Amanda; Rees, Robert C

    2005-01-01

    During the last decade, a large number of human tumour antigens have been identified. These antigens are classified as tumour-specific shared antigens, tissue-specific differentiation antigens, overexpressed antigens, tumour antigens resulting from mutations, viral antigens and fusion proteins. Antigens recognised by effectors of immune system are potential targets for antigen-specific cancer immunotherapy. However, most tumour antigens are self-proteins and are generally of low immunogenicity and the immune response elicited towards these tumour antigens is not always effective. Strategies to induce and enhance the tumour antigen-specific response are needed. This review will summarise the approaches to discovery of tumour antigens, the current status of tumour antigens, and their potential application to cancer treatment.

  20. Seroprevalence of hepatitis B Sur- face antigen among apparently ...

    African Journals Online (AJOL)

    2012-01-08

    Jan 8, 2012 ... and provision of universal HBV vaccination should be given urgent priority. Keywords: Children, HBsAg,. Primary school, Seroprevalence. Introduction. Hepatitis B virus infection is a disease of global distri- bution and constitutes a major public health prob- lem.1More than one third of the world's population ...

  1. Energy filtering transmission electron microscopy immunocytochemistry and antigen retrieval of surface layer proteins from Tannerella forsythensis using microwave or autoclave heating with citraconic anhydride

    Science.gov (United States)

    2012-01-01

    Tannerella forsythensis (Bacteroides forsythus), an anaerobic Gram-negative species of bacteria that plays a role in the progression of periodontal disease, has a unique bacterial protein profile. It is characterized by two unique protein bands with molecular weights of more than 200 kDa. It also is known to have a typical surface layer (S-layer) consisting of regularly arrayed subunits outside the outer membrane. We examined the relationship between high molecular weight proteins and the S-layer using electron microscopic immunolabeling with chemical fixation and an antigen retrieval procedure consisting of heating in a microwave oven or autoclave with citraconic anhydride. Immunogold particles were localized clearly at the outermost cell surface. We also used energy-filtering transmission electron microscopy (EFTEM) to visualize 3, 3′-diaminobenzidine tetrahydrochloride (DAB) reaction products after microwave antigen retrieval with 1% citraconic anhydride. The three-window method for electron spectroscopic images (ESI) of nitrogen by the EFTEM reflected the presence of moieties demonstrated by the DAB reaction with horseradish peroxidase (HRP)-conjugated secondary antibodies instead of immunogold particles. The mapping patterns of net nitrogen were restricted to the outermost cell surface. PMID:22984898

  2. Improved detection of equine antibodies against Sarcocystis neurona using polyvalent ELISAs based on the parasite SnSAG surface antigens.

    Science.gov (United States)

    Yeargan, Michelle R; Howe, Daniel K

    2011-02-28

    Equine protozoal myeloencephalitis (EPM) is a common neurologic disease of horses that is caused by the apicomplexan pathogen Sarcocystis neurona. To help improve serologic diagnosis of S. neurona infection, we have modified existing enzyme-linked immunosorbent assays (ELISAs) based on the immunogenic parasite surface antigens SnSAG2, SnSAG3, and SnSAG4 to make the assays polyvalent, thereby circumventing difficulties associated with parasite antigenic variants and diversity in equine immune responses. Two approaches were utilized to achieve polyvalence: (1) mixtures of the individual recombinant SnSAGs (rSnSAGs) were included in single ELISAs; (2) a collection of unique SnSAG chimeras that fused protein domains from different SnSAG surface antigens into a single recombinant protein were generated for use in the ELISAs. These new assays were assessed using a defined sample set of equine sera and cerebrospinal fluids (CSFs) that had been characterized by Western blot and/or were from confirmed EPM horses. While all of the polyvalent ELISAs performed relatively well, the highest sensitivity and specificity (100%/100%) were achieved with assays containing the rSnSAG4/2 chimera (Domain 1 of SnSAG4 fused to SnSAG2) or using a mixture of rSnSAG3 and rSnSAG4. The rSnSAG4 antigen alone and the rSnSAG4/3 chimera (Domain 1 of SnSAG4 fused to Domain 2 of SnSAG3) exhibited the next best accuracy at 95.2% sensitivity and 100% specificity. Binding ratios and percent positivity (PP) ratios, determined by comparing the mean values for positive versus negative samples, showed that the most advantageous signal to noise ratios were provided by rSnSAG4 and the rSnSAG4/3 chimera. Collectively, our results imply that a polyvalent ELISA based on SnSAG4 and SnSAG3, whether as a cocktail of two proteins or as a single chimeric protein, can give optimal results in serologic testing of serum or CSF for the presence of antibodies against S. neurona. The use of polyvalent SnSAG ELISAs will

  3. Characterization of foot- and mouth disease virus antigen by surface-enhanced laser desorption ionization-time of flight-mass spectrometry in aqueous and oil-emulsion formulations

    NARCIS (Netherlands)

    Harmsen, M.M.; Jansen, J.; Westra, D.F.; Coco-Martin, J.M.

    2010-01-01

    We have used a novel method, surface-enhanced laser desorption ionization-time of flight-mass spectrometry (SELDI-TOF-MS), to characterize foot-and-mouth disease virus (FMDV) vaccine antigens. Using specific capture with FMDV binding recombinant antibody fragments and tryptic digestion of FMDV

  4. Rapid desensitization induces internalization of antigen-specific IgE on mouse mast cells.

    Science.gov (United States)

    Oka, Tatsuya; Rios, Eon J; Tsai, Mindy; Kalesnikoff, Janet; Galli, Stephen J

    2013-10-01

    Rapid desensitization transiently prevents severe allergic reactions, allowing administration of life-saving therapies in previously sensitized patients. However, the mechanisms underlying successful rapid desensitization are not fully understood. We sought to investigate whether the mast cell (MC) is an important target of rapid desensitization in mice sensitized to exhibit IgE-dependent passive systemic anaphylaxis in vivo and to investigate the antigen specificity and underlying mechanisms of rapid desensitization in our mouse model. C57BL/6 mice (in vivo) or primary isolated C57BL/6 mouse peritoneal mast cells (PMCs; in vitro) were passively sensitized with antigen-specific anti-2,4-dinitrophenyl IgE, anti-ovalbumin IgE, or both. MCs were exposed over a short period of time to increasing amounts of antigen (2,4-dinitrophenyl-human serum albumin or ovalbumin) in the presence of extracellular calcium in vitro or by means of intravenous administration to sensitized mice in vivo before challenging the mice with or exposing the PMCs to optimal amounts of specific or irrelevant antigen. Rapidly exposing mice or PMCs to progressively increasing amounts of specific antigen inhibited the development of antigen-induced hypothermia in sensitized mice in vivo and inhibited antigen-induced PMC degranulation and prostaglandin D2 synthesis in vitro. Such MC hyporesponsiveness was induced antigen-specifically and was associated with a significant reduction in antigen-specific IgE levels on MC surfaces. Rapidly exposing MCs to progressively increasing amounts of antigen can both enhance the internalization of antigen-specific IgE on the MC surface and also desensitize these cells in an antigen-specific manner in vivo and in vitro. Copyright © 2013 American Academy of Allergy, Asthma & Immunology. Published by Mosby, Inc. All rights reserved.

  5. Author Details

    African Journals Online (AJOL)

    HBsAg) antigen in three densely populated communities in Kumasi, Ghana Abstract PDF · Vol 1, No 4 (2012) - Articles Management of complex ankle fracture: A Ghanaian experience. Abstract PDF · Vol 2, No 3 (2013) - Articles Management of ...

  6. Markers of viral hepatitis in hemophiliacs

    International Nuclear Information System (INIS)

    Malik, N.; Hussain, Z.

    2006-01-01

    Sero prevalence of Hepatitis B surface antigen (HbsAg) and anti-HCV IgG was determined in 100 persons with Hemophilia (PWH), registered with Hemophilia Patient Welfare Society (HPWS), Lahore Zone, Pakistan. The study shows that 4% were positive for HBsAg. However, there was a high level of anti-HCV sero positivity (56%) in our PWH, including many patients in younger age groups. When compared with figures from PWH in other regions of Asia like 23% in Western India, 33% in Sri Lanka and 15% of those in Iran, this figure is one of the highest. This rate is a reflection of the same rising trend in our population that is now exceeding 10%. The practice of unscreened blood/blood-products transfusions in the backdrop of high prevalence of HCV in our population is responsible for high figures seen in PWH. The need is to increase awareness amongst the patients, health care workers and policy makers about the transfusion associated viral infections in a group of patients who already had a hereditary disorder of severe nature. (author)

  7. Keratin, luminal epithelial antigen and carcinoembryonic antigen in human urinary bladder carcinomas. An immunohistochemical study.

    Science.gov (United States)

    Nathrath, W B; Arnholdt, H; Wilson, P D

    1982-01-01

    14 urinary bladder carcinomas of all main types were investigated with antisera to "broad spectrum keratin" (aK), "luminal epithelial antigen" (aLEA) and carcinoembryonic antigen (aCEA), using an indirect immunoperoxidase method on formalin fixed paraffin embedded sections. Keratin and LEA were both present in normal transitional epithelium, papilloma and carcinoma in situ whereas CEA was absent. Transitional cell carcinomas reacted with both aK and aLEA whereas CEA was seen only in a few foci. In squamous metaplasia and squamous carcinoma reaction with aK was particularly strong, while LEA was almost lacking and CEA was present in necrotic centres. In adenocarcinomas aK and aLEA reacted equally while aCEA reacted only on the surface.

  8. Reactivation of hepatitis B in patients of chronic hepatitis C with hepatitis B virus infection treated with direct acting antivirals.

    Science.gov (United States)

    Yeh, Ming-Lun; Huang, Chung-Feng; Hsieh, Meng-Hsuan; Ko, Yu-Min; Chen, Kuan-Yu; Liu, Ta-Wei; Lin, Yi-Hung; Liang, Po-Cheng; Hsieh, Ming-Yen; Lin, Zu-Yau; Chen, Shinn-Cherng; Huang, Ching-I; Huang, Jee-Fu; Kuo, Po-Lin; Dai, Chia-Yen; Yu, Ming-Lung; Chuang, Wan-Long

    2017-10-01

    Hepatitis B virus (HBV) may reactivate when treating chronic hepatitis C (CHC) with direct acting antivirals (DAA). We aim to investigate the risk of HBV reactivation during DAA therapy. Chronic hepatitis C patients receiving pan-oral DAA therapy from December 2013 to August 2016 were evaluated. Fifty-seven patients that had a past HBV infection (negative hepatitis B surface antigen [HBsAg] and positive hepatitis B core antibody) and seven patients that had a current HBV infection (positive HBsAg) were enrolled. Serum HBV and hepatitis C virus (HCV) markers were regularly measured. The endpoints were the HCV sustained virological response (SVR) and the HBV virological/clinical reactivation. The overall SVR 12 rate was 96.9%, and two patients, one with positive HBsAg, had a relapse of HCV. No episodes of HBV virological reactivation were observed among the patients with a past HBV infection. For the seven patients with a current HBV infection, HBV virological reactivation was found in four (57.1%) of the seven patients. Clinical reactivation of HBV was observed in one patient with pretreatment detectable HBV DNA and recovered after entecavir administration. For the other three patients with HBV virological reactivation, the reappearance of low level HBV DNA without clinical reactivation was observed. HBsAg levels demonstrated only small fluctuations in all the patients. There was a minimal impact of hepatitis B core antibody seropositivity on HCV efficacy and safety. For CHC patients with current HBV infection, the risk of HBV reactivation was present, and monitoring the HBV DNA level during therapy is warranted. © 2017 Journal of Gastroenterology and Hepatology Foundation and John Wiley & Sons Australia, Ltd.

  9. Co-infection of HIV and HBV in voluntary counseling and testing center in Abidjan

    Directory of Open Access Journals (Sweden)

    Kouassi-M ’Bengue A

    2011-12-01

    Full Text Available Objective: To evaluate the co-infection of hepatitis B virus (HBV and immune deficiency virus (HIV among clients consulting at the Voluntary Counseling and Testing Center (VCT Center of the Institut Pasteur de C ôte d ’Ivoire (IPCI. Methods: A cross-sectional study was conducted from April to June 2010 at the VCT of IPCI. All clients attending the VCT of IPCI for HIV test after having signed the informed consent form were included in the study. Venous blood samples were collected from the clients after an interview. Then the rapid tests for screening of HIV infection (Determine HIV 1/2 of Abbott and Genie II HIV-1/HIV-2, Bio-Rad were performed. As for hepatitis B surface antigen (HBsAg test, it was performed using ELISA test system using Monolisa HBsAg Ultra-Bio-Rad. Results: Of 278 samples analyzed, 30 were positive to antibody against HIV-1, giving a seroprevalence of about 10.8%, and 35 were positive to HBsAg, giving a seroprevalence of 12.6%. As for co-infection of HIV and HBV, it was 7/278 cases about 2.5%. Conclusions: It can be concluded that co-infection of HBV and HIV is relatively low among clients consulting at the VCT of the IPCI. Serological surveillance should be systematic in various HIV testing centers in the country. The use of rapid tests for detection of HBsAg allows a lot of tests to be realized. However, the choice of these tests depends on the evaluation results in reference laboratories and situation on ground.

  10. Helicobacter pylori, hepatitis viruses A, C, E antibodies and HBsAg-prevalence and associated risk factors in pediatric communities of karachi

    International Nuclear Information System (INIS)

    Aziz, S.; Muzzafar, R.; Hafiz, S.; Abbas, Z.; Zafar, M.N.; Naqvi, S.A.A.; Rizvi, S.A.U.H.

    2007-01-01

    To document the prevalence of Helicobacter pylori (H. pylori), Hepatitis A virus (HAV), Hepatitis C virus (HCV), Hepatitis E virus (HEV) antibodies and Hepatitis B virus surface antigen (HBsAg), in the pediatric age group of low socioeconomic urban communities of Karachi and to identify risk factors associated with these infections. Three hundred and eighty children, ages 5 months to 15 years were investigated. Venous blood samples were collected and questionnaire filled on sociodemographic characteristics (family income, number of dependents in the family, area of living, number of people per room per house, and number of children sharing bed with parents and siblings). Gastrointestinal symptoms were recorded. Anti-HAV IgG (Hepatitis A virus IgG antibody), anti-HCV (Hepatitis C virus antibody), anti-HEV (Hepatitis E antibodies) and HBsAg, were analyzed by enzyme immunoassays (EIAs). Samples were also screened for anti-HIV1/2 (human immunodeficiency virus 1 and 2 antibodies by EIA. IgG antibodies against H. pylori were detected by immunochromatography. A correlation between increasing age and seroconversion was seen for hepatotropic viruses. At 14 years and above,100% of the children were found to be positive for anti-HAV, 26% for anti-HEV, and 1.4%, for anti-HCV while HBsAg was positive in 1.9%. H. pylori infection did not show a significant increase with age. Both anti-HAV and anti-H. pylori were present simultaneously in 30% of the population investigated. With age, increasing number of children acquired antibodies against hepatotropic viruses and H. pylori. Occurrence of HBsAg and anti-HEV at a later age suggests horizontal, rather than vertical transmission. (author)

  11. Cell wall anchoring of the Campylobacter antigens to Lactococcus lactis

    Directory of Open Access Journals (Sweden)

    Patrycja Anna Kobierecka

    2016-02-01

    Full Text Available Campylobacter jejuni is the most frequent cause of human food-borne gastroenteritis and chicken meat is the main source of infection. Recent studies showed that broiler chicken immunization against Campylobacter should be the most efficient way to lower the number of human infections by this pathogen. Induction of the mucosal immune system after oral antigen administration should provide protective immunity to chickens. In this work we tested the usefulness of Lactococcus lactis, the most extensively studied lactic acid bacterium, as a delivery vector for Campylobacter antigens. First we constructed hybrid protein – CjaA antigen presenting CjaD peptide epitopes on its surface. We showed that specific rabbit anti-rCjaAD serum reacted strongly with both CjaA and CjaD produced by a wild type Campylobacter jejuni strain. Next, rCjaAD and CjaA were fused to the C-terminus of the L. lactis YndF containing the LPTXG motif. The genes expressing these proteins were transcribed under control of the L. lactis Usp45 promoter and their products contain the Usp45 signal sequences. This strategy ensures a cell surface location of both analysed proteins, which was confirmed by immunofluorescence assay. In order to evaluate the impact of antigen location on vaccine prototype efficacy, a L. lactis strain producing cytoplasm-located rCjaAD was also generated. Animal experiments showed a decrease of Campylobacter cecal load in vaccinated birds as compared with the control group and showed that the L. lactis harboring the surface-exposed rCjaAD antigen afforded greater protection than the L. lactis producing cytoplasm-located rCjaAD. To the best of our knowledge, this is the first attempt to employ LAB (Lactic Acid Bacteria strains as a mucosal delivery vehicle for chicken immunization. Although the observed reduction of chicken colonization by Campylobacter resulting from vaccination was rather moderate, the experiments showed that LAB strains can be considered

  12. IgM response to a human Pneumocystis carinii surface antigen in HIV-infected patients with pulmonary symptoms

    DEFF Research Database (Denmark)

    Lundgren, Bettina; Kovacs, J A; Mathiesen, Lars Reinhardt

    1993-01-01

    We have developed an ELISA to detect IgM antibodies to a major human Pneumocystis carinii surface antigen (gp95), and investigated the IgM response in 128 HIV-infected patients who underwent bronchoscopy for evaluation of pulmonary symptoms. Only 5 (4%) patients had IgM antibodies to P. carinii gp...... response to gp95. These patients also showed an increase in IgG antibodies to gp95 and had microbiologically proven PCP. Prior to the development of the IgM response, IgG antibodies to gp95 were detectable in all 3 patients. Thus, HIV-infected patients with PCP seldom produce IgM antibodies to the major...

  13. RTS,S/AS01E Malaria Vaccine Induces Memory and Polyfunctional T Cell Responses in a Pediatric African Phase III Trial

    Directory of Open Access Journals (Sweden)

    Gemma Moncunill

    2017-08-01

    Full Text Available Comprehensive assessment of cellular responses to the RTS,S/AS01E vaccine is needed to understand potential correlates and ultimately mechanisms of protection against malaria disease. Cellular responses recognizing the RTS,S/AS01E-containing circumsporozoite protein (CSP and Hepatitis B surface antigen (HBsAg were assessed before and 1 month after primary vaccination by intracellular cytokine staining and 16-color flow cytometry in 105 RTS,S/AS01-vaccinated and 74 rabies-vaccinated participants (controls in a pediatric phase III trial in Africa. RTS,S/AS01E-vaccinated children had significantly higher frequencies of CSP- and HBsAg-specific CD4+ T cells producing IL-2, TNF-α, and CD40L and HBsAg-specific CD4+ T producing IFN-γ and IL-17 than baseline and the control group. Vaccine-induced responses were identified in both central and effector memory (EM compartments. EM CD4+ T cells expressing IL-4 and IL-21 were detected recognizing both vaccine antigens. Consistently higher response rates to both antigens in RTS,S/AS01E-vaccinated than comparator-vaccinated children were observed. RTS,S/AS01E induced polyfunctional CSP- and HBsAg-specific CD4+ T cells, with a greater degree of polyfunctionality in HBsAg responses. In conclusion, RTS,S/AS01E vaccine induces T cells of higher functional heterogeneity and polyfunctionality than previously characterized. Responses detected in memory CD4+ T cell compartments may provide correlates of RTS,S/AS01-induced immunity and duration of protection in future correlates of immunity studies.

  14. Low prevalence of hepatitis B and C among tuberculosis patients in Duhok Province, Kurdistan: Are HBsAg and anti-HCV prerequisite screening parameters in tuberculosis control program?

    Directory of Open Access Journals (Sweden)

    Muayad A Merza

    2016-01-01

    Full Text Available Objective/background: Viral hepatitis, particularly hepatitis B virus (HBV and hepatitis C virus (HCV, infections and tuberculosis (TB are a global public health concern. Co-infection with HBV or HCV among TB patients may potentiate the risk of hepatotoxicity induced by anti-TB drugs. Hence, the aim of this study was to identify the prevalence of HBV and HCV among TB patients included in the Duhok National Tuberculosis Program (NTP. Methods: The Duhok NTP Center is a specialized institution in Duhok City, Iraq, concerned with management and follow-up of TB patients. A cross-sectional study was conducted at the center between June 2015 and May 2016. All documented TB patients were analyzed on the basis of socio-demographic and other characteristics. Thereafter, all patients underwent screening for hepatitis B surface antigen (HBsAg, anti-HCV, and anti-HIV using enzyme-linked immunosorbent assay (ELISA. The results obtained were analyzed by entering the data in binary format into a Microsoft Excel spreadsheet. A p value of <.05 was considered to be statistically significant. Results: Two-hundred fourteen documented TB patients were recruited in this study, with 127 (59.3% males and 87 (40.7% females. The mean age of the patients was 40.34 years (±20.29. Of the total number of patients, four cases (1.8% were HBsAg-positive and one case (0.9% was positive for anti-HCV. The variables significantly associated with HBV were history of surgical dental procedure [odds ratio (OR, 0.04; 95% confidence interval (CI, −0.01 to 0.04; p = .03], and nationality (OR, 13.67; 95% CI, 0.46–210.85; p = .007. Conclusion: The prevalence of HBV and HCV co-infection among TB patients in this study was low. This may be explained by the low rate of blood transfusion among the patients, the very low prevalence of HIV infections in Kurdistan, the negative history of injection drug use, and adherence to universal infection-control measures, including vaccination for HBV

  15. Seroprevalence of anti-HCV and hepatitis B surface antigen in HIV infected patients

    Directory of Open Access Journals (Sweden)

    Tankhiwale S

    2003-01-01

    Full Text Available Human immunodeficiency virus (HIV is known to influence the natural history of infections with certain hepatitis viruses and interactions between HIV and hepatitis viruses may potentiate HIV replication. There is high degree of epidemiological similarity between hepatitis B virus and HIV as regard to high-risk group and route of transmission. Transmission of hepatitis C virus (HCV through blood transfusion and intravenous drug abuse is well documented. Present study deals with the study of concurrent infection of HBV and HCV with HIV infection. In the study of 110 HIV seropositive patients, 34(30.4% were positive for HBV and 8(7.27% for HCV. The difference of concomitant infection was highly significant compared to controls. (p value < 0.0001. Heterosexual high risk behaviour was observed in 89(80.91% of 110 HIV positive patients, out of which 23(25.8% and 5(5.62% were HBsAg and anti-HCV positive respectively. History of transmission was unclear in remaining patients. Concomitant infection of HIV and HBV was found to be significantly more in the symptomatic group (40.68% compared to asymptomatic group (19.6%. As HIV infection is known to affect the natural history of both HBV and HCV infection, screening of their concurrent association is necessary.

  16. DNA immunization with fusion of CTLA-4 to hepatitis B virus (HBV core protein enhanced Th2 type responses and cleared HBV with an accelerated kinetic.

    Directory of Open Access Journals (Sweden)

    Ying Yin

    Full Text Available BACKGROUND: Typically, DNA immunization via the intramuscular route induces specific, Th1-dominant immune responses. However, plasmids expressing viral proteins fused to cytotoxic T lymphocyte antigen 4 (CTLA-4 primed Th2-biased responses and were able to induced effective protection against viral challenge in the woodchuck model. Thus, we addressed the question in the mouse model how the Th1/Th2 bias of primed immune responses by a DNA vaccine influences hepatitis B virus (HBV clearance. PRINCIPAL FINDINGS: Plasmids expressing HBV core protein (HBcAg or HBV e antigen and HBcAg fused to the extracellular domain of CTLA-4 (pCTLA-4-HBc, CD27, and full length CD40L were constructed. Immunizations of these DNA plasmids induced HBcAg-specific antibody and cytotoxic T-cell responses in mice, but with different characteristics regarding the titers and subtypes of specific antibodies and intensity of T-cell responses. The plasmid pHBc expressing HBcAg induced an IgG2a-dominant response while immunizations of pCTLA-4-HBc induced a balanced IgG1/IgG2a response. To assess the protective values of the immune responses of different characteristics, mice were pre-immunized with pCTLA-4-HBc and pHBc, and challenged by hydrodynamic injection (HI of pAAV/HBV1.2. HBV surface antigen (HBsAg and DNA in peripheral blood and HBcAg in liver tissue were cleared with significantly accelerated kinetics in both groups. The clearance of HBsAg was completed within 16 days in immunized mice while more than 50% of the control mice are still positive for HBsAg on day 22. Stronger HBcAg-specific T-cell responses were primed by pHBc correlating with a more rapid decline of HBcAg expression in liver tissue, while anti-HBs antibody response developed rapidly in the mice immunized with pCTLA-4-HBc, indicating that the Th1/Th2 bias of vaccine-primed immune responses influences the mode of viral clearance. CONCLUSION: Viral clearance could be efficiently achieved by Th1/Th2-balanced

  17. Detection and quantification of Duffy antigen on bovine red blood cell membranes using a polyclonal antibody

    Directory of Open Access Journals (Sweden)

    Ana Teresa B.F. Antonangelo

    2012-09-01

    Full Text Available Babesiosis is one of the most important diseases affecting livestock agriculture worldwide. Animals from the subspecies Bos taurus indicus are more resistant to babesiosis than those from Bos taurus taurus. The genera Babesia and Plasmodium are Apicomplexa hemoparasites and share features such as invasion of red blood cells (RBC. The glycoprotein Duffy is the only human erythrocyte receptor for Pasmodium vivax and a mutation which abolishes expression of this glycoprotein on erythrocyte surfaces is responsible for making the majority of people originating from the indigenous populations of West Africa resistant to P. vivax. The current work detected and quantified the Duffy antigen on Bos taurus indicus and Bos taurus taurus erythrocyte surfaces using a polyclonal antibody in order to investigate if differences in susceptibility to Babesia are due to different levels of Duffy antigen expression on the RBCs of these animals, as is known to be the case in human beings for interactions of Plasmodium vivax-Duffy antigen. ELISA tests showed that the antibody that was raised against Duffy antigens detected the presence of Duffy antigen in both subspecies and that the amount of this antigen on those erythrocyte membranes was similar. These results indicate that the greater resistance of B. taurus indicus to babesiosis cannot be explained by the absence or lower expression of Duffy antigen on RBC surfaces.

  18. The distribution of blood group antigens in experimentally produced carcinomas of rat palate

    DEFF Research Database (Denmark)

    Reibel, J; Philipsen, H P; Fisker, A V

    1986-01-01

    palate induced by a chemical carcinogen (4NQO). The H antigen, normally expressed on spinous cells in rats, was absent in malignant epithelium, whereas staining for the B antigen, normally expressed on basal cells, was variable. These changes are equivalent to those seen in human squamous cell carcinomas....... The blood group antigen staining pattern in experimentally produced verrucous carcinomas showed an almost normal blood group antigen expression. This may have diagnostic significance. Localized areas of hyperplastic palatal epithelium with slight dysplasia revealed loss of H antigen and the presence of B...... antigen in suprabasal strata equivalent to the pattern seen in human premalignant epithelium. We conclude from these findings, that the rat model is well suited to study changes in cell surface carbohydrates during chemical carcinogenesis....

  19. Selective elution of HLA antigens and beta 2-microglobulin from human platelets by chloroquine diphosphate

    International Nuclear Information System (INIS)

    Kao, K.J.

    1988-01-01

    To determine whether chloroquine can specifically elute HLA antigens and beta 2-microglobulin (beta 2-M) from the platelet surface, quantitative immunofluorescence flow cytometry and monoclonal antibodies were used to show that HLA antigens and beta 2-M were proportionally eluted from the platelet surface without affecting the membrane glycoproteins IIb and IIIa. Second, an autoradiogram of electrophoresed I-125-labeled platelets showed that only beta 2-M but not other I-125-labeled membrane proteins could be eluted. Although HLA antigens were poorly labeled by I-125 and could not be detected on the autoradiogram, the eluted HLA antigens could be detected by anti-HLA monoclonal antibody and immunoblotting techniques. No loss of plasma membrane integrity was observed by transmission electron microscopy after chloroquine treatment of platelets. The results indicate that chloroquine selectively elutes HLA antigens and their noncovalently associated beta 2-M without affecting other integral platelet membrane proteins

  20. Characterization of the disassembly and reassembly of the HBV glycoprotein surface antigen, a pliable nanoparticle vaccine platform

    International Nuclear Information System (INIS)

    Gallagher, John R.; Torian, Udana; McCraw, Dustin M.; Harris, Audray K.

    2017-01-01

    While nanoparticle vaccine technology is gaining interest due to the success of vaccines like those for the human papillomavirus that is based on viral capsid nanoparticles, little information is available on the disassembly and reassembly of viral surface glycoprotein-based nanoparticles. One such particle is the hepatitis B virus surface antigen (sAg) that exists as nanoparticles. Here we show, using biochemical analysis coupled with electron microscopy, that sAg nanoparticle disassembly requires both reducing agent to disrupt intermolecular disulfide bonds, and detergent to disrupt hydrophobic interactions that stabilize the nanoparticle. Particles were otherwise resistant to salt and urea, suggesting the driving mechanism of particle formation involves hydrophobic interactions. We reassembled isolated sAg protein into nanoparticles by detergent removal and reassembly resulted in a wider distribution of particle diameters. Knowledge of these driving forces of nanoparticle assembly and stability should facilitate construction of epitope-displaying nanoparticles that can be used as immunogens in vaccines.

  1. Characterization of the disassembly and reassembly of the HBV glycoprotein surface antigen, a pliable nanoparticle vaccine platform

    Energy Technology Data Exchange (ETDEWEB)

    Gallagher, John R.; Torian, Udana; McCraw, Dustin M.; Harris, Audray K., E-mail: harrisau@mail.nih.gov

    2017-02-15

    While nanoparticle vaccine technology is gaining interest due to the success of vaccines like those for the human papillomavirus that is based on viral capsid nanoparticles, little information is available on the disassembly and reassembly of viral surface glycoprotein-based nanoparticles. One such particle is the hepatitis B virus surface antigen (sAg) that exists as nanoparticles. Here we show, using biochemical analysis coupled with electron microscopy, that sAg nanoparticle disassembly requires both reducing agent to disrupt intermolecular disulfide bonds, and detergent to disrupt hydrophobic interactions that stabilize the nanoparticle. Particles were otherwise resistant to salt and urea, suggesting the driving mechanism of particle formation involves hydrophobic interactions. We reassembled isolated sAg protein into nanoparticles by detergent removal and reassembly resulted in a wider distribution of particle diameters. Knowledge of these driving forces of nanoparticle assembly and stability should facilitate construction of epitope-displaying nanoparticles that can be used as immunogens in vaccines.

  2. Major role for carbohydrate epitopes preferentially recognized by chronically infected mice in the determination of Schistosoma mansoni schistosomulum surface antigenicity

    International Nuclear Information System (INIS)

    Omer-ali, P.; Magee, A.I.; Kelly, C.; Simpson, A.J.G.

    1986-01-01

    A radioimmunoassay that makes use of whole Schistosomula and 125 I-labeled protein A has been used to characterize and to quantify the binding of antisera to the surface of 3 hr mechanically transformed schistosomula of Schistosoma mansoni. This technique facilitates the determination of epitopes on the schistosomula in addition to those detected by surface labeling and immunoprecipitation. By using this technique, it has been demonstrated that there is a much greater binding to the parasite surface of antibodies from chronically infected mice (CMS) than of antibodies from mice infected with highly irradiated cercariae (VMS), and CMS recognizes epitopes that VMS does not. Treatment of the surface of the schistosomula with trifluoromethanesulphonic acid and sodium metaperiodate has suggested that the discrepancy of the binding between the two sera is due to the recognition of a large number of additional epitopes by CMS, which are carbohydrate in nature. Some of the carbohydrate epitopes are expressed on the previously described surface glycoprotein antigens of M/sub r/ 200,000, 38,000, and 17,000

  3. Recombinant Forms of Leishmania amazonensis Excreted/Secreted Promastigote Surface Antigen (PSA Induce Protective Immune Responses in Dogs.

    Directory of Open Access Journals (Sweden)

    Elodie Petitdidier

    2016-05-01

    Full Text Available Preventive vaccination is a highly promising strategy for interrupting leishmaniasis transmission that can, additionally, contribute to elimination. A vaccine formulation based on naturally excreted secreted (ES antigens was prepared from L. infantum promastigote culture supernatant. This vaccine achieved successful results in Phase III trials and was licensed and marketed as CaniLeish. We recently showed that newly identified ES promastigote surface antigen (PSA, from both viable promastigotes and axenically-grown amastigotes, represented the major constituent and the highly immunogenic antigen of L. infantum and L. amazonensis ES products. We report here that three immunizations with either the recombinant ES LaPSA-38S (rPSA or its carboxy terminal part LaPSA-12S (Cter-rPSA, combined with QA-21 as adjuvant, confer high levels of protection in naive L. infantum-infected Beagle dogs, as checked by bone marrow parasite absence in respectively 78.8% and 80% of vaccinated dogs at 6 months post-challenge. The parasite burden in infected vaccinated dogs was significantly reduced compared to placebo group, as measured by q-PCR. Moreover, our results reveal humoral and cellular immune response clear-cut differences between vaccinated and control dogs. An early increase in specific IgG2 antibodies was observed in rPSA/QA-21- and Cter-rPSA/QA-21-immunized dogs only. They were found functionally active in vitro and were highly correlated with vaccine protection. In vaccinated protected dogs, IFN-γ and NO productions, as well as anti-leishmanial macrophage activity, were increased. These data strongly suggest that ES PSA or its carboxy-terminal part, in recombinant forms, induce protection in a canine model of zoonotic visceral leishmaniasis by inducing a Th1-dominant immune response and an appropriate specific antibody response. These data suggest that they could be considered as important active components in vaccine candidates.

  4. Mosaic VSGs and the scale of Trypanosoma brucei antigenic variation.

    Directory of Open Access Journals (Sweden)

    James P J Hall

    Full Text Available A main determinant of prolonged Trypanosoma brucei infection and transmission and success of the parasite is the interplay between host acquired immunity and antigenic variation of the parasite variant surface glycoprotein (VSG coat. About 0.1% of trypanosome divisions produce a switch to a different VSG through differential expression of an archive of hundreds of silent VSG genes and pseudogenes, but the patterns and extent of the trypanosome diversity phenotype, particularly in chronic infection, are unclear. We applied longitudinal VSG cDNA sequencing to estimate variant richness and test whether pseudogenes contribute to antigenic variation. We show that individual growth peaks can contain at least 15 distinct variants, are estimated computationally to comprise many more, and that antigenically distinct 'mosaic' VSGs arise from segmental gene conversion between donor VSG genes or pseudogenes. The potential for trypanosome antigenic variation is probably much greater than VSG archive size; mosaic VSGs are core to antigenic variation and chronic infection.

  5. Molecular characteristics of an immobilization antigen gene of the fish-parasitic protozoan Ichthyophthirius multifiliis strain ARS-6

    Science.gov (United States)

    Ichthyophthirius multifiliis, a ciliated protozoan parasite of fish, expresses surface antigens (i-antigens), which react with host antibodies that render them immobile. The nucleotide sequence of an i-antigen gene of Ichthyophthirius multifiliis strain ARS-6 was deduced. The predicted protein of 47...

  6. Ionizing radiation modulates the surface expression of human leukocyte antigen-G in a human melanoma cell line

    Energy Technology Data Exchange (ETDEWEB)

    Michelin, S.; Gallegos, C.E.; Dubner, D. [Radiopathology Laboratory, Nuclear Regulatory Authority, Buenos Aires (Argentina); Favier, B.; Carosella, E.D. [CEA, I2BM, Hopital Saint-Louis, IUH, Service de Recherches en Hemato-Immunologie, Paris (France)

    2009-07-01

    Human leukocyte antigen G (HLA-G) is a nonclassical HLA class I molecule involved in fetus protection from the maternal immune system, transplant tolerance, and viral and tumoral immune escape. Tumor-specific HLA-G expression has been described for a wide variety of malignancies, including melanomas. The aim of this study was to evaluate whether ionizing radiation (IR) could modulate the surface expression of HLA-G1 in a human melanoma cell line that expresses endogenously membrane-bound HLA-G1. For this purpose, cells were exposed to increasing doses of {gamma}-irradiation (0-20 Gy) and HLA-G1 levels at the plasma membrane were analyzed at different times postirradiation by flow cytometry. HLA-G total expression and the presence of the soluble form of HLA-G1 (sHLA-G1) in the culture medium of irradiated cells were also evaluated. IR was capable of down regulating cell surface and total HLA-G levels, with a concomitant increase of sHLA-G1 in the medium. These results could indicate that {gamma}-irradiation decreases HLA-G1 surface levels by enhancing the proteolytic cleavage of this molecule. (authors)

  7. Ionizing radiation modulates the surface expression of human leukocyte antigen-G in a human melanoma cell line

    International Nuclear Information System (INIS)

    Michelin, S.; Gallegos, C.E.; Dubner, D.; Favier, B.; Carosella, E.D.

    2009-01-01

    Human leukocyte antigen G (HLA-G) is a nonclassical HLA class I molecule involved in fetus protection from the maternal immune system, transplant tolerance, and viral and tumoral immune escape. Tumor-specific HLA-G expression has been described for a wide variety of malignancies, including melanomas. The aim of this study was to evaluate whether ionizing radiation (IR) could modulate the surface expression of HLA-G1 in a human melanoma cell line that expresses endogenously membrane-bound HLA-G1. For this purpose, cells were exposed to increasing doses of γ-irradiation (0-20 Gy) and HLA-G1 levels at the plasma membrane were analyzed at different times postirradiation by flow cytometry. HLA-G total expression and the presence of the soluble form of HLA-G1 (sHLA-G1) in the culture medium of irradiated cells were also evaluated. IR was capable of down regulating cell surface and total HLA-G levels, with a concomitant increase of sHLA-G1 in the medium. These results could indicate that γ-irradiation decreases HLA-G1 surface levels by enhancing the proteolytic cleavage of this molecule. (authors)

  8. Comparison of the effect of interferon on two human hepatoma cell lines

    Energy Technology Data Exchange (ETDEWEB)

    Crespi, M; Schoub, B D; Lyons, S F; Chiu, M N [University of the Witwatersrand, Johannesburg (South Africa). Dept. of Virology

    1985-06-01

    Two human hepatoma cell lines, the PLC/PRF/5 and the Mahlavu cells, which differ in their production of the hepatitis B surface antigen (HBsAg), responded differently to interferon (IFN). After IFN treatment both cell lines were able to inhibit Sindbis virus replication. Oligo A synthetase (E enzyme) could be activated in the PLC/PRF/5 cells although they were not sensitive to exogenous 2 - 5 oligoadenylic acid (2 - 5 A). In contrast, the Mahlavu cells were sensitive to exogenous 2 - 5 A, but unable to activate the E enzyme. Both cell lines were unable to stimulate phosphorylation of the exogenous initiator factor eIF-2.

  9. Dichotomy of the human T cell response to Leishmania antigens. I. Th1-like response to Leishmania major promastigote antigens in individuals recovered from cutaneous leishmaniasis

    DEFF Research Database (Denmark)

    Kemp, M; Hey, A S; Kurtzhals, J A

    1994-01-01

    of skin lesions, and in Danes without known exposure to Leishmania parasites. Proliferation and production of interferon-gamma (IFN-gamma) and IL-4 in antigen-stimulated cultures was measured. Lymphocytes from individuals with a history of CL proliferated vigorously and produced IFN-gamma after...... the unexposed Danes were not activated by gp63. The cells from Danish donors produced either IFN-gamma or IL-4, but not both cytokines after incubation with the crude preparation of L. major antigens. The data show that the T cell response to Leishmania antigens in humans who have had uncomplicated CL...... stimulation with either a crude preparation of L. major antigens or the major surface protease gp63. These cultures produced no or only little IL-4. Also cells from leishmanin skin test-positive donors with no history of CL produced IFN-gamma and no IL-4 in response to L. major antigens. Cells from...

  10. The evidence of mother to child transmission of hepatitis B virus infection in Pakistan and the need for hepatitis B immunization policy change

    International Nuclear Information System (INIS)

    Qureshi, H.; Javaid, N.; Alam, S.E.

    2014-01-01

    Objective: To establish the hepatitis B surface antigen and hepatitis B 'e' antigen seroprevalence of mothers and their children aged 6-36 months and to assess the risk of hepatitis B transmission occurring in infants born to hepatitis B surface antigen positive mothers in Pakistan. Methods: Mothers and their children were selected from eight districts of three provinces that have been identified as high hepatitis B prevalence areas between May 2010 to February 2011. Ages of the children and their vaccination status were obtained from the lady health workers' registers and also verified from the mothers. Five ml of blood was drawn from all the children and their mothers for testing. All sera were tested for anti-hepatitis B. Those found negative were run for HBsAg the sueface antigen and those positive for it were further run for hepatitis B 'e' antigen. All tests were run on Abbott machine using chemiluminesence method. EPI-info 12 was used for statistical purposes. Results: A total of 1561 mothers and their 1612 children were tested. Among the mothers, 590 (37.8%) were hepatitis B antibody positive. Remaining 971 (62.2%) samples were tested for surface antigen and 123 (12.7%) were found positive of which 27 (22%) showed HBeAg positivity. Out of 1612 children tested, 975 (60.5%) were positive. Remaining 637 (39.5%) were tested for surface antigen and 49 (8%) were found positive of which 24 (49%) were HBeAg positive with a perinatal hepatitis B virus transmission rate of 5.4% by 12 months of age. Of the 123 surface antigen positive mothers, 18 (14.6%) had children who were also positive, while of the 1489 children born to the 1438 surface antigen negative mothers, 31 (2.1%) were positive. Children born to surface antigen positive mothers had eight times higher risk of getting hepatitis B virus infection and the risk rose to 17 times if the mother was also HBeAg positive. Hepatitis B vaccination record showed that 1229 (76.25%) children were vaccinated at six weeks

  11. Toolbox for non-intrusive structural and functional analysis of recombinant VLP based vaccines: a case study with hepatitis B vaccine.

    Directory of Open Access Journals (Sweden)

    Anke M Mulder

    Full Text Available BACKGROUND: Fundamental to vaccine development, manufacturing consistency, and product stability is an understanding of the vaccine structure-activity relationship. With the virus-like particle (VLP approach for recombinant vaccines gaining popularity, there is growing demand for tools that define their key characteristics. We assessed a suite of non-intrusive VLP epitope structure and function characterization tools by application to the Hepatitis B surface antigen (rHBsAg VLP-based vaccine. METHODOLOGY: The epitope-specific immune reactivity of rHBsAg epitopes to a given monoclonal antibody was monitored by surface plasmon resonance (SPR and quantitatively analyzed on rHBsAg VLPs in-solution or bound to adjuvant with a competitive enzyme-linked immunosorbent assay (ELISA. The structure of recombinant rHBsAg particles was examined by cryo transmission electron microscopy (cryoTEM and in-solution atomic force microscopy (AFM. PRINCIPAL FINDINGS: SPR and competitive ELISA determined relative antigenicity in solution, in real time, with rapid turn-around, and without the need of dissolving the particulate aluminum based adjuvant. These methods demonstrated the nature of the clinically relevant epitopes of HBsAg as being responsive to heat and/or redox treatment. In-solution AFM and cryoTEM determined vaccine particle size distribution, shape, and morphology. Redox-treated rHBsAg enabled 3D reconstruction from CryoTEM images--confirming the previously proposed octahedral structure and the established lipid-to-protein ratio of HBsAg particles. Results from these non-intrusive biophysical and immunochemical analyses coalesced into a comprehensive understanding of rHBsAg vaccine epitope structure and function that was important for assuring the desired epitope formation, determinants for vaccine potency, and particle stability during vaccine design, development, and manufacturing. SIGNIFICANCE: Together, the methods presented here comprise a novel

  12. Identification of new meningococcal serogroup B surface antigens through a systematic analysis of neisserial genomes.

    Science.gov (United States)

    Pajon, Rolando; Yero, Daniel; Niebla, Olivia; Climent, Yanet; Sardiñas, Gretel; García, Darién; Perera, Yasser; Llanes, Alejandro; Delgado, Maité; Cobas, Karem; Caballero, Evelin; Taylor, Stephen; Brookes, Charlotte; Gorringe, Andrew

    2009-12-11

    The difficulty of inducing an effective immune response against the Neisseria meningitidis serogroup B capsular polysaccharide has lead to the search for vaccines for this serogroup based on outer membrane proteins. The availability of the first meningococcal genome (MC58 strain) allowed the expansion of high-throughput methods to explore the protein profile displayed by N. meningitidis. By combining a pan-genome analysis with an extensive experimental validation to identify new potential vaccine candidates, genes coding for antigens likely to be exposed on the surface of the meningococcus were selected after a multistep comparative analysis of entire Neisseria genomes. Eleven novel putative ORF annotations were reported for serogroup B strain MC58. Furthermore, a total of 20 new predicted potential pan-neisserial vaccine candidates were produced as recombinant proteins and evaluated using immunological assays. Potential vaccine candidate coding genes were PCR-amplified from a panel of representative strains and their variability analyzed using maximum likelihood approaches for detecting positive selection. Finally, five proteins all capable of inducing a functional antibody response vs N. meningitidis strain CU385 were identified as new attractive vaccine candidates: NMB0606 a potential YajC orthologue, NMB0928 the neisserial NlpB (BamC), NMB0873 a LolB orthologue, NMB1163 a protein belonging to a curli-like assembly machinery, and NMB0938 (a neisserial specific antigen) with evidence of positive selection appreciated for NMB0928. The new set of vaccine candidates and the novel proposed functions will open a new wave of research in the search for the elusive neisserial vaccine.

  13. Characterization of a 14,000 dalton antigen of Dirofilaria immitis infective third stage larvae

    International Nuclear Information System (INIS)

    Fuller, S.A.; Cachia, P.J.; Wong, M.M.; Hurrell, J.G.R.

    1986-01-01

    Immunogenic proteins of Dirofilaria immitis (canine heartworm) were identified by probing extracts of adult worms or their excretory-secretory proteins (ESP) blotted to nitrocellulose following SDS-PAGE with control or infected dog sera. A 14,000 dalton antigen (a prominent component of ESP by protein staining) was consistently recognized both in extracts and ESP by dog sera as early as three months post infection. This indicates a larval origin for the antigen since no adult worms are present until approximately five months post infection. Monoclonal antibodies (MAbs) prepared against the 14,000 dalton antigen confirmed by immunoblotting that this antigen is expressed by infective third stage larvae, adults and microfilariae and is present intact in the sera of infected dogs. Surface-labelling of whole adult D. immitis with Na 125 I produced radiolabelled antigens closely corresponding to those of ESP. An anti-14,000 dalton MAb was able to immunoprecipitate radiolabelled antigen which strongly suggest a surface or membrane location in the intact organism. Gel filtration data suggests that the protein is a native monomer. A MAb-affinity column has been used to purify the 14,000 dalton antigen to at least 98% homogeneity in one step from crude worm extracts. Further fractionation by HPLC yields a homogeneous preparation. Amino acid analysis and the N-terminal amino acid sequence data will be presented

  14. Risk factors of hepatitis B virus infection among blood donors in Duhok city, Kurdistan Region, Iraq.

    Science.gov (United States)

    R Hussein, Nawfal

    2018-01-01

    Hepatitis B virus (HBV) infection is a public health problem. The lack of information about the seroprevalence and risk factors is an obstacle for preventive public health plans to reduce the burden of viral hepatitis. Therefore, this study was conducted in Iraq, where no studies had been performed to determine the prevalence and risk factors of HBV infection. Blood samples were collected form 438 blood donors attending blood bank in Duhok city. Serum samples were tested for HBV core-antibodies (HBcAb) and HBV surface-antigen (HBsAg) by ELISA. Various risk factors were recorded and multivariate analysis was performed. 5/438 (1.14%) of the subjects were HBsAg positive (HBsAg and HBcAb positive) and 36/438 (8.2%) were HBcAb positive. Hence, 41 cases were exposed to HBV and data analysis was based on that. Univariate analysis showed that there were significant associations between history of illegitimate sexual contact, history of alcohol or history of dental surgeries and HBV exposure (p<0.05 for all). Then, multivariate analysis was conducted to find HBV exposure predictive factors. It was found that history of dental surgery was a predictive factor for exposure to the virus (P=0.03, OR: 2.397). This study suggested that the history of dental surgery was predictive for HBV transmission in Duhok city. Further population-based study is needed to determine HBV risk factors in the society and public health plan based on that should be considered.

  15. Potential use of serum HBV RNA in antiviral therapy for chronic hepatitis B in the era of nucleos(t)ide analogs.

    Science.gov (United States)

    Lu, Fengmin; Wang, Jie; Chen, Xiangmei; Xu, Dongping; Xia, Ningshao

    2017-12-01

    Although the efficacy of nucleos(t)ide analogue (NA) has been confirmed for treatment of chronic hepatitis B, long-term therapy has been recommended due to the high frequency of off-therapy viral DNA rebound and disease relapse. In this review, the RNA virion-like particles of hepatitis B virus (HBV) are integrated into the life cycle of HBV replication, and the potential significance of serum HBV RNA is systematically described. The production of HBV RNA virion-like particles should not be blocked by NA; in this regard, serum HBV RNA is found to be a suitable surrogate marker for the activity of intrahepatic covalently closed circular DNA (cccDNA), particularly among patients receiving NA therapy. Therefore, the concept of virological response is redefined as persistent loss of serum HBV DNA and HBV RNA. In contrast to hepatitis B surface antigen (HBsAg) that can originate from either the cccDNA or the integrated HBV DNA fragment, serum HBV RNA, with pregenomic RNA origination, can only be transcribed from cccDNA. Therefore, the loss of serum HBV RNA would likely be a promising predicator for safe drug discontinuation. The clinical status of consistent loss of serum HBV RNA accompanied with low serum HBsAg levels might be implicated as a "para-functional cure," a status nearly close to the functional cure of chronic hepatitis B, to distinguish the "functional cure" characterized as serum HBsAg loss with or without anti-HBs seroconversion.

  16. Is seroprevalence of hepatitis B and C among blood donors changing in Northern Pakistan?

    International Nuclear Information System (INIS)

    Butt, T.; But, B.

    2017-01-01

    Objective: To determine seroprevalence of hepatitis B and C among blood donors in 2009 and comparing with the seroprevalence in 2014. Study Design: Cross sectional study with retrospective data collection. Place and Duration of Study: Foundation University Medical College and Fauji Foundation Hospital, Rawalpindi. Data in 2009 and in 2014 were collected. Material and Methods: The blood samples collected from individuals from Province of Khyber Pakhtunkhawa, Azad Kashmir and Northern Punjab including Rawalpindi-Islamabad and comprised 3776 (in the year 2009) and 6740 (in the year 2014) adults ranging from 18 to 60 years who reported to Fauji Foundation Hospital, Rawalpindi voluntarily or as a compulsion to donate blood for their patients. Results: During 2009, there were 71 (1.88 percent) and 113 (2.99 percent) donors positive for hepatitis B surface antigen (HBsAg) and anti hepatitis C virus (Anti HCV) respectively out of a total of 3776 donors whereas during 2014 there were 106 (1.57 percent) and 174 (2.58 percent) donors positive for HBsAg and anti HCV respectively out of a total donors of 6740. There was no statistical significant difference between the year (2009 and 2014) and seroprevalence of HBsAg (p=0.239) and HCV positive donors (p=0.215). Conclusion: There is no significant change in seroprevalence of hepatitis B and C among blood donors during 2014 as compared to 2009 in Northern Pakistan. (author)

  17. Hepatitis B and C Sero-prevalence in Patients with Human Immunodeficiency Virus/Acquired Immune Deficiency Syndrome at a Tertiary Care Hospital in Izmir

    Directory of Open Access Journals (Sweden)

    Sabri ATALAY

    2018-04-01

    Full Text Available Objectives: Infections caused by human immunodeficiency virus (HIV, hepatitis B virus (HBV and hepatitis C virus (HCV represent a significant health problem. Co-infection with these viral agents is not uncommon as a result of the similar transmission routes. Our study was planned to investigate the prevalence of HBV and HCV infections in HIV/Acquired Immune Deficiency syndrome (AIDS patients followed up at our institution. Materials and Methods: In this study conducted in the Department of Infectious Diseases and Clinical Microbiology at Izmir Tepecik Training and Research Hospital, medical records of patients followed at the HIV/AIDS outpatient clinic between August 2002 and December 2014 were evaluated. Demographic data, main route of HIV transmission, hepatitis B surface antigen (HBsAg, anti-hepatitis B core (HBc immunoglobulin G (IgG, anti-HBs and anti-HCV results were evaluated. Results: A total of 157 treatment-naïve patients who were followed up at our HIV/AIDS outpatient clinic were included in this study. Four patients (2.6%, had HBsAg positivity. Anti-HBc IgG and anti-HBs positivity were detected in 34% and 28.4% of the patients, respectively. No patients had anti-HCV positivity. Conclusion: The prevalence of HBsAg in HIV-positive individuals was found to be similar to that in other population-based studies in our country. Absence of anti-HCV positivity suggests that hepatitis C infection is not a major health problem in this population.

  18. Gaps in the prevention of perinatal transmission of hepatitis B virus between recommendations and routine practices in a highly endemic region: a provincial population-based study in China

    Directory of Open Access Journals (Sweden)

    Hu Yali

    2012-09-01

    Full Text Available Abstract Background Hepatitis B virus (HBV infection is endemic in China; perinatal transmission is the main source of chronic HBV infection. Simultaneous administration of hepatitis B immune globulin (HBIG and hepatitis B vaccine is highly effective to prevent perinatal transmission of HBV; however, the effectiveness also depends on full adherence to the recommended protocols in daily practice. In the present investigation, we aimed to identify gaps in immunoprophylaxis of perinatal transmission of HBV between recommendations and routine practices in Jiangsu Province, China. Methods Totally 626 children from 6 cities and 8 rural areas across Jiangsu Province, China, born from February 2003 to December 2004, were enrolled; 298 were born to mothers with positive hepatitis B surface antigen (HBsAg and 328 were born to HBsAg-negative mothers. Immunoprophylactic measures against hepatitis B were retrospectively reviewed for about half of the children by checking medical records or vaccination cards and the vaccine status was validated for most of children. Results Of 298 children born to HBV carrier mothers, 11 (3.7% were HBsAg positive, while none of 328 children born to non-carrier mothers was HBsAg positive (P  Conclusions There are substantial gaps in the prevention of perinatal HBV infection between the recommendations and routine practices in China, which highlights the importance of full adherence to the recommendations to eliminate perinatal HBV infection in the endemic regions.

  19. Novel Treponema pallidum Recombinant Antigens for Syphilis Diagnostics: Current Status and Future Prospects

    Directory of Open Access Journals (Sweden)

    Aleksey Kubanov

    2017-01-01

    Full Text Available The recombinant protein technology considerably promoted the development of rapid and accurate treponema-specific laboratory diagnostics of syphilis infection. For the last ten years, the immunodominant recombinant inner membrane lipoproteins are proved to be sensitive and specific antigens for syphilis screening. However, the development of an enlarged T. pallidum antigen panel for diagnostics of early and late syphilis and differentiation of syphilis stages or cured syphilis remains as actual goal of multidisciplinary expertise. Current review revealed novel recombinant antigens: surface-exposed proteins, adhesins, and periplasmic and flagellar proteins, which are promising candidates for the improved syphilis serological diagnostics. The opportunities and limitations of diagnostic usage of these antigens are discussed and the criteria for selection of optimal antigens panel summarized.

  20. Novel Treponema pallidum Recombinant Antigens for Syphilis Diagnostics: Current Status and Future Prospects.

    Science.gov (United States)

    Kubanov, Aleksey; Runina, Anastassia; Deryabin, Dmitry

    2017-01-01

    The recombinant protein technology considerably promoted the development of rapid and accurate treponema-specific laboratory diagnostics of syphilis infection. For the last ten years, the immunodominant recombinant inner membrane lipoproteins are proved to be sensitive and specific antigens for syphilis screening. However, the development of an enlarged T. pallidum antigen panel for diagnostics of early and late syphilis and differentiation of syphilis stages or cured syphilis remains as actual goal of multidisciplinary expertise. Current review revealed novel recombinant antigens: surface-exposed proteins, adhesins, and periplasmic and flagellar proteins, which are promising candidates for the improved syphilis serological diagnostics. The opportunities and limitations of diagnostic usage of these antigens are discussed and the criteria for selection of optimal antigens panel summarized.

  1. Chimeric antigen receptor T cells: a novel therapy for solid tumors

    Directory of Open Access Journals (Sweden)

    Shengnan Yu

    2017-03-01

    Full Text Available Abstract The chimeric antigen receptor T (CAR-T cell therapy is a newly developed adoptive antitumor treatment. Theoretically, CAR-T cells can specifically localize and eliminate tumor cells by interacting with the tumor-associated antigens (TAAs expressing on tumor cell surface. Current studies demonstrated that various TAAs could act as target antigens for CAR-T cells, for instance, the type III variant epidermal growth factor receptor (EGFRvIII was considered as an ideal target for its aberrant expression on the cell surface of several tumor types. CAR-T cell therapy has achieved gratifying breakthrough in hematological malignancies and promising outcome in solid tumor as showed in various clinical trials. The third generation of CAR-T demonstrates increased antitumor cytotoxicity and persistence through modification of CAR structure. In this review, we summarized the preclinical and clinical progress of CAR-T cells targeting EGFR, human epidermal growth factor receptor 2 (HER2, and mesothelin (MSLN, as well as the challenges for CAR-T cell therapy.

  2. Dengue virus-like particles mimic the antigenic properties of the infectious dengue virus envelope.

    Science.gov (United States)

    Metz, Stefan W; Thomas, Ashlie; White, Laura; Stoops, Mark; Corten, Markus; Hannemann, Holger; de Silva, Aravinda M

    2018-04-02

    The 4 dengue serotypes (DENV) are mosquito-borne pathogens that are associated with severe hemorrhagic disease. DENV particles have a lipid bilayer envelope that anchors two membrane glycoproteins prM and E. Two E-protein monomers form head-to-tail homodimers and three E-dimers align to form "rafts" that cover the viral surface. Some human antibodies that strongly neutralize DENV bind to quaternary structure epitopes displayed on E protein dimers or higher order structures forming the infectious virus. Expression of prM and E in cell culture leads to the formation of DENV virus-like particles (VLPs) which are smaller than wildtype virus particles and replication defective due to the absence of a viral genome. There is no data available that describes the antigenic landscape on the surface of flavivirus VLPs in comparison to the better studied infectious virion. A large panel of well characterized antibodies that recognize epitope of ranging complexity were used in biochemical analytics to obtain a comparative antigenic surface view of VLPs in respect to virus particles. DENV patient serum depletions were performed the show the potential of VLPs in serological diagnostics. VLPs were confirmed to be heterogeneous in size morphology and maturation state. Yet, we show that many highly conformational and quaternary structure-dependent antibody epitopes found on virus particles are efficiently displayed on DENV1-4 VLP surfaces as well. Additionally, DENV VLPs can efficiently be used as antigens to deplete DENV patient sera from serotype specific antibody populations. This study aids in further understanding epitopic landscape of DENV VLPs and presents a comparative antigenic surface view of VLPs in respect to virus particles. We propose the use VLPs as a safe and practical alternative to infectious virus as a vaccine and diagnostic antigen.

  3. Anti-IL-5 attenuates activation and surface density of β2-integrins on circulating eosinophils after segmental antigen challenge

    Science.gov (United States)

    Johansson, Mats W.; Gunderson, Kristin A.; Kelly, Elizabeth A. B.; Denlinger, Loren C.; Jarjour, Nizar N.; Mosher, Deane F.

    2013-01-01

    Background IL-5 activates αMβ2 integrin on blood eosinophils in vitro. Eosinophils in bronchoalveolar lavage (BAL) following segmental antigen challenge have activated β2-integrins. Objective To identify roles for IL-5 in regulating human eosinophil integrins in vivo. Methods Blood and BAL eosinophils were analyzed by flow cytometry in ten subjects with allergic asthma who underwent a segmental antigen challenge protocol before and after anti-IL-5 administration. Results Blood eosinophil reactivity with monoclonal antibody (mAb) KIM-127, which recognizes partially activated β2-integrins, was decreased after anti-IL-5. Before anti-IL-5, surface densities of blood eosinophil β2, αM, and αL integrin subunits increased modestly post-challenge. After anti-IL-5, such increases did not occur. Before or after anti-IL-5, surface densities of β2,αM, αL, and αD and reactivity with KIM-127 and mAb CBRM1/5, which recognizes high-activity αMβ2, were similarly high on BAL eosinophils 48 h post-challenge. Density and activation state of β1-integrins on blood and BAL eosinophils were not impacted by anti-IL-5, even though anti-IL-5 ablated a modest post-challenge increase on blood or BAL eosinophils of P-selectin glycoprotein ligand-1 (PSGL-1), a receptor for P-selectin that causes activation of β1-integrins. Forward scatter of blood eosinophils post-challenge was less heterogeneous and on the average decreased after anti-IL-5; however, anti-IL-5 had no effect on the decreased forward scatter of eosinophils in post-challenge BAL compared to eosinophils in blood. Blood eosinophil KIM-127 reactivity at the time of challenge correlated with the percentage of eosinophils in BAL post-challenge. Conclusion and Clinical Relevance IL-5 supports a heterogeneous population of circulating eosinophils with partially activated β2-integrins and is responsible for upregulation of β2-integrins and PSGL-1 on circulating eosinophils following segmental antigen challenge but has

  4. Expression of variant surface antigens by Plasmodium falciparum parasites in the peripheral blood of clinically immune pregnant women indicates ongoing placental infection

    DEFF Research Database (Denmark)

    Ofori, Michael F; Staalsoe, Trine; Bam, Victoria

    2003-01-01

    Placenta-sequestered Plasmodium falciparum parasites that cause pregnancy-associated malaria (PAM) in otherwise clinically immune women express distinct variant surface antigens (VSA(PAM)) not expressed by parasites in nonpregnant individuals. We report here that parasites from the peripheral blood...... of clinically immune pregnant women also express VSA(PAM), making them a convenient source of VSA(PAM) expressors for PAM vaccine research....

  5. Transcriptional regulation of the Borrelia burgdorferi antigenically variable VlsE surface protein.

    Science.gov (United States)

    Bykowski, Tomasz; Babb, Kelly; von Lackum, Kate; Riley, Sean P; Norris, Steven J; Stevenson, Brian

    2006-07-01

    The Lyme disease agent Borrelia burgdorferi can persistently infect humans and other animals despite host active immune responses. This is facilitated, in part, by the vls locus, a complex system consisting of the vlsE expression site and an adjacent set of 11 to 15 silent vls cassettes. Segments of nonexpressed cassettes recombine with the vlsE region during infection of mammalian hosts, resulting in combinatorial antigenic variation of the VlsE outer surface protein. We now demonstrate that synthesis of VlsE is regulated during the natural mammal-tick infectious cycle, being activated in mammals but repressed during tick colonization. Examination of cultured B. burgdorferi cells indicated that the spirochete controls vlsE transcription levels in response to environmental cues. Analysis of PvlsE::gfp fusions in B. burgdorferi indicated that VlsE production is controlled at the level of transcriptional initiation, and regions of 5' DNA involved in the regulation were identified. Electrophoretic mobility shift assays detected qualitative and quantitative changes in patterns of protein-DNA complexes formed between the vlsE promoter and cytoplasmic proteins, suggesting the involvement of DNA-binding proteins in the regulation of vlsE, with at least one protein acting as a transcriptional activator.

  6. A rhamnose-rich O-antigen mediates adhesion, virulence, and host colonization for the xylem-limited phytopathogen Xylella fastidiosa.

    Science.gov (United States)

    Clifford, Jennifer C; Rapicavoli, Jeannette N; Roper, M Caroline

    2013-06-01

    Xylella fastidiosa is a gram-negative, xylem-limited bacterium that causes a lethal disease of grapevine called Pierce's disease. Lipopolysaccharide (LPS) composes approximately 75% of the outer membrane of gram-negative bacteria and, because it is largely displayed on the cell surface, it mediates interactions between the bacterial cell and its surrounding environment. LPS is composed of a conserved lipid A-core oligosaccharide component and a variable O-antigen portion. By targeting a key O-antigen biosynthetic gene, we demonstrate the contribution of the rhamnose-rich O-antigen to surface attachment, cell-cell aggregation, and biofilm maturation: critical steps for successful infection of the host xylem tissue. Moreover, we have demonstrated that a fully formed O-antigen moiety is an important virulence factor for Pierce's disease development in grape and that depletion of the O-antigen compromises its ability to colonize the host. It has long been speculated that cell-surface polysaccharides play a role in X. fastidiosa virulence and this study confirms that LPS is a major virulence factor for this important agricultural pathogen.

  7. Detection of HbsAg and hATIII genetically modified goats (Caprahircus) by loop-mediated isothermal amplification.

    Science.gov (United States)

    Tao, Chenyu; Zhang, Qingde; Zhai, Shanli; Liu, Bang

    2013-11-01

    In this study, sensitive and rapid detection systems were designed using a loop-mediated isothermal amplification (LAMP) method to detect the genetically modified goats. A set of 4 primers were designed for each exogenous nucleic acids HBsAg and hATIII. The DNA samples were first amplified with the outer and inner primers and released a single-stranded DNA,of which both ends were stem-loop structure. Then one inner primer hybridized with the loop, and initiated displacement synthesis in less than 1 h. The result could be visualized by both agarose gel electrophoresis and unaided eyes directly after adding SYBR GREEN 1. The detection limit of LAMP was ten copies of target molecules, indicating that LAMP was tenfold more sensitive than the classical PCR. Furthermore, all the samples of genetically modified goats were tested positively by LAMP, and the results demonstrated that the LAMP was a rapid and sensitive method for detecting the genetically modified organism.

  8. Cloning of a cDNA encoding a surface antigen of Schistosoma mansoni schistosomula recognized by sera of vassinated mice

    International Nuclear Information System (INIS)

    Dalton, J.P.; Tom, T.D.; Strand, M.

    1987-01-01

    Spleen cells of mice vaccinated with radiation-attenuated Schistosoma mansoni cercariae were used to produce monoclonal antibodies directed against newly transformed schistosomular surface antigens. One of these monoclonal antibodies recognized a polypeptide of 18 kDa. Binding was measured by radioimmunoassay. This glycoprotein was purified by monoclonal antibody immunoaffinity chromatography and a polyclonal antiserum was prepared against it. Immunofluorescence assays showed that the polyclonal antiserum bound to the surface of newly transformed schistosomula and lung-stage organisms but not to the surface of liver-stage and adult worms. Using this polyclonal antiserum we isolated recombinant clones from an adult worm cDNA expression library constructed in λgt11. Clone 654.2 contained an insert of 0.52 kilobase and hybridized to a 1.2-kilobase mRNA species from adult worms. Most importantly, clone 654.2 produced a fusion protein of 125 kDa that was reactive with sera of vaccinated mice that are capable of transferring resistance. This result encourages future vaccination trials with the fusion protein

  9. Hepatitis B virus in drug users in France

    DEFF Research Database (Denmark)

    Brouard, C; Pillonel, J; Sogni, P

    2017-01-01

    People who use drugs (PWUD) are a key population for hepatitis B virus (HBV) vaccination and screening. We aimed to estimate the seroprevalence of HBs antigen (HBsAg) and self-reported HBV vaccination history in French PWUD attending harm reduction centres using data from the ANRS-Coquelicot mult...

  10. Blood donor recruitment strategies and their impact on blood safety in Egypt.

    Science.gov (United States)

    Hussein, Eiman

    2014-02-01

    Because of the high incidence of HCV, blood safety presents a serious challenge in Egypt. Given the constrained economy which limits the implementation of nucleic acid amplification technology, proper recruitment of blood donors becomes of paramount importance. To evaluate the effectiveness of blood donor recruitment strategies, the seroprevalence of positive infectious markers among blood donors was studied. Donors' records covering the period from 2006-2012 were reviewed. Blood donations were screened for HCV antibodies, HBs antigen (HBsAg), HIV-1 and 2 and syphilis antibodies. Of 308,762 donors, 63.4% were voluntary donors (VD). VD of 2011-2012 were significantly younger than family replacement donors (RD) .The overall prevalences of HCV antibodies, HBsAg, HIV and syphilis antibodies were 4.3%, 1.22%, 0.07%, and 0.13%, respectively. All tested markers (except HIV) were significantly higher among RD, when compared to VD (P<0.0001). A consistent steady trend for decrease in HCV seropositivity was observed in RD and VD from 8.9% and 4.2% to 3.8% and 1.5%, respectively. A trend for decrease in HBsAg was demonstrated in VD from 1.2% to 0.53%. The decreasing trends in HCV antibody and HBs antigen is promising and may reflect the improved donor selection criteria. Copyright © 2013 Elsevier Ltd. All rights reserved.

  11. Screening for transfusion transmissible infections using rapid diagnostic tests in Africa: a potential hazard to blood safety?

    Science.gov (United States)

    Prugger, C.; Laperche, S.; Murphy, E. L.; Bloch, E. M.; Kaidarova, Z.; Tafflet, M.; Lefrère, J.-J.; Jouven, X.

    2016-01-01

    Rapid diagnostic tests (RDTs) are routinely used in African blood centres. We analysed data from two cross-sectional studies representing 95 blood centres in 29 African countries. Standardized panels of sera containing varying concentrations of anti-human immunodeficiency virus (HIV) antibodies (Ab), hepatitis B virus antigen (HBsAg) and antihepatitis C virus (HCV) Ab were screened using routine operational testing procedures at the centres. Sensitivity of detection using RDTs was high for HIV Ab-positive samples, but low for intermediately HBsAg (51·5%) and HCV Ab (40·6%)-positive samples. These findings suggest that current RDT use in Africa could pose a hazard to blood safety. PMID:26646317

  12. Trichinella britovi human infection in Spain : antibody response to surface, excretory/secretory and somatic antigens

    Directory of Open Access Journals (Sweden)

    Rodríguez-Osorio M.

    2003-06-01

    Full Text Available A third outbreak of Trichinella britovi with 140 people involved, occurred in Granada Spain (December 1998. The source of infection was sausage made from uninspected wild boar meat. Fifty-two patients agreed to participated in this study. An elevated eosinophil level (> 5 % was detected in 59.6 % of patients, and persisted in most of these cases for two months. A moderate IgG response was observed. At the onset of symptoms, Western blot (WB test detected more positive cases than Enzyme linked immunosorbent assay (ELISA and indirect immunofluorescence (IIF. Six months from infection, ELISA revealed fewer positive cases than the other two tests. It would appear that the response to somatic antigens starts earlier than those to cuticular and excretory/secretory (ES antigens and that the response to ES antigens is the first to decrease.

  13. The E7-associated cell-surface antigen: a marker for the 11p13 chromosomal deletion associated with aniridia-Wilms tumor.

    OpenAIRE

    Scoggin, C H; Fisher, J H; Shoemaker, S A; Morse, H; Leigh, T; Riccardi, V M

    1985-01-01

    Unbalanced interstitial deletions of the p13 region of human chromosome 11 have been associated with congenital hypoplasia or aplasia of the iris, mental retardation, ambiguous genitalia, and predisposition to Wilms tumor of the kidney. Utilizing somatic cell hybrids containing either the normal or abnormal chromosome 11 from a child with Wilms tumor and aniridia, we previously mapped the E7 cell-surface antigen to the 11p1300-to-11p15.1 region. To localize even further the site of this antig...

  14. Crystal structure of the anti-(carcinoembryonic antigen) single-chain Fv antibody MFE-23 and a model for antigen binding based on intermolecular contacts.

    Science.gov (United States)

    Boehm, M K; Corper, A L; Wan, T; Sohi, M K; Sutton, B J; Thornton, J D; Keep, P A; Chester, K A; Begent, R H; Perkins, S J

    2000-03-01

    MFE-23 is the first single-chain Fv antibody molecule to be used in patients and is used to target colorectal cancer through its high affinity for carcinoembryonic antigen (CEA), a cell-surface member of the immunoglobulin superfamily. MFE-23 contains an N-terminal variable heavy-chain domain joined by a (Gly(4)Ser)(3) linker to a variable light-chain (V(L)) domain (kappa chain) with an 11-residue C-terminal Myc-tag. Its crystal structure was determined at 2.4 A resolution by molecular replacement with an R(cryst) of 19.0%. Five of the six antigen-binding loops, L1, L2, L3, H1 and H2, conformed to known canonical structures. The sixth loop, H3, displayed a unique structure, with a beta-hairpin loop and a bifurcated apex characterized by a buried Thr residue. In the crystal lattice, two MFE-23 molecules were associated back-to-back in a manner not seen before. The antigen-binding site displayed a large acidic region located mainly within the H2 loop and a large hydrophobic region within the H3 loop. Even though this structure is unliganded within the crystal, there is an unusually large region of contact between the H1, H2 and H3 loops and the beta-sheet of the V(L) domain of an adjacent molecule (strands DEBA) as a result of intermolecular packing. These interactions exhibited remarkably high surface and electrostatic complementarity. Of seven MFE-23 residues predicted to make contact with antigen, five participated in these lattice contacts, and this model for antigen binding is consistent with previously reported site-specific mutagenesis of MFE-23 and its effect on CEA binding.

  15. Evaluation of hepatitis B surface antigen and hepatitis B virus-DNA results in postmortem plasma specimens

    Directory of Open Access Journals (Sweden)

    Nihan Ziyade

    2015-03-01

    Full Text Available Objective: To assess the presence of hepatitis B surface antigen, one of the serologic markers of hepatitis B virus (HBV infection, in postmortem blood samples from autopsy cases using ELISA, and to compare the results with those obtained by PCR, which is the gold standard method in assessing HBV infection. Methods: The HBV test results of the blood samples from 880 autopsy cases determined in our laboratory, were retrospectively studied. Results: When compared with the gold standard method PCR, the sensitivity and specificity of postmortem ELISA were 100% and 84.1%, respectively. Conclusions: The increasingly used molecular diagnostic methods, such as PCR, should be used in cases where serological tests remain insufficient.We think that prospective studies on the comparison of ELISA and PCR assessment of postmortem blood samples with larger material should be carried out.

  16. Committed T lymphocyte stem cells of rats. Characterization by surface W3/13 antigen and radiosensitivity

    International Nuclear Information System (INIS)

    Dyer, M.J.; Hunt, S.V.

    1981-01-01

    The existence of stem cells committed to the T lymphoid lineage was deduced from studying how rat T and B stem cells differ in their expression of membrane W3/13 antigen and in their susceptibility in vivo to gamma irradiation. Stem cell activity of rat bone marrow and fetal liver was measured in long-term radiation chimeras using B and T cell alloantigenic surface markers to identify the progeny of donor cells. Monoclonal mouse anti-rat thymocyte antibody W3/13 labeled approximately 40% of fetal liver cells and 60-70% of young rat bone marrow cells (40% brightly, 25% dimly). Bright, dim, and negative cells were separated on a fluorescence-activated cell sorter. All B and T lymphoid stem cells in fetal liver were W3/13 bright, as were B lymphoid stem cells in bone marrow. W3/13 dim bone marrow had over half the T cell repopulating activity of unseparated marrow but gave virtually no B cell repopulation. In further experiments, the radiosensitivity of endogenous B and T lymphoid stem cells was determined by exposing host rats to between 4.5 and 10 Gy of gamma irradiation before repopulation with genetically marked marrow. The results depended on whether chimerism was assayed before day 50 or after day 100. At early times, a radioresistant T stem cell was indicated, whose activity waned later. Thus committed T stem cells of rats carry moderate amounts of W3/13 antigen and are more radioresistant but less permanently chimeragenic than the stem cells that regenerate B lymphocytes

  17. 77 FR 62520 - Prospective Grant of Exclusive License: The Development of Anti-CD22 Chimeric Antigen Receptors...

    Science.gov (United States)

    2012-10-15

    ... Exclusive License: The Development of Anti- CD22 Chimeric Antigen Receptors (CARs) for the Treatment of B... ``Anti-CD22 Chimeric Antigen Receptors'' [HHS Ref. E-265-2011/0-US-01], and (b) U.S. Patent Application... CD22 on their cell surface using chimeric antigen receptors which contain the HA22 or BL22 antibody...

  18. HIV, hepatitis B, and hepatitis C in Zambia

    Directory of Open Access Journals (Sweden)

    Kenneth C Kapembwa

    2011-01-01

    Full Text Available Objectives : Epidemiologic data of HIV and viral hepatitis coinfection are needed in sub-Saharan Africa to guide health policy for hepatitis screening and optimized antiretroviral therapy (ART. Materials and Methods: We screened 323 HIV-infected, ART-eligible adults for hepatitis B surface antigen (HBsAg and hepatitis C antibody (HCV Ab at a tertiary hospital in Lusaka, Zambia. We collected basic demographic, medical, and laboratory data to determine predictors for coinfection. Results: Of 323 enrolled patients, 32 (9.9%; 95% CI=6.7-13.2% were HBsAg positive, while 4 (1.2%; 95% CI=0.03-2.4% were HCV Ab positive. Patients with hepatitis B coinfection were more likely to be 200 IU/L was uncommon and did not differ between the two groups (3.4% vs. 2.3%; P=0.5. We were unable to determine predictors of hepatitis C infection due to the low prevalence of disease. Conclusions: HIV and hepatitis B coinfection was common among patients initiating ART at this tertiary care facility. Routine screening for hepatitis B should be considered for HIV-infected persons in southern Africa.

  19. Seroprevalence and Risk Factors for Hepatitis B in an Adult Population: The First Report from Birjand, South Khorasan, Iran

    Science.gov (United States)

    Ziaee, Masood; Ebrahimzadeh, Azadeh; Azarkar, Zohreh; Namaei, Mohammad Hasan; Saburi, Amin; Fereidouni, Mohammad; Bijari, Bita; Karamian, Mehdi; Sharifzadeh, Gholamreza

    2016-01-01

    Background Infection with the hepatitis B virus (HBV) is an important global health problem. Knowledge of the geographic distribution pattern of HBV infection can help to control the spread of the disease. Objectives To determine the prevalence of HBV infections and risk factors for the disease for the first time in Birjand, Southeastern Iran. Methods This was an analytical cross-sectional study conducted in 2013 - 2014 of 5235 HBV cases in Birjand, South Khorasan Iran. Subjects aged 15 - 70 y were selected using the cluster sampling method. Blood samples were taken and tested at a reference laboratory for the hepatitis B core antibody (anti-HBc). Seropositive specimens were tested for the hepatitis B surface antigen (HBsAg). Results The mean age (± SD) was 39.07 (± 14.04) y, and 786 (15%) subjects were anti-HBc positive. The prevalence of HBsAg was 1.6% (n = 85). The prevalence of anti-HBc seropositivity was significantly higher in subjects with a lower level of education (P = 0.09), older subjects (P = 0.001), intravenous (IV) drug users (Ppiercings (P piercings and drug abuse. PMID:27822260

  20. Expression and Antigenic Evaluation of VacA Antigenic Fragment of Helicobacter Pylori

    Science.gov (United States)

    Hasanzadeh, Leila; Ghaznavi-Rad, Ehsanollah; Soufian, Safieh; Farjadi, Vahideh; Abtahi, Hamid

    2013-01-01

    Objective(s) : Helicobacter pylori, a human specific gastric pathogen is a causative agent of chronic active gastritis. The vacuolating cytotoxin (VacA) is an effective virulence factor involved in gastric injury. The aim of this study was to construct a recombinant protein containing antigenic region of VacA gene and determine its antigenicity. Materials and Methods: The antigenic region of VacA gene was detected by bioinformatics methods. The polymerase chain reaction method was used to amplify a highly antigenic region of VacA gene from chromosomal DNA of H. pylori. The eluted product was cloned into the prokaryotic expression vector pET32a. The target protein was expressed in the Escherichia coli BL21 (DE3) pLysS. The bacteria including pET32a-VacA plasmids were induced by IPTG. The antigenicity was finally studied by western blotting using sera of 15 H. pylori infected patients after purification. Results: Enzyme digestion analysis, PCR and DNA sequencing results showed that the target gene was inserted correctly into the recombinant vector. The expressed protein was purified successfully via affinity chromatography. Data indicated that antigenic region of VacA protein from Helicobacter pylori was recognized by all 15 patient’s sera. Conclusion : Our data showed that antigenic region of VacA protein can be expressed by in E. co.li. This protein was recognized by sera patients suffering from H. pylori infection. the recombinant protein has similar epitopes and close antigenic properties to the natural form of this antigen. Recombinant antigenic region of VacA protein also seems to be a promising antigen for protective and serologic diagnosis . PMID:23997913