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Sample records for antigen hbsag assays

  1. 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.

  2. [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.

  3. 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 ...

  4. 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.

  5. [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.

  6. 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....

  7. 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

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    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.

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

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    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.

  9. Prevalence of Hepatitis-B Surface Antigen (HbsAg), Hepatitis C ...

    African Journals Online (AJOL)

    The prevalence of Hepatitis-B surface antigen (HBsAg), Hepatitis C virus (HCV) and Human immunodeficiency virus (HIV) was determined among apparently healthy male blood donors in Aminu Kano Teaching Hospital, Kano, between January and December, 2002. A total of 2,288 blood samples from the blood donors ...

  10. Sero-prevalence of Hepatitis B Surface Antigen (HBsAg), in Sexually ...

    African Journals Online (AJOL)

    Sero-prevalence of Hepatitis B Surface Antigen (HBsAg), in Sexually Transmitted Disease Patients. ... partners in the past 6 months, a history of a number of episodes of STDs, history of heterosexual exposure to partners at risk, for example prostitutes; a history of symptoms of an STD at the commencement of the study.

  11. Expression of hepatitis B surface antigen (HBsAg) gene in ...

    African Journals Online (AJOL)

    The transformed nature of the plants was confirmed by polymerase chain reaction (PCR) analysis and Southern blot hybridization. Expression of HBsAg was confirmed by western blotting and levels of expression were assayed by enzyme-linked immunosorbent assay (ELISA). Southern blot hybridization confirmed the ...

  12. Transgenic lettuce seedlings carrying hepatitis B virus antigen HBsAg

    OpenAIRE

    Marcondes,Jackson; Hansen,Ekkehard

    2008-01-01

    The obtainment of transgenic edible plants carrying recombinant antigens is a desired issue in search for economic alternatives viewing vaccine production. Here we report a strategy for genetic transformation of lettuce plants (Lactuca sativa L.) using the surface antigen HBsAg of hepatitis B virus. Transgenic lettuce seedlings were obtained through the application of a regulated balance of plant growth regulators. Genetic transformation process was acquired by cocultivation of cotyledons wit...

  13. A vaccine prepared from the 22 nm particles of surface hepatitis B antigen (HBsAg)

    International Nuclear Information System (INIS)

    Karelin, V.P.; Babaeva, E.E.; Gubenko, E.F.; Kaulen, D.K.; Zhdanov, V.M.

    1980-01-01

    A method for obtaining a subunit inactivated vaccine preparation from the 22-nm particles of HBsAg is proposed. For inactivation of the residual infectious hepatitis B virus (HBV) the preparations were successively treated with 1% sodium dodecyl sulfate (SDS) and nucleases. In addition, thermal denaturation and ultraviolet irradiation of HBV DNA were used. As a control the biologic activity of a reference virus (SV40) was tested after the same treatment. The effectiveness of DNA inactivation was monitored by adding 3H-thymidine labeled reference virus to the vaccine preparations. The purified and inactivated HBsAg was adsorbed on Al2O3. Antigenicity was calculated on the basis of the determination of antibody in guinea pigs immunized with various doses of the vaccine, and the release of 125 I- HBsAg from blood and kidneys in immunized and control mice was analyzed. Possible methods of inactivation and control of HBV vaccine is discussed

  14. Transgenic lettuce seedlings carrying hepatitis B virus antigen HBsAg

    Directory of Open Access Journals (Sweden)

    Jackson Marcondes

    Full Text Available The obtainment of transgenic edible plants carrying recombinant antigens is a desired issue in search for economic alternatives viewing vaccine production. Here we report a strategy for genetic transformation of lettuce plants (Lactuca sativa L. using the surface antigen HBsAg of hepatitis B virus. Transgenic lettuce seedlings were obtained through the application of a regulated balance of plant growth regulators. Genetic transformation process was acquired by cocultivation of cotyledons with Agrobacterium tumefaciens harboring the recombinant plasmid. It is the first description of a lettuce Brazilian variety "Vitória de Verão" genetically modified.

  15. Transgenic lettuce seedlings carrying hepatitis B virus antigen HBsAg.

    Science.gov (United States)

    Marcondes, Jackson; Hansen, Ekkehard

    2008-12-01

    The obtainment of transgenic edible plants carrying recombinant antigens is a desired issue in search for economic alternatives viewing vaccine production. Here we report a strategy for genetic transformation of lettuce plants (Lactuca sativa L.) using the surface antigen HBsAg of hepatitis B virus. Transgenic lettuce seedlings were obtained through the application of a regulated balance of plant growth regulators. Genetic transformation process was acquired by cocultivation of cotyledons with Agrobacterium tumefaciens harboring the recombinant plasmid. It is the first description of a lettuce Brazilian variety 'Vitória de Verão' genetically modified.

  16. Impact of "a" determinant mutations on detection of hepatitis B surface antigen (HBsAg) in HBV strains from Chinese patients with occult hepatitis B.

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    Huang, Xiangyan; Ma, Chenyun; Zhang, Qiang; Shi, Qingfen; Huang, Tao; Liu, Chao; Li, Jie; Hollinger, F Blaine

    2017-10-01

    This study was designed to detect mutations that occur within the "a" determinant in the S gene of the hepatitis B virus (HBV) in patients with occult hepatitis B (OHB), and to analyze the influence of these mutations on expression and reactivity of the hepatitis B surface antigen (HBsAg). Twenty-three certified OHB samples were compared to 32 HBsAg positive samples from patients with chronic hepatitis B. The median HBV DNA levels in the OHB group were significantly lower than those in the control group (P determinant were analyzed by gene amplification and sequencing. This revealed mixed infections in which clones within a sample displayed either different mutations or mutations in association with clones that exhibited wild type amino acid patterns. Sequencing analysis also showed a significant difference between the proportions of amino acid mutations observed in the OHB and control groups. Seven recombinant S (rS) proteins with corresponding OHB mutations and three wild type alleles were expressed and purified in the Pichia pastoris expression system to preserve conformational attributes, and their reactivity analyzed using six commercial HBsAg assays. The OHB sera were HBsAg nonreactive while the rS proteins with corresponding OHB mutations were universally reactive. Thus, we postulate that the reduced binding affinity between mutated HBsAg and its antibody may not be as important in defining OHB as is the effect of specific mutations in the preS/S region of the genome that affect the synthesis and secretion of the S protein and/or the virion. © 2017 Wiley Periodicals, Inc.

  17. 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

  18. Evidenciação de antígeno da hepatite B (HBsAg em "manchas" obtidas de exemplares de Triatominae: nota prévia Hepatitis B antigen (HBsAg in wildcaught Triatominae in Brazil: communication

    Directory of Open Access Journals (Sweden)

    J. A. N. Candeias

    1976-09-01

    Full Text Available De 890 "manchas" provenientes de insetos dos gêneros Panstrongylus, Rhodnius e Triatoma, positivas para sangue humano, 7 deram resultados presumptivamente positivos por hemaglutinação passiva para HBsAg. Deste total só um caso foi confirmado como positivo, por RIE (radioimunoensaio, correspondendo a uma "mancha" obtida de Triatoma sordida (ninfa de 5.º estádio.A total of 890 impressions on filter paper identified as containing human blood, were examined for the presence of hepatitis B antigen (HBsAg, using the Hepanosticon haemagglutination and radioimmunoassay techniques. The samples examined belong to the Panstrongylus, Rhodnius and Triatoma genres. The Hepanosticon haemagglutination technique showed that 7 impressions, after elution, were presumably positive for HBsAg, but by radioimmunoassay, this antigen could only be detected in 1. The positive sample was obtained from a specimen of Triatoma sordida (fifth instar nymph.

  19. Prevalence of hepatitis B virus surface antigen (HBsAg) in patients undergoing extraction at the University College Hospital, Ibadan.

    Science.gov (United States)

    Odaibo, G N; Arotiba, J T; Fasola, A O; Obiechina, A E; Olaleye, O D; Ajagbe, H A

    2003-09-01

    Hepatitis B Virus (HBV) infection and its sequelae (liver chirrhosis and hepatic carcinoma) are endemic in Africa. The risk of transmission of the infection during dental treatment is real. This study was carried out to determine the rate of Hepatits B Surface Antigen (HBsAg) as a marker of hepatitis B virus infection in patients undergoing dental extraction in order to highlight the potential risk of nosocomial transmission among the Dental Health Workers (DHW) and their patients. Three hundred (143 males and 157 females) consecutive patients requiring dental extraction who volunteered were enrolled into this study. Their ages ranged from 11 years to 95 years with a mean of 37.2 years (SD = 16.725) and a median of 36 years. The overall HBsAg infection rate was 18.3% (55/300). A higher infection rate (23.1%) occurred among the male patients compared with 14% in females (p = 0.0086). The high rate of HBV infection found among this study population suggests that Dental Surgeons in this environment have a high risk of exposure to hepatitis B virus and should be immunized at the beginning of their professional life. Universal biosafety measures should be observed strictly in all invasive procedures.

  20. 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.

  1. Development of an economic and efficient strategy to detect HBsAg: application of "gray-zones" in ELISA and combined use of several detection assays.

    Science.gov (United States)

    Peng, Jing; Cheng, Liming; Yin, Botao; Guan, Qing; Liu, Yanling; Wu, Shiji; Wang, Bin; Tang, Ning; Zhang, Biyu; Wang, Lian; Yang, Dongliang; Sun, Ziyong

    2011-11-20

    ELISA and CMIA are commonly used for detection of HBsAg. However, few investigations have been performed to evaluate their value in clinical practice, especially when jointly used. A reasonable and economic HBsAg testing algorithm is in great need. A total of 161,426 specimens in China were tested for 5 serum HBV markers with commonly used ELISA kits. 498 of these specimens were further tested for HBsAg by another ELISA kit, a CMIA kit and an HBsAg confirmatory assay. The sensitivities of the 2 ELISA kits were 76.21% and 88.42%, respectively. However, when using "gray-zones", the sensitivities were significantly improved to 97.43% and 96.43%. Furthermore, the combined use of the 2 ELISA kits and their "gray-zones" improved the sensitivity to 99.04%. Nevertheless, 2.91% of the samples with S/CO values below the lower "gray-zone" limits were reactive by the CMIA kit and then confirmed as HBsAg positive. However, 71.43% of the samples with HBsAg values within 0.05 and 0.10 IU/ml detected by the CMIA kit could not be confirmed. As a rational and economic strategy, combined use of "gray-zones" in ELISA and several different detection assays can significantly increase the efficiency of HBsAg detection. Copyright © 2011 Elsevier B.V. All rights reserved.

  2. Correlation between two chemiluminescence based assays for quantification of hepatitis B surface antigen in patients with chronic hepatitis B infection

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    E Gupta

    2015-01-01

    Full Text Available Purpose: Hepatitis B surface Antigen (HBsAg is the hallmark in diagnosing hepatitis B virus (HBV infection. In India many commercial assays are available for detection of HBsAg but very few can measure it quantitatively. The present study presents the comparative evaluation of two methods and their correlation with serum HBsAg in chronic hepatitis B (CHB patients. Materials and Methods: Consecutive patients of CHB were included and there HBsAg levels were measured by two methods: (i Elecsys, Roche Diagnostics, a qualitative assay and (ii Architect, Abbott Diagnostics, a quantitative assay. The HBV DNA was measured by real-time polymerase chain reaction (qPCR. Results: Total of 136 patients were included in the study and there was a significant overall correlation between both the assays (correlation coefficient [r] = 0.83; P < 0.001. Assays correlated well with each other across all subgroups of CHB: treatment naοve (r = 0.73; P < 0.001, n = 32, on treatment (r = 0.56; P < 0.05, n = 104, hepatitis Be (HBe antigen positive (r = 0.67; P < 0.001, n = 62 and anti-HBe positive (r = 0.61; P < 0.05, n = 74 group. On correlation with serum HBV DNA, Architect assay demonstrated good correlation (r = 0.73; P < 0.001, n = 136 as compared to the Elecsys assay (r = 0.27; P = 0.068, n = 136. Architect HBsAg QT assay (A1 also correlated well with HBV DNA in the treatment naοve group (r = 0.69; P < 0.001, n = 32. Conclusions: Our study hence proved that both the assays are comparable and a simple qualitative assay with in-house modification can be used easily for quatitation of HBsAg in clinical samples.

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

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    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.

  4. Prevalence of Hepatitis B Surface Antigen (HBsAg) Amongst Alcohol ...

    African Journals Online (AJOL)

    The prevalence of Hepatitis B surface Antigen was studied amongst alcohol consumers and non– consumers (Control subjects) in Bassa Local Government Area (LGA) of Plateau State. Three hundred and five (305) subjects comprising 255(83.61%) alcoholics and 50(16.39%) non-alcoholic control subjects were screened ...

  5. 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.

  6. Heteroassembled gold nanoparticles with sandwich-immunoassay LSPR chip format for rapid and sensitive detection of hepatitis B virus surface antigen (HBsAg).

    Science.gov (United States)

    Kim, Jinwoon; Oh, Seo Yeong; Shukla, Shruti; Hong, Seok Bok; Heo, Nam Su; Bajpai, Vivek K; Chun, Hyang Sook; Jo, Cheon-Ho; Choi, Bong Gill; Huh, Yun Suk; Han, Young-Kyu

    2018-06-01

    This study aimed to develop a more sensitive method for the detection of hepatitis B surface antigen (HBsAg) using heteroassembled gold nanoparticles (AuNPs). A single layered localized surface plasmon resonance (LSPR) chip format was developed with antigen-antibody reaction-based detection symmetry using AuNPs, which detected HBsAg at 10 pg/mL. To further improve the detection limit, a modified detection format was fabricated by fixing a secondary antibody (to form a heteroassembled sandwich format) to the AuNP monolayer, which enhanced the detection sensitivity by about 100 times. The developed heteroassembled AuNPs sandwich-immunoassay LSPR chip format was able to detect as little as 100 fg/mL of HBsAg within 10-15 min. In addition, the heteroassembled AuNPs sandwich-immunoassay LSPR chip format did not show any non-specific binding to other tested antigens, including alpha fetoprotein (AFP), C-reactive protein (CRP), and prostate-specific antigen (PSA). These findings confirm that the proposed detection strategy of heteroassembled AuNPs sandwich-immunoassay LSPR chip format may provide a new platform for early diagnosis of various human diseases. Copyright © 2018 Elsevier B.V. All rights reserved.

  7. 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...

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

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    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.

  9. 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.

  10. Assaying Carcinoembryonic Antigens by Normalized Saturation Magnetization

    Science.gov (United States)

    Huang, Kai-Wen; Chieh, Jen-Jie; Shi, Jin-Cheng; Chiang, Ming-Hsien

    2015-07-01

    Biofunctionalized magnetic nanoparticles (BMNs) that provide unique advantages have been extensively used to develop immunoassay methods. However, these developed magnetic methods have been used only for specific immunoassays and not in studies of magnetic characteristics of materials. In this study, a common vibration sample magnetometer (VSM) was used for the measurement of the hysteresis loop for different carcinoembryonic antigens (CEA) concentrations ( Φ CEA) based on the synthesized BMNs with anti-CEA coating. Additionally, magnetic parameters such as magnetization ( M), remanent magnetization ( M R), saturation magnetization ( M S), and normalized parameters (Δ M R/ M R and Δ M S/ M S) were studied. Here, Δ M R and Δ M s were defined as the difference between any ΦCEA and zero Φ CEA. The parameters M, Δ M R, and Δ M S increased with Φ CEA, and Δ M S showed the largest increase. Magnetic clusters produced by the conjugation of the BMNs to CEAs showed a Δ M S greater than that of BMNs. Furthermore, the relationship between Δ M S/ M S and Φ CEA could be described by a characteristic logistic function, which was appropriate for assaying the amount of CEAs. This analytic Δ M S/ M S and the BMNs used in general magnetic immunoassays can be used for upgrading the functions of the VSM and for studying the magnetic characteristics of materials.

  11. Radioimmunoprecipitation polyethylene glycol assay for circulating Entamoeba histolytica antigens

    Energy Technology Data Exchange (ETDEWEB)

    Pillai, S.; Mohimen, A.; Mehra, S. (Calcutta Medical Research Inst., Calcutta (India). Kothari Centre of Gastroenterology)

    1982-12-17

    An assay capable of detecting circulating Entamoeba histolytica antigens in amoebiasis is described. This assay utilised a radiolabelled affinity purified rabbit anti-E. histolytica antibody that had been depleted of antibodies that cross-react with human serum proteins, and a polyethylene glycol precipitation step.

  12. 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.

  13. Laboratory Validation of the Sand Fly Fever Virus Antigen Assay.

    Science.gov (United States)

    Reeves, Will K; Szymczak, Mitchell Scott; Burkhalter, Kristen L; Miller, Myrna M

    2015-12-01

    Sandfly fever group viruses in the genus Phlebovirus (family Bunyaviridae) are widely distributed across the globe and are a cause of disease in military troops and indigenous peoples. We assessed the laboratory sensitivity and specificity of the Sand Fly Fever Virus Antigen Assay, a rapid dipstick assay designed to detect sandfly fever Naples virus (SFNV) and Toscana virus (TOSV) against a panel of phleboviruses. The assay detected SFNV and TOSV, as well as other phleboviruses including Aguacate, Anahanga, Arumowot, Chagres, and Punta Toro viruses. It did not detect sandfly fever Sicilian, Heartland, Rio Grande, or Rift Valley fever viruses. It did not produce false positive results in the presence of uninfected sand flies (Lutzomyia longipalpis) or Cache Valley virus, a distantly related bunyavirus. Results from this laboratory evaluation suggest that this assay may be used as a rapid field-deployable assay to detect sand flies infected with TOSV and SFNV, as well as an assortment of other phleboviruses.

  14. Establishment of immunoradiometric assay for free prostate-specific antigen

    International Nuclear Information System (INIS)

    Ma Lianxue

    2009-01-01

    An immunoradiometric assay (IRMA) of free prostate specific antigen (F-PSA) in serum was established. One monoclonal antibody against total PSA (T-PSA) was coated on the plastic tubes, the other against F-PSA was labeled with 125 I. The sensitivity of assay was 0.04 μg/L (n=20, +2s), the CVs were 2.9%-4.0% for the intra-assay and 3.5%-10.5% for the inter-assay and the average recovery was 102.7%. The correlative equation comparing with the FPSA-RIA (CIS BIO) is y=0.965 1 χ -0.001 1, and r=0.996 4. This F-PSA IRMA is a sensitive and precise method in detecting F-PSA and fit for the vitro assay. (authors)

  15. Cell-free antigens of Sporothrix brasiliensis: antigenic diversity and application in an immunoblot assay.

    Science.gov (United States)

    Almeida-Paes, Rodrigo; Bailão, Alexandre Melo; Pizzini, Cláudia Vera; Reis, Rosani Santos; Soares, Célia Maria de Almeida; Peralta, José Mauro; Gutierrez-Galhardo, Maria Clara; Zancopé-Oliveira, Rosely Maria

    2012-11-01

    Sporotrichosis is a subcutaneous mycosis diagnosed by isolation of the fungus in culture. Serological tests for help in diagnosis in general do not use purified or recombinant antigens, because there is a paucity of described immunoreactive proteins, especially for the new described Sporothrix species, such as Sporothrix brasiliensis. This study aims to characterise antigens from S. brasiliensis and verify their application in serodiagnosis of sporotrichosis. An immunoblot assay allied with computer-based analysis was used to identify putative antigenic molecules in a cell-free extracts of both morphological phases of this fungus, and to delineate antigenic polymorphism among seven S. brasiliensis isolates and one S. schenckii Brazilian strain. The mycelial and yeast phase of the fungus originated 14 and 23 reactive bands, respectively, which were variable in intensity. An 85 kDa antigen, verified in the yeast phase of the fungus, was observed in all strains used and the immunodominant protein was identified. This protein, however, cross-react with serum samples from patients infected with other pathogens. The results show that the S. brasiliensis cell-free antigen extract is a single and inexpensive source of antigens, and can be applied on the sporotrichosis serodiagnosis. © 2012 Blackwell Verlag GmbH.

  16. Rapid detection of cryptococcal antigen by a flow assay

    Directory of Open Access Journals (Sweden)

    Graziano Bargiggia

    2017-10-01

    Full Text Available Cryptococcosis is a life-threatening infection caused by Cryptococcus neoformans and C. gattii. Tests for quick detection of the cryptococcal antigen are needed. This study compares the performance of a lateral flow assay (LFA to the latex agglutination method. Thirty-five cryopreserved positive samples (sera and cerebrospinal fluids plus three negative sera for control have been examined. LFA does not need high-temperature incubation or enzyme pre-treatment. All the results, except for one serum, agree with previous obtained with latex agglutination method. LFA has an important clinical utility for its rapidity and sensitivity, and it also can be used as a point-of-care test.

  17. The immunoradiometric assay for carbohydrate antigen CA-242

    International Nuclear Information System (INIS)

    Chen Zhizhou

    1991-01-01

    Using 125 I-labelled monoclonal antibody (C242) against carbohydrate antigen CA-242, the sandwich immunoradiometric assay (IRMA) was developed. In preliminary clinical application of this method, the results of serum CA-242 measurements were 2.5 ± 4.5 U/ml for 77 normal individuals, 3.5 ± 7.0 U/ml for 128 cases of benign diseases, and 56.0 ± 91.3 U/ml for 210 cases of malignant tumors. The CA-242 values of patients with malignant tumors were significantly higher than that of patients with benign diseases. Taking 12 U/ml as normal upper limit, the positive detective rates of pancreatic and colorectal cancers were 86.6% and 62.0% respectively, while the false positive rate for normal individuals was 4%

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

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    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.

  19. Cryptococcus neoformans meningitis with negative cryptococcal antigen: Evaluation of a new immunochromatographic detection assay

    Directory of Open Access Journals (Sweden)

    O. Opota

    2015-03-01

    Full Text Available Detection of cryptococcal antigen in serum or cerebrospinal fluid allows cryptococcal meningitis diagnosis within few hours with >90% sensitivity. In an HIV-positive patient with Cryptococcus neoformans meningitis, initial antigen detection by immunoagglutination was negative. We thus evaluated a new immunochromatographic detection assay that exhibited a higher sensitivity.

  20. Cryptococcus neoformans meningitis with negative cryptococcal antigen: Evaluation of a new immunochromatographic detection assay.

    Science.gov (United States)

    Opota, O; Desgraz, B; Kenfak, A; Jaton, K; Cavassini, M; Greub, G; Prod'hom, G; Giulieri, S

    2015-03-01

    Detection of cryptococcal antigen in serum or cerebrospinal fluid allows cryptococcal meningitis diagnosis within few hours with >90% sensitivity. In an HIV-positive patient with Cryptococcus neoformans meningitis, initial antigen detection by immunoagglutination was negative. We thus evaluated a new immunochromatographic detection assay that exhibited a higher sensitivity.

  1. [Clinical benefit of HCV core antigen assay in patients receiving interferon and ribavirin combination therapy].

    Science.gov (United States)

    Higashimoto, Makiko; Takahashi, Masahiko; Jokyu, Ritsuko; Saito, Hidetsugu

    2006-02-01

    A highly sensitive second generation HCV core antigen assay has recently been developed. We compared viral disappearance and kinetics data between commercially available core antigen assays, Lumipulse Ortho HCV Ag, and a quantitative HCV RNA PCR assay, Cobas Amplicor HCV Monitor Test, Version 2 to estimate the predictive benefit of sustained viral response (SVR) and non-SVR in 59 patients treated with interferon and ribavirin combination therapy. We found a good correlation between HCV core Ag and HCV RNA level regardless of genotype. Although the sensitivity of the core antigen assay was lower than PCR, the dynamic range was broader than that of the PCR assay, so that we did not need to dilute the samples in 59 patients. We detected serial decline of core Ag levels in 24 hrs, 7 days and 14 days after interferon combination therapy. The decline of core antigen levels was significant in SVR patients compared to non-SVR as well as in genotype 2a, 2b patients compared to 1b. Core antigen-negative on day 1 could predict all 10 SVR patients (PPV = 100%), whereas RNA-negative could predict 22 SVR out of 25 on day 14 (PPV = 88.0%). None of the patients who had detectable serum core antigen on day 14 became SVR(NPV = 100%), although NPV was 91.2% on RNA negativity. An easy, simple, low cost new HCV core antigen detecting system seems to be useful for assessing and monitoring IFN treatment for HCV.

  2. An improved gold nanoparticle probe-based assay for HCV core antigen ultrasensitive detection.

    Science.gov (United States)

    Yin, Hui-Qiong; Ji, Chang-Fu; Yang, Xi-Qin; Wang, Rui; Yang, Shu; Zhang, He-Qiu; Zhang, Jin-Gang

    2017-05-01

    A gold nanoparticle probe-based assay (GNPA) was developed for ultrasensitive detection of Hepatitis C virus (HCV) core antigen. In the GNPA, after anti-HCV core antigen polyclonal antibodies and single-stranded barcode signal DNA were labeled on gold nanoparticle probe (NP), DNA enzyme was used to degrade the unbound barcode DNAs. The anti-HCV core antigen monoclonal antibodies were coated on magnetic microparticles probe (MMP). Then the NP-HCV core antigen-MMP sandwich immuno-complex was formed when the target antigen protein was added and captured. Magnetically separated, the immuno-complex containing the single-stranded barcode signal DNA was characterized by TaqMan probe based real-time fluorescence PCR. A detection limit of 1 fg/ml was determined for the HCV core antigen which is magnitude greater than that of ELISA (2ng/ml). The coefficients of variation (CV) of intra-assay and inter-assay respectively ranged from 0.22-2.62% and 1.92-3.01%. The improved GNPA decreased the interference of unbound barcode DNAs and may be an new way for HCV core antigen detection. Copyright © 2017. Published by Elsevier B.V.

  3. Immune responses to HBsAg conjugated to protein D of non-typeable Haemophilus influenzae in mice.

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    Qiudong Su

    Full Text Available Hepatitis B vaccine that contains an aluminum hydroxide adjuvant induces apoptotic death of Hepa 1-6 cells. Difficult-to-degrade chemical additives in vaccines effectively enhance vaccine immunogenicity, but also affect the host tissue. Identification of bio-molecules that are readily degraded and compatible in vivo as an adjuvant is important for vaccine research. The hapten-carrier effect suggests that stimulation of helper T (Th cells by carrier adjuvants is feasible. Protein D (PD of non-typeable Haemophilus influenzae covalently conjugated to some polysaccharide vaccines has been confirmed to convert T-cell independent (TI antigens into T-cell dependent (TD antigens, and elicit strong T-cell responses ultimately. Herein, we would substitube PD for aluminum hydroxide adjuvant in Hepatitis B vaccine.Truncated PD (amino acids 20-364 was expressed in Escherichia coli and purified by (NH42SO4 precipitation and DEAE chromatography. After evaluation of antigenicity by western blotting, PD was covalently conjugated to yeast-derived recombinant HBsAg by cross-linking with glutaraldehyde. Intramuscular immunization with the conjugate induced higher level of HBsAg-specific antibody than did HBsAg alone (p < 0.05, and was comparable to commercial Hepatitis B vaccine. During the surveillance period (days 35-105, anti-HBs titers were hold high. Moreover, the conjugated vaccine enhanced Th1 immune responses, while Th2 responses were also activated and induced an antibody response, as determined by IFN-γ ELISPOT and IgG1/IgG2a ratio assays.Recombinant truncated PD covalently conjugated to HBsAg antigen enhanced the immunogenicity of the antigen in mice simultaneously by humoral and cellular immune response, which would facilitate therapeutic hepatitis B vaccines.

  4. Automated alarm to detect antigen excess in serum free immunoglobulin light chain kappa and lambda assays.

    Science.gov (United States)

    Urdal, Petter; Amundsen, Erik K; Toska, Karin; Klingenberg, Olav

    2014-10-01

    Antigen excess causing a falsely low concentration result may occur when measuring serum free immunoglobulin light chains (SFLC). Automated antigen excess detection methods are available only with some analyzers. We have now developed and verified such a method. Residuals of sera with known SFLC-κ and -λ concentrations were analyzed using Binding Site reagents and methods adapted to the Roche Cobas® c.501 analyzer. We analyzed 117 sera for SFLC-κ and -λ and examined how the absorbance increased with time during the 7 minutes of reaction (absorbance reading points 12-70). From this an antigen excess alarm factor (ratio of absorbance increases between reading points 68-60 and 20-12, multiplied by 100) was defined. Upon our request, Roche added to our two SFLC assays a program which calculated this antigen excess alarm factor and triggered an alarm when the factor was below a defined value. We verified this antigen excess alarm function by analyzing serum from 325 persons of whom 143 were multiple myeloma patients. All samples with a known concentration above 30 mg/L triggered either an antigen excess alarm, an 'above test' alarm or both. Also, all samples above 200 mg/L (SFLC-λ) and 300 mg/L (SFLC-κ) triggered the antigen excess alarm and all but one triggered the above test alarm. The antigen excess alarm function presented here detected all known antigen excess samples at no increased time of analysis, a reduced workload and reduced reagent cost.

  5. Helicobacter Pylori Stool Antigen Assay in Hyperemesis Gravidarum.

    Science.gov (United States)

    Kabir, S; Khanam, R A; Basher, M S; Azam, M S; Hossain, M A; Mirza, T T; Banu, K A; Karmoker, R K

    2017-04-01

    Hyperemesis gravidarum is the most severe form of nausea and vomiting in pregnancy that seriously affects the pregnancy outcome. It is a disease with unknown etiology and varieties of contributing factors like hormonal changes, psychological and immunological factors. A significantly high prevalence of Helicobacter pylori among pregnant women with Hyperemesis gravidarum has been revealed recently. A descriptive, cross-sectional study was carried out at antenatal ward, Department of Obstetrics and Gynaecology, Mymensingh Medical College Hospital, Mymensingh for a period of twenty-one months among purposively selected thirty-six patients with Hyperemesis gravidarum with a view to assess the involvement of H. pylori in Hyperemesis gravidarum. Data were collected through interview, physical examinations and laboratory investigations by using case record form. Statistical analysis was performed using SPSS version 20.0 for Windows. Highest number 16(44.44%) of respondents were in age group 20 to 24 years with a mean of 23.81 years and a standard deviation (SD) of 4.55 years. Majority 29(80.56%) of the women had education less than 12 years, as many as 28(77.78%) women were housewives, and at least 14(38.89%) women had unplanned pregnancies. An overwhelming majority 29(80.56%) of women had their pregnancy duration between 8 to 12 weeks with a mean duration of 10.64 weeks and a standard deviation of 2.35 weeks. Majority 20(55.56%) of women were pregnant for first time, as many as 19(52.78%) women had duration of illness for 5 to 9 weeks. Of 16 multi-gravid women, 7(43.75%) had history of similar condition in their previous pregnancies. As many as 9 (25.00%) women had family history of similar condition in their mothers and sisters. First trimester was time of manifestation of the condition.At least 11 (30.56%) stool samples were positive for H. pylori stool antigen. Family history of Hyperemesis gravidarum and presence of H. pylori stool antigen are statistically

  6. Comparison of two rapid assays for Clostridium difficile Common antigen and a C difficile toxin A/B assay with the cell culture neutralization assay.

    Science.gov (United States)

    Reller, Megan E; Alcabasa, Romina C; Lema, Clara A; Carroll, Karen C

    2010-01-01

    We compared 3 rapid assays for Clostridium difficile with a cell culture cytotoxicity neutralization assay (CCNA). Of 600 stool samples, 46 were positive for toxigenic C difficile. Both rapid common antigen assays were highly sensitive (91.3%-100%) and, therefore, were appropriate screening tests. The rapid toxin assay had poor sensitivity (61%) but excellent specificity (99.3%). Testing stools for glutamate dehydrogenase (step 1) and those positive with a rapid toxin assay (step 2) would correctly classify 81% of submitted specimens within 2 hours, including during periods of limited staffing (evenings, nights, and weekends). CCNA could then be used as a third step to test rapid toxin-negative samples, thereby providing a final result for the remaining 19% of samples by 48 to 72 hours. The use of rapid assays as outlined could enhance timely diagnosis of C difficile.

  7. Performance Assessment of a Trypanosoma cruzi Chimeric Antigen in Multiplex Liquid Microarray Assays.

    Science.gov (United States)

    Santos, Fred Luciano Neves; Celedon, Paola Alejandra Fiorani; Zanchin, Nilson Ivo Tonin; Leitolis, Amanda; Crestani, Sandra; Foti, Leonardo; de Souza, Wayner Vieira; Gomes, Yara de Miranda; Krieger, Marco Aurélio

    2017-10-01

    Diagnosing chronic Chagas disease (CD) requires antibody-antigen detection methods, which are traditionally based on enzymatic assay techniques whose performance depend on the type and quality of antigen used. Previously, 4 recombinant chimeric proteins from the Instituto de Biologia Molecular do Paraná (IBMP-8.1 to 8.4) comprising immuno-dominant regions of diverse Trypanosoma cruzi antigens showed excellent diagnostic performance in enzyme-linked immunosorbent assays. Considering that next-generation platforms offer improved CD diagnostic accuracy with different T. cruzi -specific recombinant antigens, we assessed the performance of these chimeras in liquid microarrays (LMAs). The chimeric proteins were expressed in Escherichia coli and purified by chromatography. Sera from 653 chagasic and 680 healthy individuals were used to assess the performance of these chimeras in detecting specific anti- T. cruzi antibodies. Accuracies ranged from 98.1 to 99.3%, and diagnostic odds ratio values were 3,548 for IBMP-8.3, 4,826 for IBMP-8.1, 7,882 for IBMP-8.2, and 25,000 for IBMP-8.4. A separate sera bank (851 samples) was employed to assess cross-reactivity with other tropical diseases. Leishmania , a pathogen with high similarity to T. cruzi , showed cross-reactivity rates ranging from 0 to 2.17%. Inconclusive results were negligible (0 to 0.71%). Bland-Altman and Deming regression analysis based on 200 randomly selected CD-positive and negative samples demonstrated interchangeability with respect to CD diagnostic performance in both singleplex and multiplex assays. Our results suggested that these chimeras can potentially replace antigens currently used in commercially available assay kits. Moreover, the use of multiplex platforms, such as LMA assays employing 2 or more IBMP antigens, would abrogate the need for 2 different testing techniques when diagnosing CD. Copyright © 2017 American Society for Microbiology.

  8. Development of hen antihepatitis B antigen IgY-based conjugate for ELISA assay

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    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.

  9. Performance of cryptococcal antigen lateral flow assay using saliva in Ugandans with CD4 <100.

    Directory of Open Access Journals (Sweden)

    Richard Kwizera

    Full Text Available Cryptococcal meningitis can best be diagnosed by cerebrospinal fluid India ink microscopy, cryptococcal antigen detection, or culture. These require invasive lumbar punctures. The utility of cryptococcal antigen detection in saliva is unknown. We evaluated the diagnostic performance of the point-of-care cryptococcal antigen lateral flow assay (CrAg LFA in saliva.We screened HIV-infected, antiretroviral therapy naïve persons with symptomatic meningitis (n = 130 and asymptomatic persons with CD4+<100 cells/µL entering into HIV care (n = 399 in Kampala, Uganda. The diagnostic performance of testing saliva was compared to serum/plasma cryptococcal antigen as the reference standard.The saliva lateral flow assay performance was overall more sensitive in symptomatic patients (88% than in asymptomatic patients (27%. The specificity of saliva lateral flow assay was excellent at 97.8% in the symptomatic patients and 100% in asymptomatic patients. The degree of accuracy of saliva in diagnosing cryptococcosis and the level of agreement between the two sample types was better in symptomatic patients (C-statistic 92.9, κ-0.82 than in asymptomatic patients (C-statistic 63.5, κ-0.41. Persons with false negative salvia CrAg tests had lower levels of peripheral blood CrAg titers (P<0.001.There was poor diagnostic performance in testing saliva for cryptococcal antigen, particularly among asymptomatic persons screened for preemptive treatment of cryptococcosis.

  10. 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.)

  11. Development of kit for immunoradiometric assay of prostate specific antigen: Preliminary results

    International Nuclear Information System (INIS)

    Benzaid, A.; Boudjemai, S.; Benhidour, A.; Saada, B.

    1999-01-01

    This report presents the preliminary results obtained in the development of immunoradiometric assay of Prostate specific Antigen. The paper describes the immobilisation of anti-PSA on polystyrene beads and tubers and 125 I labelling of anti-T-PSA and f-PSA monoclonal antibodies. The obtained results were encouraging and work is in progress. (author)

  12. Indirect solid-phase immunosorbent assay for detection of arenavirus antigens and antibodies

    Energy Technology Data Exchange (ETDEWEB)

    Ivanov, A.P.; Rezapkin, G.V.; Dzagurova, T.K.; Tkachenko, E.A. (Institute of Poliomyelitis anU Viral Encephalities of the U.S.S.R. Academy of Medical Sciences, Moscow)

    1984-05-01

    Indirect enzyme-linked immunosorbent assay (ELISA) and solid phase radioimmunoassay (SPRIA) using either enti-human or anti-mouse IgG labelled with horseradish peroxidase and /sup 125/I, respectively, were developed for the detection of Junin, Machupo, Tacaribe, Amapari, Tamiami, Lassa and LCM arenaviruses. Both methods allow high sensitivity detection of arenavirus antigens and antibodies.

  13. Flow cytometric assay detecting cytotoxicity against human endogenous retrovirus antigens expressed on cultured multiple sclerosis cells

    DEFF Research Database (Denmark)

    Møller-Larsen, A; Brudek, T; Petersen, T

    2013-01-01

    expressing increased amounts of human endogenous retrovirus antigens. MS patients also have increased antibody levels to these antigens. The target cells are spontaneously growing peripheral blood mononuclear cells (PBMCs) of B cell lineage, expressing human endogenous retrovirus HERV epitopes...... on their surface. Polyclonal antibodies against defined peptides in the Env- and Gag-regions of the HERVs were raised in rabbits and used in antibody-dependent cell-mediated cytotoxicity (ADCC) -assays. Rituximab® (Roche), a chimeric monoclonal antibody against CD20 expressed primarily on B cells, was used...

  14. Clinical impact of prostate specific antigen (PSA) inter-assay variability on management of prostate cancer.

    Science.gov (United States)

    Murthy, Vedang; Rishi, Anupam; Gupta, Sanjeev; Kannan, Sadhana; Mahantshetty, Umesh; Tongaonkar, Hemant; Bakshi, Ganesh; Prabhash, Kumar; Bhanushali, Paresh; Shinde, Bhoopal; Inamdar, Nitin; Shrivastava, Shyamkishore

    2016-01-01

    To evaluate the inter-assay variability of six commercially available prostate specific antigen (PSA) assays, its clinical impact in prostate cancer (PCa) and comparison of automated versus manual assays. Sera from 495 patients (425 with PCa and 70 men with Benign Prostatic Hyperplasia (BPH), were measured with six different assays [three automated assays (a-PSA) and three manual ELISA based assay (m-PSA)]. Variability, agreement and bias were measured and compared among assays using Bland Altman plots and Passing and Bablok regression analysis. The possible impact of inter-assay variability on important clinical scenarios was also studied. All the assays were well correlated (r: 0.88-0.98); however there was significant disagreement and bias between the systems, which were more pronounced among the a-PSA assays. The Bland Altman plot showed that the variability was high between the m-PSA assays and the standard Abbott system with mean difference of 3.8-5.8ng/ml. In contrast, the a-PSA had better agreement with mean difference of 0.8-2.3ng/ml. Beckman Coulter showed the best agreement to the institutional reference (slope-1.097; 95% CI: 1.06-1.14; p<0.05, and intercept-0.20; 95% CI-0.38-0.58; p<0.05, Passing Bablok). It led to significant variability in PCa risk stratification and failure to detect biochemical failure in more than 50% cases. The discrepancies between the assays lead to significant clinical misinterpretation with risk group migration and detection of biochemical failure post radiotherapy. There are significant discordances between automated and ELISA based assays. Copyright © 2015 The Canadian Society of Clinical Chemists. Published by Elsevier Inc. All rights reserved.

  15. Pi overlapping ring systems contained in a homogeneous assay: a novel homogeneous assay for antigens

    Science.gov (United States)

    Kidwell, David A.

    1993-05-01

    A novel immunoassay, Pi overlapping ring systems contained in a homogeneous assay (PORSCHA), is described. This assay relies upon the change in fluorescent spectral properties that pyrene and its derivatives show with varying concentration. Because antibodies and other biomolecules can bind two molecules simultaneously, they can change the local concentration of the molecules that they bind. This concentration change may be detected spectrally as a change in the fluorescence emission wavelength of an appropriately labeled biomolecule. Several tests of PORSCHA have been performed which demonstrate this principle. For example: with streptavidin as the binding biomolecule and a biotin labeled pyrene derivative, the production of the excimer emitting at 470 nm is observed. Without the streptavidin present, only the monomer emitting at 378 and 390 nm is observed. The ratio of monomer to excimer provides the concentration of unlabeled biotin in the sample. Approximately 1 ng/mL of biotin may be detected with this system using a 50 (mu) l sample (2 X 10-16 moles biotin). The principles behind PORSCHA, the results with the streptavidin/biotin system are discussed and extensions of the PORSCHA concept to antibodies as the binding partner and DNA in homogeneous assays are suggested.

  16. Benefit of Hepatitis C Virus Core Antigen Assay in Prediction of Therapeutic Response to Interferon and Ribavirin Combination Therapy

    OpenAIRE

    Takahashi, Masahiko; Saito, Hidetsugu; Higashimoto, Makiko; Atsukawa, Kazuhiro; Ishii, Hiromasa

    2005-01-01

    A highly sensitive second-generation hepatitis C virus (HCV) core antigen assay has recently been developed. We compared viral disappearance and first-phase kinetics between commercially available core antigen (Ag) assays, Lumipulse Ortho HCV Ag (Lumipulse-Ag), and a quantitative HCV RNA PCR assay, Cobas Amplicor HCV Monitor test, version 2 (Amplicor M), to estimate the predictive benefit of a sustained viral response (SVR) and non-SVR in 44 genotype 1b patients treated with interferon (IFN) ...

  17. 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.

  18. OCCULT HEPATITIS B VIRUS INFECTION AMONG BLOOD DONORS WITH ANTIBODIES TO HEPATITIS B CORE ANTIGEN

    Directory of Open Access Journals (Sweden)

    A. Jafarzadeh

    2008-04-01

    Full Text Available Diagnosis of hepatitis B is routinely based on of serological assay of hepatitis B surface antigen (HBsAg. Occult hepatitis B virus (HBV infection is generally defined as the detection of HBV -DNA in the serum or tissues of subjects who have negative test for HBsAg. Transmission of HBV infection has been documented from HBsAg negative, anti-HBc positive blood and organ donors. The aim of this study was to determine the rate of occult HBV infection among HBsAg negative and anti-HBc positive blood donors of Rafsanjan blood transfusion center. ‎ Sera from 270 healthy blood donors who were negative for both HBsAg and anti-HCV, were tested for anti-HBc antibodies by use of ELISA technique. The samples that were negative for HBsAg but positive for anti-HBc markers also examined for the presence of HBV-DNA by polymerase chain reaction (PCR. ‎ Out of 270 HBsAg negative blood samples, 14 samples (5.18% were positive for anti-HBc antibodies. HBV-DNA was detected in 4/14 (28.57% of HBsAg negative and anti-HBc positive samples. Moreover, anti-HBs antibody was detected in 2/4 (50% of HBV-DNA positive samples. ‎ These results indicated that HBV-DNA found in the majority of HBsAg negative and anti-HBc-positive donors. In addition, the present study recommend the incorporation of routine anti-HBc screening of blood as a surrogate marker of occult HBV infection to prevent some transfusion-transmitted HBV infections.

  19. Clinical relevance of HLA donor-specific antibodies detected by single antigen assay in kidney transplantation.

    Science.gov (United States)

    Caro-Oleas, José Luis; González-Escribano, María Francisca; González-Roncero, Francisco Manuel; Acevedo-Calado, María José; Cabello-Chaves, Virginia; Gentil-Govantes, Miguel Ángel; Núñez-Roldán, Antonio

    2012-03-01

    Clinical relevance of donor-specific antibodies (DSAs) detected by a single antigen Luminex virtual crossmatch in pre-transplant serum samples from patients with a negative cytotoxicity-dependent complement crossmatch is controversial. The aim of this study was to analyse the influence of a pre-transplant positive virtual crossmatch in the outcome of kidney transplantation. A total of 892 patients who received a graft from deceased donors after a negative cytotoxicity crossmatch were included. Presence of anti-human leucocyte antigen (HLA) antibodies was investigated using a Luminex screening assay and anti-HLA specificities were assigned performing a Luminex single antigen assay. Graft survival was significantly worse among patients with anti-HLA DSA compared to both patients with anti-HLA with no DSA (P = 0.001) and patients without HLA antibodies (P HLA with no DSA and no HLA antibodies patient groups were observed (P = 0.595). Influence of both anti-Class I and anti-Class II DSA was detected (P 1500 (global P > 0.05). The presence of preformed HLA DSA in transplanted patients with a negative cytotoxicity crossmatch is associated with a lower allograft survival. The detection of anti-HLA with no DSA has no influence in the graft outcome. Finally, there were no demonstrable effects of mean fluorescence intensity (MFI) values >1500 on graft survival.

  20. Immunoradiometric assay for quantitation of Dirofilaria immitis antigen in dogs with heartworm infections

    Energy Technology Data Exchange (ETDEWEB)

    Hamilton, R.G.; Scott, A.L.

    1984-10-01

    An immunoradiometric assay (IRMA) was developed, optimized, and validated for detection of parasite-specific antigen in sera from hosts with filarial infections, using Dirofilaria immitis in dogs as a model. The precision, reproducibility, and parallelism of the IRMA were examined, using precision profile analysis. The IRMA had acceptable precision and reproducibility (less than 15% intra-assay coefficient of variation (CV)) over a working range of 10 to 2000 ng of D immitis-antigen (AG)/ml. The IRMA parallelism (agreement between dilutions) was acceptable (less than 10% interdilutional CV) with laboratory-spiked D immitis AG sera containing no D immitis-antibody (AB). However, it was not acceptable (greater than 20% interdilutional CV) for analysis of sera from naturally infected dogs containing D immitis AB, probably due to dissociation of immune-complexed AG with increasing serum dilution. Nonparallelism limited the accuracy of binding data interpolation from the standard curve. Specificity of the IRMA was enhanced by preabsorption of the radiolabeled detection antibody with Toxocara canis AG before use. Varying amounts of D immitis AG (22 to 1000 ng/ml) were detected in 42% (20/48) of microfilaremic dogs. The presence of AG-specific AB at concentrations as low as 1 microgram/ml reduced the ability of the IRMA to detect D immitis AG. Factors that influence the accuracy and sensitivity of immunoassays for circulating filarial antigens are discussed.

  1. Immunoradiometric assay for quantitation of Dirofilaria immitis antigen in dogs with heartworm infections

    International Nuclear Information System (INIS)

    Hamilton, R.G.; Scott, A.L.

    1984-01-01

    An immunoradiometric assay (IRMA) was developed, optimized, and validated for detection of parasite-specific antigen in sera from hosts with filarial infections, using Dirofilaria immitis in dogs as a model. The precision, reproducibility, and parallelism of the IRMA were examined, using precision profile analysis. The IRMA had acceptable precision and reproducibility [less than 15% intra-assay coefficient of variation (CV)] over a working range of 10 to 2000 ng of D immitis-antigen (AG)/ml. The IRMA parallelism (agreement between dilutions) was acceptable (less than 10% interdilutional CV) with laboratory-spiked D immitis AG sera containing no D immitis-antibody (AB). However, it was not acceptable (greater than 20% interdilutional CV) for analysis of sera from naturally infected dogs containing D immitis AB, probably due to dissociation of immune-complexed AG with increasing serum dilution. Nonparallelism limited the accuracy of binding data interpolation from the standard curve. Specificity of the IRMA was enhanced by preabsorption of the radiolabeled detection antibody with Toxocara canis AG before use. Varying amounts of D immitis AG (22 to 1000 ng/ml) were detected in 42% (20/48) of microfilaremic dogs. The presence of AG-specific AB at concentrations as low as 1 microgram/ml reduced the ability of the IRMA to detect D immitis AG. Factors that influence the accuracy and sensitivity of immunoassays for circulating filarial antigens are discussed

  2. A multiplexed and miniaturized serological tuberculosis assay identifies antigens that discriminate maximally between TB and non-TB sera

    NARCIS (Netherlands)

    Tong, Miao; Jacobi, Catharina E.; van de Rijke, Frans M.; Kuijper, Sjoukje; van de Werken, Sjaak; Lowary, Todd L.; Hokke, Cornelis H.; Appelmelk, Ben J.; Nagelkerke, Nico J. D.; Tanke, Hans J.; van Gijlswijk, Rob P. M.; Veuskens, Jacques; Kolk, Arend H. J.; Raap, Anton K.

    2005-01-01

    We have developed a multiplexed and miniaturized TB serological assay with the aim of identifying (combinations of) antigens that maximally discriminate between TB and non-TB patients. It features a microarray accommodating 54 TB antigens, less than 1 microl serum consumption and an indirect

  3. Immuno disc assay for screening duck hepatitis B surface antigen in serum, liver tissue and cultured hepatocytes

    NARCIS (Netherlands)

    G.A. de Wilde (G.); R.A. Heijtink

    1993-01-01

    textabstractAn immuno disc assay (IDA) for semi-quantitative analysis of the surface antigen (DHBsAg) of duck hepatitis B virus (DHBV) is described. Unpurified antigen preparations were adsorbed onto punched-out nitrocellulose membrane discs. Rabbit antiserum raised against serum-derived

  4. Comparison of five assays for antibody to varicella-zoster virus and the fluorescent-antibody-to-membrane-antigen test.

    OpenAIRE

    Larussa, P; Steinberg, S; Waithe, E; Hanna, B; Holzman, R

    1987-01-01

    Three commercially available assays (the Varicelisa Test Kit [Whittaker M.A. Bioproducts, Walkersville, Md.], the VZV Indirect Fluorescent-Antibody Test [Electro-Nucleonics, Inc., Columbia, Md.], and the Litton VZV Bio-EnzaBead Screen Kit [Litton Bionetics, Inc., Charleston, S.C.]) and two enzyme-linked immunosorbent assays used in our laboratory, one using a membrane-associated antigen and the other using a soluble antigen dotted on nitrocellulose paper, were compared with a varicella-zoster...

  5. Detection of antibodies to the extractable nuclear antigens by enzyme linked immunosorbent assay

    International Nuclear Information System (INIS)

    Aziz, Khalil A.; Fzizal, Abul A.

    2005-01-01

    Anti-extractable nuclear antigen (ENA) antibodies are a group of autoantibodies that are directed against various components of the cell nucleus. Antibodies to these antigens are closely associated with connective tissue disease. Early diagnosis of these diseases can prove very difficult and therefore clinicians rely on the use of anti-ENA antibody testing for the exclusion. Old methods of testing are time consuming and require great skills. For these reasons clinical immunology laboratories are switching to testing for anti-ENA antibodies by enzyme linked immunosorbent assay (ELISA). The latter assays are more sensitive and require little skills. In the present study we have investigated a number of different ELISA preparations. The study was conducted at Birmingham Heartlands Hospital during the period 2003. We tested a number of ENA-positive and negative samples using 3 different commercial ELISA preparations and compared the results with traditional CCIE-assay. The present study revealed that some ELISA preparations can be more sensitive than CCIE method. Laboratories still using later method should switch to ELISA. However it is important that laboratories evaluate a long range of different ELISA preparations before selecting the most optimal one. In addition it is recommended that laboratories then audit results in order to determine true significance of such results. Finally until the true significance of ELISA generated results is known, positive ENA-results should be interpreted in conjunction with the clinical picture and this would require close liaison in between the clinical immunology laboratory and clinicians

  6. Pectinesterase Inhibitor from Jelly Fig (Ficus awkeotsang Makino Achene Inhibits Surface Antigen Expression by Human Hepatitis B Virus

    Directory of Open Access Journals (Sweden)

    Yu-Chuen Huang

    2013-01-01

    Full Text Available Pectinesterase inhibitor (PEI isolated from jelly fig (Ficus awkeotsang Makino is an edible component of a popular drink consumed in Asia. Hepatitis B virus (HBV infection is prevalent in Asia, and current treatments for HBV infection need improvement. This study aimed to evaluate the effect of PEI on the surface antigen expression by HBV (HBsAg. Human hepatoma cell lines Hep3B and Huh7 served as in vitro models for assessing the cytotoxicity and HBsAg expression. A culture of primary hepatocytes cultured from mice served as the normal counterpart. Cell viability was measured by 3-(4,5-dimethylthiazol-2-yl-2,5-diphenyltetrazolium bromide (MTT colorimetric assay. HBsAg expression was evaluated by measuring HBsAg secretion into the culture medium using an enzyme-linked immunosorbent assay. The results showed that PEI did not affect the viability of the human hepatoma cell lines or primary mouse hepatocytes. PEI inhibited the expression of HBsAg in hepatoma cell lines harboring endogenous (Hep3B and integrated (Huh7 HBV genomes in a concentration- and time-dependent manner, thus implicating a universal activity against HBV gene expression. In conclusion, it suggests that PEI from jelly fig inhibits the expression of human HBsAg in host cells without toxic effects on normal primary hepatocytes.

  7. Pectinesterase Inhibitor from Jelly Fig (Ficus awkeotsang Makino) Achene Inhibits Surface Antigen Expression by Human Hepatitis B Virus.

    Science.gov (United States)

    Huang, Yu-Chuen; Jiang, Chii-Ming; Chen, Yu-Jen; Chen, Yu-Yawn

    2013-01-01

    Pectinesterase inhibitor (PEI) isolated from jelly fig (Ficus awkeotsang Makino) is an edible component of a popular drink consumed in Asia. Hepatitis B virus (HBV) infection is prevalent in Asia, and current treatments for HBV infection need improvement. This study aimed to evaluate the effect of PEI on the surface antigen expression by HBV (HBsAg). Human hepatoma cell lines Hep3B and Huh7 served as in vitro models for assessing the cytotoxicity and HBsAg expression. A culture of primary hepatocytes cultured from mice served as the normal counterpart. Cell viability was measured by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) colorimetric assay. HBsAg expression was evaluated by measuring HBsAg secretion into the culture medium using an enzyme-linked immunosorbent assay. The results showed that PEI did not affect the viability of the human hepatoma cell lines or primary mouse hepatocytes. PEI inhibited the expression of HBsAg in hepatoma cell lines harboring endogenous (Hep3B) and integrated (Huh7) HBV genomes in a concentration- and time-dependent manner, thus implicating a universal activity against HBV gene expression. In conclusion, it suggests that PEI from jelly fig inhibits the expression of human HBsAg in host cells without toxic effects on normal primary hepatocytes.

  8. Point-of-care diagnosis and prognostication of cryptococcal meningitis with the cryptococcal antigen lateral flow assay on cerebrospinal fluid.

    Science.gov (United States)

    Kabanda, Taseera; Siedner, Mark J; Klausner, Jeffrey D; Muzoora, Conrad; Boulware, David R

    2014-01-01

    The cryptococcal antigen (CRAG) lateral flow assay (LFA) had 100% sensitivity and specificity on cerebrospinal fluid samples. Pretreatment LFA titers correlated with quantitative cultures (R(2) = 0.7) and predicted 2- and 10-week mortality. The CRAG LFA is an accurate diagnostic assay for CSF and should be considered for point-of-care diagnosis of cryptococcal meningitis.

  9. [Fundamental and clinical evaluation of hepatitis B virus core-related antigen assay by LUMIPULSE f].

    Science.gov (United States)

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

    2006-07-01

    A sensitive chemiluminescence enzyme immunoassay (CLEIA) has been developed for hepatitis B virus (HBV) core-related antigens (HBcrAg) detection. The HBcrAg is designated as the precore/core gene products including HBeAg. The aim of this study is to evaluate reproducibility of HBcrAg and correlation with HBV-DNA in serum using the automatic LUMIPULSE f to estimate an assay suitable for general laboratory use. In this study, we demonstrated that HBcrAg assay had highly intra-assay reproducible [coefficients of variation(CVs); 2.8-5.2%] and inter-assay reproducible [CVs; 3.9-9.1%]. When the cutoff value was tentatively set at 1 kU/ml, all healthy controls (HBsAg/HBV-DNA negative; n=100) and anti-HCV antibody-positive (n=50) sera were identified as negative. The assay showed a detection limit of 0.5 kU/ml using four serially diluted HBV high-titer sera, indicating higher sensitivity than HBV-DNA (transcription-mediated amplification). The HBcrAg concentration correlated positively with serum HBV-DNA (n=125, r = 0.860, p < 0.0001) regardless of HBeAg, although the HBcrAg levels were higher in HBeAg-positive group than in HBeAg-negative group. In the natural course of HBV infection, the HBcrAg concentration usually changed in accordance with HBV-DNA levels, however during lamivudine therapy the change of HBcrAg was more gradual than that of HBV-DNA. In conclusion, HBcrAg concentration provides a reflection of HBV virus load equivalent to HBV-DNA level, and the assay therefore offers a simple method for monitoring hepatitis B patients.

  10. Antigenic determinants of prostate-specific antigen (PSA) and development of assays specific for different forms of PSA.

    OpenAIRE

    Nilsson, O.; Peter, A.; Andersson, I.; Nilsson, K.; Grundstr?m, B.; Karlsson, B.

    1997-01-01

    Monoclonal antibodies were raised against prostate-specific antigen (PSA) by immunization with purified free PSA, i.e. not in complex with any protease inhibitor (F-PSA) and PSA in complex with alpha1-anti-chymotrypsin (PSA-ACT). Epitope mapping of PSA using the established monoclonal antibody revealed a complex pattern of independent and partly overlapping antigenic domains in the PSA molecule. Four independent antigenic domains and at least three partly overlapping domains were exposed both...

  11. 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.

  12. Evaluation of Hepatitis C Virus Core Antigen Assays in Detecting Recombinant Viral Antigens of Various Genotypes ▿

    Science.gov (United States)

    Saeed, Mohsan; Suzuki, Ryosuke; Kondo, Madoka; Aizaki, Hideki; Kato, Takanobu; Mizuochi, Toshiaki; Wakita, Takaji; Watanabe, Haruo; Suzuki, Tetsuro

    2009-01-01

    A single substitution within the hepatitis C virus core antigen sequence, A48T, which is observed in ∼30% of individuals infected with genotype 2a virus, reduces the sensitivity of a commonly used chemiluminescence enzyme immunoassay. Quantitation of the antigen is improved by using a distinct anticore antibody with a different epitope. PMID:19812276

  13. Detection of antibody activity in human sera against meningococcal cell wall antigens using a gel-immuno-radio-assay (GIRA)

    International Nuclear Information System (INIS)

    Poolman, J.T.; Zanen, H.C.

    1980-01-01

    The authors recently described the application of the SDS-polyacrylamide-gel-electrophoresis-immuno-peroxidase (SGIP) technique to the analysis of meningococcal cell walls. However, it appeared that SGIP was not sensitive enough to detect low levels of human antibodies against meningococcal cell wall antigens. They therefore replaced the peroxidase labeled anti-IgG by 125 I-labeled protein A in order to detect antibody binding by bacterial antigens separated in gels, resulting in gel-immuno-radio-assay (GIRA). (Auth.)

  14. Multisite Validation of Cryptococcal Antigen Lateral Flow Assay and Quantification by Laser Thermal Contrast

    Science.gov (United States)

    Rolfes, Melissa A.; Rajasingham, Radha; von Hohenberg, Maximilian; Qin, Zhenpeng; Taseera, Kabanda; Schutz, Charlotte; Kwizera, Richard; Butler, Elissa K.; Meintjes, Graeme; Muzoora, Conrad; Bischof, John C.; Meya, David B.

    2014-01-01

    Cryptococcal meningitis is common in sub-Saharan Africa. Given the need for data for a rapid, point-of-care cryptococcal antigen (CRAG) lateral flow immunochromatographic assay (LFA), we assessed diagnostic performance of cerebrospinal fluid (CSF) culture, CRAG latex agglutination, India ink microscopy, and CRAG LFA for 832 HIV-infected persons with suspected meningitis during 2006–2009 (n = 299) in Uganda and during 2010–2012 (n = 533) in Uganda and South Africa. CRAG LFA had the best performance (sensitivity 99.3%, specificity 99.1%). Culture sensitivity was dependent on CSF volume (82.4% for 10 μL, 94.2% for 100 μL). CRAG latex agglutination test sensitivity (97.0%–97.8%) and specificity (85.9%–100%) varied between manufacturers. India ink microscopy was 86% sensitive. Laser thermal contrast had 92% accuracy (R = 0.91, pmeningitis diagnostics in resource-limited settings. PMID:24378231

  15. Detection of non-jejuni and -coli Campylobacter species from stool specimens with an immunochromatographic antigen detection assay.

    Science.gov (United States)

    Couturier, Brianne A; Couturier, Marc Roger; Kalp, Kim J; Fisher, Mark A

    2013-06-01

    The STAT! Campy immunochromatographic assay for Campylobacter antigen was compared to culture for 500 clinical stool specimens. Antigen was detected in six culture-negative, PCR-positive specimens. C. upsaliensis, a pathogenic species that is traditionally difficult to recover in routine stool cultures, was detected in two of these culture-negative specimens. This study provides evidence that antigen testing may cross-react with at least one additional non-jejuni and -coli Campylobacter species that may be missed by routine culture for campylobacteriosis.

  16. Assessment of Dextran Antigenicity of Intravenous Iron Preparations with Enzyme-Linked Immunosorbent Assay (ELISA

    Directory of Open Access Journals (Sweden)

    Susann Neiser

    2016-07-01

    Full Text Available Intravenous iron preparations are typically classified as non-dextran-based or dextran/dextran-based complexes. The carbohydrate shell for each of these preparations is unique and is key in determining the various physicochemical properties, the metabolic pathway, and the immunogenicity of the iron-carbohydrate complex. As intravenous dextran can cause severe, antibody-mediated dextran-induced anaphylactic reactions (DIAR, the purpose of this study was to explore the potential of various intravenous iron preparations, non-dextran-based or dextran/dextran-based, to induce these reactions. An IgG-isotype mouse monoclonal anti-dextran antibody (5E7H3 and an enzyme-linked immunosorbent assay (ELISA were developed to investigate the dextran antigenicity of low molecular weight iron dextran, ferumoxytol, iron isomaltoside 1000, ferric gluconate, iron sucrose and ferric carboxymaltose, as well as isomaltoside 1000, the isolated carbohydrate component of iron isomaltoside 1000. Low molecular weight iron dextran, as well as dextran-based ferumoxytol and iron isomaltoside 1000, reacted with 5E7H3, whereas ferric carboxymaltose, iron sucrose, sodium ferric gluconate, and isolated isomaltoside 1000 did not. Consistent results were obtained with reverse single radial immunodiffusion assay. The results strongly support the hypothesis that, while the carbohydrate alone (isomaltoside 1000 does not form immune complexes with anti-dextran antibodies, iron isomaltoside 1000 complex reacts with anti-dextran antibodies by forming multivalent immune complexes. Moreover, non-dextran based preparations, such as iron sucrose and ferric carboxymaltose, do not react with anti-dextran antibodies. This assay allows to assess the theoretical possibility of a substance to induce antibody-mediated DIARs. Nevertheless, as this is only one possible mechanism that may cause a hypersensitivity reaction, a broader set of assays will be required to get an understanding of the

  17. Evaluation of an immunoradiometric assay protocol for determining prostate-specific antigen

    International Nuclear Information System (INIS)

    Gyamfi, O.K.; Aryeetey, E.A.; Gyasi, R.K.

    2012-01-01

    The levels of Lower Limit of Detection (LLD) and the Biological Detection Limit (BDL) for prostate-specific antigen (PSA) by an assay system are essential for successful prediction of recurrent disease after radical prostatectomy. A study was conducted to evaluate an Immunoradiometric Assay (IRMA) system to establish the LLD and BDL for PSA. The IRMA was validated by Recovery and Dilution experiments, where standard quantities of purified free-PSA (f-PSA) and PSA complexed to a 1 -antichymotrypsin (PSA-ACT) were added to sera from healthy subjects and patients harbouring prostate cancer. The dilution and recovery experiments revealed an over-recovery for f-PSA (112.4 ± 12.4 %) and an under-recovery for PSA-ACT (86.4 ±) 13.6 %). Six pools of zero standard and sera from 6 radical prostatectomy patients (with no histopathological evidence of relapse) were analysed in 20 replicates by the IRMA system, and the LLD and BDL values determined were 0.11 ng mL -1 and 0.34 ng mL -1 (within the standard ranges of 0.03 - 0.11 ng mL -1 and 0.06 - 0.83 ng mL -1 respectively). The results indicated satisfactory evaluation, and the data generated with the IRMA protocol was reliable. (author)

  18. 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.

  19. Immunodiagnosis of fascioliasis using sandwich enzyme-linked immunosorbent assay for detection of Fasciola gigantica paramyosin antigen

    Science.gov (United States)

    Abou-Elhakam, Hany Mohamed Adel; Bauomy, Ibraheem Rabia; El Deeb, Somaya Osman; El Amir, Azza Mohamed

    2013-01-01

    Background: Many immunological techniques have been developed over years using the different Fasciola antigens for diagnosis of parasitic infection and to replace the parasitological techniques, which are time consuming and usually lack sensitivity and reproducibility. Materials and Methods: In this study, Fasciola gigantica paramyosin (Pmy) antigen was early detected in cattle sera using sandwich enzyme-linked immunosorbent assay (ELISA), to evaluate the Pmy antigen performance in diagnosis. This work was conducted on 135 cattle blood samples, which were classified according to parasitological investigation into, healthy control (30), fascioliasis (75), and other parasites (30) groups. Results: The sensitivity of Sandwich ELISA was 97.33%, and the specificity was 95%, in comparison with parasitological examination, which recorded 66.66% sensitivity and 100% specificity, respectively. Conclusions: It was clear that the native F. gigantica Pmy is considered as a powerful antigen in early immunodiagnosis of fascioliasis, using a highly sensitive and specific sandwich ELISA technique. PMID:23961441

  20. Evolution of full-length genomes of HBV quasispecies in sera of patients with a coexistence of HBsAg and anti-HBs antibodies.

    Science.gov (United States)

    Zhou, Tai-Cheng; Li, Xiao; Li, Long; Li, Xiao-Fei; Zhang, Liang; Wei, Jia

    2017-04-06

    Although the evolutionary changes of viral quasispecies are correlated to the pathological status of a disease, little is known in the coexistence of hepatitis B surface antigen (HBsAg) and antibodies to these antigens (anti-HBs). To examine evolutionary changes in hepatitis B virus (HBV) and their relationship to the coexistence of HBsAg and anti-HBs antibodies, HBV genomes in patients with a coexistence of HBsAg and anti-HBs antibodies (experimental group) and HBsAg positive without anti-HBs (control group) were assessed. Our results showed that quasispecies diversity was significantly higher in the experimental group for large HBsAg (LHBsAg), middle HBsAg (MHBsAg), and HBsAg genes. LHBsAg harbored dN/dS values eight times higher in the experimental group; however, the mean dN/dS ratios in genes HbxAg, Pol and PreC/C of the experimental patients had an opposite trend. Phylogenetic trees in the experimental group were more complex than the control group. More positive selection sites, mutations and deletions were observed in the experimental group in specific regions. Furthermore, several amino acid variants in epitopes were potentially associated with the immune evasion. In conclusion, cumulative evolutionary changes in HBV genome that facilitate immune evasion provide insights into the genetic mechanism of a coexistence of HBsAg and anti-HBs antibodies.

  1. Comparison of the Sofia and Veritor direct antigen detection assay systems for identification of influenza viruses from patient nasopharyngeal specimens.

    Science.gov (United States)

    Leonardi, G P; Wilson, A M; Mitrache, I; Zuretti, A R

    2015-04-01

    Influenza antigen detection assays (Sofia fluorescent immunoassay [FIA] and Veritor) yield objective results, which are potentially useful for point-of-care testing. The assays were evaluated with reverse transcriptase PCR (RT-PCR) using 411 nasopharyngeal swab specimens. Sensitivity and specificity values (percentages) of 79.0/99.0 and 64.0/99.4 for influenza A and 92.9/96.7 and 78.6/98.7 for influenza B were obtained for the Sofia and Veritor assays, respectively. Copyright © 2015, American Society for Microbiology. All Rights Reserved.

  2. Aptamer-based microchip electrophoresis assays for amplification detection of carcinoembryonic antigen.

    Science.gov (United States)

    Pan, Li; Zhao, Jingjin; Huang, Yong; Zhao, Shulin; Liu, Yi-Ming

    2015-10-23

    Carcinoembryonic antigen (CEA) as one of the most widely used tumor markers is used in the clinical diagnosis of colorectal, pancreatic, gastric, and cervical carcinomas. We developed an aptamer-based microchip electrophoresis assay technique for assaying CEA in human serum for cancer diagnosis. The magnetic beads (MBs) are employed as carriers of double strand DNA that is formed by an aptamer of the target and a complementary DNA of the aptamer. After the aptamer in the MB-dsDNA conjugate binds with the target, the complementary DNA was released from the MB-dsDNA conjugate. The released complementary DNA hybridizes with a fluorescein amidite (FAM) labeled DNA, and forms a DNA duplex, which triggers the selective cleavage of FAM labeled DNA by nicking endonuclease Nb.BbvCI, and generating a FAM labeled DNA segment. The released complementary DNA hybridizes with another FAM labeled DNA, resulting in a continuous cleavage of FAM labeled DNA, and the generation of large numbers of FAM labeled DNA segments. In MCE laser induced fluorescence detection (LIF), the FAM labeled DNA segment is separated and detected. The linear range for CEA was 130 pg/ml-8.0 ng/ml with a correlation coefficient of 0.9916 and a detection limit of 68 pg/ml. The CEA concentration in the serum samples from healthy subjects was found to be in the range 1.3 ng/ml to 3.2 ng/ml. The CEA concentration in the samples from cancer patients was found to be >15 ng/ml. This method may become a useful tool for rapid analysis of CEA and other tumor markers in biomedical analysis and clinical diagnosis. Copyright © 2015 Elsevier B.V. All rights reserved.

  3. Analytical assessment of the novel Maglumi squamous cell carcinoma antigen (SCCA) immunoluminometric assay.

    Science.gov (United States)

    Dipalo, Mariella; Gnocchi, Cecilia; Aloe, Rosalia; Lippi, Giuseppe

    2015-12-01

    The demand for routine measurement of squamous cell carcinoma antigen (SCCA) is rapidly increasing in clinical laboratories, due to the central role that this biomarker plays in staging and monitoring patients with various forms of squamous cell carcinomas (SCCs). The present analytical evaluation of Maglumi SCCA was aimed to assess the imprecision, linearity and comparability against a widely used technique. The intra- and inter-assay imprecision was comprised between 2.6-4.2% and between 5.0-7.3%, respectively. The linearity of the test was excellent in the range of SCC values comprised between 1.0 and 18.0 ng/mL (r=0.998; PMaglumi SCCA and BRAHMS Kryptor SCC in the range of values comprised between 0.44 and 15.18 ng/mL (r=0.960; PMaglumi SCCA may be regarded as a suitable alternative to Kryptor SCC for routine and fully-automated assessment of SCCA in clinical laboratories.

  4. Radioimmunometric assay of carbohydrate antigen 549 in diagnosis and follow-up of breast carcinoma

    International Nuclear Information System (INIS)

    Hervas, I.; Gonzalez-Cabezas, P.; Flores, D.; Perez-Pastor, J.L.; Bello, P.; Perez-Velasco, R.; Torres, I.; Olivas, C.; Mateo, A.

    2002-01-01

    Aim: The aim of this study is to assess the value of carbohydrate antigen 549 (CA 549) in diagnosis and follow-up of breast carcinoma and compare CA 549 with other tumoral markers. Methods: A. We have studied 1230 determinations of CA 549 corresponding to 460 patients (3 male) with confirmed or suspected diagnosis of breast carcinoma. CA 549 was determined using a radioimmunometric assay that use a 'sandwich' technique on solid phase. B. To compare CA 549 with other tumoral markers we have reviewed the case history of 40 patients with advanced breast carcinoma. The tumoral markers studied were: CEA, CA 19.9, CA 15.3 and CA 549. C. We have performed a correlation study between the different tumoral markers on 124 evaluations and calculated the Pearson's correlation coefficient. Results: In the group of confirmed or suspected diagnosis of breast carcinoma (n=460): 187 patients (40,65%) showed pathological levels of CA 549. In the group of patients with advanced breast carcinoma (36 patients with metastasis and 4 with advanced local extension). the results of the different tumoral markers are presented. The Pearson's correlation coefficient between CA 549 and CA 15.3 was 0.814, while no correlation was found in the remaining markers. Conclusion: CA 549 is a good marker of progression or persistence of tumoral disease in breast carcinoma

  5. Predictive role of serum HBsAg and HBcrAg kinetics in patients with HBeAg-negative chronic hepatitis B receiving pegylated interferon-based therapy.

    Science.gov (United States)

    Chuaypen, N; Posuwan, N; Chittmittraprap, S; Hirankarn, N; Treeprasertsuk, S; Tanaka, Y; Shinkai, N; Poovorawan, Y; Tangkijvanich, P

    2018-03-01

    To investigate the role of serum hepatitis B core-related antigen (HBcrAg) kinetics in predicting long-term outcome of pegylated interferon (PEG-IFN)-based therapy in patients with hepatitis B e antigen (HBeAg)-negative chronic hepatitis B (CHB). A total of 121 Thai patients with HBeAg-negative CHB recruited from a previous randomized trial of 48-week PEG-IFN alone or combined with entecavir were enrolled. Hepatitis B surface antigen (HBsAg) and HBcrAg levels were serially examined. Paired biopsy samples taken at baseline and after treatment were assessed for intrahepatic covalently closed circular DNA (cccDNA). Persistent virologic remission (PVR, defined by persistent hepatitis B virus (HBV) DNA <2000 IU/mL) and HBsAg clearance at 3 years after treatment were 29% (35/121) and 9% (11/121) respectively. Baseline HBcrAg correlated with HBV DNA and cccDNA but not with HBsAg. Baseline HBsAg, as well as HBsAg and HBcrAg, declines were associated with PVR, while HBsAg decline was predictive of HBsAg clearance. High baseline antigen levels (HBsAg ≥3.4 log 10 IU/mL plus HBcrAg ≥3.7 log 10 U/mL) yielded high negative predictive values of PVR (45/50, 90%) and HBsAg clearance (50/50, 100%). At week 12, declines of HBsAg, HBcrAg and both antigens combined of <0.5 log 10 yielded negative predictive values for PVR of 90% (71/79), 82% (61/74) and 96% (48/50) respectively. Quantitative HBcrAg was significantly associated with cccDNA in HBeAg-negative CHB. This novel antigen, together with HBsAg, could identify patients with low probability of PVR and HBsAg clearance in long-term follow-up. Copyright © 2017 European Society of Clinical Microbiology and Infectious Diseases. Published by Elsevier Ltd. All rights reserved.

  6. Clinical utility of the cryptococcal antigen lateral flow assay in a diagnostic mycology laboratory.

    Directory of Open Access Journals (Sweden)

    Brendan J McMullan

    Full Text Available BACKGROUND: Cryptococcus neoformans causes life-threatening meningitis. A recently introduced lateral flow immunoassay (LFA to detect cryptococcal antigen (CRAG is reportedly more rapid and convenient than standard latex agglutination (LA, but has not yet been evaluated in a diagnostic laboratory setting. METHODS: One hundred and six serum, 42 cerebrospinal fluid (CSF, and 20 urine samples from 92 patients with known or suspected cryptococcosis were tested by LA and LFA, and titres were compared. Results were correlated with laboratory-confirmed cryptococcosis. Serial samples were tested in nine treated patients. RESULTS: Twenty-five of 92 patients had confirmed cryptococcosis; all sera (n = 56 from these patients were positive by LFA (sensitivity 100%, 95% confidence interval (CI 93.6-100% compared with 51/56 positive by LA (sensitivity 91.1%, 95% CI 80.7-96.1%. Fifty sera from 67 patients without cryptococcosis tested negative in both assays. While LA yielded more false negative results (5/56 this did not reach statistical significance (p = 0.063. Nine CSF samples from patients with cryptococcal meningitis yielded positive results using both assays while 17/18 urine samples from patients with cryptococcosis were positive by the LFA. The LFA detected CRAG in C. gattii infection (n = 4 patients. Agreement between titres obtained by both methods (n = 38 samples was imperfect; correlation between log-transformed titres (r was 0.84. Turn-around-time was 20 minutes for the LFA and 2 h for LA. The cost per qualitative sample was 18USD and 91 USD, respectively and per quantitative sample was 38USD and 144USD, respectively. CONCLUSIONS: Qualitative agreement between the LFA and LA assays performed on serum and CSF was good but agreement between titres was imperfect. Ease of performance of the LFA and the capacity for testing urine suggest it has a role in the routine laboratory as a rapid diagnostic test or point-of-care test.

  7. Localization of immunodominant epitopes within the "a" determinant of hepatitis B surface antigen using monoclonal antibodies.

    Science.gov (United States)

    Golsaz-Shirazi, Forough; Mohammadi, Hamed; Amiri, Mohammad Mehdi; Khoshnoodi, Jalal; Kardar, Gholam Ali; Jeddi-Tehrani, Mahmood; Shokri, Fazel

    2016-10-01

    The common "a" determinant is the major immunodominant region of hepatitis B surface antigen (HBsAg) shared by all serotypes and genotypes of hepatitis B virus (HBV). Antibodies against this region are thought to confer protection against HBV and are essential for viral clearance. Mutations within the "a" determinant may lead to conformational changes in this region, which can affect the binding of neutralizing antibodies. There is an increasing concern about identification and control of mutant viruses which is possible by comprehensive structural investigation of the epitopes located within this region. Anti-HBs monoclonal antibodies (mAbs) against different epitopes of HBsAg are a promising tool to meet this goal. In the present study, 19 anti-HBs mAbs were employed to map epitopes localized within the "a" determinant, using a panel of recombinant mutant HBsAgs. The topology of the epitopes was analyzed by competitive enzyme-linked immunosorbent assay (ELISA). Our results indicate that all of the mAbs seem to recognize epitopes within or in the vicinity of the "a" determinant of HBsAg. Different patterns of binding with mutant forms were observed with different mAbs. Amino acid substitutions at positions 123, 126, 129, 144, and 145 dramatically reduced the reactivity of antibodies with HBsAg. The T123N mutation had the largest impact on antibody binding to HBsAg. The reactivity pattern of our panel of mAbs with mutant forms of HBsAg could have important clinical implications for immunoscreening, diagnosis of HBV infection, design of a new generation of recombinant HB vaccines, and immunoprophylaxis of HBV infection as an alternative to therapy with hepatitis B immune globulin (HBIG).

  8. Detection of immunoglobulin M and G antibodies against cytomegalovirus early and late antigens by enzyme-linked immunosorbent assay.

    OpenAIRE

    Middeldorp, J M; Jongsma, J; ter Haar, A; Schirm, J; The, T H

    1984-01-01

    A sensitive and reproducible enzyme-linked immunosorbent assay (ELISA) is described for the detection of immunoglobulin M and antibodies with specifity for human cytomegalovirus (CMV) early (CMV-EA) and late (CMV-LA) antigens. The emphasis is on the production of high-quality CMV antigens, CMV-EA and CMV-LA separately, and conditions for their application in the ELISA. The induction of CMV-EA and -LA in infected cell extracts was studied in detail by using human sera with defined antibody spe...

  9. Statistical prediction of immunity to placental malaria based on multi-assay antibody data for malarial antigens

    DEFF Research Database (Denmark)

    Siriwardhana, Chathura; Fang, Rui; Salanti, Ali

    2017-01-01

    to 28 malarial antigens and used the data to develop statistical models for predicting if a woman has sufficient immunity to prevent PM. Methods Archival plasma samples from 1377 women were screened in a bead-based multiplex assay for Ab to 17 VAR2CSA-associated antigens (full length VAR2CSA (FV2), DBL...... in the following seven statistical approaches: logistic regression full model, logistic regression reduced model, recursive partitioning, random forests, linear discriminant analysis, quadratic discriminant analysis, and support vector machine. Results The best and simplest model proved to be the logistic...

  10. Detection of immunoglobulin M and G antibodies against cytomegalovirus early and late antigens by enzyme-linked immunosorbent assay.

    Science.gov (United States)

    Middeldorp, J M; Jongsma, J; ter Haar, A; Schirm, J; The, T H

    1984-10-01

    A sensitive and reproducible enzyme-linked immunosorbent assay (ELISA) is described for the detection of immunoglobulin M and antibodies with specifity for human cytomegalovirus (CMV) early (CMV-EA) and late (CMV-LA) antigens. The emphasis is on the production of high-quality CMV antigens, CMV-EA and CMV-LA separately, and conditions for their application in the ELISA. The induction of CMV-EA and -LA in infected cell extracts was studied in detail by using human sera with defined antibody specificity for CMV-EA and CMV-LA. This resulted in the development of a simple whole cell extraction procedure that provided a high yield of CMV antigens with reproducible antigen quality. The antigens were specific for the detection of anti-CMV antibodies. The influence of autoantibodies on the determination of CMV-specific antibodies was investigated. Parallel analysis of 322 human sera by indirect immunofluorescence and ELISA showed a high correlation between both assays (r = 0.9674 for CMV-EA and 0.9362 for CMV-LA). Antibody titers determined by ELISA were equal to (for CMV-EA) or slightly higher (for CMV-LA) that those determined by immunofluorescence but significantly higher (20- to 5,120-fold) than those determined by complement fixation. From 191 sera positive by ELISA (titer greater than or equal to 40) 4 (2.1%) were negative by immunofluorescence (titer less than 40), and from 61 ELISA-positive sera 12 (19.6%) were negative (titer less than 8) when tested by complement fixation. Consequently, ELISA for CMV may prove to be more reliable for the selection of CMV-seronegative blood donors than these other methods. The use of high-quality antigens allows more economic handling of large-scale serum determinations. Possibilities for further automation are discussed.

  11. Sensitivity of hepatitis C virus core antigen and antibody combination assays in a global panel of window period samples

    Science.gov (United States)

    Laperche, Syria; Nubling, C. Micha; Stramer, Susan L.; Brojer, Ewa; Grabarczyk, Piotr; Yoshizawa, Hiroshi; Kalibatas, Vytenis; El Elkyabi, Magdy; Moftah, Faten; Girault, Annie; van Drimmelen, Harry; Busch, Michael P.; Lelie, Nico

    2016-01-01

    BACKGROUND Hepatitis C virus (HCV) antigen and antibody combination assays have been launched as a cost-effective alternative to nucleic acid testing (NAT) for reducing the antibody-negative window period (WP). Later, a HCV antigen chemiluminescence immunoassay (CLIA) became available. STUDY DESIGN AND METHODS A panel composed of 337 HCV NAT–yield samples that were characterized for viral load (VL) and genotype was used to compare the sensitivity of two combination enzyme-linked immunosorbent assays (Monolisa, Bio-Rad; and Murex, formerly Abbott) and a HCV antigen CLIA (Abbott). Analytic sensitivity was compared with HCV RNA detection using Ultrio (Grifols) by testing serial dilutions of 10 genotype (gt)1 to gt4 samples. RESULTS HCV antigen CLIA detected 92.4% of samples, whereas Monolisa and Murex detected 38.3 and 47.5%, respectively. In the HCV RNA VL range of 105 to 107 IU/mL, Monolisa and Murex detected 38% to 56% of gt1, 85% to 78% of gt2, and 21% to 37% of gt3. The overall geometric mean 50% limit of detection (range) of Ultrio on gt1 to gt4 dilution series was 3.5 (1.2–7.7) copies/mL, compared to 3.3 × 106 (4.4 × 105-2.7 × 107), 3.4 × 106 (2.2 × 105–4.2 × 107), and 2728 (415–7243) copies/mL for Monolisa, Murex, and HCV antigen CLIA, respectively. CONCLUSION Analytical sensitivity of NAT was on average 1 million- and 780-fold higher than combination assays and HCV antigen CLIA, respectively. Relative sensitivities of combination assays differed for genotypes with Murex being more sensitive for gt1 and gt3 and Monolisa more sensitive for gt2. Although being less sensitive than NAT, combination assays could be considered in resource-limited settings since they detect 38% to 47% of seronegative WP donations. PMID:26013970

  12. Development of new immunoradiometric assay for CA 125 antigen using two monoclonal antibodies produced by immunizing lung cancer cells

    International Nuclear Information System (INIS)

    Kunimatsu, Mihoko; Endo, Keigo; Awaji, Toshikazu

    1988-01-01

    CA 125 is an antigen associated with non-mucinous epithelial ovarian cancer, which is defined by OC 125 antibody developed by immunizing ovarian cancer cells. We have produced two monoclonal antibodies, 130-22 and 145-9, by using the human lung adenocarcinoma cell line PC-9. Both 130-22 and 145-9 antibodies recognized CA 125 antigen. However, the binding sites seemed to be separate from those of OC 125. Testing by 9 immunoradiometric assays (IRMA), using different combinations of the 3 monoclonal antibodies 130-22, 145-9 and OC 125 demonstrated that the best standard curve for detecting CA 125 could be obtained by a 'simultaneous sandwich' assay based on a mixture of 125 I-labeled OC 125 and 130-22 or 145-9 coated beads. One-step IRMA, using 130-22 as a tracer and 145-9 as an immunoadsorbent, also showed good reproducibility and sensitivity for measuring CA 125. Antigens were detectable in the culture supernatants of PC-9 cells and 5 of 6 ovarian cancer and endometrial adenocarcinoma cells. These results indicate that one-step IRMA using 130-22 and 145-9 is useful for detecting CA 125 antigen. (author)

  13. [Improvement of sensitivity in the second generation HCV core antigen assay by a novel concentration method using polyethylene glycol (PEG)].

    Science.gov (United States)

    Higashimoto, Makiko; Takahashi, Masahiko; Jokyu, Ritsuko; Syundou, Hiromi; Saito, Hidetsugu

    2007-11-01

    A HCV core antigen (Ag) detection assay system, Lumipulse Ortho HCV Ag has been developed and is commercially available in Japan with a lower detection level limit of 50 fmol/l, which is equivalent to 20 KIU/ml in PCR quantitative assay. HCV core Ag assay has an advantage of broader dynamic range compared with PCR assay, however the sensitivity is lower than PCR. We developed a novel HCV core Ag concentration method using polyethylene glycol (PEG), which can improve the sensitivity five times better than the original assay. The reproducibility was examined by consecutive five-time measurement of HCV patients serum, in which the results of HCV core Ag original and concentrated method were 56.8 +/- 8.1 fmol/l (mean +/- SD), CV 14.2% and 322.9 +/- 45.5 fmol/l CV 14.0%, respectively. The assay results of HCV negative samples in original HCV core Ag were all 0.1 fmol/l and the results were same even in the concentration method. The results of concentration method were 5.7 times higher than original assay, which was almost equal to theoretical rate as expected. The assay results of serially diluted samples were also as same as expected data in both original and concentration assay. We confirmed that the sensitivity of HCV core Ag concentration method had almost as same sensitivity as PCR high range assay in the competitive assay study using the serially monitored samples of five HCV patients during interferon therapy. A novel concentration method using PEG in HCV core Ag assay system seems to be useful for assessing and monitoring interferon treatment for HCV.

  14. An Enhanced ELISPOT Assay for Sensitive Detection of Antigen-Specific T Cell Responses to Borrelia burgdorferi

    Directory of Open Access Journals (Sweden)

    Gottfried H. Kellermann

    2013-09-01

    Full Text Available Lyme Borreliosis is an infectious disease caused by the spirochete Borrelia burgdorferi that is transmitted through the bite of infected ticks. Both B cell-mediated humoral immunity and T cell immunity develop during natural Borrelia infection. However, compared with humoral immunity, the T cell response to Borrelia infection has not been well elucidated. In this study, a novel T cell-based assay was developed and validated for the sensitive detection of antigen-specific T cell response to B. burgdorferi. Using interferon-g as a biomarker, we developed a new enzyme-linked immunospot method (iSpot Lyme™ to detect Borrelia antigen-specific effector/memory T cells that were activated in vivo by exposing them to recombinant Borrelia antigens ex vivo. To test this new method as a potential laboratory diagnostic tool, we performed a clinical study with a cohort of Borrelia positive patients and healthy controls. We demonstrated that the iSpot Lyme assay has a significantly higher specificity and sensitivity compared with the Western Blot assay that is currently used as a diagnostic measure. A comprehensive evaluation of the T cell response to Borrelia infection should, therefore, provide new insights into the pathogenesis, diagnosis, treatment and monitoring of Lyme disease.

  15. New Automated Hepatitis C Virus (HCV) Core Antigen Assay as an Alternative to Real-Time PCR for HCV RNA Quantification▿ †

    OpenAIRE

    Park, Yongjung; Lee, Jong-Han; Kim, Beom Seok; Kim, Do Young; Han, Kwang-Hyub; Kim, Hyon-Suk

    2010-01-01

    An automated hepatitis C virus (HCV) antigen (Ag) assay was evaluated with clinical samples. Determination of HCV Ag and RNA levels in 282 subjects using Abbott HCV Ag and Roche Cobas TaqMan assays revealed that these two tests were highly correlated (r = 0.9464). Thus, the HCV Ag assay could be an alternative test to quantitative reverse transcription-PCR.

  16. 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 ...

  17. Seroprevalence of Hepatitis B Surface Antigen (HBsAg) among ...

    African Journals Online (AJOL)

    Globally, Hepatitis B Virus has been identified as one of the most common infectious diseases and a major public health problem.This study was therefore carried out to assess the prevalence of Hepatitis B virus infection among primary school children attending LGE primary school, Sabon Pegi, Kuru, Nigeria.

  18. Comparison of Seven Commercial Antigen and Antibody Enzyme-Linked Immunosorbent Assays for Detection of Acute Dengue Infection

    Science.gov (United States)

    Jarman, Richard G.; Gibbons, Robert V.; Tanganuchitcharnchai, Ampai; Mammen, Mammen P.; Nisalak, Ananda; Kalayanarooj, Siripen; Bailey, Mark S.; Premaratna, Ranjan; de Silva, H. Janaka; Day, Nicholas P. J.; Lalloo, David G.

    2012-01-01

    Seven commercial assays were evaluated to determine their suitability for the diagnosis of acute dengue infection: (i) the Panbio dengue virus Pan-E NS1 early enzyme-linked immunosorbent assay (ELISA), second generation (Alere, Australia); (ii) the Panbio dengue virus IgM capture ELISA (Alere, Australia); (iii) the Panbio dengue virus IgG capture ELISA (Alere, Australia); (iv) the Standard Diagnostics dengue virus NS1 antigen ELISA (Standard Diagnostics, South Korea); (v) the Standard Diagnostics dengue virus IgM ELISA (Standard Diagnostics, South Korea); (vi) the Standard Diagnostics dengue virus IgG ELISA (Standard Diagnostics, South Korea); and (vii) the Platelia NS1 antigen ELISA (Bio-Rad, France). Samples from 239 Thai patients confirmed to be dengue virus positive and 98 Sri Lankan patients negative for dengue virus infection were tested. The sensitivities and specificities of the NS1 antigen ELISAs ranged from 45 to 57% and 93 to 100% and those of the IgM antibody ELISAs ranged from 85 to 89% and 88 to 100%, respectively. Combining the NS1 antigen and IgM antibody results from the Standard Diagnostics ELISAs gave the best compromise between sensitivity and specificity (87 and 96%, respectively), as well as providing the best sensitivity for patients presenting at different times after fever onset. The Panbio IgG capture ELISA correctly classified 67% of secondary dengue infection cases. This study provides strong evidence of the value of combining dengue virus antigen- and antibody-based test results in the ELISA format for the diagnosis of acute dengue infection. PMID:22441389

  19. Lymphocyte transformation assay for C neoformans antigen is not reliable for detecting cellular impairment in patients with neurocryptococcosis.

    Science.gov (United States)

    Rocha, Katya C; Pinhal, Cinthia; Cavalcanti, Sônia; Vidal, Monica S M; Toscano, Matheus; Moraes-Vasconcelos, Dewton; Duarte, Alberto J S; Fonseca, Fernando L A; de Abreu, Luiz Carlos; Valenti, Vitor E; Grumach, Anete S G

    2012-10-30

    Cryptococcus neoformans causes meningitis and disseminated infection in healthy individuals, but more commonly in hosts with defective immune responses. Cell-mediated immunity is an important component of the immune response to a great variety of infections, including yeast infections. We aimed to evaluate a specific lymphocyte transformation assay to Cryptococcus neoformans in order to identify immunodeficiency associated to neurocryptococcosis (NCC) as primary cause of the mycosis. Healthy volunteers, poultry growers, and HIV-seronegative patients with neurocryptococcosis were tested for cellular immune response. Cryptococcal meningitis was diagnosed by India ink staining of cerebrospinal fluid and cryptococcal antigen test (Immunomycol-Inc, SP, Brazil). Isolated peripheral blood mononuclear cells were stimulated with C. neoformans antigen, C. albicans antigen, and pokeweed mitogen. The amount of 3H-thymidine incorporated was assessed, and the results were expressed as stimulation index (SI) and log SI, sensitivity, specificity, and cut-off value (receiver operating characteristics curve). We applied unpaired Student t tests to compare data and considered significant differences for p<0.05. The lymphotoxin alpha showed a low capacity with all the stimuli for classifying patients as responders and non-responders. Lymphotoxin alpha stimulated by heated-killed antigen from patients with neurocryptococcosis was not affected by TCD4+ cell count, and the intensity of response did not correlate with the clinical evolution of neurocryptococcosis. Response to lymphocyte transformation assay should be analyzed based on a normal range and using more than one stimulator. The use of a cut-off value to classify patients with neurocryptococcosis is inadequate. Statistical analysis should be based on the log transformation of SI. A more purified antigen for evaluating specific response to C. neoformans is needed.

  20. Determinants of spontaneous surface antigen loss in hepatitis B e antigen-negative patients with a low viral load.

    Science.gov (United States)

    Tseng, Tai-Chung; Liu, Chun-Jen; Yang, Hung-Chih; Su, Tung-Hung; Wang, Chia-Chi; Chen, Chi-Ling; Kuo, Stephanie Fang-Tzu; Liu, Chen-Hua; Chen, Pei-Jer; Chen, Ding-Shinn; Kao, Jia-Horng

    2012-01-01

    Loss of hepatitis B surface antigen (HBsAg) usually indicates the cure of hepatitis B virus (HBV) infection. In spontaneous hepatitis B e antigen (HBeAg) seroconverters, lower serum HBsAg and HBV DNA levels have been shown to be associated with HBsAg loss over time. However, little is known about their impacts on HBsAg loss in HBeAg-negative patients with limited viral replication. A total of 688 HBeAg-negative patients with baseline serum HBV DNA levels loss were investigated. In a mean follow-up of 11.6 years, the average annual rate of HBsAg loss was 1.6%. Baseline HBsAg and HBV DNA levels were inversely associated with subsequent HBsAg loss. When compared to patients who had HBsAg levels >1000 IU/mL, the rates of HBsAg loss were significantly higher in patients with HBsAg levels of 100-999, 10-99, and loss was 13.2 (95% CI, 7.8-22.1) for HBsAg level loss. In HBeAg-negative patients with HBV genotype B or C infection who have HBV DNA level loss. Copyright © 2011 American Association for the Study of Liver Diseases.

  1. Designing binding kinetic assay on the bio-layer interferometry (BLI) biosensor to characterize antibody-antigen interactions.

    Science.gov (United States)

    Kamat, Vishal; Rafique, Ashique

    2017-11-01

    The Octet biosensors provide a high-throughput alternative to the well-established surface plasmon resonance (SPR) and SPR imaging (SPRi) biosensors to characterize antibody-antigen interactions. However, the utility of the Octet biosensors for accurate and reproducible measurement of binding rate constants of monoclonal antibodies (mAbs) is limited due to challenges such as analyte rebinding, and mass transport limitation (MTL). This study focuses on addressing these challenges and provides experimental conditions to reliably measure kinetics of mAb-antigen interactions. The mAb capture density of less than 0.6 nm was found to be optimal to measure a wide range of binding affinities on Octet HTX biosensor. The titration kinetic and single cycle kinetic assays performed on Octet HTX generated reproducible binding kinetic parameters and correlated with the values measured on Biacore 4000 and MASS-1. Kinetic assays performed on 0.1 nm density mAb surfaces significantly reduced MTL and enabled characterization of picomolar affinity mAbs. Finally, kinetic analysis performed on 150 antibodies to 10 antigens with molecular weights ranging from 21kD to 105kD showed concordance between Octet HTX, Biacore 4000 and MASS-1 (R 2  > 0.90). The data presented in this study suggest that under optimal experimental conditions, Octet biosensor is capable of generating kinetic values comparable to SPR/SPRi biosensors. Copyright © 2017 The Authors. Published by Elsevier Inc. All rights reserved.

  2. Detection of Giardia duodenalis antigen in human fecal eluates by enzyme-linked immunosorbent assay using polyclonal antibodies

    Directory of Open Access Journals (Sweden)

    Sofía Duque-Beltrán

    2002-12-01

    Full Text Available The present study developed and standardized an enzime-linked immunosorbent assay (ELISA to detect Giardia antigen in feces using rabbit polyclonal antibodies. Giardia cysts were purified from human fecal samples by sucrose and percoll gradients. Gerbils (Meriones unguiculatus were infected to obtain trophozoites. Rabbits were inoculated with either cyst or trophozoite antigens of 14 Colombian Giardia isolates to develop antibodies against the respective stages. The IgG anti-Giardia were purified by sequential caprylic acid and ammonium sulfate precipitation. A portion of these polyclonal antibodies was linked to alkaline phosphatase (conjugate. One hundred and ninety six samples of human feces, from different patients, were tested by parasitologic diagnosis: 69 were positive for Giardia cysts, 56 had no Giardia parasites, and 71 revealed parasites other than Giardia. The optimal concentration of polyclonal antibodies for antigen capture was 40 µg/ml and the optimal conjugate dilution was 1:100. The absorbance cut-off value was 0.24. The parameters of the ELISA test for Giardia antigen detection were: sensitivity, 100% (95% CI: 93.4-100%; specificity, 95% (95% CI: 88.6-97.6%; positive predictive value, 91% (95% CI: 81.4-95.9%; and negative predictive value, 100% (95% CI: 96.1-100%. This ELISA will improve the diagnosis of Giardia infections in Colombia and will be useful in following patients after treatment.

  3. Mutation in the S gene a determinant of the hepatitis B virus associated with concomitant HBsAg and anti-HBs in a population in Northeastern Brazil.

    Science.gov (United States)

    de Campos Albuquerque, Ingrid; Sousa, Marinilde Teles; Santos, Max Diego Cruz; Nunes, Jomar Diogo Costa; Moraes, Maria Josélia Diniz; Gomes-Gouvêa, Michele Soares; Pinho, João Renato Rebelo; Carrilho, Flair José; Fonseca, Lena Maria Barros; de Sousa Paiva Ferreira, Adalgisa

    2017-03-01

    Mutations in the a determinant of S gene may develop co-existence of hepatitis B surface antigen (HBsAg) and antibodies to HBsAg (anti-HBs) in the serum of infected hepatitis B virus (HBV) individuals. Mutations in this region may change the antigenicity of HBsAg, which in turn, lead to escape of neutralizing action of anti-HBs antibodies. This study identified individuals with concomitant HBsAg and anti-HBs serological markers in individuals of Maranhão, Northeastern Brazil. Samples from a population-based study were evaluated for HBsAg, anti-HBs, and anti-HBc, and those that tested positive for simultaneous HBsAg and anti-HBs were submitted to HBV DNA quantification and S gene characterization by Sanger sequencing. Mutations were investigated in the a determinant located in major hydrophilic region (MHR) of the S gene. Among 3,984 samples analyzed, 92 (2.3%) were positive for HBsAg and three had the atypical HBsAg and anti-HBs-positive profile (3.26%). The frequency of HBsAg and anti-HBs co-existence was similar to previous studies. Only one individual harbored mutation in the S gene a determinant associated with this profile. Little is known about this phenomenon; however, studies as ours may contribute for future enlightenment of this important issue. J. Med. Virol. 89:458-462, 2017. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

  4. Influence of various desinfectants on the radioimmuno-assay for Australia antigen

    International Nuclear Information System (INIS)

    Bernhard, U.

    1979-01-01

    At normal room temperature dilution series were produced out of pooled serum, serum previously treated with UV irradiation and beta propiolacton, and serum of patients with hepatitis type B and various desinfectants. After differing incubation times the Australia antigen titre was measured in the radioimmunoassay. Electronmicroscopic examinations should detect possible morphologic changes of the Dane particles. The counts/min. measured for Australia antigen after an incubation with aldehyde-containing preparations, are below the limit value with serum treated previously with UV light and beta propiolacton; in negative Australia-antigen-positive serum the counts/min. are close to the limit value. The antigenity is clearly reduced. The comparison with an insulin containing serum showed that also the radioimmunoassay was influenced by the aldehyde. A direct influence of the aldehydes on the protein seems to be possible. From this results that the radioimmunoassay for Australia antigen cannot be used as the exclusive method for measuring the efficacy of desinfectants compared to Dane particles. The morphologic changes of the Dane particles observed in the electronic microscope confirm the supposition that the desinfectants influence the hepatitis viruses. (orig./MG) [de

  5. Analysis of larval antigens of Oestrus ovis for the diagnosis of oestrosis by enzyme-linked immunosorbent assay.

    Science.gov (United States)

    Alcaide, M; Reina, D; Frontera, E; Navarrete, I

    2005-06-01

    A serodiagnostic test for the diagnosis of infestation by the sheep nasal bot fly, Oestrus ovis (Linné) was examined. The enzyme-linked immunosorbent assay (ELISA) technique was used to analyze and compare the production of immunoglobulin G (IgG) antibodies against excretory-secretory products (ESP) and crude extract (CE) antigens from all the different larval stages of O. ovis in the sera of 276 adult sheep sampled in summer (n = 135) and winter (n = 141). ESP from first stage larvae was the most sensitive, coating antigen in winter and ESP from second stage larvae during summer. The most specific values were obtained by ESP against L1 in winter and by CE against L3 in summer. These results show that the stage of larval development has a significant impact on the humoral immune response over the course of a season. A significant correlation (P oestrosis immunodiagnosis.

  6. Whole blood assay to access T cell-immune responses to Mycobacterium tuberculosis antigens in healthy Brazilian individuals

    Directory of Open Access Journals (Sweden)

    Paulo RZ Antas

    2004-02-01

    Full Text Available The production of interferon gamma (IFNgamma guarantees effective T cell-mediated immunity against Mycobacterium tuberculosis infection. In the present study, we simply compare the in vitro immune responses to Mycobacterium antigens in terms of IFNg production in a total of 10 healthy Brazilian volunteers. Whole blood and mononuclear cells were cultivated in parallel with PPD, Ag85B, and M. bovis hsp65, and five-days supernatants were harvested for cytokine detection by ELISA. The inter-assay result was that the overall profile of agreement in response to antigens was highly correlated (r² = 0.9266; p = 0.0102. Potential analysis is in current progress to dictate the usefulness of this method to access the immune responses also in tuberculosis patients and its contacts.

  7. An improved haemolytic plaque assay for the detection of cells secreting antibody to bacterial antigens

    DEFF Research Database (Denmark)

    Barington, T; Heilmann, C

    1992-01-01

    SC with specificity for tetanus and diphtheria toxoid as well as for Haemophilus influenzae type b and pneumococcal capsular polysaccharides. These assays were found to be less time consuming, more economical and yielded 1.9-3.4-fold higher plaque numbers than traditional Jerne-type PFC assays. In the case of anti...

  8. 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.

  9. A radioactive antigen-binding assay for the measurement of antibody to Haemophilus influenzae type b capsular polysaccharide

    International Nuclear Information System (INIS)

    Kuo, J.S.-C.; Monji, N.; Schwalbe, R.S.; McCoy, D.W.

    1981-01-01

    A new polyethylene glycol (PEG) radioimmunoprecipitation assay was developed for the detection of antibody to Haemophilus influenzae b capsular polysaccharide, polyribosylribitol phosphate (PRP). The radioactive antigen, [ 3 H]PRP, with a high specific activity, was produced by growing the organism in the presence of [ 3 H]ribose and was purified by hydroxylapatite and sepharose 4B column chromatography. In the assay, PEG (12.5%) was used to separate antibody-bound [ 3 H]PRP from free [ 3 H]PRP. The present RIA is a simple, specific, sensitive and reproducible procedure for the evaluation of antibody responses of young animals and infants to H. influenzae b vaccines and infections. (Auth.)

  10. Benefit of hepatitis C virus core antigen assay in prediction of therapeutic response to interferon and ribavirin combination therapy.

    Science.gov (United States)

    Takahashi, Masahiko; Saito, Hidetsugu; Higashimoto, Makiko; Atsukawa, Kazuhiro; Ishii, Hiromasa

    2005-01-01

    A highly sensitive second-generation hepatitis C virus (HCV) core antigen assay has recently been developed. We compared viral disappearance and first-phase kinetics between commercially available core antigen (Ag) assays, Lumipulse Ortho HCV Ag (Lumipulse-Ag), and a quantitative HCV RNA PCR assay, Cobas Amplicor HCV Monitor test, version 2 (Amplicor M), to estimate the predictive benefit of a sustained viral response (SVR) and non-SVR in 44 genotype 1b patients treated with interferon (IFN) and ribavirin. HCV core Ag negativity could predict SVR on day 1 (sensitivity = 100%, specificity = 85.0%, accuracy = 86.4%), whereas RNA negativity could predict SVR on day 7 (sensitivity = 100%, specificity = 87.2%, accuracy = 88.6%). None of the patients who had detectable serum core Ag or RNA on day 14 achieved SVR (specificity = 100%). The predictive accuracy on day 14 was higher by RNA negativity (93.2%) than that by core Ag negativity (75.0%). The combined predictive criterion of both viral load decline during the first 24 h and basal viral load was also predictive for SVR; the sensitivities of Lumipulse-Ag and Amplicor-M were 45.5 and 47.6%, respectively, and the specificity was 100%. Amplicor-M had better predictive accuracy than Lumipulse-Ag in 2-week disappearance tests because it had better sensitivity. On the other hand, estimates of kinetic parameters were similar regardless of the detection method. Although the correlations between Lumipulse-Ag and Amplicor-M were good both before and 24 h after IFN administration, HCV core Ag seemed to be relatively lower 24 h after IFN administration than before administration. Lumipulse-Ag seems to be useful for detecting the HCV concentration during IFN therapy; however, we still need to understand the characteristics of the assay.

  11. Rapid screening and identification of dominant B cell epitopes of HBV surface antigen by quantum dot-based fluorescence polarization assay

    Science.gov (United States)

    Meng, Zhongji; Song, Ruihua; Chen, Yue; Zhu, Yang; Tian, Yanhui; Li, Ding; Cui, Daxiang

    2013-03-01

    A method for quickly screening and identifying dominant B cell epitopes was developed using hepatitis B virus (HBV) surface antigen as a target. Eleven amino acid fragments from HBV surface antigen were synthesized by 9-fluorenylmethoxy carbonyl solid-phase peptide synthesis strategy, and then CdTe quantum dots were used to label the N-terminals of all peptides. After optimizing the factors for fluorescence polarization (FP) immunoassay, the antigenicities of synthetic peptides were determined by analyzing the recognition and combination of peptides and standard antibody samples. The results of FP assays confirmed that 10 of 11 synthetic peptides have distinct antigenicities. In order to screen dominant antigenic peptides, the FP assays were carried out to investigate the antibodies against the 10 synthetic peptides of HBV surface antigen respectively in 159 samples of anti-HBV surface antigen-positive antiserum. The results showed that 3 of the 10 antigenic peptides may be immunodominant because the antibodies against them existed more widely among the samples and their antibody titers were higher than those of other peptides. Using three dominant antigenic peptides, 293 serum samples were detected for HBV infection by FP assays; the results showed that the antibody-positive ratio was 51.9% and the sensitivity and specificity were 84.3% and 98.2%, respectively. In conclusion, a quantum dot-based FP assay is a very simple, rapid, and convenient method for determining immunodominant antigenic peptides and has great potential in applications such as epitope mapping, vaccine designing, or clinical disease diagnosis in the future.

  12. Seven-Year Treatment Outcome of Entecavir in a Real-World Cohort: Effects on Clinical Parameters, HBsAg and HBcrAg Levels.

    Science.gov (United States)

    Lam, Yuk-Fai; Seto, Wai-Kay; Wong, Danny; Cheung, Ka-Shing; Fung, James; Mak, Lung-Yi; Yuen, John; Chong, Chun-Kong; Lai, Ching-Lung; Yuen, Man-Fung

    2017-10-26

    We aimed to determine the levels of alanine aminotransferase (ALT), hepatitis B virus DNA (HBV DNA), HBsAg, and a novel viral marker (hepatitis B core-related antigen (HBcrAg)); hepatitis B e antigen (HBeAg) seroconversion and drug resistance rates after 7 years of entecavir treatment in chronic hepatitis B (CHB) patients. Two hundred and twenty-two Chinese CHB patients on continuous entecavir treatment were recruited. Serologic, virologic, biochemical outcomes, and the occurrence of entecavir signature mutations were determined. The rates of ALT normalization, HBeAg seroconversion, and undetectable HBV DNA were 98.3%, 82.1%, and 98.7%, respectively, after 7 years of entecavir treatment. The genotypic resistance rate was 1.2%. Decline of HBsAg level was modest with a median decline rate of 0.107 log IU/ml/year. Among patients with baseline HBsAg <1,000 IU/ml and annual HBsAg decline rate of ≥0.166 log IU/ml, all have HBsAg of <200 IU/ml (a level highly predictive for HBsAg seroclearance) at year 7. In contrast, in patients with baseline HBsAg ≥1,000 IU/ml and annual HBsAg decline rate of <0.166 log IU/ml, 95.5% had HBsAg of ≥200 IU/ml at year 7. Decline of HBcrAg levels was moderate with a median decline rate of 0.244 log kU/ml/year. Forty-seven patients (32.0%) had undetectable HBcrAg level at year 7. Long-term entecavir therapy continued to have good responses with low drug resistance rate. However, the decline of HBsAg with treatment was suboptimal. HBcrAg level declined at a relatively better rate. Baseline HBsAg level of <1,000 IU/ml and annual decline of 0.166 log IU/ml could be used to predict HBsAg response.

  13. A robust dry reagent lateral flow assay for diagnosis of active schistosomiasis by detection of Schistosoma circulating anodic antigen.

    Science.gov (United States)

    van Dam, Govert J; de Dood, Claudia J; Lewis, Melanie; Deelder, André M; van Lieshout, Lisette; Tanke, Hans J; van Rooyen, Louis H; Corstjens, Paul L A M

    2013-10-01

    An earlier reported laboratory assay, performed in The Netherlands, to diagnose Schistosoma infections by detection of the parasite antigen CAA in serum was converted to a more user-friendly format with dry reagents. The improved assay requires less equipment and allows storage and worldwide shipping at ambient temperature. Evaluation of the new assay format was carried out by local staff at Ampath Laboratories, South Africa. The lateral flow (LF) based assay utilized fluorescent ultrasensitive up-converting phosphor (UCP) reporter particles, to be read by a portable reader (UPlink) that was also provided to the laboratory. Over a period of 18 months, about 2000 clinical samples were analyzed prospectively in parallel with a routinely carried out CAA-ELISA. LF test results and ELISA data correlated very well at CAA concentrations above 300 pg/mL serum. At lower concentrations the UCP-LF test indicates a better performance than the ELISA. The UCP-LF strips can be stored as a permanent record as the UCP label does not fade. At the end of the 18 months testing period, LF strips were shipped back to The Netherlands where scan results obtained in South Africa were validated with different UCP scanning equipment including a novel, custom developed, small lightweight UCP strip reader (UCP-Quant), well suited for testing in low resource settings. The dry format UCP-LF assay was shown to provide a robust and easy to use format for rapid testing of CAA antigen in serum. It performed at least as good as the ELISA with respect to sensitivity and specificity, and was found to be superior with respect to speed and simplicity of use. Worldwide shipping at ambient temperature of the assay reagents, and the availability of small scanners to analyze the CAA UCP-LF strip, are two major steps towards point-of-care (POC) applications in remote and resource poor environments to accurately identify low (30 pg CAA/mL serum; equivalent to about 10 worm pairs) to heavy Schistosoma

  14. Using a genomic assay for the detection of SNPs of Knops blood group antigens leads to the identification of two caucasians homozygous for the SNP associated with the knops SL3 antigen

    DEFF Research Database (Denmark)

    Jakobsen, M. A.; Sprogoe, U.

    2015-01-01

    Background/Case Studies: The antigens of the Knops (Kn) blood group system are associated with SNPs located on exon 29 and (to lesser extent) on exon 26 of the complement receptor 1 (CR1) gene. Because of a lack of proper typing antibodies, serologic detection of Kn antigens is not feasible. We...... previously described to be Sl3- (personal communication from the International Blood Group Reference Laboratory in Bristol). * Number indicates the nucleotide position of the CR1 gene. Conclusion: In this study, we have set up a genomic assay for identifying the antigens in the Knops system. We found...... designed a genomic assay based on sequencing targeting the SNPs underlying the antigens of the Knops system. Study Design/Methods: Samples from a total of 105 blood donors and 2 patients were examined for polymorphisms in CR1 exon 29 by using PCR and subsequent Sanger sequencing. Results...

  15. 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.

  16. Evaluation of a Direct Immunofluorescent Assay and/or Conjunctival Cytology for Detection of Canine Distemper Virus Antigen.

    Science.gov (United States)

    Athanasiou, Labrini V; Kantere, Maria C; Kyriakis, Constantinos S; Pardali, Dimitra; Adamama Moraitou, Katerina; Polizopoulou, Zoe S

    2017-11-29

    Canine distemper is a common and potentially lethal multisystemic disease caused by the Canine distemper virus (CDV). We evaluated the diagnostic performance of direct immunofluorescent assay (FA) and cytology to detect CDV antigen in conjunctival cells compared with an established polymerase chain reaction (PCR) detection assay used as a gold standard for CDV diagnosis. Samples were collected from 57 young dogs presenting with central nervous system signs compatible with distemper disease. Exfoliative epithelial cells were collected from the right and left conjunctiva of each animal using nylon-bristled cytobrushes for cytology and cotton swabs for FA and PCR. For the direct FA, samples were stained with anti-CDV polyclonal antiserum conjugated to fluorescein isothiocyanate and imaged using a fluorescent microscope. Out of 57 dogs tested, 19 were PCR positive (15 positive in direct FA and 4 positive in cytology, including one that was negative by PCR), whereas 37 dogs were negative in all methods. A good agreement was observed between the FA and PCR, with a κ-value of 0.833 (95% CI: 0.678-0.989). Meanwhile, there was poor agreement between cytology and PCR (κ-value of 0.164; 95% CI: -0.045 to 0.373) and a fair agreement between FA and cytology (κ-value of 0.231; 95% CI: -0.026 to 0.487). Our results indicated a poor performance of cytology for the detection of CDV antigen. In contrast, FA is a 100% specific and an adequately sensitive assay (sensitivity: 78.95%, negative likelihood ratio: 0.21, 95% CI: 0.09-0.50) for antemortem diagnosis of canine distemper.

  17. 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

  18. Low yield of screening for cryptococcal antigen by latex agglutination assay on serum and cerebrospinal fluid from Danish patients with AIDS or ARC

    DEFF Research Database (Denmark)

    Hoffmann, S; Stenderup, J; Mathiesen, Lars Reinhardt

    1991-01-01

    From July 1, 1989 to September 5, 1990, 530 serum specimens and 50 cerebrospinal fluid (CSF) specimens from 334 HIV-1 infected patients, most of whom had AIDS or ARC, were analysed in a cryptococcal antigen latex agglutination assay, and all were negative. Three cases of meningitis due...... to Cryptococcus neoformans diagnosed by microscopy and culture in 3 HIV-1 infected patients are presented. Stored specimens of serum and CSF from these patients were assayed for cryptococcal antigen, and in all 3 the onset of meningitis was preceded by the presence of cryptococcal antigen in serum....... It is concluded that the low occurrence of cryptococcosis in our patient population does not justify a routine serum screening for cryptococcal antigen....

  19. The persistence ofhepatitis B antigen in the bloodtneal of the ...

    African Journals Online (AJOL)

    Abstract The persistence of the hepatitis B virus surface antigen (HBsAg) was used as an index of the sur- vival tim.e ofthis virus within the gastro-intestinal tract of the potential southern African medicinal leech, Asiaticobdella buntonensis. HBsAg was tested for in blood/faecal material at five intervals over 15 weeks. Samples ...

  20. An improved haemolytic plaque assay for the detection of cells secreting antibody to bacterial antigens

    DEFF Research Database (Denmark)

    Barington, T; Heilmann, C

    1992-01-01

    -polysaccharide AbSC of the IgG isotype, the increase was as high as 7.4-11.8 times. Evidence is presented that the pronounced improvement in the detection of the latter is due to the presence of aggregating anti-IgG antibody from the beginning of the assay. It is proposed that in the case of low affinity of anti...

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

    Directory of Open Access Journals (Sweden)

    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.

  2. Hepatitis B assays in serum, plasma and whole blood on filter paper

    Directory of Open Access Journals (Sweden)

    Mayer Theodor K

    2012-05-01

    Full Text Available Abstract Background Screening and determining the immune status of individuals for hepatitis B is usually done by detecting hepatitis B surface antigen (HBsAg and hepatitis B surface antigen-specific antibodies (HBsAb. In some countries with the highest viral burden, performing these assays is currently impractical. This paper explores the use of filter paper as a blood specimen transport medium. Methods Samples, chosen from routine clinical laboratory pool, were applied and dried onto filter paper. Eluates, from the paper samples, were analyzed as routine clinical specimens on ADVIA Centaur 5634® immunoassay analyzers using the standard HBsAg and HBsAb kits. Dried blood samples were subjected to a range of environmental conditions in order to assess stability. Results After drying and elution the assays showed linearity and precision comparable to clinical assays performed on fresh serum. Elutions at various times during a 149 day incubation period showed very little variability in the Index numbers. All analytes were temperature stable except for a decrease in the HBsAg signal at 42°C. Conclusions Filter paper is an acceptable storage and transport medium for serum to be used in the detection of hepatitis B markers if atmospheric variability can be controlled. HBsAg, HBsAb and HBcAb are all stable for at least five months under storage conditions below room temperature. Drying specimens, particularly serum, on filter paper at remote locations, offers a reasonable solution to the problem of hepatitis surveillance in underdeveloped regions, although some attempt at temperature control might be desirable.

  3. Expression of a hantavirus N protein and its efficacy as antigen in immune assays

    Directory of Open Access Journals (Sweden)

    L.T.M. Figueiredo

    2008-07-01

    Full Text Available Hantavirus cardiopulmonary syndrome (HCPS has been recognized as an important public heath problem. Five hantaviruses associated with HCPS are currently known in Brazil: Juquitiba, Araraquara, Laguna Negra-like, Castelo dos Sonhos, and Anajatuba viruses. The laboratory diagnosis of HCPS is routinely carried out by the detection of anti-hantavirus IgM and/or IgG antibodies. The present study describes the expression of the N protein of a hantavirus detected in the blood sample of an HCPS patient. The entire S segment of the virus was amplified and found to be 1858 nucleotides long, with an open reading frame of 1287 nucleotides that encodes a protein of 429 amino acids. The nucleotide sequence described here showed a high identity with the N protein gene of Araraquara virus. The entire N protein was expressed using the vector pET200D and the Escherichia coli BL21 strain. The expression of the recombinant protein was confirmed by the detection of a 52-kDa protein by Western blot using a pool of human sera obtained from HCPS patients, and by specific IgG detection in five serum samples of HCPS patients tested by ELISA. These results suggest that the recombinant N protein could be used as an antigen for the serological screening of hantavirus infection.

  4. Identified OAS3 gene variants associated with coexistence of HBsAg and anti-HBs in chronic HBV infection.

    Science.gov (United States)

    Wang, Sa; Wang, Jing; Fan, Mengjie; Li, Tengyan; Pan, Hong; Wang, Xi; Liu, Hankui; Lin, Qiongfen; Zhang, Jianguo; Guan, Liping; Zhernakova, Daria V; O'Brien, Stephen J; Feng, Zhenru; Chang, Le; Dai, Erhei; Lu, Jianhua; Xi, Hongli; Zeng, Zheng; Yu, Yanyan; Wang, Binbin

    2018-03-27

    The underlying mechanism of coexistence of hepatitis B surface antigen (HBsAg) and hepatitis B surface antigen antibody (anti-HBs) is still controversial. To identify the host genetic factors related to this unusual clinical phenomenon, a two-staged study was conducted in the Chinese Han population. In the first stage, we performed a case-control (1:1) age, gender matched study of 101 cases with concurrent HBsAg and anti-HBs and 102 controls with negative HBsAg and positive anti-HBs using whole exome sequencing. In the second validation stage, we directly sequence the 16 exomes on the OAS3 gene in two dependent cohorts of 48 cases and 200 controls. Although in the first stage, a genome-wide association study of 58,563 polymorphism variants in 101 cases and 102 controls found no significant loci (P-value ≤ 0.05/58563), and neither locus achieved a conservative genome-wide significance threshold (P-value ≤ 5e-08), gene burden analysis showed that OAS3 gene rare variants were associated with the coexistence of HBsAg and anti-HBs. (P-value =4.127e-06 ≤ 0.05/6994). 16 rare variants were screened out from 21 cases and 3 controls. In the second validation stage, one case with a new different rare variant was identified. Fisher's exact test of all 149 cases and 302 controls showed that the rare coding-sequence mutations were more frequent in cases versus controls [P-value=7.299e-09, OR=17.27, 95% CI (5.01-58.72)]. Protein-coding rare variations on the OAS3 gene are associated with the coexistence of HBsAg and anti-HBs in patients with chronic HBV infection in Chinese Han population. This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.

  5. Development of a quantitative sandwich enzyme-linked immunosorbent assay for detecting the MPT64 antigen of Mycobacterium tuberculosis.

    Science.gov (United States)

    Ji, Mijung; Cho, Byungki; Cho, Young Shik; Park, Song-Yong; Cho, Sang-Nae; Jeon, Bo-Young; Yoon, Byoung-Su

    2014-05-01

    Tuberculosis (TB) is a major infectious disease and is responsible for two million deaths annually. For the identification and quantitation of Mycobacterium tuberculosis (M. tuberculosis), a causative agent of TB, a sandwich enzyme-linked immunosorbent assay (ELISA) against the MPT64 protein of M. tuberculosis, an antigen marker of the M. tuberculosis complex, was developed. The MPT64 protein was expressed, and anti-MPT64 monoclonal antibodies were prepared. A sandwich ELISA was established using recombinant MPT64 protein and anti-MPT64 monoclonal antibodies. The sandwich MPT64 ELISA was evaluated using reference and clinical mycobacterial strains. The sandwich MPT64 ELISA detected MPT64 protein from 2.1 ng/mL to 250 ng/mL (equivalent to 1.7×10⁴ CFU/mL and 2.0×10⁶ CFU/mL). All 389 clinical M. tuberculosis isolates tested positive in the sandwich MPT64 ELISA (sensitivity, 100%), and the assay showed no cross reactivity to any tested nontuberculous mycobacterial strain (specificity, 100%). The sandwich MPT64 ELISA is a highly sensitive and quantitative test for MPT64 protein, which can identify M. tuberculosis.

  6. Establishment of an in vivo potency assay for the recombinant hepatit is B surface antigen in monovalent and combined vaccines

    Directory of Open Access Journals (Sweden)

    Mabel Izquierdo-López

    2014-12-01

    Full Text Available In this paper the development of potency assay in animals (mice was made, with the objective of demonstrating the immunogenic power of the recombinant Hepatitis B surface antigen in monovalent and combined vaccines, produced at the Center of Genetic Engineering and Biotechnology. The potency test is a parameter in quality control and it is also a tool to demonstrate the consistency of the production process. Parameters such as duration of the test, number of animals in the test, as well as different areas for the maintenance of the animals were evaluated. The results on the applicability of the potency test, to two presentations of the vaccines; monovalent Heberbiovac HB and pentavalent liquid in one vial Heberpenta-L are shown, for which specificity studies, evaluating different vaccine lots, the behavior of linearity, and parallelism, as well as establishing quality specification of the test were performed. This assay led to the obtainment of reliable results for the vaccines evaluated, the consistent evaluation of the immunogenic power and the monitoring of different production processes.

  7. The role of serum prostate specific antigen assayed by TRFIA in diagnosis of prostate cancer

    International Nuclear Information System (INIS)

    Deng Yongmei; Zhang Jinshan; Li Min

    2002-01-01

    The authors evaluate the diagnostic value of serum free prostate specific antigen (F-PSA), total-PSA(T-PSA) and free/total (F/T) PSA ratio in differentiation between benign and malignant prostatic diseases. Serum samples were measured by time-resolved fluoroimmunoassay (TRFIA), there were 86 patients whose T-PSA levels were limited within 2-20 ng/mL, from the results of prostate biopsies after operation, the patients were classified into two groups: the group with prostate hyperplasia (68 patients) and the group with prostate cancer (18 patients). The serum F-PSA and T-PSA of the two groups were analysed and compared, and the F/T PSA ratio was calculated. Results were: 1) the means of F-PSA and T-PSA were not significantly different between patients with prostate hyperplasia (BPH) and with prostate cancer (P>0.05), but the mean of F/T PSA ratio for prostate cancer was significantly lower than that for BPH (P<0.001); 2) sensitivity, specificity and positive predictive value for prostate cancer detection at a cutoff value of 0.18 for the F/T PSA ratio were 85%, 72.5% and 43.6%, respectively. Conclusion is the F/T PSA ratio may be used in differentiation prostate cancer from BPH, and when T-PSA level is within the range of 2-20 ng/mL, selecting 0.18 as the cutoff value has great clinical value

  8. A novel colloidal gold labeled antigen for the detection of Deoxynivalenol using an immunochromatographic assay method

    Science.gov (United States)

    Jin, Yu; Liu, Renrong; Zhu, Lixin; Chen, Zhenzhen

    2017-11-01

    In this paper, an immunochromatographic assay card was developed for the detection of DON in feed and cereals using a novel colloidal gold labeling method. For the colloidal gold immunochromatographic rapid detection (GICD) card, a monoclonal antibody DON-mAb and a goat anti-chicken IgY were drawn on NC membrane as the test line (T line) and the control line (C line) respectively. A gold labeled DON-CBSA conjugate and a gold labeled chicken IgY were sprayed onto the conjugate pad. The GICD card has cut-off levels of 50ng/mL for DON, which is invulnerable to matrix interference, and applicable to a wide range of samples. The GICD detecting results of feed and grain samples were compared with the results of ELISA testing, which showed good consistency.

  9. Analytical performance of a new one-step quantitative prostate-specific antigen assay, the FREND™ PSA Plus.

    Science.gov (United States)

    Park, Hae-Il; Lee, Seungok; Kim, Yonggoo; Shin, Dong-Yeok; Lee, Changseop; Han, Sunmi; Chung, Chanil; Chang, Jun Keun; Seo, In Bum

    2014-05-01

    We evaluated the analytical performance of a new one-step rapid quantitative sandwich immunoassay for total prostate-specific antigen (tPSA), the FREND™ PSA Plus (FREND PSA) (NanoEnTek Inc., Seoul, Korea). The imprecision, linearity, hook effect, detection limit (LoD), and interference were evaluated and trueness verification and matrix validation were performed. For method comparison, 79 patient specimens were analyzed with FREND PSA and two comparative tPSA assays (Architect® total PSA and cobas® total PSA assay). Total CVs of the imprecision for low (0.208 ng/mL), medium (4.051 ng/mL), and high PSA levels (5.469 ng/mL) were 15.9%, 6.4%, and 9.1%, respectively. Linearity was observed from 1.01 to 19.15 ng/mL and the hook phenomenon was absent up to 171.48 ng/mL. The LoD was 0.094 ng/mL. The regression equations between FREND (y) and Architect or cobas were as follows: y=0.0133+1.054x (r=0.973), y=-0.2144+1.066x (r=0.977), respectively. Differences between FREND PSA and the comparative methods at a medical decision level of 4.0 ng/mL were less than the optimum specification bias (9.3%). The percentage biases from the trueness verification and interference test were less than the desirable specifications for bias (18.7%). The plasma tPSA level measured with lithium heparin or K2EDTA was comparable to that in the serum. The FREND PSA provided reliable analytical performance and test results in comparison to two widely used tPSA assays. It is a simple and rapid test for tPSA and can be applied in point-of-care testing.

  10. HPLC purification of recombinant NcGRA6 antigen improves enzyme-linked immunosorbent assay for serodiagnosis of bovine neosporosis.

    Science.gov (United States)

    Jenkins, M C; Fetterer, R; Schares, G; Björkman, C; Wapenaar, W; McAllister, M; Dubey, J P

    2005-08-10

    The gene for a dense granule protein (NcGRA6) of Neospora caninum was expressed in Escherichia coli as a His-tag fusion protein and purified by NiNTA affinity chromatography. In a preliminary study, high binding of antibodies from N. caninum-negative cows was observed in enzyme-linked immunosorbent assay (ELISA) using NiNTA-purified NcGRA6. Analysis of NiNTA eluates revealed a significant number of E. coli proteins that co-purified with recombinant NcGRA6. In an attempt to improve the relative sensitivity and specificity of the NcGRA6-based ELISA, the rNcGRA6 eluates were subjected to a secondary purification using reverse phase-high performance liquid chromatography (RP-HPLC). Analysis of RP-HPLC eluates by SDS-PAGE/silver staining revealed the purification of recombinant NcGRA6 from contaminating E. coli proteins. ELISAs using the RP-HPLC purified NcGRA6 (dELISA) or singly purified NcGRA6 (sELISA) for identifying seropositive and seronegative cows in a beef herd experiencing an epidemic outbreak of neosporosis were compared to standard assays based on native tachyzoite protein-immunofluorescence antibody test, immunoblot assay, and ISCOM-ELISA. The relative sensitivity, specificity, and kappa value of the NcGRA6d-ELISA were greatly improved over the NcGRA6s-ELISA when compared to the three native antigen immunoassays. These results indicate that removal of contaminating E. coli proteins improves the performance of recombinant NcGRA6 ELISA in diagnosing bovine neosporosis, and may have applicability to the use of recombinant proteins in diagnosing other infectious agents.

  11. Ultrasensitive prostate specific antigen assay following laparoscopic radical prostatectomy--an outcome measure for defining the learning curve.

    Science.gov (United States)

    Viney, R; Gommersall, L; Zeif, J; Hayne, D; Shah, Z H; Doherty, A

    2009-07-01

    Radical retropubic prostatectomy (RRP) performed laparoscopically is a popular treatment with curative intent for organ-confined prostate cancer. After surgery, prostate specific antigen (PSA) levels drop to low levels which can be measured with ultrasensitive assays. This has been described in the literature for open RRP but not for laparoscopic RRP. This paper describes PSA changes in the first 300 consecutive patients undergoing non-robotic laparoscopic RRP by a single surgeon. To use ultrasensitive PSA (uPSA) assays to measure a PSA nadir in patients having laparoscopic radical prostatectomy below levels recorded by standard assays. The aim was to use uPSA nadir at 3 months' post-prostatectomy as an early surrogate end-point of oncological outcome. In so doing, laparoscopic oncological outcomes could then be compared with published results from other open radical prostatectomy series with similar end-points. Furthermore, this end-point could be used in the assessment of the surgeon's learning curve. Prospective, comprehensive, demographic, clinical, biochemical and operative data were collected from all patients undergoing non-robotic laparoscopic RRP. We present data from the first 300 consecutive patients undergoing laparoscopic RRP by a single surgeon. uPSA was measured every 3 months post surgery. Median follow-up was 29 months (minimum 3 months). The likelihood of reaching a uPSA of learning curve for laparoscopic radical prostatectomy and in bench-marking performance. With experience, a surgeon can achieve in excess of an 80% chance of obtaining a uPSA nadir of < or = 0.01 ng/ml at 3 months after laparoscopic RRP for a British population. This is equivalent to most published open series.

  12. A recombinant antigen-based enzyme-linked immunosorbent assay (ELISA) for lungworm detection in seals.

    Science.gov (United States)

    Ulrich, Sophia Arlena; Lehnert, Kristina; Siebert, Ursula; Strube, Christina

    2015-09-02

    Pinnipeds are frequently infected by the lungworms Otostrongylus circumlitus and Parafilaroides gymnurus (Metastrongyloidea). Infections are frequently associated with secondary bacterial bronchopneumonia and are often lethal. To date, a reliable lungworm diagnosis in individual seals is only possible during necropsy as examination of faeces collected from resting places does not allow assignment to individuals. Therefore, a diagnostic tool for lungworm detection in living seals is desirable for monitoring health of seals in the wild and in captivity. Previously, an ELISA based on recombinant bovine lungworm major sperm protein (MSP) as diagnostic antigen was developed for lungworm diagnosis in cattle. In the present study, this test was adapted for detection of antibodies against lungworms in harbour (Phoca vitulina) and grey seals (Halichoerus grypus). Furthermore, sera of northern elephant seals (Mirounga angustirostris) were tested to evaluate whether the harbour/grey seal ELISA is suitable for this seal species as well. For ELISA evaluation, lungworm-positive and -negative sera of harbour and grey seals were analysed using horseradish peroxidase (HRP)-conjugated Protein A as secondary antibody. Optical density was measured and a receiver operating characteristic (ROC) analysis was performed to determine a cut-off value. Potential cross-reactions were examined by testing serum of seals positive for gastrointestinal and heart nematodes, but negative for lungworm infections. In addition, sera of northern elephant seals were analysed. Harbour and grey seal serum samples showed significant differences in optical density (OD) between serum of infected and uninfected animals resulting in a cut-off value of 0.422 OD with a specificity of 100% (95% CI: 87.23-100%) and a sensitivity of 97.83% (95% CI: 88.47-99.94%). Cross-reactions with heart or gastrointestinal nematodes were not observed. Analysis of northern elephant seal samples resulted in detection of antibodies

  13. 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

  14. Biochemical and biophysical characterization of maize-derived HBsAg for the development of an oral vaccine.

    Science.gov (United States)

    Shah, Shweta; Hayden, Celine A; Fischer, Maria E; Rao, A Gururaj; Howard, John A

    2015-12-15

    Although a vaccine against hepatitis B virus (HBV) has been available since 1982, it is estimated that 600,000 people die every year due to HBV. An affordable oral vaccine could help alleviate the disease burden and to this end the hepatitis B surface antigen (HBsAg) was expressed in maize. Orally delivered maize material induced the strongest immune response in mice when lipid was extracted by CO2 supercritical fluid extraction (SFE), compared to full fat and hexane-extracted material. The present study provides a biochemical and biophysical basis for these immunological differences by comparing the active ingredient in the differently treated maize material. Purified maize-derived HBsAg underwent biophysical characterization by gel filtration, transmission electron microscopy (TEM), dynamic light scattering (DLS), UV-CD, and fluorescence. Gel filtration showed that HBsAg forms higher-order oligomers and TEM demonstrated virus-like particle (VLP) formation. The VLPs obtained from SFE were more regular in shape and size compared to hexane or full fat material. In addition, SFE-derived HBsAg showed the greatest extent of α-helical structure by far UV-CD spectrum. Fluorescence experiments also revealed differences in protein conformation. This work establishes SFE-treated maize material as a viable oral vaccine candidate and advances the development of the first oral subunit vaccine. Copyright © 2015 Elsevier Inc. All rights reserved.

  15. A whole blood monokine-based reporter assay provides a sensitive and robust measurement of the antigen-specific T cell response

    Directory of Open Access Journals (Sweden)

    Bennett Sophia C

    2011-08-01

    Full Text Available Abstract Background The ability to measure T-cell responses to antigens is proving critical in the field of vaccine development and for understanding immunity to pathogens, allergens and self-antigens. Although a variety of technologies exist for this purpose IFNγ-ELISpot assays are widely used because of their sensitivity and simplicity. However, ELISpot assays cannot be performed on whole blood, and require relatively large volumes of blood to yield sufficient numbers of peripheral blood mononuclear cells. To address these deficiencies, we describe an assay that measures antigen-specific T cell responses through changes in monokine gene transcription. The biological amplification of the IFNγ signal generated by this assay provides sensitivity comparable to ELISpot, but with the advantage that responses can be quantified using small volumes of whole blood. Methods Whole blood or peripheral blood mononuclear cells (PBMCs from healthy controls and immunosuppressed recipients of solid organ transplants were incubated with peptide pools covering viral and control antigens or mitogen for 20 hours. Total RNA was extracted and reverse transcribed before amplification in a TaqMan qPCR reaction using primers and probes specific for MIG (CXCL9, IP-10 (CXCL10 and HPRT. The induction of MIG and IP-10 in response to stimuli was analysed and the results were compared with those obtained by ELISpot. Results Antigen-specific T cell responses can be measured through the induction of MIG or IP-10 gene expression in PBMCs or whole blood with results comparable to those achieved in ELISpot assays. The biological amplification generated by IFNγ-R signaling allows responses to be detected in as little as 25 μL of whole blood and enables the assay to retain sensitivity despite storage of samples for up to 48 hours prior to processing. Conclusions A monokine-based reporter assay provides a sensitive measure of antigen-specific T cell activation. Assays can be

  16. Initial prostate biopsy: development and internal validation of a biopsy-specific nomogram based on the prostate cancer antigen 3 assay

    NARCIS (Netherlands)

    Hansen, J.; Auprich, M.; Ahyai, S.A.; Taille, A. De La; Poppel, H. van; Marberger, M.; Stenzl, A.; Mulders, P.F.A.; Huland, H.; Fisch, M.; Abbou, C.C.; Schalken, J.A.; Fradet, Y.; Marks, L.S.; Ellis, W.; Partin, A.W.; Pummer, K.; Graefen, M.; Haese, A.; Walz, J.; Briganti, A.; Shariat, S.F.; Chun, F.K.

    2013-01-01

    BACKGROUND: Urinary prostate cancer antigen 3 (PCA3) assay in combination with established clinical risk factors improves the identification of men at risk of harboring prostate cancer (PCa) at initial biopsy (IBX). OBJECTIVE: To develop and validate internally the first IBX-specific PCA3-based

  17. Mycobacterium tuberculosis thymidylate kinase antigen assays for designating incipient, high-risk latent M.tb infection.

    Science.gov (United States)

    Wayengera, Misaki; Kateete, David P; Asiimwe, Benon; Joloba, Moses L

    2018-03-16

    Precise designation of high risk forms of latent Mycobacterium tuberculosis-M.tb infections (LTBI) is impossible. Delineation of high-risk LTBI can, however, allow for chemoprophylaxis and curtail majority cases of active tuberculosis (ATB). There is epidemiological evidence to support the view that LTBI in context of HIV-1 co-infection is high-risk for progression to ATB relative to LTBI among HIV-ve persons. We recently showed that assays of M.tb thymidylate kinase (TMKmt) antigen and host specific IgG can differentiate ATB from LTBI and or no TB (NTB, or healthy controls). In this study, we aimed to expose the differential levels of TMKmt Ag among HIV+ve co-infected LTBI relative to HIV-ve LTBI as a strategy to advance these assays for designating incipient LTBI. TMKmt host specific IgM and IgG detection Enzyme Immuno-Assays (EIA) were conducted on 40 TB exposed house-hold contacts (22 LTBI vs. 18 no TB (NTB) by QunatiFERON-TB GOLD®); and TMKmt Ag detection EIA done on 82 LTBI (46 HIV+ve vs 36 HIV-ve) and 9 NTB (American donors). Purified recombinant TMKmt protein was used as positive control for the Ag assays. IgM levels were found to be equally low across QuantiFERON-TB GOLD® prequalified NTB and TB exposed house-hold contacts. Higher TMKmt host specific IgG trends were found among TB house-hold contacts relative to NTB controls. TMKmt Ag levels among HIV+ve LTBI were 0.2676 ± 0.0197 (95% CI: 0.2279 to 0.3073) relative to 0.1069 ± 0.01628 (95% CI: 0.07385 to 0.14) for HIV-ve LTBI (supporting incipient nature of LTBI in context of HIV-1 co-infection). NTB had TMKmt Ag levels of 0.1013 ± 0.02505 (5% CI: 0.0421 to 0.1606) (intimating that some were indeed LTBI). TMKmt Ag levels represent a novel surrogate biomarker for high-risk LTBI, while host-specific IgG can be used to designate NTB from LTBI.

  18. Chagas disease-specific antigens: characterization of epitopes in CRA/FRA by synthetic peptide mapping and evaluation by ELISA-peptide assay.

    Science.gov (United States)

    Bottino, Carolina G; Gomes, Luciano P; Pereira, José B; Coura, José R; Provance, David William; De-Simone, Salvatore G

    2013-12-03

    The identification of epitopes in proteins recognized by medically relevant antibodies is useful for the development of peptide-based diagnostics and vaccines. In this study, epitopes in the cytoplasmic repetitive antigen (CRA) and flagellar repetitive antigen (FRA) proteins from Trypanosoma cruzi were identified using synthetic peptide techniques and pooled sera from Chagasic patients. The epitopes were further assayed with an ELISA assay based on synthetic peptides. Twenty-two overlapping synthetic peptides representing the coding sequence of the T. cruzi CRA and FRA proteins were assessed by a Spot-synthesis array analysis using sera donated by patients with Chagas disease. Shorter peptides were selected that represented the determined epitopes and synthesized by solid phase synthesis to evaluate the patterns of cross-reactivities and discrimination through an ELISA-diagnostic assay. The peptide Spot-synthesis array successfully identified two IgG antigenic determinants in the CRA protein and four in FRA. Bioinformatics suggested that the CRA antigens were unique to T. cruzi while the FRA antigen showed similarity with sequences present within various proteins from Leishmania sp. Subsequently, shorter peptides representing the CRA-1, CRA-2 and FRA-1 epitopes were synthesized by solid phase synthesis and assayed by an ELISA-diagnostic assay. The CRA antigens gave a high discrimination between Chagasic, Leishmaniasis and T. cruzi-uninfected serum. A sensitivity and specificity of 100% was calculated for CRA. While the FRA antigen showed a slightly lower sensitivity (91.6%), its specificity was only 60%. The epitopes recognized by human anti-T. cruzi antibodies have been precisely located in two biomarkers of T. cruzi, CRA and FRA. The results from screening a panel of patient sera through an ELISA assay based on peptides representing these epitopes strongly suggest that the sequences from CRA would be useful for the development of diagnostic reagents that could

  19. Chagas disease-specific antigens: characterization of epitopes in CRA/FRA by synthetic peptide mapping and evaluation by ELISA-peptide assay

    Science.gov (United States)

    2013-01-01

    Background The identification of epitopes in proteins recognized by medically relevant antibodies is useful for the development of peptide-based diagnostics and vaccines. In this study, epitopes in the cytoplasmic repetitive antigen (CRA) and flagellar repetitive antigen (FRA) proteins from Trypanosoma cruzi were identified using synthetic peptide techniques and pooled sera from Chagasic patients. The epitopes were further assayed with an ELISA assay based on synthetic peptides. Methods Twenty-two overlapping synthetic peptides representing the coding sequence of the T. cruzi CRA and FRA proteins were assessed by a Spot-synthesis array analysis using sera donated by patients with Chagas disease. Shorter peptides were selected that represented the determined epitopes and synthesized by solid phase synthesis to evaluate the patterns of cross-reactivities and discrimination through an ELISA-diagnostic assay. Results The peptide Spot-synthesis array successfully identified two IgG antigenic determinants in the CRA protein and four in FRA. Bioinformatics suggested that the CRA antigens were unique to T. cruzi while the FRA antigen showed similarity with sequences present within various proteins from Leishmania sp. Subsequently, shorter peptides representing the CRA-1, CRA-2 and FRA-1 epitopes were synthesized by solid phase synthesis and assayed by an ELISA-diagnostic assay. The CRA antigens gave a high discrimination between Chagasic, Leishmaniasis and T. cruzi-uninfected serum. A sensitivity and specificity of 100% was calculated for CRA. While the FRA antigen showed a slightly lower sensitivity (91.6%), its specificity was only 60%. Conclusions The epitopes recognized by human anti-T. cruzi antibodies have been precisely located in two biomarkers of T. cruzi, CRA and FRA. The results from screening a panel of patient sera through an ELISA assay based on peptides representing these epitopes strongly suggest that the sequences from CRA would be useful for the

  20. An immune sandwich assay of carcinoembryonic antigen based on the joint use of upconversion phosphors and magnetic beads.

    Science.gov (United States)

    Li, Yaohua; Wu, Zhengjun; Liu, Zhihong

    2015-06-21

    We herein report a sensitive and selective immunosensor for carcinoembryonic antigen (CEA) based on the joint use of upconversion phosphors (UCPs) and magnetic beads (MBs). UCPs as the signal probe were designed with a core-shell structure which provided a 40-fold enhancement of the luminescence intensity. Poly(acrylic acid) (PAA)-modified UCPs were covalently conjugated with the anti-CEA antibody (coating), and streptavidin functionalized magnetic beads were combined with another biotin-tagged anti-CEA antibody. With the assistance of a magnet, the as-formed immune sandwich in the presence of CEA can be readily separated from the assay matrix. The immunosensor showed a linear dynamic range for CEA within 0.05-20 ng mL(-1) in a buffered aqueous solution, and 0.1-20 ng mL(-1) in a human serum sample. The sensor was highly specific to CEA. Our results have suggested the potential application of the UCP-MB based immunoassay for CEA in clinical analysis.

  1. Comparison of three stool antigen assays with the 13C- urea breath test for the primary diagnosis of Helicobacter pylori infection and monitoring treatment outcome.

    LENUS (Irish Health Repository)

    Hooton, Carmel

    2012-02-03

    BACKGROUND: The urea breath test (UBT) is the gold-standard non-invasive test for the detection of Helicobacter pylori infection, however, the lack of availability of the UBT due to the high cost of the test, and in particular the need for expensive analytical instrumentation, limits the usefulness of this method. Stool antigen assays may offer an alternative non-invasive method for the diagnosis of infection. OBJECTIVE: To compare the accuracy of three stool antigen assays (HpSA, IDEIA HpStAR, and ImmunoCard STAT) against the UBT for the primary diagnosis of H. pylori infection and for monitoring treatment outcome. METHODS: A total of 102 patients attending two gastroenterology day-case clinics for the investigation of dyspepsia were included. Each patient provided breath and stool samples for analysis. Patients who tested positive for H. pylori by the validated UBT were prescribed triple therapy and invited to return for repeat breath and stool sample analysis 6 weeks post-treatment. RESULTS: Of the 102 patients tested, 48 were diagnosed with H. pylori infection by the UBT. The HpSA assay interpreted 38 of these as positive (79% sensitive). Of the 54 UBT-negative patients the HpSA assay interpreted all 54 as negative (100% specific). The IDEIA HpStAR assay correctly identified 44 patients as positive (92% sensitive) and 50 as negative (92.5% specific). The ImmunoCard STAT assay interpreted 38 patients as positive (79% sensitive) and 52 as negative (96.3% specific). CONCLUSION: The findings indicate that the IDEIA HpStAR stool antigen kit is the most accurate assay of the three assays evaluated, and possibly represents a viable alternative to the UBT for the primary diagnosis of H. pylori infection and for monitoring treatment outcome.

  2. Evaluation of two Neospora caninum recombinant antigens for use in an enzyme-linked immunosorbent assay for the diagnosis of bovine neosporosis.

    Science.gov (United States)

    Lally, N C; Jenkins, M C; Dubey, J P

    1996-01-01

    Neospora caninum is a recently described apicomplexan parasite which causes paralysis and death in dogs. Neospora parasites also cause abortion and neonatal morbidity in cattle, sheep, goats, and horses, and neosporosis is emerging as an important cause of bovine abortion worldwide. The purpose of this study was to identify N. caninum cDNA clones encoding antigens that would be useful for the immunodiagnosis of bovine neosporosis. Two N. caninum tachyzoite cDNA clones expressing antigens that were recognized by serum from naturally and experimentally infected cattle were identified. The DNA sequences of these clones were determined, and the inserts were subcloned into the plasmid expression vector pTrcHisB. Both recombinant antigens, expressed as fusion proteins with a His6 tag, were purified on a nickel-chelating affinity column and evaluated in separate enzyme-linked immunosorbent assays (ELISAs). Both recombinant antigen ELISAs were capable of distinguishing between sera from Neospora-infected cows and sera from uninfected control cows. Furthermore, both assays were able to detect an antibody response in animals that were experimentally inoculated with N. caninum. Neither antigen showed evidence of cross-reactivity with serum from animals inoculated with the closely related parasites Toxoplasma gondii, Sarcocystis cruzi, Sarcocystis hominis, and Sarcocystis hirsuta. PMID:8705668

  3. Development and Application of a Double-Antigen Sandwich Enzyme-Linked Immunosorbent Assay for Detection of Antibodies to Porcine Circovirus 2

    Science.gov (United States)

    Ge, Meng; Luo, Wei; Jiang, Daliang; Li, Runcheng; Zhao, Wenwei; Chen, Guoliang; Yang, Xingdong

    2012-01-01

    A double-antigen sandwich enzyme-linked immunosorbent assay (ELISA) is described for detection of porcine circovirus 2 (PCV2) antibodies using the well-characterized recombinant PCV2 capsid protein. In a comparative test of 394 pig sera against an indirect immunofluorescence (IIF) test and a commercial ELISA kit (also based on the recombinant PCV2 capsid protein), the results showed that the diagnostic sensitivity, specificity, and accuracy of the assay were, respectively, 90.61, 94.02, and 91.62% compared with IIF and 94.38, 95.28, and 94.67% compared with the commercial ELISA kit. Assay of 12 PCV-free pigs over a 5-week period produced only PCV2-negative titers by all 3 methods. These results and the seroprofiles of 4 pig farms obtained by both the commercial ELISA kit and the double-antigen sandwich ELISA indicate that the sandwich ELISA is a reliable method for detection of antibodies to PCV2. Additionally, the method described here permits the use of undiluted test serum samples simultaneously loaded with horseradish peroxidase (HRP)-conjugated antigen into the test well, and the complete test procedure can be performed in less than 90 min. This double-antigen sandwich ELISA should be a useful tool to aid swine industry professionals in deciding the intervention strategies for the control of PCV2-associated diseases. PMID:22815145

  4. A molecular analysis of viral persistence in surface antigen-negative chronic hepatitis B.

    Science.gov (United States)

    Kato, J; Hasegawa, K; Torii, N; Yamauchi, K; Hayashi, N

    1996-03-01

    To identify the mechanisms of viral persistence in patients with chronic hepatitis B after the acquisition of anti-hepatitis B surface antigen antibodies (antiHBs), we serially analyzed the nucleotide sequence of the envelope region in a cohort of infected patients. Four patients with histological diagnoses of chronic hepatitis B who had at least 5 years of observance by our hospital staff were studied. All but one showed normalization of serum alanine aminotransferase (ALT) concentration after clearance of the hepatitis B surface of antigen (HBsAg) and the appearance of anti-HBs. Hepatitis B virus (HBV) DNA was still detectable by polymerase chain reaction (PCR) amplification assay in serum specimens from two patients, even in the presence of circulating anti-HBs. The envelope gene was amplified by PCR in serum samples obtained both before and after seroconversion, and direct cycle sequencing of the PCR products was performed. A mutation resulting in a premature stop codon was found in the pre-S1 region of one patient just prior to clearance of HBsAg. Two years later, the stop codon was converted to a leucine codon and three mutations developed in the "a" loop. In the other patient, 16 amino acids had been deleted between amino acids 8 and 23 in the pre-S2 region before clearance of HBsAg. After the appearance of circulating anti-HBs, the pre-S2 gene reverted to the wild type but three additional mutations appeared inside the "a" loop. These results suggest that HBV mutates when HBsAg is cleared, which may contribute to viral persistence due to an evasion of the host immune surveillance.

  5. The Study on the Prevalence and Significance of Urinary HBsAg Detection

    International Nuclear Information System (INIS)

    Han, Jin Suk; Pyo, Heui Jung; Shin, Young Tae; Park, Jeong Sik; Kim, Suhng Gwon; Choe, Kang Won; Lee, Jung Sang; Lee, Mon Ho

    1981-01-01

    HBsAg. was identified in the urine of the patients positive for serum HBsAg. by Tripatzis in 1970. In 1977, Hourani et al reported the incidence of HBsAg. in urine was about 52% in the patients positive for serum HBsAg. with hemodialysis treatment due to chronic renal failure. A series of studies on the HBsAg. in urine has revealed the urine of the patients positive for serum HBsAg. to be important source of infection. But there's much room to debate on the relationship of HBsAg. in urine with infectivity and the exact mechanism of urinary emergence of HBsAg. The authors detected HBsAg. in serum and urine by employing sandwitch solid-phase radioimmunoassay, and performed urinalysis, liver function test and renal function evaluation. Percutanous liver and/or kidney biopsies were done. Among 38 renal disease patients, 9 cases(23.4%) were shown to be positive for serum HBsAg. and 5 cases(55.5%) among above 9 patients positive for urine HBsAg. 56 cases(67.4%) of 83 liver disease patients revealed positive for serum HBsAg. All 10 renal and liver disease patients revealed positive serum HBsAg., and among the 9 cases(90%) positive for urine HBsAg. In the 25 patients positive for urine HBsAg. all of 5 renal patients and 9 renal and liver patients had hematuria or/and proteinuria above 2 positive for albumin. But in the 11 liver patients 6 cases(55.1%) were normal findings. And there's no significant in cpm of urine HBsAg. between the patient positive for serum HBsAg. and negative, and in cpm of serum HBsAg. between liver and renal disease patients. But there's statistical significance in cm of urine HBsAg. between renal and liver diseases.

  6. Development of a single-antigen magnetic bead assay (SAMBA) for the sensitive detection of HPA-1a alloantibodies using tag-engineered recombinant soluble β3 integrin.

    Science.gov (United States)

    Skaik, Younis; Battermann, Anja; Hiller, Oliver; Meyer, Oliver; Figueiredo, Constanca; Salama, Abdulgabar; Blasczyk, Rainer

    2013-05-31

    Timely and accurate testing for human platelet antigen 1a (HPA-1a) alloantibodies is vital for clinical diagnosis of neonatal alloimmune thrombocytopenia (NAIT). Current antigen-specific assays used for the detection of HPA-1 alloantibodies are technically very complex and cumbersome for most diagnostic laboratories. Hence, we designed and applied recombinant soluble (rs) β3 integrins displaying HPA-1a or HPA-1b epitopes for the development of a single-antigen magnetic bead assay (SAMBA). Soluble HPA-1a and HPA-1b were produced recombinantly in human embryonic kidney 293 (HEK293) cells and differentially tagged. The recombinant soluble proteins were then immobilized onto paramagnetic beads and used for analysis of HPA-1 alloantibodies by enzyme-linked immunosorbent assay (ELISA). HPA-1a serum samples (n=7) from NAIT patients, inert sera and sera containing non-HPA-1a antibodies were used to evaluate the sensitivity and specificity of the SAMBA. Fusion of V5-His or GS-SBP-His tags to the rsβ3 integrins resulted in high-yield expression. SAMBA was able to detect all HPA-1a and -1b alloantibodies recognized by monoclonal antibody-specific immobilization of platelet antigens assay (MAIPA). No cross-reactions between the sera were observed. Two out of seven of the HPA-1a alloantibody-containing sera demonstrated weak to moderate reactivity in MAIPA but strong signals in SAMBA. SAMBA provides a very reliable method for the detection of HPA-1 antibodies with high specificity and sensitivity. This simple and rapid assay can be adapted for use in any routine laboratory and can be potentially adapted for use on automated systems. Copyright © 2013 Elsevier B.V. All rights reserved.

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

    African Journals Online (AJOL)

    HBe status, HBV DNA concentrations and serum ALT levels, based on the European Association for the study of the liver (EASL) guidelines.Serum HBsAg titres were measured using the Elecsys HBsAg II Quant assay (Roche Diagnostics).

  8. Generation of murine triomas secreting bi-specific monoclonal antibodies that recognize HBsAG ad and ay subtypes.

    Science.gov (United States)

    Falero, G; Rodríguez, I; Sarracent, J; Otero, A J; Rodríguez, B L; Rojas, A; Ochoa, E

    1992-12-01

    We report the generation of murine triomas by fusing splenocytes from mice previously immunized with HBsAg ay-subtype and a hybridoma, secreting anti-HBsAg ad-subtype monoclonal antibody, which was rendered HGPRT- by induced mutagenesis with N-methyl-N'nitro-N-nitrosoguanidine. The fusion yielded a 83.8% of hybrids showing the antigen specificity of the parental hybridoma and a 16.1% of bi-specific monoclonal antibodies. One of them, coded as 1C8A5, showing a heavy chain isotype (IgG1/IgG2b) was used as capture reagent in an ultramicro-ELISA. As little as 0.78 I.U. of both HBsAg ad- and ay-subtypes could be realiably detected.

  9. 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)

  10. Usefulness of pneumococcal antigen detection in pleural fluid samples by immunochromatographic assay for diagnosis of pneumococcal pneumonia.

    Science.gov (United States)

    Andreo, F; Domínguez, J; Ruiz-Manzano, J; Prat, C; Blanco, S; Lores, L; Sánchez, M D; Latorre, I; Giménez, M; Ausina, V

    2006-07-01

    This study investigated the utility of an immunochromatographic test (ICT) for the detection of Streptococcus pneumoniae antigens in pleural fluid. Antigen was detected in 15 of 19 (79%) patients with pneumococcal pneumonia. The ICT was always negative in patients with non-pneumococcal pneumonia, but was positive in three cases with a non-infectious aetiology. In patients with pneumonia for which no pathogen was identified, antigen was detected in one of 24 pleural fluids tested. The ICT can be a valuable tool for the management of pneumonia because it can detect pneumococcal antigen in pleural effusion samples.

  11. 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...

  12. Production of monoclonal antibodies against GPCR using cell-free synthesized GPCR antigen and biotinylated liposome-based interaction assay.

    Science.gov (United States)

    Takeda, Hiroyuki; Ogasawara, Tomio; Ozawa, Tatsuhiko; Muraguchi, Atsushi; Jih, Pei-Ju; Morishita, Ryo; Uchigashima, Motokazu; Watanabe, Masahiko; Fujimoto, Toyoshi; Iwasaki, Takahiro; Endo, Yaeta; Sawasaki, Tatsuya

    2015-06-10

    G-protein-coupled receptors (GPCRs) are one of the most important drug targets, and anti-GPCR monoclonal antibody (mAb) is an essential tool for functional analysis of GPCRs. However, it is very difficult to develop GPCR-specific mAbs due to difficulties in production of recombinant GPCR antigens, and lack of efficient mAb screening method. Here we describe a novel approach for the production of mAbs against GPCR using two original methods, bilayer-dialysis method and biotinylated liposome-based interaction assay (BiLIA), both of which are developed using wheat cell-free protein synthesis system and liposome technology. Using bilayer-dialysis method, various GPCRs were successfully synthesized with quality and quantity sufficient for immunization. For selection of specific mAb, we designed BiLIA that detects interaction between antibody and membrane protein on liposome. BiLIA prevented denaturation of GPCR, and then preferably selected conformation-sensitive antibodies. Using this approach, we successfully obtained mAbs against DRD1, GHSR, PTGER1 and T1R1. With respect to DRD1 mAb, 36 mouse mAbs and 6 rabbit mAbs were obtained which specifically recognized native DRD1 with high affinity. Among them, half of the mAbs were conformation-sensitive mAb, and two mAbs recognized extracellular loop 2 of DRD1. These results indicated that this approach is useful for GPCR mAb production.

  13. Analysis of MHC class II antigens in Japanese IDDM by a novel HLA-typing method, hybridization protection assay.

    Science.gov (United States)

    Maruyama, T; Shimada, A; Kasuga, A; Kasatani, T; Ozawa, Y; Ishii, M; Takei, I; Suzuki, Y; Kobayashi, A; Takeda, S

    1994-03-01

    We examined HLA Class II antigens in 116 Japanese IDDM patients [84 typical IDDM (T-IDD); 32 slowly progressive IDDM (S-IDD)] by the hybridization protection assay (HPA) which is a novel HLA typing method based on hybridization of acridinium-ester-labeled DNA probes to amplified DNA. We detected HLA-DRB1, -DQA1 and -DQB1 genes by this method which is capable of analyzing over 50 samples within 4 h with high sensitivity. Positive associations were found in DRB1*0405, DRB1*0802, DRB1*0901, DQA1*0301, DQB1*0303 and DQB1*0401, negative correlations in DRB1*0403, DR2, DR12, DRB1*0801 or 03, DQA1*0101 or 02, DQA1*0501, DQB1*0301 and DQB1*0602 alleles. The absence of aspartic acid (Asp) at position 57 of the DRB1 chain and the presence of arginine (Arg) at position 52 of the DQA1 chain correlated positively with both types of IDDM. There were no significant differences in HLA between T-IDD and S-IDD. These results suggest that the absence of Asp at position 57 of the DRB1 chain and the presence of Arg at position 52 of the DQA1 chain are significant Japanese IDDM patients and that DRB1*0802, in which the amino acid at position 57 is aspartic acid, may play a role in the pathogenesis of IDDM. Also, T-IDD and S-IDD have common bases in the HLA gene.

  14. Quantification of HBsAg to predict low levels and seroclearance in HBeAg-negative patients receiving nucleos(tide analogues.

    Directory of Open Access Journals (Sweden)

    Teresa Broquetas

    Full Text Available HBeAg-negative chronic hepatitis B patients require long-term nucleos(tide analogues(NAs because loss of surface antigen (HBsAg is unusual. Low quantitative HBsAg (qHBsAg levels can identify patients with higher probability of seroclearance. The aim of our study was to evaluate qHBsAg in HBeAg-negative patients receiving NAs to predict a reduction of HBsAg levels and seroclearance.Retrospective analysis of qHBsAg in HBeAg-negative patients before and at years 1, 3, 5, 8 and over of NAs treatment.From 1999 to 2015, HBsAg was quantified in 358 serum samples from 95 HBeAg-negative patients. Low qHBsAg (0.3 log IU/mL showing a positive and negative predictive value of 42% and 100% to identify patients achieving low levels of HBsAg.Reduction of qHBsAg is slow in HBeAg-negative patients receiving NAs, although low levels or faster qHBsAg decline may occur in 14%. A qHBsAg reduction >0.3 log IU/mL at year 3 can identify patients with a higher probability of achieving low levels and HBsAg seroclearance.

  15. Hepatitis B e Antigen Seroconversion Is Related with the Function of Dendritic Cells in Chronic Hepatitis B Virus Infection

    Directory of Open Access Journals (Sweden)

    Chunjing Lin

    2014-01-01

    Full Text Available Aim. To investigate the relationship between hepatitis B e antigen seroconversion and the function of dendritic cells (DC in patients with hepatitis B virus. Methods. The peripheral blood mononuclear cells (PBMC from 21 chronic HBV patients in immune tolerance state, 23 patients in inactive HBsAg carrier state, and 10 healthy HBV-naive blood donors were incubated and induced into DC in presence of granulocyte-macrophage colony stimulating factor (GM-CSF and interleukin-4 (IL-4, respectively. The expressions of surface markers on DC were detected by flow cytometry, and the stimulatory capacity of DC in allogenic mixed leukocyte reaction (MLR was tested by CCK-8, and the level of cytokines released by DC was analyzed by enzyme-linked immunosorbent assay (ELISA. Results. DC from patients in immune tolerance showed a remarkably lower surface expression of CD80, CD86, and HLA-DR and exhibited an impaired stimulatory capacity in MLR and reduced secretion of IL-12, as compared to the patients in inactive HBsAg carrier state. There was no significant difference between the indicators from the patients in inactive HBsAg carrier state and healthy subjects. There was a significant difference of HBV DNA level between immune tolerance and inactive HBsAg carrier group (P<0.01 and a negative correlation between HBV DNA level and the expressions of dendritic cells in both groups, respectively (P=0.01. Conclusion. DC from patients in inactive HBsAg carrier state shows stronger function in comparison with patients in immune tolerance, the expressions of dendritic cells correlate with HBV DNA level, and the function stage of DC may play an important role in HBeAg seroconversion.

  16. Novel biotechnological platform based on baculovirus occlusion bodies carrying Babesia bovis small antigenic peptides for the design of a diagnostic enzyme-linked immunosorbent assay (ELISA).

    Science.gov (United States)

    López, M G; Pallarés, H M; Alfonso, V; Carmona, S J; Farber, M; Taboga, O; Wilkowsky, S E

    2018-01-01

    Baculoviruses are large DNA virus of insects principally employed in recombinant protein expression. Its ability to form occlusion bodies (OBs), which are composed mainly of polyhedrin protein (POLH), makes them biotechnologically attractive, as these crystals (polyhedra) can incorporate foreign peptides and can be easily isolated. On the other hand, peptide microarrays allow rapid and inexpensive high-throughput serological screening of new candidates to be incorporated to OBs. To integrate these 2 biotechnological approaches, we worked on Babesia bovis, one of the causative agents of bovine babesiosis. Current molecular diagnosis of infection with B. bovis includes enzyme-linked immunosorbent assay (ELISA) techniques, which use merozoite lysate obtained from infected bovine erythrocytes. However, it is important to produce recombinant antigens that replace the use of crude antigens. Here, we describe a new biotechnological platform for the design of indirect ELISAs based on 5 antigenic peptides of 15 amino acid residues of B. bovis (ApBb), selected from a peptide microarray and expressed as a fusion to POLH. An Sf9POLH E44G packaging cell line infected with recombinant baculoviruses carrying POLH-ApBb fusions yielded higher levels of chimeric polyhedra, highlighting the advantage of a trans-contribution of a mutant copy of polyhedrin. Finally, the use of dissolved recombinant polyhedra as antigens was successful in an ELISA assay, as B. bovis-positive sera recognized the fusion POLH-ApBb. Thus, the use of this platform resulted in a promising alternative for molecular diagnosis of relevant infectious diseases.

  17. Development of a serogroup-specific multiplex PCR assay to detect a set of Escherichia coli serogroups based on the identification of their O-antigen gene clusters.

    Science.gov (United States)

    Wang, Quan; Ruan, Xiaojuan; Wei, Dongmei; Hu, Zhidong; Wu, Lixia; Yu, Ting; Feng, Lu; Wang, Lei

    2010-10-01

    The Escherichia coli serogroups O115, O126, O137, O158, O165, and O173 are pathogenic strains associated with diarrhea. Molecular approaches such as PCR have been proven to be rapid, inexpensive, and accurate. The sequences of the O-antigen-processing genes wzx and wzy are specific for different O antigens and are generally used as the target genes for the detection and identification of E. coli strains belonging to different O serogroups. In this report, the O-antigen gene clusters of these 6 O serogroups were sequenced, and genes were identified on the basis of homology. By screening these sequences against all 186 E. coli and Shigella strains, we found that the sequences of the wzx and wzy genes were serogroup-specific, and 2 specific primer pairs for each serogroup were screened out. A multiplex PCR assay targeting all 6 serogroups was developed. Twenty-nine strains were used to validate the specificity of the assay. The detection sensitivity was 1ng genomic DNA. As the assay was shown to be accurate and sensitive, it can be used for the identification and detection of strains belonging to these serogroups in stool and other environmental samples after being isolated by culture. Copyright (c) 2010 Elsevier Ltd. All rights reserved.

  18. Development of a Nucleoprotein-Based Enzyme-Linked Immunosorbent Assay Using a Synthetic Peptide Antigen for Detection of Avian Metapneumovirus Antibodies in Turkey Sera

    Science.gov (United States)

    Alvarez, Rene; Njenga, M. Kariuki; Scott, Melissa; Seal, Bruce S.

    2004-01-01

    Avian metapneumoviruses (aMPV) cause an upper respiratory tract disease with low mortality but high morbidity, primarily in commercial turkeys, that can be exacerbated by secondary infections. There are three types of aMPV, of which type C is found only in the United States. The aMPV nucleoprotein (N) amino acid sequences of serotypes A, B, and C were aligned for comparative analysis. On the basis of the predicted antigenicity of consensus sequences, five aMPV-specific N peptides were synthesized for development of a peptide antigen enzyme-linked immunosorbent assay (aMPV N peptide-based ELISA) to detect aMPV-specific antibodies among turkeys. Sera from naturally and experimentally infected turkeys were used to demonstrate the presence of antibodies reactive to the chemically synthesized aMPV N peptides. Subsequently, aMPV N peptide 1, which had the sequence 10-DLSYKHAILKESQYTIKRDV-29, with variations at only three amino acids among aMPV serotypes, was evaluated as a universal aMPV ELISA antigen. Data obtained with the peptide-based ELISA correlated positively with total aMPV viral antigen-based ELISAs, and the peptide ELISA provided higher optical density readings. The results indicated that aMPV N peptide 1 can be used as a universal ELISA antigen to detect antibodies for all aMPV serotypes. PMID:15013970

  19. 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 ...

  20. 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.

  1. 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+

  2. Prevalence of HBsAg, knowledge, and vaccination practice against ...

    African Journals Online (AJOL)

    Among the respondents, 56.7% had good knowledge and 94.8% reported poor practice of vaccination against viral hepatitis B infection. Mean knowledge and vaccination practices scores (%) were 72.54+7.60 and 29.44+14.37 respectively. Only 29% of the respondents did post vaccination testing for anti HBsAg.

  3. 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.

  4. Artificial neural network accurately predicts hepatitis B surface antigen seroclearance.

    Directory of Open Access Journals (Sweden)

    Ming-Hua Zheng

    Full Text Available BACKGROUND & AIMS: Hepatitis B surface antigen (HBsAg seroclearance and seroconversion are regarded as favorable outcomes of chronic hepatitis B (CHB. This study aimed to develop artificial neural networks (ANNs that could accurately predict HBsAg seroclearance or seroconversion on the basis of available serum variables. METHODS: Data from 203 untreated, HBeAg-negative CHB patients with spontaneous HBsAg seroclearance (63 with HBsAg seroconversion, and 203 age- and sex-matched HBeAg-negative controls were analyzed. ANNs and logistic regression models (LRMs were built and tested according to HBsAg seroclearance and seroconversion. Predictive accuracy was assessed with area under the receiver operating characteristic curve (AUROC. RESULTS: Serum quantitative HBsAg (qHBsAg and HBV DNA levels, qHBsAg and HBV DNA reduction were related to HBsAg seroclearance (P<0.001 and were used for ANN/LRM-HBsAg seroclearance building, whereas, qHBsAg reduction was not associated with ANN-HBsAg seroconversion (P = 0.197 and LRM-HBsAg seroconversion was solely based on qHBsAg (P = 0.01. For HBsAg seroclearance, AUROCs of ANN were 0.96, 0.93 and 0.95 for the training, testing and genotype B subgroups respectively. They were significantly higher than those of LRM, qHBsAg and HBV DNA (all P<0.05. Although the performance of ANN-HBsAg seroconversion (AUROC 0.757 was inferior to that for HBsAg seroclearance, it tended to be better than those of LRM, qHBsAg and HBV DNA. CONCLUSIONS: ANN identifies spontaneous HBsAg seroclearance in HBeAg-negative CHB patients with better accuracy, on the basis of easily available serum data. More useful predictors for HBsAg seroconversion are still needed to be explored in the future.

  5. Understanding early serum hepatitis D virus and HBsAg kinetics during pegylated interferon-alfa therapy via mathematical modeling

    Science.gov (United States)

    Guedj, Jeremie; Rotman, Yaron; Cotler, Scott J.; Koh, Christopher; Schmid, Peter; Albrecht, Jeff; Haynes-Williams, Vanessa; Liang, Jake T.; Hoofnagle, Jay H.; Heller, Theo; Dahari, Harel

    2014-01-01

    There is little information on the early kinetics of hepatitis delta virus (HDV) and hepatitis B surface antigen (HBsAg) during interferon-α therapy. Here a mathematical model was developed and fitted to frequent HDV and HBsAg kinetic data from 10 patients during the first 28 weeks of pegylated-interferon-α2a (peg-IFN) therapy. Three patients achieved a complete virological response (CVR), defined as undetectable HDV 6 months after treatment stopped with loss of HBsAg and anti-HBsAg seroconversion. After initiation of therapy a median delay of 9 days (interquartile range IQR:[5;15]) was observed with no significant changes in HDV level. Thereafter, HDV declined in a biphasic manner, where a rapid first-phase lasting for 25 days (IQR:[23;58]) was followed by a slower or plateau second-phase. The model predicts that the main effect of peg-IFN is to reduce HDV production/release with a median effectiveness of 96% (IQR:[93;99.8]). Median serum HDV half-life (t1/2) was estimated to 2.9 days (IQR:[1.5;5.3]) with pretreatment production and clearance of about 1010 (IQR:[109.8-1010.8]) virions/day. None of the patients with flat 2nd phase in HDV achieved CVR. HBsAg kinetics of decline paralleled the second-phase of HDV decline consistent with HBsAg-productive-infected cells being the main source of production of HDV, with a median t1/2 of 135 days (IQR:[20-460]. The interferon lambda-3 polymorphism (rs12979860) was not associated with kinetic parameters. Conclusions Modeling results provide insights into HDV-host dynamics, the relationship between serum HBsAg levels and HBsAg-infected cells, IFN's mode of action and its effectiveness. The observation that a flat second phase in HDV and HBsAg kinetics was associated with failure to achieve CVR provides the basis to develop early stopping rules during peg-IFN treatment in HDV-infected patients. PMID:25098971

  6. 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...... of delayed type hypersensitivity (DTH) reaction and CD4(+) T-cell proliferation. In addition, Posintro™-HBsAg was the only vaccine tested that also induced a strong cytotoxic T lymphocyte (CTL) response, with high levels of antigen specific CD8 T-cells secreting IFN-gamma mediating cytolytic activity...

  7. Development and Application of an ELISA Assay Using Excretion/Secretion Proteins from Epimastigote Forms of T. cruzi (ESEA Antigens) for the Diagnosis of Chagas Disease

    Science.gov (United States)

    Berrizbeitia, Mariolga; Figueroa, Milagros; Ward, Brian J.; Rodríguez, Jessicca; Jorquera, Alicia; Figuera, Maria A.; Romero, Leomerys; Ndao, Momar

    2012-01-01

    An indirect enzyme-linked immunoabsorbent assay (ELISA) for Trypanosoma cruzi was developed using epimastigote secretion/excretion proteins (ESEA antigens) obtained from axenic culture supernatants. A panel of 120 serum samples from subjects with confirmed Chagas disease (n = 50), healthy controls (n = 50), and patients with other parasitic diseases (n = 20) was used to evaluate the new ESEA-based ELISA (ELISAESEA). This new test had excellent sensitivity (98%) and acceptable specificity (88%). Cross-reactivity was observed largely in sera from subjects with Leishmania and Ascaris infections. Using Western blotting and epimastigotes from two distinct T. cruzi isolates, several polypeptide bands with molecular masses ranging from 50 to 220 kDa were detected in pooled chagasic sera. However, the band pattern for each isolate was different. These data suggest that an inexpensive and technically simple ELISA based on ESEA antigens is a promising new tool for the diagnosis of Chagas disease. PMID:23049572

  8. Development & validation of a quantitative anti-protective antigen IgG enzyme linked immunosorbent assay for serodiagnosis of cutaneous anthrax

    Directory of Open Access Journals (Sweden)

    N Ghosh

    2015-01-01

    Full Text Available Background & objectives: Anthrax caused by Bacillus anthracis is primarily a disease of herbivorous animals, although several mammals are vulnerable to it. ELISA is the most widely accepted serodiagnostic assay for large scale surveillance of cutaneous anthrax. The aims of this study were to develop and evaluate a quantitative ELISA for determination of IgG antibodies against B. anthracis protective antigen (PA in human cutaneous anthrax cases. Methods: Quantitative ELISA was developed using the recombinant PA for coating and standard reference serum AVR801 for quantification. A total of 116 human test and control serum samples were used in the study. The assay was evaluated for its precision, accuracy and linearity. Results: The minimum detection limit and lower limit of quantification of the assay for anti-PA IgG were 3.2 and 4 µg/ml, respectively. The serum samples collected from the anthrax infected patients were found to have anti-PA IgG concentrations of 5.2 to 166.3 µg/ml. The intra-assay precision per cent CV within an assay and within an operator ranged from 0.99 to 7.4 per cent and 1.7 to 3.9 per cent, respectively. The accuracy of the assay was high with a per cent error of 6.5 - 24.1 per cent. The described assay was found to be linear between the range of 4 to 80 ng/ml (R [2] =0.9982; slope=0.9186; intercept = 0.1108. Interpretation & conclusions: The results suggested that the developed assay could be a useful tool for quantification of anti-PA IgG response in human after anthrax infection or vaccination.

  9. Carcinoembryonic antigen: assay following heat compared with perchloric acid extraction in patients with colon cancer, non-neoplastic gastrointestinal diseases, or chronic renal failure

    International Nuclear Information System (INIS)

    Witherspoon, L.R.; Shuler, S.E.; Alyea, K.; Husserl, F.E.; Alton Ochsner Medical Foundation, New Orleans, LO)

    1983-01-01

    Heat inactivation has been proposed as an alternative to perchloric acid (PCA) precipitation for the extraction of carcinoembryonic antigen (CEA) from human plasma. A commercial RIA kit using heat inactivation was examined and results compared with those obtained with PCA precipitation. Adequate sensitivity (1.5 μg CEA/I plasma), satisfactory analytical recovery of CEA added to plasma, and dilutional linearity of samples found to have elevated CEA concentrations, were demonstrated for the heat-inactivation assay. Between-assay precision was better with the heat inactivation than with the PCA assay. Although the absolute concentration of CEA estimated after heat inactivation was consistently lower than that estimated after PCA extraction of plasma specimens, there was excellent correlation between results obtained with the two methods in colon cancer patients free of disease, colon cancer patients with residual or recurrent disease, patients with benign gastrointestinal disease, and in patients with chronic renal failure. The heat-inactivation assay is an excellent alternative to the PCA assay

  10. Evaluation of Antigen-Specific IgM and IgG Production during an In Vitro Peripheral Blood Mononuclear Cell Culture Assay

    Directory of Open Access Journals (Sweden)

    Yoshiko Matsuda

    2017-07-01

    Full Text Available The recent attention given to diseases associated with memory B-cell (mBC-produced antibodies (Abs suggests the need for a similar in vitro assay to evaluate the functions of mBCs. Here, we cultured peripheral blood mononuclear cells (PBMCs with the intent to collect mBC-derived Abs in vitro and maintain their cell–cell contact-dependent interactions with helper T-cells. PBMCs were cultured with interleukin (IL-21, CpG-oligodeoxynucleotides (ODN, phorbol myristate acetate (PMA, and phytohemagglutinin/leucoagglutinin (PHA-L in 24-well flat-bottom plates (5 × 105 cells/well. A culture supernatant analysis of PBMCs from healthy donors (n = 10 indicated that antigen-specific IgM Ab levels in a PBMC culture supernatant might be better able to demonstrate the antigen sensitization status in a smaller peripheral blood sample, compared to IgG because Epstein–Barr virus-specific IgM mBCs circulate peripherally at a significantly higher frequency once antiviral humoral immunity has stabilized. Thus, our in vitro assay demonstrated the potential significance of antigen-specific IgM Ab production in the culture supernatants. Furthermore, an analysis of cultured PBMCs from allograft kidney recipients (n = 16 sensitized with de novo donor-specific human leukocyte antigen (HLA-specific Abs (DSAs showed that IgM-type HLA-specific Abs were detected mainly from the culture supernatants from PBMCs of patients with stable graft function, whereas IgG isotype HLA Abs were detectable only from patients with biopsy-proven antibody-mediated rejection. In other words, these IgG isotype Abs also represented an activated humoral immune response in vivo. Additionally, IgM- and IgG-expressing mBCs from healthy donors (n = 5 were cultured with IL-21, CpG-ODN, and a supernatant produced by stimulating CD19+ B-cell-depleted PBMCs with PHA-L and PMA in 24-well flat-bottom plates (1 × 105 cells/well, and the resulting in vitro analysis provided some

  11. FULL-LENGTH PEPTIDE ASSAY OF ANTIGENIC PROFILE OF ENVELOPE PROTEINS FROM SIBERIAN ISOLATES OF HEPATITIS C VIRUS

    Directory of Open Access Journals (Sweden)

    A. A. Grazhdantseva

    2010-01-01

    Full Text Available Antigenic profiles of envelope glycoproteins of hepatitis C virus presented by three genotypes 1b, 2a/2c and 3a, which are most widespread in the territory of Russia and, in particular, in Novosibirsk, were studied using a panel of overlapping synthetic peptides. It was shown that highly immunogenic peptide epitopes of Е1 and Е2 proteins common for all HCV genotypes, are located in amino acid positions 250-260, 315-325 (Е1 protein, 390-400 (hypervariable region 1, 430-440, and 680-690 (Е2 protein. The greatest inter-genotypic differences were recorded in positions 280-290, 410-430 and 520-540. A novel antigenic determinant was detected in the region of aa 280-290 of the Е1 protein which was typical only for HCV 2a/2c genotype. A broad variation in the boundaries for the most epitopes suggests a high variability of the Е1 and Е2 viral proteins; however, a similar repertoire of antibodies induced by different HCV genotypes indicates to an opportunity of designing a new generation of cross-reactive HCV vaccines based on mapping of the E1 and E2 antigenic regions.

  12. Monitoring T-Cell Responses in Translational Studies: Optimization of Dye-Based Proliferation Assay for Evaluation of Antigen-Specific Responses

    Science.gov (United States)

    Ten Brinke, Anja; Marek-Trzonkowska, Natalia; Mansilla, Maria J.; Turksma, Annelies W.; Piekarska, Karolina; Iwaszkiewicz-Grześ, Dorota; Passerini, Laura; Locafaro, Grazia; Puñet-Ortiz, Joan; van Ham, S. Marieke; Hernandez-Fuentes, Maria P.; Martínez-Cáceres, Eva M.; Gregori, Silvia

    2017-01-01

    Adoptive therapy with regulatory T cells or tolerance-inducing antigen (Ag)-presenting cells is innovative and promising therapeutic approach to control undesired and harmful activation of the immune system, as observed in autoimmune diseases, solid organ and bone marrow transplantation. One of the critical issues to elucidate the mechanisms responsible for success or failure of these therapies and define the specificity of the therapy is the evaluation of the Ag-specific T-cell responses. Several efforts have been made to develop suitable and reproducible assays. Here, we focus on dye-based proliferation assays. We highlight with practical examples the fundamental issues to take into consideration for implementation of an effective and sensitive dye-based proliferation assay to monitor Ag-specific responses in patients. The most critical points were used to design a road map to set up and analyze the optimal assay to assess Ag-specific T-cell responses in patients undergoing different treatments. This is the first step to optimize monitoring of tolerance induction, allowing comparison of outcomes of different clinical studies. The road map can also be applied to other therapeutic interventions, not limited to tolerance induction therapies, in which Ag-specific T-cell responses are relevant such as vaccination approaches and cancer immunotherapy. PMID:29312346

  13. Monitoring T-Cell Responses in Translational Studies: Optimization of Dye-Based Proliferation Assay for Evaluation of Antigen-Specific Responses

    Directory of Open Access Journals (Sweden)

    Anja Ten Brinke

    2017-12-01

    Full Text Available Adoptive therapy with regulatory T cells or tolerance-inducing antigen (Ag-presenting cells is innovative and promising therapeutic approach to control undesired and harmful activation of the immune system, as observed in autoimmune diseases, solid organ and bone marrow transplantation. One of the critical issues to elucidate the mechanisms responsible for success or failure of these therapies and define the specificity of the therapy is the evaluation of the Ag-specific T-cell responses. Several efforts have been made to develop suitable and reproducible assays. Here, we focus on dye-based proliferation assays. We highlight with practical examples the fundamental issues to take into consideration for implementation of an effective and sensitive dye-based proliferation assay to monitor Ag-specific responses in patients. The most critical points were used to design a road map to set up and analyze the optimal assay to assess Ag-specific T-cell responses in patients undergoing different treatments. This is the first step to optimize monitoring of tolerance induction, allowing comparison of outcomes of different clinical studies. The road map can also be applied to other therapeutic interventions, not limited to tolerance induction therapies, in which Ag-specific T-cell responses are relevant such as vaccination approaches and cancer immunotherapy.

  14. 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.

  15. [Comparative study between HBsAg positive and HBsAg negative panarteritis nodosa in a series of 25 cases (author's transl)].

    Science.gov (United States)

    Iturralde, J F; Miranda, C F; Barbado, J; Peña, J; Seoane, J; Gil, A; Arnalich, F; Vázquez, J J

    1980-06-25

    Clinical symptoms, biochemical analyses, immunologic status and angiographic findings corresponding to seven HBsAg positive patients with panarteritis nodosa and to 16 HBsAg negative patients with panarteritis nodosa have been compared. HBsAg positive cases showed a statistical significant higher incidences of Raynaud's phenomenon (p less than 0.05) and cardiopathies (p les than 0.05), as well as high occurrence of blood hypertension, artropathy, liver involvement and peripheral neuropathy. Significant differences in relation to cell immunity were not found. Humoral immune disturbances were more common among HBsAg positive patients, being hypergammaglobulinemia (p less than 0.01), IgM increase and decrease of complement factors (C3, C4 and C3PA) the most frequent abnormalities recorded. Angiographic studies revealed a high incidence of microaneurisms for the HBsAg positive group.

  16. Higher lifetime chance of spontaneous surface antigen loss in hepatitis B carriers with genotype C infection.

    Science.gov (United States)

    Tseng, T-C; Liu, C-J; Chen, C-L; Yang, W-T; Yang, H-C; Su, T-H; Wang, C-C; Kuo, S F-T; Liu, C-H; Chen, P-J; Chen, D-S; Kao, J-H

    2015-05-01

    Clearance of hepatitis B surface antigen (HBsAg) indicates clinical control of hepatitis B virus (HBV) infection. However, little is known about the impact of viral genomic variations on HBsAg loss. We explored the association between viral genomic factors and HBsAg loss in 2121HBeAg-negative patients. HBV pre-core stop codon (1896) and basal core promoter (BCP) (1762/1764) sequences were determined in patients with HBV DNA ≥200 IU/mL (N = 1693). The effect of HBV genotype on HBsAg loss was further validated in the whole cohort of 3445 HBsAg carriers. The cumulative lifetime (age 28-75 years) incidence of HBsAg loss was 50.4% in 2121 HBeAg-negative patients. We found that genotype C, but not pre-core stop codon or BCP mutants, was associated with HBsAg loss. Compared to genotype B patients, genotype C patients had higher lifetime chance of HBsAg loss, with hazard ratio of 1.8 (95% confidence interval: 1.4-2.4). Multivariable analysis showed that male sex, elevated ALT levels, lower serum HBV DNA and HBsAg levels, and genotype C infection were associated with higher chance of HBsAg loss independently. We then performed sensitivity analysis, which re-included HBeAg-positive, cirrhotic and treatment-experienced patients, and confirmed the robustness of our results in 3445 HBsAg carriers. Genotype C infection, compared to genotype B, is associated with a higher lifetime chance of HBsAg loss in Asian HBV carriers. © 2015 John Wiley & Sons Ltd.

  17. The CIMT-monitoring panel: a two-step approach to harmonize the enumeration of antigen-specific CD8+ T lymphocytes by structural and functional assays.

    Science.gov (United States)

    Britten, C M; Gouttefangeas, C; Welters, M J P; Pawelec, G; Koch, S; Ottensmeier, C; Mander, A; Walter, S; Paschen, A; Müller-Berghaus, J; Haas, I; Mackensen, A; Køllgaard, T; thor Straten, P; Schmitt, M; Giannopoulos, K; Maier, R; Veelken, H; Bertinetti, C; Konur, A; Huber, C; Stevanović, S; Wölfel, T; van der Burg, S H

    2008-03-01

    The interpretation of the results obtained from immunomonitoring of clinical trials is a difficult task due to the variety of methods and protocols available to detect vaccine-specific T-cell responses. This heterogeneity as well as the lack of standards has led to significant scepticism towards published results. In February 2005, a working group was therefore founded under the aegis of the Association for Immunotherapy of Cancer ("CIMT") in order to compare techniques and protocols applied for the enumeration of antigen-specific T-cell responses. Here we present the results from two consecutive phases of an international inter-laboratory testing project referred to as the "CIMT monitoring panel". A total of 13 centers from six European countries participated in the study in which pre-tested PBMC samples, synthetic peptides and PE-conjugated HLA-tetramers were prepared centrally and distributed to participants. All were asked to determine the number of antigen-specific T-cells in each sample using tetramer staining and one functional assay. The results of the first testing round revealed that the total number of cells analyzed was the most important determinant for the sensitive detection of antigen-specific CD8(+) T-cells by tetramer staining. Analysis by ELISPOT was influenced by a combination of cell number and a resting phase after thawing of peripheral blood mononuclear cells. Therefore, the experiments were repeated in a second phase but now the participants were asked to change their protocols according to the new guidelines distilled from the results of the first phase. The recommendations improved the number of antigen-specific T-cell responses that were detected and decreased the variability between the laboratories. We conclude that a two-step approach in inter-laboratory testing allows the identification of distinct variables that influence the sensitivity of different T-cell assays and to formally show that a defined correction to the protocols

  18. Immuno-chromatographic wicking assay for the rapid detection of dengue viral antigens in mosquitoes (Diptera: Culicidae).

    Science.gov (United States)

    Wanja, Elizabeth; Parker, Zahra F; Odusami, Oluwakemi; Rowland, Tobin; Davé, Kirti; Davé, Sonia; Turell, Michael J

    2014-01-01

    There is a threat for dengue virus (DENV) reemergence in many regions of the world, particularly in areas where the DENV vectors, Aedes aegypti (L.) and Aedes albopictus (Skuse), are readily available. However, there are currently no accurate and reliable diagnostic methods to provide critical, real-time information for early detection of DENV within the vector populations to implement appropriate vector control and personal protective measures. In this article, we report the ability of an immuno-chromatographic assay developed by VecTOR Test Systems Inc. to detect DENV in a pool of female Aedes mosquitoes infected with any of the four viral serotypes. The DENV dipstick assay was simple to use, did not require a cold chain, and provided clear results within 30 min. It was highly specific and did not cross-react with samples spiked with West Nile, yellow fever, Japanese encephalitis, Rift Valley fever, chikungunya, Venezuelan equine encephalomyelitis, Ross River, LaCrosse, or Caraparu viruses. The DENV assay can provide real-time critical information on the presence of DENV in mosquitoes to public health personnel. Results from this assay will allow a rapid threat assessment and the focusing of vector control measures in high-risk areas.

  19. HIV incidence in the Estonian population in 2013 determined using the HIV-1 limiting antigen avidity assay

    NARCIS (Netherlands)

    Soodla, P.; Simmons, R.; Huik, K.; Pauskar, M.; Jõgeda, E.-L.; Rajasaar, H.; Kallaste, E.; Maimets, M.; Avi, R.; Murphy, G.; Porter, K.; Lutsar, I.; del Amo, Julia; Meyer, Laurence; Bucher, Heiner C.; Chêne, Geneviève; Hamouda, Osamah; Pillay, Deenan; Prins, Maria; Rosinska, Magda; Sabin, Caroline; Touloumi, Giota; Olson, Ashley; Cartier, Andrea; Fradette, Lorraine; Walker, Sarah; Babiker, Abdel; de Luca, Andrea; Fisher, Martin; Muga, Roberto; Kelleher, Tony; Cooper, David; Grey, Pat; Finlayson, Robert; Bloch, Mark; Ramacciotti, Tim; Gelgor, Linda; Smith, Don; Zangerle, Robert; Gill, John; Dabis, Francois; Thiebaut, Rodolphe; Costagliola, Dominique; Guiguet, Marguerite; Vanhems, Philippe; Chaix, Marie-Laure; Ghosn, Jade; Boufassa, Faroudy; Meixenberger, Karolin; Bannert, Norbert; Bartmeyer, Barbara; Antoniadou, Anastasia; Chrysos, Georgios; Daikos, Georgios L.; Pantazis, Nikos; Katsarou, Olga; Rezza, Giovanni; Dorrucci, Maria; Monforte, Antonella d'Arminio; Geskus, Ronald; van der Helm, Jannie; Schuitemaker, Hanneke; Sannes, Mette; Brubakk, Oddbjorn; Kran, Anne-Marte Bakken; Rosinska, Magdalena; Tor, Jordi; de Olalla, Patricia Garcia; Cayla, Joan; Moreno, Santiago; Monge, Susana; del Romero, Jorge; Pérez-Hoyos, Santiago; Sönnerborg, Anders; Günthard, Huldrych; Scherrer, Alexandra; Malyuta, Ruslan; Johnson, Anne; Phillips, Andrew; Morrison, Charles; Price, Matt A.; Giaquinto, Carlo; Grarup, Jesper; Kirk, Ole; Bailey, Heather; Volny Anne, Alain; Panteleev, Alex; Thorne, Claire; Aboulker, Jean-Pierre; Albert, Jan; Asandi, Silvia; de Wit, Stéphane; Reiss, Peter; Gatell, José; Karpov, Igor; Ledergerber, Bruno; Møller, Claus; Rakhmanova, Aza; Rockstroh, Jürgen; Sandhu, Manjinder; Dedes, Nikos; Pizzuti, David; Faggion, Silvia; Raben, Dorthe; Schwimmer, Christine; Scott, Martin

    2018-01-01

    Estonia has one the highest number of new HIV diagnoses in the European Union, mainly among injecting drug users and heterosexuals. Little is known of HIV incidence, which is crucial for limiting the epidemic. Using a recent HIV infection testing algorithm (RITA) assay, we aimed to estimate HIV

  20. Effect of lubricants and a vaginal spermicide gel on the detection of prostate specific antigen, a biomarker of semen exposure, using a quantitative (Abbott ARCHITECT) assay.

    Science.gov (United States)

    Snead, Margaret C; Melendez, Johan H; Kourtis, Athena P; Chaney, Dorothy M; Brown, Teresa M; Black, Carolyn M; Mauck, Christine K; Schwartz, Jill L; Zenilman, Jonathan M; Jamieson, Denise J; Macaluso, Maurizio; Doncel, Gustavo F

    2014-02-01

    Little is known about the effects of commonly used lubricants on detection of biomarkers of semen exposure. We investigated the in vitro effect of Gynol®, K-Y Jelly®, Replens®, Astroglide®, Carbopol, and Silicorel on quantitative detection of prostate specific antigen (PSA). A predetermined concentration of each of the gels was added to serially diluted semen samples. Additionally, serial dilutions of each of the gels were added to three different semen dilutions (high, medium, or low). The resulting samples were tested for PSA on the Abbott ARCHITECT System. When using the Abbott ARCHITECT system, the only products that inhibited PSA detection were Gynol® and Replens®. The inhibition caused by Gynol® was dose-dependent, but that of Replens was dose-independent. K-Y Jelly®-spiked samples had higher PSA values than controls. Caution is warranted when using the Abbott quantitative assay for PSA detection as a biomarker of semen exposure in settings where Gynol®, Replens® or K-Y Jelly® might also have been used. Neither Astroglide® nor Silicorel inhibited PSA detection. Additional studies evaluating other vaginal products, including microbicides, and their effects on other assays, are needed. In vivo studies will be especially important to optimize PSA detection from clinical samples. Researchers should consider the potential for specific lubricants or any vaginal products to affect the particular assay used for semen biomarker detection. The Abbott ARCHITECT's total PSA assay should not be used with the product Replens. Caution is warranted when using the assay in settings where Gynol or K-Y jelly may have been used. Published by Elsevier Inc.

  1. 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.

  2. Hepatitis B reactivation characterized by HBsAg negativity and anti-HbsAg antibodies persistence in haematopoietic stem cell transplanted patient after lamivudine withdrawal.

    Science.gov (United States)

    Cerva, C; Maffongelli, G; Svicher, V; Salpini, R; Colagrossi, L; Battisti, A; Mariotti, B; Cerretti, R; Cudillo, L; Sarmati, L

    2017-08-15

    HBV reactivation is associated with high mortality rates in hematopoietic stem cell transplantation (HSCT) and prophylactic lamivudine (LMV) treatment is suggested to prevent this phenomenon. However, the duration of LMV treatment in HSCT patients is not fully defined and the time of immune recovery is considered the best parameter for a drug to be safely interrupted. In patients undergoing allogeneic HSCT, the time of immune recovery is not easy to define and may take years after transplantation and prolonged LMV treatments, which can lead to drug-resistant viral strains. An anti-HBc-positive hematological patient who was undergoing prolonged immunosuppression and who experienced HBV reactivation 3 months after the suspension of a prolonged LMV prophylaxis is described. HBV-DNA matching an atypical serological profile characterized by HbsAg negativity and anti-HBs positivity was detected in the patient. The genotypic analysis of the HBV strain identified T127P, F170FL and S204R mutations of HbsAg, which can hinder HBsAg recognition in a diagnostic assay. HBV reactivation in the HSCT host can be sustained by HBsAg viral variants with characteristics of altered immunogenicity that cannot be detected by usual laboratory tests. This clinical case description suggests the importance of screening for serum HBV-DNA levels in the diagnosis of HBV reactivation and monitoring HBV-DNA after prophylaxis suspension, particularly in HSCT subjects who have undergone prolonged periods of LMV treatment.

  3. The development of standard samples with a defined number of antigen-specific T cells to harmonize T cell assays: a proof-of-principle study.

    Science.gov (United States)

    Singh, Satwinder Kaur; Tummers, Bart; Schumacher, Ton N; Gomez, Raquel; Franken, Kees L M C; Verdegaal, Els M; Laske, Karoline; Gouttefangeas, Cécile; Ottensmeier, Christian; Welters, Marij J P; Britten, Cedrik M; van der Burg, Sjoerd H

    2013-03-01

    The validation of assays that quantify antigen-specific T cell responses is critically dependent on cell samples that contain clearly defined measurable numbers of antigen-specific T cells. An important requirement is that such cell samples are handled and analyzed in a comparable fashion to peripheral blood mononuclear cells (PBMC). We performed a proof-of-principle study to show that retrovirally TCR-transduced T cells spiked at defined numbers in autologous PBMC can be used as standard samples for HLA/peptide multimer staining. NY-ESO-1157-165-specific, TCR-transduced CD8+ T cell batches were successfully generated from PBMC of several HLA-A*0201 healthy donors, purified by magnetic cell sorting on the basis of HLA tetramer (TM) staining and expanded with specific antigen in vitro. When subsequently spiked into autologous PBMC, the detection of these CD3+CD8+TM+ T cells was highly accurate with a mean accuracy of 91.6 %. The standard cells can be preserved for a substantial period of time in liquid nitrogen. Furthermore, TM staining of fresh and cryopreserved standard samples diluted at decreasing concentrations into autologous cryopreserved unspiked PBMC revealed that the spiked CD3+CD8+TM+ T cells could be accurately detected at all dilutions in a linear fashion with a goodness-of-fit of over 0.99 at a frequency of at least 0.02 % among the CD3+CD8+ T cell population. Notably, the CD3+CD8+TM+ cells of the standard samples were located exactly within the gates used to analyze patient samples and displayed a similar scatter pattern. The performance of the cryopreserved standard samples in the hands of 5 external investigators was good with an inter-laboratory variation of 32.9 % and the doubtless identification of one outlier.

  4. The hybrid EIA test: a specific and sensitive assay for the detection of woodchuck antibody to hepatitis surface antigen (anti-WHs).

    Science.gov (United States)

    Millman, I; Glass, R G

    1988-05-01

    'Ausria II' polystyrene beads (Abbott Labs, N. Chicago) are reacted with woodchuck serum positive for WHsAg in a dilution predetermined by titration. This modified bead is used in a blocking assay to detect the presence of antibody to the surface antigen of woodchuck hepatitis virus (anti-WHs). Serum containing woodchuck anti-WHs and commercial horseradish peroxidase (HRP) labeled anti-HBs are sequentially added. A drop in optical density at 492 nm of 50% or more due to the blocking of HRP conjugated anti-HBs by anti-WHs compared with a control (negative woodchuck serum) is a measure of anti-WHs. The ease and simplicity of converting readily available 'Ausria II' beads to specific reagents for detecting anti-WHs should be welcomed by investigators studying WHV. The method described is both sensitive and reproducible.

  5. A Comparative Evaluation of Giardiasis Prevalence by Rutine Parasitical Assays and Antigen Detection in Elementary School Children in Delfan Town, Iran

    Directory of Open Access Journals (Sweden)

    shirzad Fllahi

    2008-02-01

    Full Text Available Fllahi Sh1, Ghorvi MJ2, Qara-gozlou B3, Sepahvand A1, Mahouti F4 1. Instructor, Department of Parasitology, Faculty of Medicine, Lorestan University of Medical Sciences 2. Associate Professor, Department of Parasitology, Faculty of Para-medicine, Iran University of Medical Sciences 3. Instructor, Department of Immunology, Faculty of Para-medicine, Iran University of Medical Sciences 4. B.Sc of Nursing, Staff Member of Research and Technology Office, Lorestan University of Medical Sciences Abstract Background: With regard to the high prevalence of Giardiasis in elementary school children of most countries and the nececerity of rapid and sensitive detection of the disease in laboratories, this study was performed to compare routine parasitical assays and new techniques in antigen detection by Elisa for the detection of Giardia lamblia. Moreover, it was aimed to measure the prevalence of Giardiasis in Delfan town. Materials and methods: This study was an analytical-comparative study that was performed on 500 school children at elementary schools aged 6-12. After the selection of samples by systematic random sampling methods, the questionnaires were completed by every child and 3 fecal samples were collected from each child. The method of getting fecal samples from children was demonstrated for parents. All the samples were examined by wet-mount and Formalin-ether concentration assays. Then, the Elisa technique was performed to all samples and the findings were compared. Results: Out of 500 male and female subjects aged 6-12 in Delfan elementary schools, 97 samples examined by three laboratory techniques (Wetmount, Formalin-ether concentration, and Elisa were found to be positive for Giardia lamblia. %19.4 of the subjects (68 were positive for Giardia lamblia, (%70.1 in Wetmount assay, 88 samples (%90.72 in Formalin-ether concentration test, and 95 samples (%97.93 in Elisa technique. Conclusion: The findings of this study revealed that Elisa

  6. LATERAL FLOW ASSAY FOR CRYPTOCOCCAL ANTIGEN: AN IMPORTANT ADVANCE TO IMPROVE THE CONTINUUM OF HIV CARE AND REDUCE CRYPTOCOCCAL MENINGITIS-RELATED MORTALITY

    Science.gov (United States)

    VIDAL, Jose E.; BOULWARE, David R.

    2015-01-01

    SUMMARY AIDS-related cryptococcal meningitis continues to cause a substantial burden of death in low and middle income countries. The diagnostic use for detection of cryptococcal capsular polysaccharide antigen (CrAg) in serum and cerebrospinal fluid by latex agglutination test (CrAg-latex) or enzyme-linked immunoassay (EIA) has been available for over decades. Better diagnostics in asymptomatic and symptomatic phases of cryptococcosis are key components to reduce mortality. Recently, the cryptococcal antigen lateral flow assay (CrAg LFA) was included in the armamentarium for diagnosis. Unlike the other tests, the CrAg LFA is a dipstick immunochromatographic assay, in a format similar to the home pregnancy test, and requires little or no lab infrastructure. This test meets all of the World Health Organization ASSURED criteria (Affordable, Sensitive, Specific, User friendly, Rapid/robust, Equipment-free, and Delivered). CrAg LFA in serum, plasma, whole blood, or cerebrospinal fluid is useful for the diagnosis of disease caused by Cryptococcus species. The CrAg LFA has better analytical sensitivity for C. gattii than CrAg-latex or EIA. Prevention of cryptococcal disease is new application of CrAg LFA via screening of blood for subclinical infection in asymptomatic HIV-infected persons with CD4 counts < 100 cells/mL who are not receiving effective antiretroviral therapy. CrAg screening of leftover plasma specimens after CD4 testing can identify persons with asymptomatic infection who urgently require pre-emptive fluconazole, who will otherwise progress to symptomatic infection and/or die. PMID:26465368

  7. LATERAL FLOW ASSAY FOR CRYPTOCOCCAL ANTIGEN: AN IMPORTANT ADVANCE TO IMPROVE THE CONTINUUM OF HIV CARE AND REDUCE CRYPTOCOCCAL MENINGITIS-RELATED MORTALITY.

    Science.gov (United States)

    Vidal, Jose E; Boulware, David R

    2015-09-01

    AIDS-related cryptococcal meningitis continues to cause a substantial burden of death in low and middle income countries. The diagnostic use for detection of cryptococcal capsular polysaccharide antigen (CrAg) in serum and cerebrospinal fluid by latex agglutination test (CrAg-latex) or enzyme-linked immunoassay (EIA) has been available for over decades. Better diagnostics in asymptomatic and symptomatic phases of cryptococcosis are key components to reduce mortality. Recently, the cryptococcal antigen lateral flow assay (CrAg LFA) was included in the armamentarium for diagnosis. Unlike the other tests, the CrAg LFA is a dipstick immunochromatographic assay, in a format similar to the home pregnancy test, and requires little or no lab infrastructure. This test meets all of the World Health Organization ASSURED criteria (Affordable, Sensitive, Specific, User friendly, Rapid/robust, Equipment-free, and Delivered). CrAg LFA in serum, plasma, whole blood, or cerebrospinal fluid is useful for the diagnosis of disease caused by Cryptococcus species. The CrAg LFA has better analytical sensitivity for C. gattii than CrAg-latex or EIA. Prevention of cryptococcal disease is new application of CrAg LFA via screening of blood for subclinical infection in asymptomatic HIV-infected persons with CD4 counts < 100 cells/mL who are not receiving effective antiretroviral therapy. CrAg screening of leftover plasma specimens after CD4 testing can identify persons with asymptomatic infection who urgently require pre-emptive fluconazole, who will otherwise progress to symptomatic infection and/or die.

  8. Diagnostic efficacy of monoclonal antibody based sandwich enzyme linked immunosorbent assay (ELISA for detection of Fasciola gigantica excretory/secretory antigens in both serum and stool

    Directory of Open Access Journals (Sweden)

    Zoheiry Mona K

    2011-09-01

    Full Text Available Abstract Background This research was carried out to develop a reliable monoclonal antibody (MoAb-based sandwich enzyme linked immunosorbent assay (ELISA for the diagnosis of active Fasciola gigantica infection in both serum and stool for comparative purposes. Methods From a panel of MoAbs raised against F. gigantica excretory/secretory antigens (ES Ags, a pair (12B/11D/3F and 10A/9D/10G was chosen due to its high reactivity and strict specificity to F. gigantica antigen by indirect ELISA. Results The two MoAbs were of the IgG1 and IgG2a subclasses, respectively. Using SDS-PAGE and EITB, the selected MoAbs recognized 83, 64, 45 and 26 kDa bands of ES Ags. The lower detection limit of ELISA assay was 3 ng/ml. In stool, the sensitivity, specificity and diagnostic efficacy of ELISA was 96%, 98.2 and 97.1%; while in serum they were 94%, 94.6% and 94.3%, respectively. Moreover, a positive correlation was found between ova count in stool of F. gigantica infected patients and the OD readings of ELISA in both stool and serum samples (r = 0.730, p Conclusions These data showed that the use of MoAb-based sandwich ELISA for the detection of F. gigantica coproantigens in stool specimens was superior to serum samples; it provides a highly efficient, non-invasive technique for the diagnosis of active F. gigantica infection.

  9. LATERAL FLOW ASSAY FOR CRYPTOCOCCAL ANTIGEN: AN IMPORTANT ADVANCE TO IMPROVE THE CONTINUUM OF HIV CARE AND REDUCE CRYPTOCOCCAL MENINGITIS-RELATED MORTALITY

    Directory of Open Access Journals (Sweden)

    Jose E. VIDAL

    2015-09-01

    Full Text Available SUMMARYAIDS-related cryptococcal meningitis continues to cause a substantial burden of death in low and middle income countries. The diagnostic use for detection of cryptococcal capsular polysaccharide antigen (CrAg in serum and cerebrospinal fluid by latex agglutination test (CrAg-latex or enzyme-linked immunoassay (EIA has been available for over decades. Better diagnostics in asymptomatic and symptomatic phases of cryptococcosis are key components to reduce mortality. Recently, the cryptococcal antigen lateral flow assay (CrAg LFA was included in the armamentarium for diagnosis. Unlike the other tests, the CrAg LFA is a dipstick immunochromatographic assay, in a format similar to the home pregnancy test, and requires little or no lab infrastructure. This test meets all of the World Health Organization ASSURED criteria (Affordable, Sensitive, Specific, User friendly, Rapid/robust, Equipment-free, and Delivered. CrAg LFA in serum, plasma, whole blood, or cerebrospinal fluid is useful for the diagnosis of disease caused by Cryptococcusspecies. The CrAg LFA has better analytical sensitivity for C. gattii than CrAg-latex or EIA. Prevention of cryptococcal disease is new application of CrAg LFA via screening of blood for subclinical infection in asymptomatic HIV-infected persons with CD4 counts < 100 cells/mL who are not receiving effective antiretroviral therapy. CrAg screening of leftover plasma specimens after CD4 testing can identify persons with asymptomatic infection who urgently require pre-emptive fluconazole, who will otherwise progress to symptomatic infection and/or die.

  10. The diagnostic sensitivity of dengue rapid test assays is significantly enhanced by using a combined antigen and antibody testing approach.

    Directory of Open Access Journals (Sweden)

    Scott R Fry

    2011-06-01

    Full Text Available BACKGROUND: Serological tests for IgM and IgG are routinely used in clinical laboratories for the rapid diagnosis of dengue and can differentiate between primary and secondary infections. Dengue virus non-structural protein 1 (NS1 has been identified as an early marker for acute dengue, and is typically present between days 1-9 post-onset of illness but following seroconversion it can be difficult to detect in serum. AIMS: To evaluate the performance of a newly developed Panbio® Dengue Early Rapid test for NS1 and determine if it can improve diagnostic sensitivity when used in combination with a commercial IgM/IgG rapid test. METHODOLOGY: The clinical performance of the Dengue Early Rapid was evaluated in a retrospective study in Vietnam with 198 acute laboratory-confirmed positive and 100 negative samples. The performance of the Dengue Early Rapid in combination with the IgM/IgG Rapid test was also evaluated in Malaysia with 263 laboratory-confirmed positive and 30 negative samples. KEY RESULTS: In Vietnam the sensitivity and specificity of the test was 69.2% (95% CI: 62.8% to 75.6% and 96% (95% CI: 92.2% to 99.8 respectively. In Malaysia the performance was similar with 68.9% sensitivity (95% CI: 61.8% to 76.1% and 96.7% specificity (95% CI: 82.8% to 99.9% compared to RT-PCR. Importantly, when the Dengue Early Rapid test was used in combination with the IgM/IgG test the sensitivity increased to 93.0%. When the two tests were compared at each day post-onset of illness there was clear differentiation between the antigen and antibody markers. CONCLUSIONS: This study highlights that using dengue NS1 antigen detection in combination with anti-glycoprotein E IgM and IgG serology can significantly increase the sensitivity of acute dengue diagnosis and extends the possible window of detection to include very early acute samples and enhances the clinical utility of rapid immunochromatographic testing for dengue.

  11. Differentiation of foot-and-mouth disease virus-infected from vaccinated pigs by enzyme-linked immunosorbent assay using nonstructural protein 3AB as the antigen and application to an eradication program

    DEFF Research Database (Denmark)

    Chung, Wen Bin; Sørensen, Karl Johan; Liao, Pei Chih

    2002-01-01

    . Positive reactions were found in sera from fattening pigs and sows 16 weeks and 3.5 years postoutbreak, respectively. There was, however, no positive reaction in sows with at least 10 vaccinations. Maternally derived antibodies to the 3AB antigen persisted in piglets up to 13 weeks of age. A high......Baculovirus-expressed foot-and-mouth disease virus (FMDV) nonstructural protein 3AB was used as the antigen in an enzyme-linked immunosorbent assay. This assay allowed the differentiation of vaccinated from infected pigs. Serial studies were performed using sera collected from pigs in the field...

  12. Comparison of Real Time Polymerase Chain Reaction with Microscopy and Antigen Detection Assay for the Diagnosis of Malaria

    International Nuclear Information System (INIS)

    Khan, S. A.; Ahmed, S.; Khan, F. A.; Shamshad, G. U.; Joyia, Z.; Mushahid, N.; Saeed, S.

    2013-01-01

    Objective: To determine the sensitivity of a real time polymerase chain reaction (PCR) for malaria diagnosis and to compare its accuracy with microscopy and an antigen based rapid diagnostic test (OptiMal). Study Design: Cross-sectional analytical study. Place and Duration of Study: Military Hospital, Armed Forces Institute of Transfusion and Armed Forces Institute of Pathology, Rawalpindi, from July to December 2011. Methodology: Venous blood samples of 300 clinically suspected patients of malaria were tested for malaria parasite by microscopy and OptiMal; and malaria parasite index was calculated for the positive samples. Plasmodium genus specific real time PCR was performed on all specimens, targeting small subunit rRNA gene. Diagnostic accuracy of three tests was compared and cost analysis was done. Results: Out of 300 patients, malaria parasite was detected in 110, 106 and 123 patients by microscopy, OptiMAL and PCR respectively. Real time PCR was 100% sensitive while microscopy and OptiMal had sensitivity of 89.4% and 86.2% respectively. All methods were 100% specific. The cost per test was calculated to be 0.2, 2.75 and 3.30 US dollar by microscopy, OptiMal and PCR respectively, excluding the once capital cost on PCR equipment. Conclusion: Genus specific real time PCR for the diagnosis of malaria was successfully established as a highly sensitive and affordable technology that should be incorporated in the diagnostic algorithm in this country. (author)

  13. Assessment of a 27-kDa antigen in enzyme-linked immunosorbent assay for the diagnosis of fasciolosis in Vietnamese patients.

    Science.gov (United States)

    Nguyen, T G T; Le, T H; De, N V; Doan, T T; Dao, T H T; Vercruysse, J; Dorny, P

    2010-04-01

    Fasciolosis has emerged as an important zoonotic disease in many parts of the world. In recent years, an increasing number of human cases were reported in Vietnam. In this study, the 27-kDa component protein from the excretory/secretory production of adult Fasciola gigantica, purified by high performance liquid chromatography, was assessed in an enzyme-linked immunosorbent assay (ELISA) to detect antibodies against Fasciola spp. for diagnosis of human fasciolosis. The ELISA showed a high sensitivity (100%) and specificity (97.67%) when tested on patients with fasciolosis, other parasitic infections, cholangiocarcinoma and on healthy controls. The assay was applied for diagnosis on 143 patients in the Viet Duc-Hanoi hospital who presented with clinical signs of liver disease and lesions in their livers as shown by imaging techniques. Antibodies were found in 37 (25.9%) of these patients, of whom only 3 shed Fasciola eggs in their stools (2.1%). The excellent response to triclabendazole treatment of 37 sero-positive patients confirmed the diagnosis of fasciolosis. This study demonstrated the diagnostic potential for human fasciolosis of the 27-kDa antigen ELISA. Fasciolosis should be considered in the differential diagnosis of hepatic disease in Vietnam.

  14. Trypanosomosis surveillance on Zanzibar island, using the trypanosomal antigen detection ELISA (enzyme-linked immunosorbent assay) technique

    International Nuclear Information System (INIS)

    Mbwambo, H.A.

    1997-01-01

    The effectiveness of trypanosomosis control programs depends greatly on prior knowledge of basic data of the epidemiological situation of the disease, which in turns depends, among others, on the use of techniques that give a fairly quick and accurate diagnosis. An antigen-detection (Ag) ELISA was first introduced into Tanzania and validated at the Animal Disease Research Institute (ADRI) through the FAO/IAEA Research Contract (RC) No. 5030/NL. Incorporation of the Ag-ELISA technique into a FAO animal disease control project (1986-1993) on Unguja island, in 1992, revealed useful information of high trypanosomosis prevalence in an area previously declared free of the disease using just stained blood smears and buffy coat examinations. This triggered further efforts into more intensive surveys of the tsetse and trypanosomosis situation on Unguja island. The present study is a continuation of previous work in an effort to confirm the practical application of Ag-ELISA in trypanosomosis control operations. Results obtained from a known tsetse and trypanosomosis-free area, on Pemba island, showed a high specificity of the test for Trypanosoma congolense, T. vivax and T. brucei. A preliminary cut-off value of 10% (Percent Positivity = PP) was used. When the PP of 10 was used on sera of trypanosomosis-endemic areas (Mangapwani, Ndijani, Dunga and Kikungwi) on Unguja island, the results reflected the 'real' trypanosomis situation in the affected area. This was most strongly felt in the Mangapwani area, where tsetse and trypanosomosis were considered under control by 1994 (no tsetse flies were caught and no samples were encountered positive by the buffy coat technique). However, it should be stressed that the buffy coat technique and the Ag-ELISA complement each other and should be used in conjunction. (author). 8 refs, 1 fig., 5 tabs

  15. Tumour associated antigen CA-50, CA-242 immunoradiometric assay (IRMA) in genitourinary malignancy and gastrointestinal carcinoma early diagnosis

    International Nuclear Information System (INIS)

    Chen Zhizhou.

    1992-04-01

    Tumour markers CA-50 and CA-242 were measured by immunometric assay (IRMA) to investigate their usefulness in the diagnosis of cancer of the pancreas, biliary tract, liver, breast, lung, gastrointestinal and genitourinary systems. The cutoff points, derived from studies on normal subjects and those with proven benign disease, were 20 u/ml and 12 u/ml for CA-50 and CA-242 respectively. Both markers were found to be generally useful with significant differences between malignant and non malignant disease. The highest positive rates, were found in cancers of the pancreas and gall bladder. The overall rate of false positives was low. It is concluded that measurements of CA-50 and CA-242 are useful in the detection of malignancy, particularly of the pancreas and biliary tract. 2 figs, 2 tabs

  16. A FRET-based high throughput screening assay to identify inhibitors of anthrax protective antigen binding to capillary morphogenesis gene 2 protein.

    Directory of Open Access Journals (Sweden)

    Michael S Rogers

    Full Text Available Anti-angiogenic therapies are effective for the treatment of cancer, a variety of ocular diseases, and have potential benefits in cardiovascular disease, arthritis, and psoriasis. We have previously shown that anthrax protective antigen (PA, a non-pathogenic component of anthrax toxin, is an inhibitor of angiogenesis, apparently as a result of interaction with the cell surface receptors capillary morphogenesis gene 2 (CMG2 protein and tumor endothelial marker 8 (TEM8. Hence, molecules that bind the anthrax toxin receptors may be effective to slow or halt pathological vascular growth. Here we describe development and testing of an effective homogeneous steady-state fluorescence resonance energy transfer (FRET high throughput screening assay designed to identify molecules that inhibit binding of PA to CMG2. Molecules identified in the screen can serve as potential lead compounds for the development of anti-angiogenic and anti-anthrax therapies. The assay to screen for inhibitors of this protein-protein interaction is sensitive and robust, with observed Z' values as high as 0.92. Preliminary screens conducted with a library of known bioactive compounds identified tannic acid and cisplatin as inhibitors of the PA-CMG2 interaction. We have confirmed that tannic acid both binds CMG2 and has anti-endothelial properties. In contrast, cisplatin appears to inhibit PA-CMG2 interaction by binding both PA and CMG2, and observed cisplatin anti-angiogenic effects are not mediated by interaction with CMG2. This work represents the first reported high throughput screening assay targeting CMG2 to identify possible inhibitors of both angiogenesis and anthrax intoxication.

  17. 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....

  18. 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

  19. One or two serological assay testing strategy for diagnosis of HBV and HCV infection? The use of predictive modelling.

    Science.gov (United States)

    Parry, John V; Easterbrook, Philippa; Sands, Anita R

    2017-11-01

    Initial serological testing for chronic hepatitis B virus (HBV) and hepatitis C virus (HCV) infection is conducted using either rapid diagnostic tests (RDT) or laboratory-based enzyme immunoassays (EIA)s for detection of hepatitis B surface antigen (HBsAg) or antibodies to HCV (anti-HCV), typically on serum or plasma specimens and, for certain RDTs, capillary whole blood. WHO recommends the use of standardized testing strategies - defined as a sequence of one or more assays to maximize testing accuracy while simplifying the testing process and ideally minimizing cost. Our objective was to examine the diagnostic outcomes of a one- versus two-assay serological testing strategy. These data were used to inform recommendations in the 2017 WHO Guidelines on hepatitis B and C testing. Few published studies have compared diagnostic outcomes for one-assay versus two-assay serological testing strategies for HBsAg and anti-HCV. Therefore, the principles of Bayesian statistics were used to conduct a modelling exercise to examine the outcomes of a one-assay versus two-assay testing strategy when applied to a hypothetical population of 10,000 individuals. The resulting model examined the diagnostic outcomes (true and false positive diagnoses; true and false negative diagnoses; positive and negative predictive values as a function of prevalence; and total tests required) for both one-assay and two-assay testing strategies. The performance characteristics assumed for assays used within the testing strategies were informed by WHO prequalification assessment findings and systematic reviews for diagnostic accuracy studies. Each of the presumptive testing strategies (one-assay or two-assay) was modelled at varying prevalences of HBsAg (10%, 2% and 0.4%) and of anti-HCV (40%, 10%, 2% and 0.4%), aimed at representing the range of testing populations typically encountered in WHO Member States. When the two-assay testing strategy was considered, the model assumed the independence of the

  20. HIV Incidence Estimates Using the Limiting Antigen Avidity EIA Assay at Testing Sites in Kiev City, Ukraine: 2013-2014

    Science.gov (United States)

    Kruglov, Yuri; Yurchenko, Alexander

    2016-01-01

    Objective To estimate HIV incidence and highlight the characteristics of persons at greatest risk of HIV in the Ukraine capital, Kiev. Method Residual samples from newly-diagnosed persons attending the Kiev City AIDS Centre were tested for evidence of recent HIV infection using an avidity assay. Questions on possible risk factors for HIV acquisition and testing history were introduced. All persons (≥16yrs) presenting for an HIV test April’13–March’14 were included. Rates per 100,000 population were calculated using region-specific denominators. Results During the study period 6370 individuals tested for HIV. Of the 467 individuals newly-diagnosed with HIV, 21 had insufficient samples for LAg testing. Of the remaining 446, 39 (8.7%) were classified as recent with an avidity index <1.5ODn, 10 were reclassified as long-standing as their viral load was <1000 copies/mL, resulting in 29 (6.5%) recent HIV infections. The only independent predictor for a recent infection was probable route of exposure, with MSM more likely to present with a recent infection compared with heterosexual contact [Odds Ratio 8.86; 95%CI 2.65–29.60]. We estimated HIV incidence at 21.5 per 100,000 population, corresponding to 466 new infections. Using population estimates for MSM and PWID, incidence was estimated to be between 2289.6 and 6868.7/100,000 MSM, and 350.4 for PWID. Conclusion A high proportion of persons newly-infected remain undiagnosed, with MSM disproportionally affected with one in four newly-HIV-diagnosed and one in three recently-HIV-infected. Our findings should be used for targeted public health interventions and health promotion. PMID:27276170

  1. Development and evaluation of an in-house ELISA to detect hepatitis B virus surface antigen in resource-limited settings.

    Science.gov (United States)

    Fatema, K; Tabassum, S; Nessa, A; Jahan, M

    2013-08-01

    Hepatitis B virus (HBV) infection is of global public health concern. Among various serological tests used for the diagnosis and screening of HBV infection, the enzyme-linked immunosorbent assay (ELISA) to detect hepatitis B surface antigen (HbsAg) is most widely used. The present study was designed to develop and standardize a cost effective in-house ELISA for the detection of HbsAg and compare its performance with two established commercial kits. The concentrations of coating antibody, conjugates and sera were fixed by checkerboard titration. Using known HBsAg positive and negative sera, four different concentrations (1, 0.5, 0.25 and 0.125 microg/well) of coating anti-HBs were applied. Similarly, serial dilutions of patients' sera (1 in 2, 1 in 3, 1 in 5 and 1 in 9) and conjugates (1 in 2, 1 in 3, 1 in 5, 1 in 9 and 1 in 17) were evaluated by checkerboard titration. The optimal concentration of coating antibody was determined at 0.25 microg/well and 1 in 9 dilution for both conjugates and sera. The performance comparison of our in-house ELISA showed excellent correlation with two commercial kits (Pearson 0.957, P = 0.001 for monoclonal antibody coated kit and Pearson 0.929, P = 0.000 for polyclonal antibody coated kit) when OD values were compared. All commercial kit proven positive samples was positive while all negative samples were negative with the in-house ELISA resulting in 100% sensitivity and specificity. The results of our study demonstrated that our in-house ELISA for detection of HBsAg was equally as sensitive and specific as two well-known commercial kits. Thus, this system may be a useful tool for diagnostic and screening purposes, as well as outbreak investigations.

  2. Isolation of a 14 kDa antigen from Taenia solium cyst fluid by HPLC and its evaluation in enzyme linked immunosorbent assay for diagnosis of porcine cysticercosis.

    Science.gov (United States)

    Assana, E; Kanobana, K; Tume, C B; Zoli, P A; Nguekam; Geerts, S; Berkvens, D; Dorny, P

    2007-06-01

    A fraction with a major band of 14kDa was obtained from crude cyst fluid of Taenia solium cysticerci by 2-step chromatography. A first fraction isolated by gel filtration (Sephacryl S-300 high resolution) was purified using an anion exchange column (Mono Q HR 5/5) on high performance liquid chromatography. Evaluation of the analytic sensitivity of this fraction (F3) was carried out in an antibody enzyme linked immunosorbent assay (Ab-ELISA-F3) using serum samples from pigs experimentally infected with different doses of T. solium eggs. The cross-reactivity of F3 was evaluated with serum samples from pigs that were naturally or experimentally infected with Taenia hydatigena, Taenia saginata asiatica, Fasciola hepatica, Trichinella spiralis, Metastrongylus apri, Trypanosoma congolense and Sarcoptes scabiei, and with serum samples of rabbits hyper-immunised with metacestode cyst fluid of T. hydatigena and T. solium. Antibody titres of lightly or heavily infected pigs differed in their kinetics. However, the increase in F3-specific antibodies could not be related to the infection level. Analysis of the specificity of the F3 showed that serum samples of pigs infected with other parasites did not recognise this antigen. Cross-reaction with T. hydatigena occurred in ELISA using cyst fluid as antigen, but the F3 antigen fraction was not recognized by rabbit hyper-immune serum samples to T. hydatigena. Evaluation of the diagnostic sensitivity and specificity of the Ab-ELISA-F3 was done by a non-parametric receiver operating characteristic (ROC) analysis using 66 serum samples from Zambian village pigs. The total number of cysticerci of these pigs was determined by dissection (28 pigs harboured T. solium cysticerci and 38 were negative at dissection). In addition, 58 serum samples from Cameroonian pigs (28 pigs from cysticercosis-free farms and 30 pigs with cysticerci at tongue inspection) were used in a separate ROC analysis. The results from the ROC analysis yielded a low

  3. Initial prostate biopsy: development and internal validation of a biopsy-specific nomogram based on the prostate cancer antigen 3 assay.

    Science.gov (United States)

    Hansen, Jens; Auprich, Marco; Ahyai, Sascha A; de la Taille, Alexandre; van Poppel, Hendrik; Marberger, Michael; Stenzl, Arnulf; Mulders, Peter F A; Huland, Hartwig; Fisch, Margit; Abbou, Clement-Claude; Schalken, Jack A; Fradet, Yves; Marks, Leonard S; Ellis, William; Partin, Alan W; Pummer, Karl; Graefen, Markus; Haese, Alexander; Walz, Jochen; Briganti, Alberto; Shariat, Shahrokh F; Chun, Felix K

    2013-02-01

    Urinary prostate cancer antigen 3 (PCA3) assay in combination with established clinical risk factors improves the identification of men at risk of harboring prostate cancer (PCa) at initial biopsy (IBX). To develop and validate internally the first IBX-specific PCA3-based nomogram that allows an individual assessment of a man's risk of harboring any PCa and high-grade PCa (HGPCa). Clinical and biopsy data including urinary PCA3 score of 692 referred IBX men at risk of PCa were collected within two prospective multi-institutional studies. IBX (≥ 10 biopsy cores) with standard risk factor assessment including prebiopsy urinary PCA3 measurement. PCA3 assay cut-off thresholds were investigated. Regression coefficients of logistic risk factor analyses were used to construct specific sets of PCA3-based nomograms to predict any PCa and HGPCa at IBX. Accuracy estimates for the presence of any PCa and HGPCa were quantified using area under the curve of the receiver operator characteristic analysis and compared with a clinical model. Bootstrap resamples were used for internal validation. Decision curve analyses quantified the clinical net benefit related to the novel PCA3-based IBX nomogram versus the clinical model. Any PCa and HGPCa were diagnosed in 46% (n=318) and 20% (n=137), respectively. Age, prostate-specific antigen, digital rectal examination, prostate volume, and PCA3 were independent predictors of PCa at IBX (all p<0.001). The PCA3-based IBX nomograms significantly outperformed the clinical models without PCA3 (all p<0.001). Accuracy was increased by 4.5-7.1% related to PCA3 inclusion. When applying nomogram-derived PCa probability thresholds ≤ 30%, only a few patients with HGPCa (≤ 2%) will be missed while avoiding up to 55% of unnecessary biopsies. External validation of the PCA3-based IBX-specific nomogram is warranted. The internally validated PCA3-based IBX-specific nomogram outperforms a clinical prediction model without PCA3 for the prediction of any

  4. 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.

  5. PRISM hepatitis B surface antigen detection of hepatits B virus minipool nucleic acid testing yield samples.

    Science.gov (United States)

    Linauts, Sandy; Saldanha, John; Strong, D Michael

    2008-07-01

    Hepatitis B virus (HBV) residual risk has been estimated at 1:63,000-1:205,000 and introduction of more sensitive serological tests and nucleic acid testing (NAT) would reduce that risk. Sensitivity of the recently licensed Abbott PRISM hepatitis B surface antigen (HBsAg) CLIA and minipool (MP) HBV NAT has been described as comparable and thus the need for HBV NAT has not been compelling. In this study, eight samples identified as yield samples with MP HBV NAT were tested using the PRISM test. Seven samples were identified using the Roche COBAS AmpliScreen HBV test and one additional sample was obtained from the clinical trial for the Roche cobas TaqScreen MPX test. Each of these samples was reactive by MP HBV NAT and nonreactive for HBsAg using one of three licensed enzyme immunoassay (EIA) tests. After licensure of the PRISM HBsAg, aliquots were tested with this assay, and DNA quantitation and genotyping were repeated where sample volume permitted. Three samples (2000, 2300, and 61,000 copies/mL) produced reactive results with PRISM. Four samples with viral loads less than 300 copies per mL produced nonreactive results. One sample, originally quantitated at 37,000 copies per mL (but 3850 copies/mL in repeat testing) was also nonreactive by PRISM. Genotyping of this sample indicated a type C genotype with no mutations. Adding serological sensitivity of PRISM CLIA reduced the NAT yield from the original 1: 385,555 to 1:610,488. However, MP HBV NAT still provides additional sensitivity over CLIA, even for a donation with a viral load of almost 4000 copies per mL.

  6. 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.

  7. HBV reactivation with fatal fulminating hepatitis during rituximab treatment in a subject negative for HBsAg and positive for HBsAb and HBcAb.

    Science.gov (United States)

    Sarrecchia, Cesare; Cappelli, Alessandra; Aiello, Pasquale

    2005-08-01

    A 51-year-old man who was hepatitis B surface antigen (HBsAg)-negative and positive for anti-hepatitis B surface antigen (anti-HBs) and anti-hepatitis B core antigen (anti-HBc), during rituximab therapy for chronic Lymphocytic leukemia, developed reactivation of hepatitis B virus (HBV) infection with hepatitis that proceeded towards hepatic failure and death in spite of lamivudine therapy. HBsAg remained persistently negative, notwithstanding a high HBV-DNA titer. Our observation, following other cases of fatal reactivation of HBV infection in patients receiving rituximab, suggests that, in all patients with previous markers of HBV infection, lamivudine prophylaxis should be considered during rituximab therapy.

  8. 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

  9. 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

    NARCIS (Netherlands)

    Endmann, Anne; Klunder, Katharina; Kapp, Kerstin; Riede, Oliver; Oswald, Detlef; Talman, Eduard G.; Schroff, Matthias; Kleuss, Christiane; Ruiters, Marcel H. J.; Juhls, Christiane

    2014-01-01

    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

  10. 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

  11. Asymptomatic cryptococcal antigen prevalence detected by lateral flow assay in hospitalised HIV-infected patients in São Paulo, Brazil.

    Science.gov (United States)

    Vidal, José E; Toniolo, Carolina; Paulino, Adriana; Colombo, Arnaldo; Dos Anjos Martins, Marilena; da Silva Meira, Cristina; Pereira-Chioccola, Vera Lucia; Figueiredo-Mello, Claudia; Barros, Tiago; Duarte, Jequelie; Fonseca, Fernanda; Alves Cunha, Mirella; Mendes, Clara; Ribero, Taiana; Dos Santos Lazera, Marcia; Rajasingham, Radha; Boulware, David R

    2016-12-01

    To determine the prevalence of asymptomatic cryptococcal antigen (CRAG) using lateral flow assay (LFA) in hospitalised HIV-infected patients with CD4 counts 18 years old without prior cryptococcal meningitis, without clinical suspicion of cryptococcal meningitis, regardless of antiretroviral (ART) status, and with CD4 counts <200 cells/μl. Serum CRAG was tested by LFA in all patients, and whole blood CRAG was tested by LFA in positive cases. We enrolled 163 participants of whom 61% were men. The duration of HIV diagnosis was a median of 8 (range, 1-29) years. 26% were antiretroviral (ART)-naïve, and 74% were ART-experienced. The median CD4 cell count was 25 (range, 1-192) cells/μl. Five patients (3.1%; 95%CI, 1.0-7.0%) were asymptomatic CRAG-positive. Positive results cases were cross-verified by performing LFA in whole blood. 3.1% of HIV-infected inpatients with CD4 <200 cells/μl without symptomatic meningitis had cryptococcal antigenemia in São Paulo, suggesting that routine CRAG screening may be beneficial in similar settings in South America. Our study reveals another targeted population for CRAG screening: hospitalised HIV-infected patients with CD4 <200 cells/μl, regardless of ART status. Whole blood CRAG LFA screening seems to be a simple strategy to prevention of symptomatic meningitis. © 2016 John Wiley & Sons Ltd.

  12. Novel rolling circle amplification and DNA origami-based DNA belt-involved signal amplification assay for highly sensitive detection of prostate-specific antigen (PSA).

    Science.gov (United States)

    Yan, Juan; Hu, Chongya; Wang, Ping; Liu, Rui; Zuo, Xiaolei; Liu, Xunwei; Song, Shiping; Fan, Chunhai; He, Dannong; Sun, Gang

    2014-11-26

    Prostate-specific antigen (PSA) is one of the most important biomarkers for the early diagnosis and prognosis of prostate cancer. Although many efforts have been made to achieve significant progress for the detection of PSA, challenges including relative low sensitivity, complicated operation, sophisticated instruments, and high cost remain unsolved. Here, we have developed a strategy combining rolling circle amplification (RCA)-based DNA belts and magnetic bead-based enzyme-linked immunosorbent assay (ELISA) for the highly sensitive and specific detection of PSA. At first, a 96-base circular DNA template was designed and prepared for the following RCA. Single stranded DNA (ssDNA) products from RCA were used as scaffold strand for DNA origami, which was hybridized with three staple strands of DNA. The resulting DNA belts were conjugated with multiple enzymes for signal amplification and then employed to magnetic bead based ELISA for PSA detection. Through our strategy, as low as 50 aM of PSA can be detected with excellent specificity.

  13. Prevalence of hepatitis B antigen and C antibody among blood ...

    African Journals Online (AJOL)

    The prevalence of hepatitis B surface antigen (HBsAg) and hepatitis C (HCV) antibody were determined in 560 blood donor sera using ELISA kits (DIALAB Austria). Out of these 48(8.57%) were positive to hepatitis B virus infection, while 33(5.89%) were positive to hepatitis C virus antibodies. The sex distribution of ...

  14. Prevalence of hepatitis B surface antigen seropositivity among HIV ...

    African Journals Online (AJOL)

    Hepatitis B surface antigen (HBsAg) was tested for using a one step lateral flow rapid chromatographic immunoassay (Acumen labs and diagnostic centre, Bangalore, India) and HIV 1/2 was tested using two kits, Determine (made by Abbot, Japan for Inverness Medical, Japan). Results: A total of 2018 subjects were studied ...

  15. HBsAg positivity during pregnancy and adverse maternal outcomes: a retrospective cohort analysis.

    Science.gov (United States)

    Tan, J; Liu, X; Mao, X; Yu, J; Chen, M; Li, Y; Sun, X

    2016-10-01

    Hepatitis B virus infection characterized by HBsAg positivity during pregnancy is a well-recognized issue in developing countries, but the association between HBsAg positivity and adverse maternal outcomes remains uncertain. To examine the association between HBsAg positivity during pregnancy and adverse maternal outcomes, a retrospective cohort study was conducted in Sichuan province, China. Deliveries were recorded from six hospitals between 1 January 2009 and 31 December 2010. Pre-eclampsia, gestational diabetes mellitus (GDM), postpartum haemorrhage (PPH), intrahepatic cholestasis, Caesarean section and placenta previa were prespecified adverse maternal outcomes. We used two multivariate logistic regression models to assess the association between HBsAg positivity and adverse maternal outcomes. In total, 948 (4.2%) pregnant women were HBsAg positive from 22 374 deliveries. Pregnant women with positive HBsAg had higher risk of GDM (aOR1.41, 95%CI 1.15-1.74), PPH (1.44, 1.13-1.83), intrahepatic cholestasis (1.74, 1.40-2.16) and Caesarean section (1.24, 1.06-1.45). No statistical associations were found between HBsAg positivity and pre-eclampsia (1.36, 0.94-1.97), and placenta previa (1.21, 0.87-1.67). HBsAg positivity during pregnancy was associated with higher risk of multiple adverse maternal outcomes. Although the causality has yet to be established, efforts may be warranted in routine care, particularly in those with high risk for adverse maternal outcomes, given the volume population infected with HBsAg. Future studies are needed to establish causality and examine the impact of HBeAg on the adverse outcomes. © 2016 John Wiley & Sons Ltd.

  16. Screening for simian foamy virus infection by using a combined antigen Western blot assay: evidence for a wide distribution among Old World primates and identification of four new divergent viruses

    International Nuclear Information System (INIS)

    Hussain, Althaf I.; Shanmugam, Vedapuri; Bhullar, Vinod B.; Beer, Brigitte E.; Vallet, Dominique; Gautier-Hion, Annie; Wolfe, Nathan D.; Karesh, William B.; Kilbourn, Annelisa M.; Tooze, Zeena; Heneine, Walid; Switzer, William M.

    2003-01-01

    Simian foamy viruses (SFVs) belong to a genetically and antigenically diverse class of retroviruses that naturally infect a wide range of nonhuman primates (NHPs) and can also be transmitted to humans occupationally exposed to NHPs. Current serologic detection of SFV infection requires separate Western blot (WB) testing by using two different SFV antigens [SFV AGM (African green monkey) and SFV CPZ (chimpanzee)]. However, this method is labor intensive and validation is limited to only small numbers of NHPs. To facilitate serologic SFV testing, we developed a WB assay that combines antigens from both SFV AGM and SFV CPZ . The combined-antigen WB (CA-WB) assay was validated with 145 serum samples from 129 NHPs (32 African and Asian species) and 16 humans, all with known SFV infection status determined by PCR. Concordant CA-WB results were obtained for all 145 PCR-positive or -negative primate and human specimens, giving the assay a 100% sensitivity and specificity. In addition, no reactivity was observed in sera from persons positive for human immunodeficiency virus or human T cell lymphotropic virus (HIV/HTLV) (n = 25) or HIV/HTLV-negative U.S. blood donors (n = 100). Using the CA-WB assay, we screened 360 sera from 43 Old World primate species and found an SFV prevalence of about 68% in both African and Asian primates. We also isolated SFV from the blood of four seropositive primates (Allenopithecus nigroviridis, Trachypithecus francoisi, Hylobates pileatus, and H. leucogenys) not previously known to be infected with SFV. Phylogenetic analysis of integrase sequences from these isolates confirmed that all four SFVs represent new, distinct, and highly divergent lineages. These results demonstrate the ability of the CA-WB assay to detect infection in a large number of NHP species, including previously uncharacterized infections with divergent SFVs

  17. Incidência pós-transfusional do HBsAg em crianças com doenças neoplásicas Post-transfusional incidence of HBsAg in children with neoplastic diseases

    Directory of Open Access Journals (Sweden)

    Maria Zélia Fernandes

    2009-04-01

    newborn babies. An individual who is chronically infected by HBV during childhood has a 25% risk of dying due to cirrhosis or liver cancer. This data led the authors to design a study with the objective of estimating the post-transfusion incidence of the hepatitis B virus surface antigen (HBsAg in children with neoplasias who were transfused during treatment or during the follow up. A retrospective study was performed that revisited 333 medical records from the oncology service in the HIVS from January 1993 to January 2005. The inclusion criteria were: age less than 16 years old, diagnosis of cancer and the results of the HBsAg test. Thus, 199 patients were excluded because they did not fulfill the criteria. The remaining 134 patients’ records were analyzed in regards to blood transfusion. Of the 134 children who satisfied the criteria, 116 were transfused and 18 were not. Results of the HBsAg test were positive in 32.8% of the transfused patients and in only 5.6% of non-transfused individuals. The Fisher Exact Test demonstrated a statistically significant difference (p = 0.023. The ODDS ratio of a transfused patient presenting with reactive results for HBsAG was calculated at 8.28 times greater than non-transfused individuals.

  18. Strong interferon-gamma mediated cellular immunity to scrub typhus demonstrated using a novel whole cell antigen ELISpot assay in rhesus macaques and humans.

    Directory of Open Access Journals (Sweden)

    Manutsanun Sumonwiriya

    2017-09-01

    Full Text Available Scrub typhus is a febrile infection caused by the obligate intracellular bacterium Orientia tsutsugamushi, which causes significant morbidity and mortality across the Asia-Pacific region. The control of this vector-borne disease is challenging due to humans being dead-end hosts, vertical maintenance of the pathogen in the vector itself, and a potentially large rodent reservoir of unclear significance, coupled with a lack of accurate diagnostic tests. Development of an effective vaccine is highly desirable. This however requires better characterization of the natural immune response of this neglected but important disease. Here we implement a novel IFN-γ ELISpot assay as a tool for studying O. tsutsugamushi induced cellular immune responses in an experimental scrub typhus rhesus macaque model and human populations. Whole cell antigen for O. tsutsugamushi (OT-WCA was prepared by heat inactivation of Karp-strain bacteria. Rhesus macaques were infected intradermally with O. tsutsugamushi. Freshly isolated peripheral blood mononuclear cells (PBMC from infected (n = 10 and uninfected animals (n = 5 were stimulated with OT-WCA, and IFN-γ secreting cells quantitated by ELISpot assay at five time points over 28 days. PBMC were then assayed from people in a scrub typhus-endemic region of Thailand (n = 105 and responses compared to those from a partially exposed population in a non-endemic region (n = 14, and to a naïve population in UK (n = 12. Mean results at Day 0 prior to O. tsutsugamushi infection were 12 (95% CI 0-25 and 15 (2-27 spot-forming cells (SFC/106 PBMC for infected and control macaques respectively. Strong O. tsutsugamushi-specific IFN-γ responses were seen post infection, with ELISpot responses 20-fold higher than baseline at Day 7 (mean 235, 95% CI 200-270 SFC/106 PBMC, 105-fold higher at Day 14 (mean 1261, 95% CI 1,097-1,425 SFC/106 PBMC, 125-fold higher at Day 21 (mean 1,498, 95% CI 1,496-1,500 SFC/106 PBMC and 118-fold higher at

  19. Occult Hbv Infection in Hbsag Negative and Anti-Hbc Positive Blood Donors.

    Directory of Open Access Journals (Sweden)

    A Shebanizadeh

    2007-04-01

    Full Text Available Introduction: In recent years with introduction of better screening tests, the risk of infection with transfusion-transmitted viruses has been reduced remarkably, although obtaining a zero-risk blood supply still remains international blood transfusion services goal. The routine test for detection of HBV infected blood samples is examination of HBsAg with ELISA method but in occult HBV infection, HBsAg is not detectable by ELISA. Therefore, a more sensitive or complementary test is needed. Some international blood transfusion services have introduced anti-HBc screening as a surrogate test for the presence of HBV infection. The aim of this study was to evaluate the prevalence of occult HBV infection in Isfahanian blood donors and the potential value of anti-HBc testing of donors as a screening test to detect occult HBV infection. Methods: In this descriptive cross-sectional study, 545 blood units were collected (from Isfahan blood center and tested by HBsAg ELISA kit from April to June 2004 and then all HBsAg negative samples were tested by anti-HBc ELISA kit. To detect occult HBV infection, all HBsAg negative and anti-HBc positive samples were tested by PCR method. Results: All samples were negative for HBsAg while 43 blood units were anti-HBc positive (8%. These HBsAg negative and anti-HBc positive blood units were tested for HBV DNA of which five units (%11.6 were HBV DNA positive. Conclusion: Occult HBV infection is a clinical form of HBV infection that cannot be detected by usual method (ELISA for HBsAg and therefore more sensitive techniques are needed for detection of HBV infection. PCR is a sensitive technique that detects HBV DNA even in a trace mounts. Our results identified that more sensitive and complementary tests such as, PCR and anti-HBc, are essential and helpful to ensure safety of blood units.

  20. Prevalence of Hepatitis B Cab with or Without Anti Hbsab in Hbsag Seronegative Blood Donors

    OpenAIRE

    H Salman Roughani

    2005-01-01

    Introduction: There are multiple reports of Acute Hepatitis B after blood transfusion inspite of good screening for Hepatitis B before transfusion. Therefore, occult hepatitis B is a serious concern for Blood transfusion. There is a lot of evidence that positive HBCAb in seronegative HBSAg blood donors is associated with occult Hepatitis B. Aim: Evaluation of the prevalence of HBCAb in seronegative HBSAg blood donors. Method: In a cross sectional descriptive study, we evaluated the serum of 1...

  1.  Active-passive Immunization Effectiveness Against Hepatitis B Virus in Children Born to HBsAg Positive Mothers in Amol, North of Iran

    Directory of Open Access Journals (Sweden)

    2011-11-01

    Full Text Available  Objectives: HBV infection is a contagious disease that may transmit vertically from mothers to their neonates or horizontally by blood products and body secretions. Over 50�0of Iranian carriers have contracted the infection perinatally, making this the most likely route of transmission of HBV in Iran. This study assesses the serologic markers of HBV in children born to HBsAg positive mothers who received HBIG and 3 doses of HBV vaccine. Methods: To evaluate the effectiveness of vaccination against HBV, a study was conducted on 95 Children, born to hepatitis B surface antigen (HBsAg-positive mothers, who had received Hepatitis B Immune Globulin and HBV vaccines during 2004-2008. All children were tested for the presence of HBsAg, anti-HBs and anti-HB core antigen (anti-HBc. Results: Among an estimated 30000 pregnant women during the five year study, about 130 (0.42�20were HBV carriers. Ninety-five children from these mothers were enrolled in this study. Only one child (1.1�20was HBsAg positive, while 88.4�0of children were Anti-HBs Positive. Eleven children (11.6�20were exposed to HBV as shown by the presence of anti-HBc. A significant difference was observed between the children’s age and Anti-HBs (p=0.0001. Conclusion: Passive-active immunoprophylaxis of high risk babies was highly efficacious in preventing perinatal transmission of the HBV carrier state. Also, evaluation of serologic markers in HBV infected people is important for designing the strategies for disease control.

  2. Comparison of T24H-his, GST-T24H and GST-Ts8B2 recombinant antigens in western blot, ELISA and multiplex bead-based assay for diagnosis of neurocysticercosis.

    Science.gov (United States)

    Hernández-González, Ana; Noh, John; Perteguer, María Jesús; Gárate, Teresa; Handali, Sukwan

    2017-05-15

    Currently, the reference standard assay for the serodiagnosis of neurocysticercosis (NCC) is the lentil lectin-bound glycoproteins/enzyme-linked immunoelectrotransfer blot (LLGP-EITB). The main disadvantage of this technique is the complexity of obtaining and purifying the LLGP extract. This could be solved by replacement with highly specific recombinant antigens from Taenia solium. Based on previous studies, we selected and produced the recombinant Ts8B2 and T24H proteins and applied them to three diagnostic techniques: western blot (WB), enzyme-linked immunosorbent assay (ELISA) and the multiplex bead-based assay (MBA). The Ts8B2 and T24H cDNA sequences were expressed in a prokaryotic system and the corresponding expression products purified; three recombinant proteins were further characterized: T24H-his, GST-T24H and GST-Ts8B2. The proteins on WB, ELISA and MBA were tested against 149 sera from patients with NCC confirmed by brain imaging, 40 sera from patients with other parasitic diseases, and 131 sera from US. individuals without evidence of neurocysticercosis (clinical/serological/brain imaging). The sensitivity and specificity of each antigen by WB were calculated by counting the number of true positive, false positive, true negative and false negative results. Using the receiver operating characteristic (ROC) curves, the cut-off values for the ELISA and MBA were established as well as the sensitivity and specificity of each assay. All three antigens showed a high sensitivity on WB in active NCC cases with two or more viable cysts and low sensitivity for cases with single viable cyst or calcified lesions and inactive NCC. WB showed the highest specificity and sensitivity out of the three diagnostic techniques. The recombinant T24H-his was the best diagnostic reagent in WB (100% sensitivity, 99.4% specificity), exhibiting similar results to the LLGP-EITB, against the same panel of NCC sera. The GST-T24H antigen worked better than the others in ELISA and MBA

  3. 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)

  4. In Vitro Use of Autologous Dendritic Cells Improves Detection of T Cell Responses to Hepatitis B Virus (HBV) Antigens

    NARCIS (Netherlands)

    Carotenuto, Patrizia; Artsen, Andre; Niesters, Hubert G.; Osterhaus, Albert D.; Pontesilli, Oscar

    T lymphocyte responses to hepatitis B virus (HBV) core antigen (HBcAg) are vigorous and easily detectable in vitro during recovery from acute hepatitis B but significantly weaker in patients with chronic HBV infection. In contrast, T cell responses to hepatitis B surface antigen (HBsAg) are almost

  5. 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.

  6. Multiplex assay (Mikrogen recomBead) for detection of serum IgG and IgM antibodies to 13 recombinant antigens of Borrelia burgdorferi sensu lato in patients with neuroborreliosis

    DEFF Research Database (Denmark)

    Dessau, Ram Benny; Møller, Jens K.; Kolmos, Birte

    2015-01-01

    A multiplex-bead-based assay for the detection of serum antibodies to Borrelia burgdorferi sensu lato was evaluated. The assay contained 13 different antigens in both the IgG and the IgM assay; thus, a total of 26 measurement results were available from each sample. A total of 49 Danish patients......%, respectively. Overall, the patients with LNB had serum reactivity in IgG VlsE, but modest antibody reactivity in the remaining 12 IgG and 13 IgM antibody measurements. Using a logistic regression model with five IgG and two IgM antigens, the sensitivity and specificity of the assay was improved; but the Ig...... with Lyme neuroborreliosis (LNB), 218 Danish blood donor controls, a set of 61 Swedish patients with LNB and 139 Swedish non-LNB patients investigated for suspected LNB were used. There are four parts developed in this study: a characterization of the sero-epidemiological antibody-response pattern...

  7. 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)

  8. Identification and evaluation of new Mycobacterium bovis antigens in the in vitro interferon gamma release assay for bovine tuberculosis diagnosis.

    Science.gov (United States)

    Eirin, María E; Macias, Analia; Magnano, Gabriel; Morsella, Claudia; Mendez, Laura; Blanco, Federico C; Bianco, María V; Severina, Walter; Alito, Alicia; Pando, Maria de Los Angeles; Singh, Mahavir; Spallek, Ralph; Paolicchi, Fernando A; Bigi, Fabiana; Cataldi, Angel A

    2015-12-01

    Bovine tuberculosis (bTB) is a common zoonotic disease, caused by Mycobacterium bovis (M. bovis), responsible for significant economic losses worldwide. Its diagnosis is based on the detection of cell mediated immunity under the exposure to protein purified derivative tuberculin (PPD), a complex and poorly characterized reagent. The cross-reactivity to non-tuberculous mycobacterium species (false-positive results) has been crucial to develop a more proper antigen. In the present study, we selected six M. bovis Open Reading Frames (Mb1992, Mb2031c, Mb2319, Mb2843c, Mb2845c and Mb3212c) by in-silico analysis and evaluated them in experimental and natural infection; none of these antigens had been previously assessed as diagnostic antigens for bTB. The reactivity performance was tested in animals with both positive and negative Tuberculin Skin Test (TST) results as well as in cattle infected with Mycobacterium avium subesp. paratuberculosis (MAP). The six recombinant antigens individually induced an IFN-γ response, with overall responder frequency ranging from 18.3 to 31%. Mb2845c was the most valuable antigen with the potential to discriminate TST-positive cattle from either TST-negative or MAP infected animals. Mb2845c showed similar performance to that observed with ESAT-6 and PPD-B among TST and MTC specific-PCR positive animals, although this result needs to be proven in further studies with a higher sample size. Our data confirm the feacibility to implement bioinformatic screening tools and suggest Mb2845c as a potential diagnostic antigen to be tested in protein cocktails to evaluate their contribution to bTB diagnosis. Copyright © 2015 Elsevier Ltd. All rights reserved.

  9. Anti-hepatits B core antigen testing, viral markers, and occult hepatitis B virus infection in Pakistani blood donors: implications for transfusion practice.

    Science.gov (United States)

    Bhatti, Farhat Abbas; Ullah, Zia; Salamat, Nuzhat; Ayub, Muhammad; Ghani, Ejaz

    2007-01-01

    The purpose of this study was to determine the seroprevalence of anti-hepatitis B core antigen (HBc) and the impact of its testing along with other markers of hepatitis B, hepatitis B virus (HBV) DNA, hepatitis C virus antibody (anti-HCV), and syphilis in Pakistani blood donors. The study design was cross-sectional. A total of 966 donors were selected randomly for testing of anti-HBc and HBV markers, including HBV DNA, of 94,177 blood donors who were routinely screened for hepatitis B surface antigen (HBsAg), anti-HCV, human immunodeficiency virus antibody (anti-HIV), Treponema pallidum hemagglutination assay (TPHA), and malarial parasites from 2003 to October 2005. The seroprevalence of various infectious markers was as follows: HBsAg, 2.16 percent; anti-HCV, 4.16 percent; anti-HIV, 0.004 percent; TPHA, 0.75 percent; and malaria, 0.002 percent. Anti-HBc prevalence in HBsAg-negative, HBV DNA-negative blood donors was 167 of 966 (17.28%), with 76 percent demonstrating anti-HBs positivity. Younger donors with mean age of 25 years were exposed to HBV to a lesser extent compared to those with a mean age of 29 years. Anti-HBc positivity was significantly higher in anti-HCV-reactive individuals. HBV DNA was detectable in 5 blood donors who were HBsAg-, anti-HBc-positive and were categorized as having occult HBV infection. The study shows that more than 17 percent of healthy, young blood donors in Pakistan are already exposed to HBV, with two-thirds showing anti-HBs levels of greater than 100 mIU per mL. One in 200 blood donors who are HBsAg-, anti-HBc-positive, however, have occult HBV infection, with likelihood of transmission of hepatitis B in recipients of blood components derived from them. HBsAg-negative individuals who are anti-HBc-negative and those who are anti-HBc-positive, anti-HBs-positive, and HBV DNA-negative should be selected as regular blood donors to minimize transmission due to occult hepatitis B infection.

  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

    OBJECTIVES: 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. METHODS: 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...

  11. 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...... infectious virions. Interestingly, circulating HBsAg particles have been shown to carry microRNAs. A thorough characterisation of the identified microRNAs and HBsAg over time in plasma from children with CHB may provide useful information about the natural course of childhood CHB....

  12. High hepatitis B surface antigen levels predict insignificant fibrosis in hepatitis B e antigen positive chronic hepatitis B.

    Directory of Open Access Journals (Sweden)

    Wai-Kay Seto

    Full Text Available INTRODUCTION: There is no data on the relationship between hepatitis B surface antigen (HBsAg levels and liver fibrosis in hepatitis B e antigen (HBeAg-positive patients with chronic hepatitis B (CHB. METHODS: Serum HBsAg and HBV DNA levels in HBeAg-positive CHB patients with liver biopsies were analyzed. The upper limit of normal (ULN of alanine aminotransferase (ALT was 30 and 19 U/L for men and women respectively. Histologic assessment was based on Ishak fibrosis staging for fibrosis and Knodell histologic activity index (HAI for necroinflammation. RESULTS: 140 patients (65% male, median age 32.7 years were recruited. 56 (40% had ALT ≤2×ULN. 72 (51.4% and 42 (30% had fibrosis score ≤ 1 and necroinflammation grading ≤ 4 respectively. Patients with fibrosis score ≤ 1, when compared to patients with fibrosis score >1, had significantly higher median HBsAg levels (50,320 and 7,820 IU/mL respectively, p<0.001. Among patients with ALT ≤2×ULN, serum HBsAg levels achieved an area under receiver operating characteristic curve of 0.869 in predicting fibrosis score ≤ 1. HBsAg levels did not accurately predict necroinflammation score. HBsAg ≥ 25,000 IU/mL was independently associated with fibrosis score ≤ 1 (p=0.025, odds ratio 9.042.Using this cut-off HBsAg level in patients with ALT ≤2×ULN, positive and negative predictive values for predicting fibrosis score ≤ 1 were 92.7% and 60.0% respectively. HBV DNA levels had no association with liver histology. CONCLUSION: Among HBeAg-positive patients with ALT ≤2×ULN, high serum HBsAg levels can accurately predict fibrosis score ≤ 1, and could potentially influence decisions concerning treatment commencement and reduce the need for liver biopsy.

  13. New amperometric and potentiometric immunosensors based on gold nanoparticles/tris(2,2'-bipyridyl)cobalt(III) multilayer films for hepatitis B surface antigen determinations.

    Science.gov (United States)

    Tang, Dianping; Yuan, Ruo; Chai, Yaqin; Fu, Yingzi; Dai, Jianyuan; Liu, Yan; Zhong, Xia

    2005-10-15

    Two generic, fast, sensitive and novel electrochemical immunosensors have been developed. Initially, a layer of plasma-polymerized Nafion film (PPF) was deposited on the platinum electrode surface, then positively charged tris(2,2'-bipyridyl)cobalt(III) (Co(bpy)(3)(3+)) and negatively charged gold nanoparticles were assembled on the PPF-modified Pt electrode by layer-by-layer technique. Finally, hepatitis B surface antibody (HBsAb) was electrostatically adsorbed on the gold nanoparticles surface. Electrochemical behavior of the {Au/Co(bpy)(3)(3+)}(n) multilayer film-modified electrodes was studied. Cyclic voltammetry, electrochemical impedance spectroscopy (EIS) were adopted to monitor the regular growth of the multilayer films. The performance and factors influencing the performance of the resulting immunosensors were studied in detail. The multilayer film-modified immunosensor was used for hepatitis B surface antigen (HBsAg) determination via the amperometric and potentiometric immunosensor systems, and both systems provided the same linear ranges from 0.05 to 4.5 microg/mL with different detection limits for the amperometric system 0.005 microg/mL and for the potentiometric system 0.015 microg/mL. The immunosensors were used to analyse HBsAg in human serum samples. Analytical results of clinical samples show that the developed immunoassay is comparable with the enzyme-linked immunosorbent assays (ELISAs) method, implying a promising alternative approach for detecting HBsAg in the clinical diagnosis. In addition, the multilayer films also showed better stability for 1 month at least.

  14. Seroprevalence and risk factors of hepatitis B virus surface antigen among the workers in a garment factory

    Directory of Open Access Journals (Sweden)

    Mohammad Mizanur Rahman

    2017-11-01

    Full Text Available The purpose of this study is to find out the prevalence of seropositivity and risk factors associated with hepatitis B virus infection. A total of 2,737 readymade garment workers were initially screened after getting departmental as well as the individuals consent and simultaneously a questionnaire was filled up by the field research assistants to assess the risk factors. Initially 59 cases were found positive for hepatitis B virus surface antigen (HBsAg by immunochromato-graphic test. Enzyme linked immunosorbant technique was then applied to the screened positive HBsAg individuals and four cases turned out as negative and therefore a total of 55  HBsAg positive cases were detected in this factory. Statistically significant risk factors associated with HBsAg positivity were jaundice, history of previous surgery and accident, needle stick injuries and unsafe injections. This study concludes that the seropositivity found garment workers is similar to the general population of Bangladesh.

  15. Triple positivity of HBsAg, anti-HCV antibody, and HIV and their ...

    African Journals Online (AJOL)

    Background: Few studies exist on hospital-based seroprevalence of triple positivity of HIV/HBV/HCV in Nigeria. Objectives: The study aimed at determining the triple positivity of HIV, HBsAg and HCV among HIV-infected individuals in Abeokuta, Nigeria and defining the influence of these triple infections on CD4+ counts of ...

  16. Prevalence of Hepatitis B Cab with or Without Anti Hbsab in Hbsag Seronegative Blood Donors

    Directory of Open Access Journals (Sweden)

    H Salman Roughani

    2005-01-01

    Full Text Available Introduction: There are multiple reports of Acute Hepatitis B after blood transfusion inspite of good screening for Hepatitis B before transfusion. Therefore, occult hepatitis B is a serious concern for Blood transfusion. There is a lot of evidence that positive HBCAb in seronegative HBSAg blood donors is associated with occult Hepatitis B. Aim: Evaluation of the prevalence of HBCAb in seronegative HBSAg blood donors. Method: In a cross sectional descriptive study, we evaluated the serum of 1230 Blood donors for HBCAb, HCVAb and Aminotranferase levels. HBSAg or AntiHIV Ab positive cases were excluded from the study. Detection of Anti HBSAb was done in HBCAb positive patients and liver biopsy was performed in all HCVAb positive cases. Results: 15.1% of blood donors were positive for HBCAb and 51.6% of them had Anti HBSAb. Aminotranferase levels were normal in all people who were positive for HBCAb ,but about 50% of HCVAb positive persons had elevated aminotransferase levels and liver biopsy of all these patients showed inflammation Conclusion: Prevalence of HBCAb is high in our seronegative HBSAg Blood donors and biomolecular studies such as PCR for HBV DNA is indicated in HBCAb positive people, especially in people with isolated HBCAb .

  17. LATERAL FLOW ASSAY FOR CRYPTOCOCCAL ANTIGEN: AN IMPORTANT ADVANCE TO IMPROVE THE CONTINUUM OF HIV CARE AND REDUCE CRYPTOCOCCAL MENINGITIS-RELATED MORTALITY

    OpenAIRE

    VIDAL, Jose E.; BOULWARE, David R.

    2015-01-01

    SUMMARY AIDS-related cryptococcal meningitis continues to cause a substantial burden of death in low and middle income countries. The diagnostic use for detection of cryptococcal capsular polysaccharide antigen (CrAg) in serum and cerebrospinal fluid by latex agglutination test (CrAg-latex) or enzyme-linked immunoassay (EIA) has been available for over decades. Better diagnostics in asymptomatic and symptomatic phases of cryptococcosis are key components to reduce mortality. Recently, the cry...

  18. 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

  19. 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

  20. 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

  1. Evaluation of two Taenia solium cysticercal antigenic preparations (vesicular fluid and a glycoprotein fraction with affinity for lentil lectin for the immunodiagnosis of neurocysticercosis by enzyme-linked immunosorbent assay (ELISA

    Directory of Open Access Journals (Sweden)

    Lisandra Akemi Suzuki

    2011-06-01

    Full Text Available OBJECTIVE: To evaluate the performance of two antigenic preparations (vesicular fluid - VF and a glycoprotein fraction, LLa-Gp fraction, purified from a whole parasite extract by lentil lectin affinity chromatography from Taenia solium cysticerci for the immunodiagnosis of neurocysticercosis. METHOD: Fifty-six cerebrospinal fluid (CSF samples (22 from patients with neurocysticercosis and 34 from patients with other neurological disorders and 57 serum samples (22 from patients with neurocysticercosis, 18 from patients with other infections and 17 from presumably healthy persons were assayed for anticysticercal IgG antibodies with an enzyme-linked immunosorbent assay (ELISA. RESULTS: The VF ELISA showed 100% sensitivity and specificity in CSF and serum samples, whereas the sensitivity and specificity of the LLa-Gp ELISA were, respectively, 90.9% and 97.1%, with the CSF samples and 95.5% and 100% with serum samples. There was no significant difference in the sensitivity and specificity of the two antigenic preparations used to screen CSF and serum samples. CONCLUSION: Considering the complexity and high cost of obtaining the LLa-Gp fraction, VF could be more suitable for screening specific antibodies by ELISA in CSF and serum samples from patients with neurocysticercosis.

  2. Comparison of automated multiplexed bead-based ANA screening assay with ELISA for detecting five common anti-extractable nuclear antigens and anti-dsDNA in systemic rheumatic diseases.

    Science.gov (United States)

    Kim, Yoonjung; Park, Yongjung; Lee, Eun Young; Kim, Hyon-Suk

    2012-01-18

    A newly developed and totally automated Luminex-based assay, the BioPlex™ 2200 system, is able to detect various autoantibodies simultaneously from a single sample. We compared the BioPlex™ 2200 system with ELISA for the detection of six autoantibodies. A total of 127 serum samples from the patients with systemic rheumatic diseases were collected and assayed with the BioPlex™ 2200 system (Bio-Rad, USA) and conventional ELISA (INOVA Diagnostics, USA) for 5 anti-extractable nuclear antigens. Additionally, relative sensitivity of the BioPlex™ 2200 system for detecting anti-dsDNA was evaluated with 79 specimens from SLE patients, which were positive for anti-dsDNA by ELISA. The concordance rates between ELISA and the BioPlex ranged from 88.1% for anti-RNP to 95.2% for anti-Scl-70, and the kappa coefficients between the results by the two assays were from 0.48 to 0.67. Among the 79 anti-dsDNA positive specimens by ELISA, seventy-eight (98.7%) showed positive results for anti-dsDNA by the BioPlex. The BioPlex™ 2200 system showed comparable results with those by conventional ELISA for detecting autoantibodies, and this automated assay could measure multifarious autoantibodies concurrently in a single sample. It could be effectively used in clinical laboratories for screening autoimmune diseases. Copyright © 2011 Elsevier B.V. All rights reserved.

  3. Rough lipopolysaccharide of Brucella abortus RB51 as a common antigen for serological detection of B. ovis, B. canis, and B. abortus RB51 exposure using indirect enzyme immunoassay and fluorescence polarization assay.

    Science.gov (United States)

    Nielsen, K; Smith, P; Conde, S; Draghi de Benitez, G; Gall, D; Halbert, G; Kenny, K; Massengill, C; Muenks, Q; Rojas, X; Perez, B; Samartino, L; Silva, P; Tollersrud, T; Jolley, M

    2004-01-01

    Rough lipopolysaccharide (RLPS) antigens were prepared from cultures of Brucella abortus RB51, B. ovis, and B. canis. The preparations were standardized by weight and tested with sera from cattle immunized with B. abortus RB51, sheep infected with B. ovis, and dogs infected with B. canis. Populations of unexposed animals of each species were also tested. The tests used were the indirect enzyme immunoassay (IELISA) using RLPS and the fluorescence polarization assay (FPA) using RLPS core fractions, labeled with fluorescein isothiocyanate. The IELISA using B. abortus RB51 RLPS antigen resulted in sensitivity and specificity values of 94.8% and 97.3%, respectively, when testing bovine sera, 98.5% and 97.8% when testing ovine sera, and 95.8% and 100% when testing dog sera. The IELISA using B. ovis RLPS antigen gave sensitivity and specificity values of 80.5% and 91.7%, respectively with bovine sera, 98.9% and 93.8% with sheep sera, and 70.8% and 79.8% with dog sera. The IELISA using B. canis RLPS antigen resulted in sensitivity and specificity values of 97.0% and 97.4%, respectively, with bovine sera, 96.2% and 96.3% with sheep sera, and 95.8% and 98.8% with dog sera. Labeling RLPS core from B. ovis and B. canis with fluorescein was not successful. B. abortus RB51 core labeled with fluorescein resulted in sensitivity and specificity values of 93.5% and 99.8%, respectively, with bovine sera and 78.1% and 99.0% with sheep sera. It was not possible to test the dog sera in the FPA.

  4. Carcinoembryonic antigen (CEA)

    International Nuclear Information System (INIS)

    Ephraim, K.H.; Cox, P.H.; Hamer, C.J.A. v.d.; Berends, W.; Delhez, H.

    1977-01-01

    The carcinoembryonic antigen (CEA) is a complex of antigen determinants and also the carrier of these determinants. Chemically it is a glycoprotein. Its occurrence in blood serum or urine is correlated with malignant disease. Several radioimmunoassays (RIA) have been developed, one by Hoffmann-Laroche and one by the Rotterdam Radiotherapeutic Institute. Both methods and the Hoffmann assay kit are tested. Specifications are given for isolation of the antigen, preparation of the antiserum, and the execution of the RIA. Biochemical and clinical aspects are discussed

  5. 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

  6. 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.

  7. 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.

  8. 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.

  9. Quantitative hepatitis B surface antigen combined with hepatitis B e antigen as sustained virological response predictors during extended therapy with Peginterferon alfa-2a for hepatitis B e antigen-positive chronic hepatitis B.

    Science.gov (United States)

    Chen, Jie; Zhang, Dong-Hua; Xu, Cheng-Run; Zhu, Ming-Yu; Yang, Zhi-Tao; Gong, Qi-Ming; Yu, De-Min; Zhang, Xin-Xin

    2015-11-01

    The best strategy for chronic hepatitis B patients with poor response to 48 weeks of Peginterferon-based therapy has been controversial and the predictive value of hepatitis B surface antigen (HBsAg), hepatitis B e antigen (HBeAg) and hepatitis B virus (HBV) DNA levels for determining the sustained virological response (SVR) of these patients is uncertain. To optimize management of these patients and evaluate the use of these serobiomarkers to predict SVR. Eighty-one patients with an unsatisfactory response after 48 weeks of Peginterferon-based therapy were treated with extended Peginterferon therapy with or without nucleo(s) tide analogues (NAs), for a total of 96 weeks of Peginterferon treatment. HBsAg, HBeAg and HBV DNA levels were measured serially during the treatment and follow-up. Twenty-six of 81 patients (32.1%) attained SVR during the 72-week follow-up. The SVR rate was not statistically different between groups receiving 1-year prolongation of Peginterferon with or without NAs. The serum HBsAg cut-off of 1800IU/mL at week 48 had area under curve (AUC) of 0.727, and the serum HBsAg cut-off of 1500IU/mL, combined with HBeAg loss at week 72, had AUC of 0.753 to predict SVR during the follow-up. In conclusion, extended treatment with Peginterferon with or without NAs for patients with unsatisfactory response after 48 weeks of Peginterferon-based therapy is a promising strategy to achieve SVR, and quantitative serum HBsAg at week 48 and HBsAg level combined with HBeAg loss at week 72 of therapy can predict SVR to prolongation therapy with Peginterferon. Copyright © 2015 Elsevier B.V. All rights reserved.

  10. The risk of transmission of hepatitis B from HBsAg(-), HBcAb(+), HBIgM(-) organ donors.

    Science.gov (United States)

    Wachs, M E; Amend, W J; Ascher, N L; Bretan, P N; Emond, J; Lake, J R; Melzer, J S; Roberts, J P; Tomlanovich, S J; Vincenti, F

    1995-01-27

    Liver allografts from HBcAb(+), IgM(-), HBsAg(-) donors can transmit HBV to uninfected recipients. We currently no longer accept these livers for transplantation while continuing to accept the kidneys. The purpose of this study is to determine the risk of donor-transmitted HBV infections from HBcAb(+), HBIgM(-), HBsAg(-) organ donors and determine if the risk of donor-transmitted HBV infections and their severity is dependent on the organ being transplanted. This study consists of a retrospective review of the posttransplant course of recipients of HBcAb(+), HBIgM(-), HBsAg(-) donors accepted at UCSF from 6/85 to 12/93. Transmitted HBV infection was defined as one in which the recipient changed from HBsAg(-) prior to transplantation to HBsAg(+) posttransplant, with no other source. There were 25 of 1190 donors who were HBcAb(+), HBIgM(-), HBsAg(-); 1/42 kidney, 3/6 liver, and 0/7 heart HBsAg(-) transplant recipients of organs from these donors became HBsAg(+) after transplantation. This difference in infection rate (liver vs. kidney and heart) is statistically significant. The clinical course of the liver recipients was also more severe. All of the patients who became infected were HBsAb(-) and HBcAb(-) prior to transplant. We conclude that (1) HBV can be transmitted from HBcAb(+), HBIgM(-), HBsAg(-) organ donors, (2) the rate of transmission is highest and severity of infection is worst in the liver recipients; and (3) we will continue to transplant kidneys from these donors, preferably into immunized recipients.

  11. ANTIGENIC PROMOTION

    Science.gov (United States)

    Wu, Chin-Yu; Cinader, Bernard

    1971-01-01

    Rabbits were immunized with p-azobenzene arsonic acid derivatives of human serum albumin (HA-As) or of dissociated keyhole limpet hemocyanin. The IgM response to the hapten was evaluated in terms of the number of hapten-specific plaque-forming cells in the lymph node draining the injection site. In some experiments, antibody was measured by agglutination of tanned and sensitized erythrocytes. The hapten response of animals immunized with HA-As was increased (promoting effect) when the animals were injected with one of several structurally unrelated macromolecules: keyhole limpet hemocyanin (KLH), horse spleen ferritin (HSF), lysozyme (Lys), alum-precipitated human gamma globulin (alum-precipitated HGG). Different macromolecules differed in the magnitude of the promoting effect they induced, e.g., promotion by the associated form of KLH was greater than that by the dissociated form; alum-precipitated HGG was a better promoter than was soluble HGG. The relative magnitude of promotion by different macromolecules (associated vs. dissociated KLH, alum-precipitated vs. soluble HGG) correlated with the relative magnitude of the carrier effect, as judged by the hapten response induced by p-azobenzene arsonic acid conjugated to various proteins. Promotion was detected by agglutination assay of circulating antibody, by plaque assay of cells from the popliteal lymph node draining the site of preinjection, but not by plaque assay of cells from the contralateral lymph node. Promotion was dependent on the dose of the promoting macromolecule and on the dose of the hapten-protein conjugate. It was not observed in animals tolerant to the promoting macromolecule. Inhibition (i.e. antigenic competition), rather than promotion, was observed upon a secondary response to the preinjected macromolecule or when the hapten-protein conjugate was incorporated in Freund's adjuvant. PMID:15776570

  12. Rapid detection and semi-quantification of IgG-accessible Staphylococcus aureus surface-associated antigens using a multiplex competitive Luminex assay

    NARCIS (Netherlands)

    Hansenova Manaskova, S.; Bikker, F.J.; Veerman, E.C.I.; van Belkum, A.; van Wamel, W.J.B.

    2013-01-01

    The surface characterization of Staphylococcus aureus is currently labor intensive and time consuming. Therefore, we developed a novel method for the rapid yet comprehensive characterization of S. aureus cell-surface-associated proteins and carbohydrates, based on a competitive Luminex assay. In

  13. SERO-DIAGNOSIS OF TUBERCULOSIS WITH A60 ANTIGEN ENZYME-LINKED-IMMUNOSORBENT-ASSAY - FAILURE IN HIV-INFECTED INDIVIDUALS IN GHANA

    NARCIS (Netherlands)

    VANDERWERF, TS; DAS, PK; VANSOOLINGEN, D; YONG, S; VANDERMARK, TW

    In order to assess the diagnostic usefulness of the A60 (ANDA Biologicals, Strassbourg, France) sero-diagnostic enzyme-linked immunosorbent assay (ELISA) kit for tuberculosis in Africa, sera of 53 pulmonary smear-positive tuberculosis (TB) patients, 30 apparently healthy control subjects and 6 AIDS

  14. The use of enzyme-linked immunosorbent assay systems for the serology and antigen detection in parvovirus, coronavirus and rotavirus infections in dogs in The Netherlands.

    NARCIS (Netherlands)

    G.F. Rimmelzwaan (Guus); J. Groen (Jan); H.F. Egberink (Herman); G.H.A. Borst (Gerrit); F.G.C.M. Uytdehaag (Fons); A.D.M.E. Osterhaus (Albert)

    1991-01-01

    textabstractComplex trapping blocking (CTB) enzyme-linked immunosorbent assays (ELISAs) and indirect ELISAs for the detection of antibodies to canine parvovirus (CPV), canine coronavirus (CCV) and rotavirus in sera of dogs were established. Double antibody sandwich ELISAs for the detection of CPV-,

  15. Usefulness of antigen-specific IgE probability curves derived from the 3gAllergy assay in diagnosing egg, cow's milk, and wheat allergies

    Directory of Open Access Journals (Sweden)

    Sakura Sato

    2017-04-01

    Conclusions: Measurements of sIgE against egg, milk, and wheat as determined by 3gAllergy may be used as a tool to facilitate the diagnosis of food allergy in subjects with suspected food allergies. However, these probability curves should not be applied interchangeably between different assays.

  16. Hepatitis B Viral DNA Among HBs Antigen Negative Healthy Blood Donors

    OpenAIRE

    Vaezjalali, Maryam; Rashidpour, Shabnam; Rezaee, Hanieh; Hajibeigi, Bashir; Zeidi, Majid; Gachkar, Latif; Aghamohamad, Shadi; Najafi, Ronak; Goudarzi, Hossein

    2013-01-01

    Background Presence of occult hepatitis B infection (OBI) renders HBs antigen (HBsAg) undetectable by ELISA. Therefore it is valuable to evaluate the frequency of OBI among healthy blood donors to improve and perhaps change the strategies of blood screening to reduce the risk of HBV transmission. Objectives The aim of this study was to determine the presence of HBcAb and HBV DNA among Iranian HBsAg negative healthy blood donors who donated their blood to the Tehran Blood Transfusion Center du...

  17. Response-guided therapy of regimens based on PEG-interferon for chronic hepatitis B using on-treatment hepatitis B surface antigen quantification: a meta-analysis.

    Science.gov (United States)

    Peng, Hong; Wei, Fang; Liu, Jun-Ying; Hu, Huai-Dong; Ren, Hong; Hu, Peng

    2015-10-01

    The efficacy of on-treatment hepatitis B surface antigen (HBsAg) levels in guiding pegylated interferon (PEG-IFN) therapy for chronic hepatitis B (CHB) infections is still controversial. The aim of this study is to quantitatively evaluate the efficacy of on-treatment HBsAg levels as a response-guided therapy strategy to guide PEG-IFN-based therapies for CHB. We searched PUBMED, EMBASE, and the Cochrane Library (1997-2013) for clinical research involving HBsAg quantification, and the response to PEG-IFN-based therapy. Pooled effect of HBsAg levels on guiding PEG-IFN-based therapies for CHB was evaluated using fixed-effects or random-effects model. From 13 studies (n = 1493 patients), patients with optimal on-treatment HBsAg levels were found to have a greater chance of attaining a response (RR 5.17, 95 % CI 3.75-7.11, p response rate was 54 % (95 % CI 44-63 %). At week 12, patients without optimal on-treatment HBsAg levels had hardly achieved a response (the early non-response rate: 99 %, 95 % CI 98-100 %). At 24 weeks, the response rate increased to 79 % in HBeAg-negative patients. This meta-analysis suggested that on-treatment HBsAg quantification is effective in guiding the therapy of PEG-IFN in CHB infections, especially in HBeAg-negative patients.

  18. Circulating filarial antigen in the hydrocele fluid from individuals living in a bancroftian filariasis area - Recife, Brazil : detected by the monoclonal antibody Og4C3-assay

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    Rocha Abraham

    2004-01-01

    Full Text Available The purpose of this study was to examine the circulating filarial antigen (CFA detected by the monoclonal antibody (mAb Og4C3-ELISA in paired samples of serum and hydrocele fluid from 104 men with hydrocele, living in an endemic area of Wuchereria bancrofti. Nocturnal blood specimens were filtered and examined for microfilariae (MF and ultrasound was used in order to identify the presence of adult worms (the filaria dance sign - FDS in the lymphatic vessels of the scrotal area. Four groups were selected according to their parasitological status: group I - 71 MF- and FDS-; group II - 21 MF+ and FDS+; group III - 10 MF- and FDS+ and group IV- 2 MF+ and FDS-. CFA was identified simultaneously (fluid and serum in 11 (15.5%, 21 (100%, 3 (30%, and 1 (50% in groups I, II, III, and IV, respectively. In despite of high CFA+ level (antigen Og4C3 units/ml, the Geometrical Mean (GM = 2696 in the sera of these 36/104 paired samples, when compared to the hydrocele fluid, (GM = 1079, showed a very good correlation between the CFA level in the serum and CFA level in the fluid (r = 0.731. CFA level in the serum of the 23 microfilaremics (groups II and IV was extremely high (GM = 4189 and was correlated with MF density (r = 0.442. These findings report for the first time the potential alternative use of the hydrocele fluid to investigate CFA using the mAb Og4C3-ELISA.

  19. Limited Value of Assays Using Detection of Immunoglobulin G Antibodies to the Two Recombinant Dense Granule Antigens, GRA1 and GRA6 Nt of Toxoplasma gondii, for Distinguishing between Acute and Chronic Infections in Pregnant Women

    Science.gov (United States)

    Ferrandiz, Josette; Mercier, Corinne; Wallon, Martine; Picot, Stéphane; Cesbron-Delauw, Marie-France; Peyron, François

    2004-01-01

    An enzyme-linked immunosorbent assay (ELISA) using two recombinant antigens of Toxoplasma gondii (GRA1 and GRA6 Nt) was developed in order to differentiate between pregnant women with a serological profile of recently acquired infection and those with chronic infection. Both proteins were expressed in Escherichia coli as glutathione S-transferase fusion proteins. Thirty-two serum samples from subjects who presented seroconversion within 3 months before sampling (group 1; acute profile), 46 serum samples from women who had a positive serology at least 1 year before sampling (group 2; chronic profile), and 100 serum samples from pregnant women who were not infected by T. gondii (group 3) were examined for immunoglobulin G (IgG) reactivity. For both antigens, the specificity reached 98%. In both groups of infected patients, the overall sensitivity scored was 60% for GRA1 and 83% for GRA6 Nt. In group 1, 34% of sera reacted with GRA1 whereas 84% of sera reacted with GRA6 Nt; in group 2, however, sensitivities were 78.2 and 82.6%, respectively. Combination of the readings obtained with both antigens yielded a sensitivity of 91%. A serological follow-up of 10 women who seroconverted during pregnancy displayed three different serological patterns: (i) a GRA profile paralleling the IgG curve, as detected by the commercial kit, (ii) a GRA1 profile, or (iii) GRA1 and GRA6 Nt profiles remaining negative for at least 8 weeks after the reference test gave positive results. Taken together, these results suggest that neither GRA1 nor GRA6 Nt is sensitive enough to be used routinely to differentiate between acute and chronic toxoplasmic infections. PMID:15539499

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

    Directory of Open Access Journals (Sweden)

    Tam Yew

    2012-10-01

    Full Text Available Abstract 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.

  1. Safety of using hepatitis B virus core antibody or surface antigen-positive donors in kidney or pancreas transplantation.

    Science.gov (United States)

    Akalin, Enver; Ames, Scott; Sehgal, Vinita; Murphy, Barbara; Bromberg, Jonathan S

    2005-06-01

    Hepatitis B virus core antibody (HBcAb) or surface antigen (HBsAg)-positive organ donors have the potential to transmit infection to transplant recipients. We investigated the safety of using HBcAb(+) or HBsAg(+) donors in kidney or pancreas transplant recipients with 1 yr lamivudine prophylaxis. While HBsAb(-) recipients of HBcAb(+) donors received prophylaxis, HBsAb(+) recipients did not. HBsAg(+) organs were only used in patients who were both HBcAb and HBsAb(+). Forty-six patients received HBcAb(+) and four received HBsAg(+) organs (47 kidney, two pancreas, and one kidney/pancreas). All but one recipient were HBsAg(-), 25 were HBsAb(+), and 19 HBcAb(+). During a median 36 months of follow-up (range 6-66 months), with 43 of a total 50 patients having at least 1 yr follow-up and were off lamivudine, and none of the patients developed hepatitis B viremia or seroconversion to HBsAg or HBsAb(+). These results suggest that HBcAb(+) or HBsAg(+) organs can be used safely in selected recipients with lamivudine prophylaxis without requiring hepatitis B immunglobulin.

  2. 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

  3. A Intervention Study to Improve HBsAg Testing and Preventive Practices for Hepatitis B in an Obstetrics Hospital

    Directory of Open Access Journals (Sweden)

    Ibrahim Koruk

    2011-06-01

    Full Text Available Objectives: This study was conducted to determine the effectiveness of a multicomponent intervention in Sanliurfa Gynecology and Obstetrics Hospital (SGOH, which is designed to overcome the obstacles encountered in the application of HBsAg testing to all delivering women, the administration of hepatitis B vaccine and Hepatitis B Immunglobulin(HBIG to newborns of HBsAg positive pregnant women. Methods: This is an intervention study, conducted between December 15, 2007 and December 30, 2008. Intervention procedure is composed of four methods; namely, motivation of all parties through academic leadership, implementation of workshops to determine the obstacles, provision of administrative commitment, and training of healthcare personnel. Results: In 2007, a total of 18,709 deliveries were realized in SGOH; HBsAg testing was performed in only 16.5% of the pregnant women and 0.8% of these women were found to be HBsAg positive. It was determined that HBIG was administered to 28.2% of newborns of HBsAg positive mothers and hepatitis B vaccine was given to 71.4% (n=13349 of all newborns. After the intervention, the increase in HBsAg test application status, HBsAg positivity, HIBG administration and hepatitis B vaccination was 6.0, 5.8, 2.0 and 1.2 fold, respectively (P<0.05. Conclusions: In order to reduce the incidence of hepatitis B and maintain patient safety in newborns, HBsAg testing should be included in routine pregnancy screening programs and this approach should be supported by legal arrangements and systematic continuous training activities. [TAF Prev Med Bull 2011; 10(3.000: 287-292

  4. Usefulness of antigen-specific IgE probability curves derived from the 3gAllergy assay in diagnosing egg, cow's milk, and wheat allergies.

    Science.gov (United States)

    Sato, Sakura; Ogura, Kiyotake; Takahashi, Kyohei; Sato, Yasunori; Yanagida, Noriyuki; Ebisawa, Motohiro

    2017-04-01

    Specific IgE (sIgE) antibody detection using the Siemens IMMULITE ® 3gAllergy™ (3gAllergy) assay have not been sufficiently examined for the diagnosis of food allergy. The aim of this study was to evaluate the utility of measuring sIgE levels using the 3gAllergy assay to diagnose allergic reactions to egg, milk, and wheat. This retrospective study was conducted on patients with diagnosed or suspected allergies to egg, milk and wheat. Patients were divided into two groups according to their clinical reactivity to these allergens based on oral food challenge outcomes and/or convincing histories of immediate reaction to causative food(s). The sIgE levels were measured using 3gAllergy and ImmunoCAP. Predicted probability curves were estimated using logistic regression analysis. We analyzed 1561 patients, ages 0-19 y (egg = 436, milk = 499, wheat = 626). The sIgE levels determined using 3gAllergy correlated with those of ImmunoCAP, classifying 355 patients as symptomatic: egg = 149, milk = 123, wheat = 83. 3gAllergy sIgE levels were significantly higher in symptomatic than in asymptomatic patients (P allergies. However, these probability curves should not be applied interchangeably between different assays. Copyright © 2016 Japanese Society of Allergology. Production and hosting by Elsevier B.V. All rights reserved.

  5. The use of an in vitro microneutralization assay to evaluate the potential of recombinant VP5 protein as an antigen for vaccinating against Grass carp reovirus

    Directory of Open Access Journals (Sweden)

    Xu Dan

    2011-03-01

    Full Text Available Abstract Background Grass carp reovirus (GCRV is the causative pathogen of grass carp hemorrhagic disease, one of the major diseases damaging grass carp Ctenopharyngon idellus breeding industry in China. Prevention and control of the disease is impeded largely due to the lack of research in economic subunit vaccine development. This study aimed to evaluate the potential of viral outer shell protein VP5 as subunit vaccine. Methods The vp5 gene was isolated from the viral genome through RT-PCR and genetically engineered to express the recombinant VP5 protein in E coli. The viral origin of the recombinant protein was confirmed by Western blot analysis with a monoclonal antibody against viral VP5 protein. Polyclonal antibody against the recombinant VP5 protein was prepared from mice. A microneutralization assay was developed to test its neutralizing ability against GCRV infection in cell culture. Results The GST-VP5 fusion protein (rVP5 was produced from E. Coli with expected molecular weight of 90 kDa. The protein was purified and employed to prepare anti-VP5 polyclonal antibody from mice. The anti-VP5 antibody was found to neutralize GCRV through in vitro microneutralization assay and viral progeny quantification analysis. Conclusions The present study showed that the viral VP5 protein was involved in viral infection and bacterially-expressed VP5 could be suitable for developing subunit vaccine for the control of GCRV infection.

  6. Enzyme-Linked Immunosorbent Assay Based on Soluble Promastigote Antigen Detects Immunoglobulin M (IgM) and IgG Antibodies in Sera from Cases of Visceral and Cutaneous Leishmaniasis

    Science.gov (United States)

    Ryan, Jeffrey R.; Smithyman, Anthony M.; Rajasekariah, G-Halli; Hochberg, Lisa; Stiteler, John M.; Martin, Samuel K.

    2002-01-01

    Leishmaniasis causes significant morbidity and mortality in areas where it is endemic. In areas where it is nonendemic, global travel and increased incidence of the disease in human immunodeficiency virus and intravenous-drug user populations are also causes for concern. The unavailability of rapid and reliable tests for diagnosis of the various leishmaniases makes patient management difficult. We have developed an enzyme-linked immunosorbent assay (ELISA) that can detect immunoglobulin M (IgM) and IgG antibodies in patients with visceral and cutaneous leishmaniasis. These practical assays are based on soluble antigens from promastigotes cultivated in a protein-free medium. In preliminary studies, 129 visceral (Brazil, Italy, North Africa, and Nepal) and 143 cutaneous (Brazil) leishmaniasis patients with controls were tested. Overall, the tests showed a sensitivity of 95.1%. In addition, the ELISA correctly identified 42 sera from Brazilian dogs with canine leishmaniasis and 10 healthy controls. Serological tests for the various clinical manifestations of leishmaniasis could be useful epidemiological and patient management tools in populations of areas of endemicity and nonendemicity. PMID:11880434

  7. Evaluation of an Antigen-Antibody

    African Journals Online (AJOL)

    GB

    1. ABSTRACT. BACKGROUND: Development of “combination” assays detecting in parallel, within a single test,. Hepatitis C Virus (HCV) antigens and antibodies, not ... considered above threshold of detection for antigen proteins suggested a lack of sensitivity by this assay ..... Hepatic veno-occlusive disease (sinusoidal.

  8. Treponema pallidum hemagglutination assay seroreactivity among healthy Indian donors and its association with other transfusion transmitted diseases

    Directory of Open Access Journals (Sweden)

    Sangeeta Pahuja

    2014-01-01

    Full Text Available Background: The aim of the present study was to determine the prevalence of syphilis infection by Treponema pallidum hemagglutination assay (TPHA among blood donors in Delhi and to study their correlation with other markers of transfusion transmitted infections such as hepatitis C virus (HCV, human immunodeficiency virus (HIV and hepatitis B surface antigen (HBsAg so as to establish the utility of TPHA over and above venereal diseases research laboratory test (VDRL, not only as a marker for testing T. pallidum infection, but also as a marker of high risk behavior. Materials and Methods: This prospective study was carried out in the Regional Blood Transfusion Centre, Lady Hardinge Medical College and associated Sucheta Kriplani Hospital, New Delhi for a period of 2 years. Donated blood was screened for TPHA seroreactivity along with screening for anti HIV I and II, anti-HCV, HBsAg by third generation enzyme-linked immunosorbent assay test. A total of 8082 serum samples of blood donors were collected from healthy blood donors in our blood bank. They were classified into two groups- test group and control group based on TPHA positivity. The co-occurrence of HBsAg, HIV and HCV infection were determined in TPHA positive blood donors (test group in comparison with TPHA negative blood donors (control group. Results: We found the TPHA seroreactivity to be 4.4% in Delhi′s blood donors. Nearly 8.2% (663/8082 of the donated blood had serological evidence of infection by at least one pathogen (syphilis/HIV/hepatitis B virus/HCV and 6.63% (44/663 donors with positive serology had multiple infections (two or more. Quadruple infection was seen in one donor, triple infection was seen in three donors and double infection was seen in 40 donors. Prevalence of HIV seroreactivity was found to be statistically significant and HCV seroreactivity statistically insignificant in TPHA positive group in comparison to TPHA negative group. Discussion: In our study, the

  9. A comparison of antigen dipstick assays with polymerase chain reaction (PCR) technique and blood film examination in the rapid diagnosis of malaria.

    Science.gov (United States)

    Lee, M A; Aw, L T; Singh, M

    1999-07-01

    Early diagnosis of malaria for military personnel training in the field is crucial in providing proper treatment for the infected and in taking appropriate preventive measures for the non-infected. Present preliminary diagnosis of malaria in the field depends on the clinical symptoms of the patients and there is a need for rapid diagnosis of malaria in the field. The presence of drug-resistant strains of the Plasmodium species in the region also increases the urgency of finding a quick and sensitive way of identifying the different strains. This study evaluated current methods available for the diagnosis of Plasmodium falciparum and Plasmodium vivax. The dipstick assays, the ParaSight F test and the OptiMAL malaria rapid test were compared with the methods of microscopic examination of blood film and polymerase chain reaction (PCR). On comparison to the blood film and PCR methods, the ParaSight F test has specificity of 98.6% and sensitivity of 91% for P. falciparum detection. The OptiMAL malaria rapid test has a specificity of 100% and 98.6% and sensitivity of 92.8% and 92.6% for P. vivax and P. falciparum detection respectively. We conclude that both tests are suitable for use for rapid malaria diagnosis in the field but the OptiMAL rapid malaria test, which can detect both vivax and falciparum malaria, would be more useful.

  10. 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

  11. Development and clinical validation of a real-time PCR assay for PITX2 DNA methylation to predict prostate-specific antigen recurrence in prostate cancer patients following radical prostatectomy.

    Science.gov (United States)

    Dietrich, Dimo; Hasinger, Oliver; Bañez, Lionel L; Sun, Leon; van Leenders, Geert J; Wheeler, Thomas M; Bangma, Chris H; Wernert, Nicolas; Perner, Sven; Freedland, Stephen J; Corman, John M; Ittmann, Michael M; Lark, Amy L; Madden, John F; Hartmann, Arndt; Schatz, Philipp; Kristiansen, Glen

    2013-03-01

    Prostate cancer is the most common cancer among men. The prospective discrimination of aggressive and clinically insignificant tumors still poses a significant and, as yet, unsolved problem. PITX2 DNA methylation is a strong prognostic biomarker in prostate cancer. Recently, a diagnostic microarray for prostate cancer prognosis based on PITX2 methylation has been developed and validated. Because this microarray requires nonstandard laboratory equipment, its use in a diagnostic setting is limited. This study aimed to develop and validate an alternative quantitative real-time PCR assay for measuring PITX2 methylation that can easily be established in clinical laboratories, thereby facilitating the implementation of this biomarker in clinical practice. A methylation cut-off for patient stratification was established in a training cohort (n = 157) and validated in an independent test set (n = 523) of men treated with radical prostatectomy. In univariate Cox proportional hazards analysis, PITX2 hypermethylation was a significant predictor for biochemical recurrence (P PITX2 hypermethylation added significant prognostic information (P = 0.003, hazard ratio = 1.814) to the Gleason score, pathological T stage, prostate-specific antigen, and surgical margins in a multivariate analysis. The clinical performance was particularly high in patients at intermediate risk (Gleason score of 7) and in samples containing high tumor cell content. This assay might aid in risk stratification and support the decision-making process when determining whether a patient might benefit from adjuvant treatment after radical prostatectomy. Copyright © 2013 American Society for Investigative Pathology and the Association for Molecular Pathology. Published by Elsevier Inc. All rights reserved.

  12. COMPARATIVE STUDY OF FILARIAL DETECTION BY MICROSCOPIC EXAMINATION AND SEROLOGICAL ASSAY UTILIZING BMR1 AND BMXSP RECOMBINANT ANTIGENS FOR EVALUATION OF FILARIASIS ELIMINATION PROGRAM AT KAMPUNG SAWAH AND PAMULANG, SOUTH TANGERANG DISTRICT, BANTEN, INDONESIA

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    Silvia F. Nasution

    2015-09-01

    Full Text Available South Tangerang district is one of the endemic areas for filariasis; and based on an evaluation study in 2008-2009 which covered several subdistricts, the prevalence of microfilaria was between 1–2.4%. Nevertheless, the evaluation by serological assay has never been reported. A cross-sectional study was conducted to detect the microfilaremia and anti-filarial IgG4 antibody status in Kp Sawah and Pamulang subdistricts. Cluster sampling was performed in Kp Sawah by collecting finger-prick blood (FPB and venous blood samples from inhabitants who lived with and nearby the four elephantiasis subjects in the area. The FPB were only collected in Pamulang area by consecutive sampling method. The detection method included microscopic evaluation of FPB and serological detection using recombinant antigens BmR1 and BmSXP by ELISA and lateral flow rapid tests. Symptomatic patients who had 2nd and 3rd degree of elephantiasis were clinically determined in 10% (4/40 subjects. Among those with elephantiasis, 2 were positive serologically but their microscopic results were all negative (40/40. Meanwhile, the microscopic result for 107 subjects from Pamulang were all negative. The results of the rapid tests showed that 15% (6/40 of the positive cases were detected by Brugia Rapid and 27.5% (11/40 by PanLF. Meanwhile, the ELISA showed that 20% (8/40 of the cases were positive with BmSXP, whereas only 2.5% or 1/40 sample was found to be positive with BmR1. Even though the sensitivity of the Rapid test was lower when compared to microscopic examination for these samples, the assay showed good specificity ranging from 72.5 to 97.5%. The optical density (OD values of ELISA has ranged between 0.3–3.045.

  13. Performance of cryptococcal antigen lateral flow assay in serum, cerebrospinal fluid, whole blood, and urine in HIV-infected patients with culture-proven cryptococcal meningitis admitted at a Brazilian referral center

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    José E. Vidal

    2018-02-01

    Full Text Available ABSTRACT Cryptococcal meningitis is the most common cause of opportunistic meningitis in HIV-infected patients in Brazil and causes unacceptable high mortality rates. In this study, HIV-infected patients with a first episode of culture-proven cryptococcal meningitis in cerebrospinal fluid (CSF were prospectively included in order to evaluate sensitivity of cryptococcal antigen (CrAg lateral flow assay (LFA in serum, CSF, whole blood (fingerstick, and fresh urine. In addition, HIV-infected patients with other neurological confirmed diseases were included in order to evaluate the specificity of CrAg LFA in serum. Twenty patients with cryptococcal meningitis were included and in 19 of them, CrAg LFA in CSF, serum, and whole blood were positive (95% sensitivity. In 18 patients, India ink test was positive in CSF (90% sensitivity, and in 16 cases, CrAg LFA was positive in urine (80% sensitivity. Thirty-six HIV-infected patients with other neurological diseases had negative results of CrAg LFA in serum (100% specificity. In conclusion, CrAg LFA in serum, CSF, and whole blood showed high sensitivity and specificity. Whole blood CrAg LFA seems to be a good and reliable strategy to improve AIDS-related cryptococcal meningitis diagnosis in Brazil.

  14. Performance of cryptococcal antigen lateral flow assay in serum, cerebrospinal fluid, whole blood, and urine in HIV-infected patients with culture-proven cryptococcal meningitis admitted at a Brazilian referral center.

    Science.gov (United States)

    Vidal, José E; Toniolo, Carolina; Paulino, Adriana; Colombo, Arnaldo L; Martins, Marilena Dos Anjos; Meira, Cristina da Silva; Azevedo, Renata Guise Soares; Pereira-Chioccola, Vera Lucia; Gomes, Hélio Rodrigues; Lazera, Marcia Dos Santos; Oliveira, Augusto C Penalva de; Boulware, David R

    2018-01-01

    Cryptococcal meningitis is the most common cause of opportunistic meningitis in HIV-infected patients in Brazil and causes unacceptable high mortality rates. In this study, HIV-infected patients with a first episode of culture-proven cryptococcal meningitis in cerebrospinal fluid (CSF) were prospectively included in order to evaluate sensitivity of cryptococcal antigen (CrAg) lateral flow assay (LFA) in serum, CSF, whole blood (fingerstick), and fresh urine. In addition, HIV-infected patients with other neurological confirmed diseases were included in order to evaluate the specificity of CrAg LFA in serum. Twenty patients with cryptococcal meningitis were included and in 19 of them, CrAg LFA in CSF, serum, and whole blood were positive (95% sensitivity). In 18 patients, India ink test was positive in CSF (90% sensitivity), and in 16 cases, CrAg LFA was positive in urine (80% sensitivity). Thirty-six HIV-infected patients with other neurological diseases had negative results of CrAg LFA in serum (100% specificity). In conclusion, CrAg LFA in serum, CSF, and whole blood showed high sensitivity and specificity. Whole blood CrAg LFA seems to be a good and reliable strategy to improve AIDS-related cryptococcal meningitis diagnosis in Brazil.

  15. 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.

  16. Hepatocellular carcinoma. A study of 50 autopsy cases with detection of hepatitis B surface antigen in fixed tissues.

    Science.gov (United States)

    Perez-Barrios, A; Colina-Ruizdelgado, F; Gallego, I; Martinez-Tello, F J

    1983-03-01

    Fifty patients who died of hepatocellular carcinoma (HCC) were autopsied at the Ciudad Sanitaria "1 degree de Octubre" and the Hospital de la Cruz Roja (Madrid) from 1974 to 1980. Formalin fixed paraffin-embedded autopsy tissue of liver and tumor from the 50 HCC and liver tissue from 50 liver cirrhosis (LC) and from 50 autopsy of non cirrhotic control cases were examined for the presence of cytoplasmic hepatitis B surface antigen (HBsAg). The study was carried out using orcein staining, immunoperoxidase technique (IP) and indirect immunofluorescence (IF). In livers with HCC the HBsAg was detected in the cytoplasm of the hepatocytes in 10 cases (20%) with the orcein staining and in 11 (22%) with the IP and IF techniques. In one case (2%) HBsAg was found in the cytoplasm of tumor cells with the three methods--In four cases (8%) of LC and 2 (4%) control cases cytoplasmic positive cells were found. In 41 patients with HCC HBsAg was studied in the serum by radio-immunoassay (RIA) (13 cases) and immunodiffussion (28 cases). 5 patients (12,1%) were positive and 36 (72%) were negative. In the 5 serum positive HBsAg HCC the staining methods for cytoplasmic HBsAg were positive (100%). In 36 serum negative HBsAg HCC the staining method were positive in 2 cases. The results let us to conclude that HBV is a probable important etiologic factor of HCC in our milieu. 54% of the patients with HCC had a previous history of alcohol abuse; however, histologic features compatible with an alcoholic etiology were found in only 5 cases. Nevertheless we consider that the described histopathologic findings do not exclude excess alcohol consumption as a possible etiologic factor for HCC in our series.

  17. Una prueba de captura rápida de antígenos con tiras reactivas para el diagnóstico de malaria por P. falciparum A rapid dipstick antigen capture assay for the diagnosis of falciparum malaria

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    1997-01-01

    Full Text Available Los avances recientes en el diagnóstico de infecciones causadas por Plasmodium falciparum han permitido considerar la posibilidad de complementar la microscopia óptica con una prueba estandarizada de captura de antígenos con tiras reactivas basada en la detección de una proteína específica del parásito, que es segregada por los estadios sanguíneos asexuados y los gametocitos inmaduros, pero no por otros estadios. Los ensayos de campo indican que esta prueba proporciona resultados replicables con un umbral de detección de parasitemia de P. falciparum similar al obtenido con microscopia habitual de alta calidad para malaria y una especificidad y sensibilidad de alrededor de 90% en comparación con la microscopia habitual con extensión de sangre en capa gruesa. La estabilidad, reproducibilidad y facilidad de uso de la prueba indican claramente sus posibilidades de aplicación en el tratamiento de la malaria, particularmente en el nivel de atención de salud periférico, siempre y cuando se pueda garantizar su precisión y su costo sea módico. También debe considerarse la posibilidad de usarla más ampliamente donde lo justifiquen los requisitos operativos y los recursos y donde las decisiones se basen en una evaluación adecuada de los sistemas de prestación de asistencia de salud existentes.Recent advances in the diagnosis of Plasmodium falciparum infections have made it possible to consider supplementing light microscopy with a standardized dipstick antigen capture assay based on the detection of a parasite-specific protein, which is secreted by the asexual blood stages and immature gametocytes but not by the other stages. Field trials indicate that this dipstick assay provides consistently reproducible results, with a threshold of detection of P. falciparum parasitaemia similar to that obtained by high quality routine malaria microscopy and a specificity and sensitivity of around 90% compared with standard thick blood film

  18. 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

  19. Hepatitis B Vaccination Coverage and Prevalence of Hepatitis B Surface Antigen Among Children in French Polynesia, 2014.

    Science.gov (United States)

    Patel, Minal K; Le Calvez, Evelyne; Wannemuehler, Kathleen; Ségalin, Jean-Marc

    2016-06-01

    French Polynesia is considered to be moderately endemic for chronic hepatitis B virus infection, with an estimated 3% of the population having hepatitis B surface antigen (HBsAg). From 1990 to 1992, a 3-dose hepatitis B vaccination series was introduced into the routine infant immunization schedule in French Polynesia, including a birth dose (BD). In 2014, a nationally representative 2-stage cluster survey was undertaken to evaluate the impact of the vaccination program on HBsAg prevalence among school children (∼6 years of age) in Cours Préparatoire (CP). Documented vaccination data were reviewed for all eligible children; children with consent were tested for HBsAg with a rapid point-of-care test. In total, 1,660 students were identified; 1,567 (94%) had vaccination data for review and 1,196 (72%) participated in the serosurvey. Three-dose vaccination coverage was 98%, while timely BD coverage, defined as a dose administered within 24 hours of life, was 89%. Receipt of the second and third doses was often delayed, with 75% and 55% receiving a second and third dose within 1 month of the recommended age, respectively. No children tested positive for HBsAg. French Polynesia's vaccination program has achieved high coverage and an HBsAg seroprevalence of 0% (0-0.5%) among CP school children, but timeliness of vaccination could be improved. © The American Society of Tropical Medicine and Hygiene.

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

    Science.gov (United States)

    Lee, Han Ah; Seo, Yeon Seok; Park, Seung Woon; Park, Sang Jung; Kim, Tae Hyung; Suh, Sang Jun; Jung, Young Kul; Kim, Ji Hoon; An, Hyunggin; Yim, Hyung Joon; Yeon, Jong Eun; Byun, Kwan Soo; Um, Soon Ho

    2016-09-01

    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. 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 log 10 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. 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 log 10 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 log 10 IU/mL (n=11) and >3 log 10 IU/mL (n=28), respectively. The off-treatment HBsAg level is closely related to clinical relapse after treatment cessation. A serum HBsAg level of response in CHB

  1. 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

  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...... and five of the seven male homosexuals had human immunodeficiency virus infection. The patients were followed for 1 to 180 months (median, 24 months) while HBV DNA negative, anti-HBe positive. Reactivation, defined as reappearance of HBV DNA or HBeAg, or both, was detected in six patients corresponding...... 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. 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

  4. Concepts and applications for influenza antigenic cartography

    Science.gov (United States)

    Cai, Zhipeng; Zhang, Tong; Wan, Xiu-Feng

    2011-01-01

    Influenza antigenic cartography projects influenza antigens into a two or three dimensional map based on immunological datasets, such as hemagglutination inhibition and microneutralization assays. A robust antigenic cartography can facilitate influenza vaccine strain selection since the antigenic map can simplify data interpretation through intuitive antigenic map. However, antigenic cartography construction is not trivial due to the challenging features embedded in the immunological data, such as data incompleteness, high noises, and low reactors. To overcome these challenges, we developed a computational method, temporal Matrix Completion-Multidimensional Scaling (MC-MDS), by adapting the low rank MC concept from the movie recommendation system in Netflix and the MDS method from geographic cartography construction. The application on H3N2 and 2009 pandemic H1N1 influenza A viruses demonstrates that temporal MC-MDS is effective and efficient in constructing influenza antigenic cartography. The web sever is available at http://sysbio.cvm.msstate.edu/AntigenMap. PMID:21761589

  5. 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

  6. 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.

  7. 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.

  8. High throughput functional assays of the variant antigen PfEMP1 reveal a single domain in the 3D7 Plasmodium falciparum genome that binds ICAM1 with high affinity and is targeted by naturally acquired neutralizing antibodies.

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    Andrew V Oleinikov

    2009-04-01

    Full Text Available Plasmodium falciparum-infected erythrocytes bind endothelial receptors to sequester in vascular beds, and binding to ICAM1 has been implicated in cerebral malaria. Binding to ICAM1 may be mediated by the variant surface antigen family PfEMP1: for example, 6 of 21 DBLbetaC2 domains from the IT4 strain PfEMP1 repertoire were shown to bind ICAM1, and the PfEMP1 containing these 6 domains are all classified as Group B or C type. In this study, we surveyed binding of ICAM1 to 16 DBLbetaC2 domains of the 3D7 strain PfEMP1 repertoire, using a high throughput Bioplex assay format. Only one DBL2betaC2 domain from the Group A PfEMP1 PF11_0521 showed strong specific binding. Among these 16 domains, DBL2betaC2(PF11_0521 best preserved the residues previously identified as conserved in ICAM1-binding versus non-binding domains. Our analyses further highlighted the potential role of conserved residues within predominantly non-conserved flexible loops in adhesion, and, therefore, as targets for intervention. Our studies also suggest that the structural/functional DBLbetaC2 domain involved in ICAM1 binding includes about 80 amino acid residues upstream of the previously suggested DBLbetaC2 domain. DBL2betaC2(PF11_0521 binding to ICAM1 was inhibited by immune sera from east Africa but not by control US sera. Neutralizing antibodies were uncommon in children but common in immune adults from east Africa. Inhibition of binding was much more efficient than reversal of binding, indicating a strong interaction between DBL2betaC2(PF11_0521 and ICAM1. Our high throughput approach will significantly accelerate studies of PfEMP1 binding domains and protective antibody responses.

  9. The Murine Humoral Immune Response to Hepatitis B Surface Antigen: Idiotype Network Pathways.

    Science.gov (United States)

    Schick, Michael Roy

    Recognition of a wide spectrum in disease outcomes following Hepatitis B Virus (HBV) infection has led to the suggestion that individual differences may be due to characteristics of the immune response. HBV, a hepatotropic virus, is not directly cytopathic to the host hepatocytes but the cellular damage which does not occur may be due to the host's own immune response. It is this variety in immune response capabilities following natural infection or vaccination which led to the present study in which the murine humoral immune response to hepatitis B surface antigen (HBsAg) was examined. Following immunization with purified HBsAg an anti-HBs response could be detected in 19 inbred strains of mice. The response, which varied among the strains, was linked to the major histocompatibility complex (MHC). Among high responders to HBsAg were two strains in which a poor response to a single epitope could be detected. Although quantitatively serum from these strains resembled serum from other high responders, there was a major difference in the qualitative aspects. Included within this study was the role of idotype networks within the murine anti-HBs response. By directly targeting HBsAg-specific B cells within the framework of an idiotype network by an Ab-2, it was possible to circumvent T cell-dependent regulation of an immune response. In each of five inbred strains of mice immunized with a polyclonal rabbit Ab-2 an Ab-3 population with HBsAg-specificity (Ab -1^') was induced. These mice were also immunized with HBsAg resulting in a higher anti-HBs response as compared to HBsAg immunization alone in all of the strains tested except for one. The response in this strain, normally a low responder to HBsAg, indicated that the mechanisms for genetic restriction of the anti -HBs response was still active, although it was not apparent during anti-Id immunization. The effects of an anti-Id on the murine antibody response to HBsAg may lead to insights on the presence of idiotype

  10. 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

  11. Microbead agglutination based assays

    KAUST Repository

    Kodzius, Rimantas

    2013-01-21

    We report a simple and rapid room temperature assay for point-of-care (POC) testing that is based on specific agglutination. Agglutination tests are based on aggregation of microbeads in the presence of a specific analyte thus enabling the macroscopic observation. Such tests are most often used to explore antibody-antigen reactions. Agglutination has been used for protein assays using a biotin/streptavidin system as well as a hybridization based assay. The agglutination systems are prone to selftermination of the linking analyte, prone to active site saturation and loss of agglomeration at high analyte concentrations. We investigated the molecular target/ligand interaction, explaining the common agglutination problems related to analyte self-termination, linkage of the analyte to the same bead instead of different microbeads. We classified the agglutination process into three kinds of assays: a two- component assay, a three-component assay and a stepped three- component assay. Although we compared these three kinds of assays for recognizing DNA and protein molecules, the assay can be used for virtually any molecule, including ions and metabolites. In total, the optimized assay permits detecting analytes with high sensitivity in a short time, 5 min, at room temperature. Such a system is appropriate for POC testing.

  12. ALT flares during nucleotide analogue therapy are associated with HBsAg loss in genotype A HBeAg-positive chronic hepatitis B.

    Science.gov (United States)

    Wong, Darren; Littlejohn, Margaret; Edwards, Rosalind; Jackson, Kathy; Revill, Peter; Gaggar, Anuj; Kitrinos, Kathryn; Subramanian, Mani; Marcellin, Patrick; Buti-Ferret, Maria; Janssen, Harry; Gane, Ed; Locarnini, Stephen; Thompson, Alexander

    2018-02-10

    Alanine aminotransferase (ALT) flares during NA therapy are uncommon but occur. Evaluation of ALT flares during nucleos(t)ide analogue (NA) therapy is important as new immunomodulatory therapies for hepatitis B virus (HBV) are developed. We evaluated the association between ALT flares and HBsAg loss during long-term therapy for genotype A CHB. This analysis included genotype A subjects from a phase III study of tenofovir vs adefovir in HBeAg-positive HBV. ALT flare was defined as (i) a rise in ALT >2x ULN from normal ALT levels; or (ii) a rise in ALT >2x baseline ALT level. HBsAg response at week 384 was recorded as one of HBsAg loss vs HBsAg decline (≥1 log 10  IU/mL decline) vs non-response. The primary analysis evaluated the association between ALT flare and HBsAg response. 54 subjects were included. 23/54 (43%) subjects experienced an on-treatment ALT flare. 45% achieved an HBsAg reduction ≥1 log 10  IU/mL, and of these 67% achieved HBsAg loss at a median of 102 weeks [IQR: 64-156]. Flare was associated with HBsAg decline vs non-response (67% vs 23%, P = .002), and were more common in subjects who achieved HBsAg loss vs non-response (56% vs 23%), P = .049). There was a median delay of 56 weeks [IQR: 40-80] between a flare and HBsAg loss. In genotype A subjects undergoing long-term NA therapy, ALT flares predict for HBsAg response. The delay between ALT flare and HBsAg loss has implications for clinical trial design for early phase development of immunomodulatory strategies aiming for HBsAg loss. © 2018 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

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

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    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. Liver cancer: expression features of hepatitis B antigens

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    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

  15. Evaluation of a novel enzyme-linked immunosorbent assay for detection of antibodies against Salmonella, employing a stable coating of lipopolysaccharide-derived antigens covalently attached to polystyrene microwells

    DEFF Research Database (Denmark)

    Wiuff, C.; Jauho, E. S.; Stryhn, H.

    2000-01-01

    Polysaccharides derived from Salmonella typhimurium lipopolysaccharide (LPS) representing the O-antigen factors 1, 4, 5, and 12 and the O-antigen factors 6 and 7 from Salmonella choleraesuis LPS were derivatized with the photoreactive compound anthraquinone and subsequently covalently coupled...... of a panel of pig sera as determined by a conventional ELISA on the basis of passive coating of the two Salmonella LPS antigens (the mix-ELISA). The covalent anthraquinone mix-ELISA shows promise as a stable and durable alternative to the existing conventional ELISA for serological surveillance of Salmonella...

  16. [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.

  17. Co-incubation with IL-18 potentiates antigen-specific IFN-γ response in a whole-blood stimulation assay for measurement of cell-mediated immune responses in pigs experimentally infected with Lawsonia intracellularis

    DEFF Research Database (Denmark)

    Riber, Ulla; Boesen, Henriette Toft; Jakobsen, Jeanne Toft

    2011-01-01

    The whole-blood interferon-gamma (IFN-γ) assay is a quantitative in-vitro assay for a direct read out of Ag-specific cell-mediated immune (CMI) responses to infectious diseases. The IFN-γ assay is robust in severe intracellular infections like Brucella or mycobacteria, but more difficult to evalu......The whole-blood interferon-gamma (IFN-γ) assay is a quantitative in-vitro assay for a direct read out of Ag-specific cell-mediated immune (CMI) responses to infectious diseases. The IFN-γ assay is robust in severe intracellular infections like Brucella or mycobacteria, but more difficult...

  18. Non-apical membrane antigen 1 (AMA1 IgGs from Malian children interfere with functional activity of AMA1 IgGs as judged by growth inhibition assay.

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    Kazutoyo Miura

    Full Text Available BACKGROUND: Apical membrane antigen 1 (AMA1 is one of the best-studied blood-stage malaria vaccine candidates. When an AMA1 vaccine was tested in a malaria naïve population, it induced functionally active antibodies judged by Growth Inhibition Assay (GIA. However, the same vaccine failed to induce higher growth-inhibitory activity in adults living in a malaria endemic area. Vaccination did induce functionally active antibodies in malaria-exposed children with less than 20% inhibition in GIA at baseline, but not in children with more than that level of baseline inhibition. METHODS: Total IgGs were purified from plasmas collected from the pediatric trial before and after immunization and pools of total IgGs were made. Another set of total IgGs was purified from U.S. adults immunized with AMA1 (US-total IgG. From these total IgGs, AMA1-specific and non-AMA1 IgGs were affinity purified and the functional activity of these IgGs was evaluated by GIA. Competition ELISA was performed with the U.S.-total IgG and non-AMA1 IgGs from malaria-exposed children. RESULTS: AMA1-specific IgGs from malaria-exposed children and U.S. vaccinees showed similar growth-inhibitory activity at the same concentrations. When mixed with U.S.-total IgG, non-AMA1 IgGs from children showed an interference effect in GIA. Interestingly, the interference effect was higher with non-AMA1 IgGs from higher titer pools. The non-AMA1 IgGs did not compete with anti-AMA1 antibody in U.S.-total IgG in the competition ELISA. CONCLUSION: Children living in a malaria endemic area have a fraction of IgGs that interferes with the biological activity of anti-AMA1 antibody as judged by GIA. While the mechanism of interference is not resolved in this study, these results suggest it is not caused by direct competition between non-AMA1 IgG and AMA1 protein. This study indicates that anti-malaria IgGs induced by natural exposure may interfere with the biological effect of antibody induced by an AMA1

  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. 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)

  1. 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.

  2. Hepatitis B viral DNA among HBs antigen negative healthy blood donors.

    Science.gov (United States)

    Vaezjalali, Maryam; Rashidpour, Shabnam; Rezaee, Hanieh; Hajibeigi, Bashir; Zeidi, Majid; Gachkar, Latif; Aghamohamad, Shadi; Najafi, Ronak; Goudarzi, Hossein

    2013-03-01

    Presence of occult hepatitis B infection (OBI) renders HBs antigen (HBsAg) undetectable by ELISA. Therefore it is valuable to evaluate the frequency of OBI among healthy blood donors to improve and perhaps change the strategies of blood screening to reduce the risk of HBV transmission. The aim of this study was to determine the presence of HBcAb and HBV DNA among Iranian HBsAg negative healthy blood donors who donated their blood to the Tehran Blood Transfusion Center during 2011. 1000 serum specimens negative for HBsAg, HCV antibody and HIV antibody were collected from healthy blood donors and tested for HBcAb. Presence of hepatitis B viral DNA was checked in HBcAb positive samples by nested PCR with two sets of primers to amplify part of HBV S gene. There were 64 women and 936 men in the population under study. The mean ± SD age of the donors was 38 ± 11 years. 80 out of 1000 samples (8%) were found to be positive for HBcAb. HBV DNA was detected in 50% of HBcAb positive specimens. The mean ± SD age of donors without HBV DNA was 37.7 ± 10.5 years and for donors with HBV DNA was 40.9 ± 11.2 years (P = 0.05). OBI was prevalent among 50% of HBcAb positive healthy blood donors. The frequency of positive HBcAb among healthy HBsAg negative blood donors was comparable to previous studies reported from Iran. On the other hand, the frequency of HBV DNA in HBsAg negative blood donors was higher than previous reports.

  3. Immunomodulatory effects of HBsAg vaccine and levamisole in chronic hepatitis B and hepatitis B carrier children.

    Science.gov (United States)

    Demirci, Fikret; Bayraktaroğlu, Ziya; Karaoğlan, Murat; Coşkun, Yavuz; Karaoğlan, Ilkay; Okan, Vahap

    2005-12-01

    Pathogenesis of chronic hepatitis B and hepatitis B carrier status is related to deficiencies in the immune system. Thus, treatments regulating the immune system are under discussion. The aim of this study was to investigate the effects of HBsAg vaccine and levamisole on lymphocyte subgroups and immunoglobulins in children with chronic hepatitis B and hepatitis B carriers. A total of 93 naive children (43 chronic hepatitis B carriers, 50 chronic hepatitis B patients) were treated in three groups with HBsAg vaccine, levamisole or levamisole plus HBsAg vaccine. Levamisole (ketrax) was delivered as 2.5 mg/kg/day per os, three times per week for three months; the vaccine (Gen HevacB) was administered subcutaneously as 20, 30, 40 microg at one-month intervals. Both medications were delivered at same dosages in the combined group. The examinations were performed at pre-treatment and at the end of the third month when the treatment concluded. After treatments, CD3, CD4 and CD4/CD8 significantly increased and CD8 significantly decreased in chronic hepatitis B patient groups, except in the levamisole treated group. IgG and IgA were significantly decreased in all groups of chronic hepatitis B patients. It was found that HBsAg vaccine induced cellular immunostimulation in children with chronic hepatitis B; however, levamisole did not. The immune cells of hepatitis B carriers did not manifest a significant change in any treatment group. Although there was no change in B-cell, significant decreases were determined in immunoglobulins (IgG, IgA), especially in chronic hepatitis B patients.

  4. A pilot external quality assurance study of transfusion screening for HIV, HCV and HBsAG in 12 African countries.

    Science.gov (United States)

    Bloch, E M; Shah, A; Kaidarova, Z; Laperche, S; Lefrere, J-J; van Hasselt, J; Zacharias, P; Murphy, E L

    2014-11-01

    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. 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. 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 for both HBsAg (P < 0·0001) and HCV (P < 0·05). Sensitivity also varied by country and selected infrastructure variables. 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. © 2014 International Society of Blood Transfusion.

  5. 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

  6. Generation of hepatitis B virus PreS2-S antigen in Hansenula polymorpha.

    Science.gov (United States)

    Xu, Xiaowei; Ren, Sulin; Chen, Xiaoxiao; Ge, Jun; Xu, Zhenxing; Huang, Hongying; Sun, Honglin; Gu, Yue; Zhou, Tong; Li, Jianqiang; Xu, Hanmei

    2014-12-01

    Despite the long availability of a traditional prophylactic vaccine containing the HBV surface antigen (HBsAg) and aluminum adjuvant, nearly 10% of the population remains unable to generate an effective immune response. Previous studies have indicated that hepatitis B virus (HBV) PreS2-S is abundant in T/B cell epitopes, which induces a stronger immune response than HBsAg, particularly in terms of cytotoxic T lymphocyte (CTL) reaction. In the current study, the HBV PreS2-S gene encoding an extra 26 amino acids (PreS2 C-terminus) located at the N-terminus of HBsAg was cloned into the pVCH1300 expression vector. PreS2-S expressed in the methylotrophic yeast, Hansenula polymorpha, was produced at a yield of up to 250 mg/L. Subsequent purification steps involved hydrophobic adsorption to colloidal silica, ion-exchange chromatography and density ultracentrifugation. The final product was obtained with a total yield of ∼ 15% and purity of ∼ 99%. In keeping with previous studies, ∼ 22 nm viruslike particles were detected using electron microscopy. The generated PreS2-S antigen will be further studied for efficacy and safty in animals.

  7. Cytotoxicity assay automation

    Science.gov (United States)

    Levinthal, E. C.; Payne, R. O.

    1971-01-01

    The design and construction of a system to automatically test HLP antigens are described. Major efforts were made to test and evaluate the performance of such a system, and compare its performance with nonautomatic tissue typing techniques. The system is based on the fluorochromatic cytotoxicity assay. Results show the system will work but is subject to malfunctions after a few samplings, and poses problems in showing correctly the necessary readings.

  8. 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:…

  9. 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.

  10. Co-Administration of Lipid Nanoparticles and Sub-Unit Vaccine Antigens Is Required for Increase in Antigen-Specific Immune Responses in Mice

    Directory of Open Access Journals (Sweden)

    Elizabeth A. Thoryk

    2016-12-01

    Full Text Available A vast body of evidence suggests that nanoparticles function as potent immune-modulatory agents. We have previously shown that Merck proprietary Lipid NanoParticles (LNPs markedly boost B-cell and T-cell responses to sub-unit vaccine antigens in mice. To further evaluate the specifics of vaccine delivery and dosing regimens in vivo, we performed immunogenicity studies in BALB/c and C57BL/6 mice using two model antigens, Hepatitis B Surface Antigen (HBsAg and Ovalbumin (OVA, respectively. To assess the requirement for co-administration of antigen and LNP for the elicitation of immune responses, we evaluated immune responses after administering antigen and LNP to separate limbs, or administering antigen and LNP to the same limb but separated by 24 h. We also evaluated formulations combining antigen, LNP, and aluminum-based adjuvant amorphous aluminum hydroxylphosphate sulfate (MAA to look for synergistic adjuvant effects. Analyses of antigen-specific B-cell and T-cell responses from immunized mice revealed that the LNPs and antigens must be co-administered—both at the same time and in the same location—in order to boost antigen-specific immune responses. Mixing of antigen with MAA prior to formulation with LNP did not impact the generation of antigen-specific B-cell responses, but drastically reduced the ability of LNPs to boost antigen-specific T-cell responses. Overall, our data demonstrate that the administration of LNPs and vaccine antigen together enables their immune-stimulatory properties.

  11. Epidemiological characteristics of the carriers with coexistence of HBsAg and anti-HBs based on a community cohort study.

    Science.gov (United States)

    Pu, Z; Li, D; Wang, A; Su, H; Shao, Z; Zhang, J; Ji, Z; Gao, J; Choi, B C K; Yan, Y

    2016-04-01

    The coexistence of HBsAg and anti-HBs is an atypical serological pattern in HBV infection. There is no epidemiological characteristics of this serological pattern in the community and there is controversy over the molecular mechanisms underlying this pattern. We investigated the epidemiological characteristics of the carriers with HBsAg and anti-HBs in a longitudinal community cohort study. The prevalence of this atypical serological pattern was 2.93% (122/4169) in HBsAg-positive populations. The prevalence progressively increased with age from 40 to 70 years old. The rate of HBeAg positive and detectable HBV DNA were both significantly higher in carriers with this pattern than in carriers who were HBsAg positive but anti-HBs negative (26/122 verse 598/4047, P = 0.046; 86/122 verse 275/529,P coexistence HBsAg and anti-HBs, 14.81% of the carriers lost their anti-HBs. Viral sequencing showed that carriers with coexistence of HBsAg and anti-HBs had higher numbers of residue changes within the S gene than carriers who were HBsAg positive but anti-HBs negative (2.42 verse 1.33 changes per 100 residues, P coexistence of HBsAg and anti-HBs is a unique serological pattern which may be associated with an increased risk of adverse clinical outcome and may be related to HBsAg immune variants which have genotypic heterogeneity. © 2015 John Wiley & Sons Ltd.

  12. ADCC-Mediated CD56dim NK Cell Responses Are Associated with Early HBsAg Clearance in Acute HBV Infection

    Directory of Open Access Journals (Sweden)

    Wen-Han Yu

    2018-02-01

    Full Text Available 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. In conclusion, the cytolytic CD56dim 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.

  13. 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.

  14. Hepatitis B surface antigen variants in voluntary blood donors in Nanjing, China

    Directory of Open Access Journals (Sweden)

    Yong-lin Yang

    2012-04-01

    Full Text Available Abstract Background Hepatitis B virus (HBV is still one of the serious infectious risks for the blood transfusion safety in China. One plausible reason is the emergence of the variants in the major antigenic alpha determinant within the major hydrophilic region (MHR of hepatitis B surface antigen (HBsAg, which have been assumed to evade the immune surveillance and pose a challenge to the disease diagnosis. It is well documented that some commercial ELISA kits could detect the wild-type but not the mutant viruses. The high prevalence of HBV in China also impaired the application of nucleic acid testing (NAT in the improvement of blood security. Molecular epidemiological study of HBsAg variations in China is still limited. This study was designed to identify the prevalence of mutations in the HBsAg in voluntary blood donors in Nanjing, China. Methods A total of 20,326 blood units were enrolled in this study, 39 donors were positive for HBV S gene in the nested-PCR. Mutations in the major hydrophilic region (MHR; aa 99-169 were identified by direct sequencing of S region. Results Among of 20,326 blood units in the Red Cross Transfusion Center of Nanjing from October 2008 to April 2009, 296 samples (1.46%, 296/20,326 were HBsAg positive in the 2 successive rounds of the ELISA test. In these HBsAg positive units, HBV S gene could be successfully amplified from 39 donors (13.18%, 39/296 in the nested-PCR. Sequence analysis revealed that 32 strains (82.1%, 32/39 belong to genotype B, 7 strains (17.9%, 7/39 to genotype C. Besides well known G145R, widely dispersed variations in the MHR of S region, were observed in 20 samples of all the strains sequenced. Conclusions HBV/B and HBV/C are dominant in Nanjing, China. The mutations in the MHR of HBsAg associated with disease diagnosis are common.

  15. Development of a digital droplet PCR assay to measure HBV DNA in patients receiving long-term TDF treatment.

    Science.gov (United States)

    Liu, Yang; Cathcart, Andrea L; Delaney, William E; Kitrinos, Kathryn M

    2017-11-01

    The COBAS TaqMan assay has a lower limit of quantification (LLOQ) of 169 HBV copies/mL and a lower limit of detection (LLOD) of 58 copies/mL. HBV DNA below the TaqMan LLOQ is classified as target not detected (TND) (HBV DNA to 8 copies/mL. HBV DNA levels in plasma from patients with or without HBsAg seroconversion were assessed by ddPCR. For patients who did not achieve HBsAg seroconversion, the majority of TD samples (33/58, 57%) were HBV DNA positive by ddPCR while (10/37, 27%) of TND samples were positive. In contrast, for patients who achieved HBsAg seroconversion, HBV DNA was rarely detected by ddPCR after HBsAg seroconversion (1/28, 3.6%). ddPCR is a sensitive method to evaluate low-level viral replication in plasma samples. Frequent detection of HBV DNA by ddPCR among patients who did not achieve HBsAg seroconversion suggests new agents may be needed to suppress low levels of replicating HBV. Copyright © 2017. Published by Elsevier B.V.

  16. Performance evaluation of the Bio-Rad Laboratories GS HIV Combo Ag/Ab EIA, a 4th generation HIV assay for the simultaneous detection of HIV p24 antigen and antibodies to HIV-1 (groups M and O) and HIV-2 in human serum or plasma.

    Science.gov (United States)

    Bentsen, Christopher; McLaughlin, Lisa; Mitchell, Elizabeth; Ferrera, Carol; Liska, Sally; Myers, Robert; Peel, Sheila; Swenson, Paul; Gadelle, Stephane; Shriver, M Kathleen

    2011-12-01

    A multi-center study was conducted to evaluate the Bio-Rad GS HIV Combo Ag/Ab EIA, a 4th generation HIV-1/HIV-2 assay for the simultaneous detection of HIV p24 antigen and antibodies to HIV-1 (groups M and O) and HIV-2 in human serum or plasma in adult and pediatric populations. The objectives of the study were to assess assay performance for the detection of acute HIV infections; sensitivity in known HIV positive samples; percent agreement with HIV status; specificity in low and high risk individuals of unknown HIV status; and to compare assay performance to a 3rd generation HIV assay. The evaluation included testing 9150 samples at four U.S. clinical trial sites, using three kit lots. Unlinked samples were from routine testing, repositories or purchased from vendors. GS HIV Combo Ag/Ab EIA detection in samples from individuals in two separate populations with acute HIV infection was 95.2% (20/21) and 86.4% (38/44). Sensitivity was 100% (1603/1603) in known antibody positive [HIV-1 Groups M and O, and HIV-2] samples. HIV p24 antigen detection was 100% (53/53) in HIV-1 culture supernatants. HIV-1 seroconversion panel detection improved by a range of 0-20 days compared to a 3rd generation HIV test. Specificity was 99.9% (5989/5996) in low risk, 99.9% (959/960) in high risk and 100% (100/100) in pediatric populations. The GS HIV Combo Ag/Ab EIA significantly reduced the diagnostic window when compared to the 3rd generation screening assay, enabling earlier diagnosis of HIV infection. The performance parameters of the Bio-Rad GS HIV Combo Ag/Ab EIA are well suited for use in HIV diagnostic settings. Copyright © 2011 Elsevier B.V. All rights reserved.

  17. Monoclonal antibodies to Nocardia asteroides and Nocardia brasiliensis antigens.

    OpenAIRE

    Jiménez, T; Díaz, A M; Zlotnik, H

    1990-01-01

    Nocardia asteroides and Nocardia brasiliensis whole-cell extracts were used as antigens to generate monoclonal antibodies (MAbs). Six stable hybrid cell lines secreting anti-Nocardia spp. MAbs were obtained. These were characterized by enzyme-linked immunosorbent assay, Western blot (immunoblot), and immunofluorescence assay. Although all the MAbs exhibited different degrees of cross-reactivity with N. asteroides and N. brasiliensis antigens as well as with culture-filtrate antigens from Myco...

  18. [A retrospective study on HBsAg clearance rate after antiviral therapy in children with HBeAg-positive chronic hepatitis B aged 1-7 years].

    Science.gov (United States)

    Zhu, S S; Dong, Y; Xu, Z Q; Wang, L M; Chen, D W; Gan, Y; Wang, F C; Yan, J G; Cao, L L; Wang, P; Zhang, H F

    2016-10-20

    Objective: To investigate the HBsAg clearance rate after antiviral therapy in children with HBeAg-positive chronic hepatitis B (CHB) aged 1-7 years. Methods: A retrospective analysis was performed for the HBsAg clearance rate in 293 children who were hospitalized in 302 Hospital of PLA from June 2006 to December 2013, met the inclusion criteria, received antiviral therapy, and were followed up for at least 6 months after the withdrawal of antiviral therapy. The t-test or the rank sum test was applied according to the distribution of continuous data, and the chi-square test was used for comparison of categorical data. Results: The HBsAg positive rate of children's mothers was 91.1%. In the age groups of >1-≤2 years, >2-≤3 years, >3-≤4 years, >4-≤5 years, >5-≤6 years, and >6-≤7 years, the HBsAg clearance rates were 66.1%, 65.5%, 45.7%, 41.3%, 20.6%, and 27.6%, respectively. There were significant differences in HBsAg clearance rate between the age groups of >1-≤3 years and >3-≤5 years, >1-≤3 years and >5-≤7 years, and >3-≤5 years and >5-≤7 years ( P = 0.001, 0.000, and 0.008). Of all children, 64.8% were boys, among whom 41.1% achieved HBsAg clearance, and 35.2% were girls, among whom 61.2% achieved HBsAg clearance; there was a significant difference in HBsAg clearance rate between boys and girls (P = 0.001). The children with pretreatment alanine aminotransferase (ALT) levels of ≤80 IU/L, > 80 IU/L, ≤200 IU/L, and > 200 IU/L had HBsAg clearance rates of 40.7%, 51.2%, 47.6%, and 49.4%, respectively; there were no significant differences in HBsAg clearance rate between the ALT ≤80 IU/L and ALT > 80 IU/L groups and the ALT ≤200 IU/L and ALT > 200 IU/L groups ( P = 0.101 and 0.778). There was no significant difference in HBsAg clearance rate between the pretreatment HBV DNA load antiviral therapy alone and had an HBsAg clearance rate of 48.8%, and 41.3% received interferon alone for 6 months followed by lamivudine antiviral therapy and

  19. Improved diagnostic performance of a commercial anaplasma antibody competitive enzyme-linked immunosorbent assay using recombinant major surface protein 5–glutathione S-transferase fusion protein as antigen

    Science.gov (United States)

    This study tested the hypothesis that removal of maltose binding protein from recombinant antigen used for plate coating would improve the specificity of Anaplasma antibody competitive ELISA. Three hundred and eight sera with significant MBP antibody binding (=30%I) in Anaplasma negative herds was 1...

  20. 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.

  1. Evaluation of an immunoradiometric assay protocol for determining ...

    African Journals Online (AJOL)

    BDL) for prostate-specific antigen (PSA) by an assay system are essential for successful prediction of recurrent disease after radical prostatectomy. A study was conducted to evaluate an Immunoradiometric Assay (IRMA) system to establish the ...

  2. A lateral electrophoretic flow diagnostic assay.

    Science.gov (United States)

    Lin, Robert; Skandarajah, Arunan; Gerver, Rachel E; Neira, Hector D; Fletcher, Daniel A; Herr, Amy E

    2015-03-21

    Immunochromatographic assays are a cornerstone tool in disease screening. To complement existing lateral flow assays (based on wicking flow) we introduce a lateral flow format that employs directed electrophoretic transport. The format is termed a "lateral e-flow assay" and is designed to support multiplexed detection using immobilized reaction volumes of capture antigen. To fabricate the lateral e-flow device, we employ mask-based UV photopatterning to selectively immobilize unmodified capture antigen along the microchannel in a barcode-like pattern. The channel-filling polyacrylamide hydrogel incorporates a photoactive moiety (benzophenone) to immobilize capture antigen to the hydrogel without a priori antigen modification. We report a heterogeneous sandwich assay using low-power electrophoresis to drive biospecimen through the capture antigen barcode. Fluorescence barcode readout is collected via a low-resource appropriate imaging system (CellScope). We characterize lateral e-flow assay performance and demonstrate a serum assay for antibodies to the hepatitis C virus (HCV). In a pilot study, the lateral e-flow assay positively identifies HCV+ human sera in 60 min. The lateral e-flow assay provides a flexible format for conducting multiplexed immunoassays relevant to confirmatory diagnosis in near-patient settings.

  3. Immune chromatography: a quantitative radioimmunological assay

    International Nuclear Information System (INIS)

    Davis, J.W.; Demetriades, M.; Bowen, J.M.

    1984-01-01

    Immune chromatography, a radioimmunological binding assay, employs paper chromatography to separate immune complexes from free antigen and antibodies. During chromatography free antigen and antibodies become distributed throughout the paper, while immune complexes remain near the bottoms of the strips. The chromatographic differences can be made quantitative by using either iodinated antigens or antibodies. Under these conditions nanogram quantities of antigen can be detected or antibodies in sera diluted several 1000-fold. The immune chromatography assay can also be performed as an indirect assay, since the paper strips are cut from nitrocellulose paper. In this case the immune components are absorbed by the paper during chromatography. Antigen is then detected with an iodinated second antibody. The indirect immune chromatography assay is particularly useful for identifying different sera that react with the same antigen. Reaction with the first serum before chromatography reduces the amount of antigen available to the second serum following chromatography. In addition to characterizing the immune chromatography procedure, we discuss the possible applications of chromatography assays for the quantitation of other types of molecular binding interactions. (Auth.)

  4. Potential infectivity of blood from HBsAG asymptomatic carriers due to the presence of HBV-DNA and comparison with other markers of hbv infection Potencial de infectividade em sangue de portadores assintomáticos de HBsAg caracterizado pela presença de HBV-DNA e comparação com outros marcadores da Hepatite B.

    Directory of Open Access Journals (Sweden)

    M. Valeria Tedeschi

    1989-12-01

    Full Text Available Serum samples from 356 HBsAg positive asymptomatic carriers, which were titrated by reverse passive hemagglutination, were analysed for the presence of HBV-DNA, HBsAg and IgM anti-HBc. The samples were divided in three classes, according to the titers of HBsAg and IgM anti-HBc and the distribution of HBV-DNA and HBsAg among these classes was studied. In the high titer class of HBsAg, 65% of samples have one or both markers against only 19% in the low titer class. From the total of 356 samples, 121 gave positive results for IgM anti-HBc (33.9%. From these, 38.9% of HBV-DNA and 47.9% of HBeAg were observed, whereas in samples with absence of IgM anti-HBc, 18.3% and 16.6% were respectively found. A higher frequency of agreement between all these markers was found in the class of high titers of HBsAg; however, HBV-DNA was detected in the low titer class of HBsAg and little or no IgM anti-HBc, showing potential blood infectivity even in HBsAg positive borderline samples.Em 356 soros HBsAg positivos de portadores assintomáticos, titulados por hemaglutinação passiva reversa, foi analisada a presença de HBV DNA, HBeAg e IgM anti-HBc, da seguinte forma: as amostras foram divididas em três classes de acordo com o título de HBsAg e IgM anti-HBc e foi verificada a distribuição de HBV DNA e HBsAg nestas classes. Em amostras com títulos elevados de HBsAg, 65% das amostras tiveram um ou ambos os marcadores HBV-DNA e HBsAg e as mesmas foram encontradas em apenas 19% das amostras com baixo título de HBsAg. Do total de 356 amostras, 121 foram positivas para IgM anti-HBc (33.9%. Destas, 38.9% de HBV-DNA e 47.9% de HBeAg foram observadas, ao passo que em amostras com ausência de IgM anti-HBc, 18.3% e 16.6% foram respectivamente encontrados. A concordância entre os três marcadores foi encontrada em. amostras com alto título de HBsAg, entretanto HBV-DNA foi também detectado em grupo de baixo título de HBsAg na ausência de IgM anti-HBc ou em n

  5. Enzyme assays.

    Science.gov (United States)

    Brodelius, P E

    1991-02-01

    The past year or so has seen the development of new enzyme assays, as well as the improvement of existing ones. Assays are becoming more rapid and sensitive as a result of modifications such as amplification of the enzyme product(s). Recombinant DNA technology is now being recognized as a particularly useful tool in the search for improved assay systems.

  6. Assessment of the repeatability and border-plate effects of the B158/B60 enzyme-linked-immunosorbent assay for the detection of circulating antigens (Ag-ELISA) of Taenia saginata.

    Science.gov (United States)

    Jansen, Famke; Dorny, Pierre; Berkvens, Dirk; Van Hul, Anke; Van den Broeck, Nick; Makay, Caroline; Praet, Nicolas; Gabriël, Sarah

    2016-08-30

    The monoclonal antibody-based circulating antigen detecting ELISA (B158/B60 Ag-ELISA) has been used elaborately in several studies for the diagnosis of human, bovine and porcine cysticercosis. Interpretation of test results requires a good knowledge of the test characteristics, including the repeatability and the effect of the borders of the ELISA plates. Repeatability was tested for 4 antigen-negative and 5 antigen-positive reference bovine serum samples by calculating the Percentage Coefficient of Variation (%CV) within and between plates, within and between runs, overall, for two batches of monoclonal antibodies and by 2 laboratory technicians. All CV values obtained were below 20% (except one: 24.45%), which indicates a good repeatability and a negligible technician error. The value of 24.45% for indicating the variability between batches of monoclonal antibodies for one positive sample is still acceptable for repeatability measures. Border effects were determined by calculating the %CV values between the inner and outer wells of one plate for 2 positive serum samples. Variability is a little more present in the outer wells but this effect is very small and no significant border effect was found. Copyright © 2016 Elsevier B.V. All rights reserved.

  7. A computational framework for influenza antigenic cartography.

    Science.gov (United States)

    Cai, Zhipeng; Zhang, Tong; Wan, Xiu-Feng

    2010-10-07

    Influenza viruses have been responsible for large losses of lives around the world and continue to present a great public health challenge. Antigenic characterization based on hemagglutination inhibition (HI) assay is one of the routine procedures for influenza vaccine strain selection. However, HI assay is only a crude experiment reflecting the antigenic correlations among testing antigens (viruses) and reference antisera (antibodies). Moreover, antigenic characterization is usually based on more than one HI dataset. The combination of multiple datasets results in an incomplete HI matrix with many unobserved entries. This paper proposes a new computational framework for constructing an influenza antigenic cartography from this incomplete matrix, which we refer to as Matrix Completion-Multidimensional Scaling (MC-MDS). In this approach, we first reconstruct the HI matrices with viruses and antibodies using low-rank matrix completion, and then generate the two-dimensional antigenic cartography using multidimensional scaling. Moreover, for influenza HI tables with herd immunity effect (such as those from Human influenza viruses), we propose a temporal model to reduce the inherent temporal bias of HI tables caused by herd immunity. By applying our method in HI datasets containing H3N2 influenza A viruses isolated from 1968 to 2003, we identified eleven clusters of antigenic variants, representing all major antigenic drift events in these 36 years. Our results showed that both the completed HI matrix and the antigenic cartography obtained via MC-MDS are useful in identifying influenza antigenic variants and thus can be used to facilitate influenza vaccine strain selection. The webserver is available at http://sysbio.cvm.msstate.edu/AntigenMap.

  8. 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)

  9. 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.

  10. Prognostic implications of recipient or donor hepatitis B seropositivity in thoracic transplantation: analysis of 426 hepatitis B surface antigen-positive recipients.

    Science.gov (United States)

    Manickam, P; Krishnamoorthi, R; Kanaan, Z; Gunasekaran, P K; Cappell, M S

    2014-08-01

    Prognostic data on survival of hepatitis B surface antigen-positive (HBsAg+) recipients and of hepatitis B core antibody-positive (HBcAb+) donors are limited in the thoracic transplantation (TT) cohort. Improved understanding of risks could potentially expand the recipient and donor pools. Post-hoc analysis of limited-access dataset of the United Network for Organ Sharing database from January 2000-September 2010 was performed. Analyses were performed for all TT, including single and bilateral lung, orthotopic heart, and simultaneous heart-lung transplants. The primary analyzed outcome was overall survival. A Cox proportional multivariate hazards model was used to adjust for significant risk predictors. Of 24,817 patients included, 426 recipients were HBsAg+, of whom 106 (25%) died during a mean follow-up of 3.6 years. On multivariate analysis, recipient HBsAg+ (hazard ratio [HR] = 0.88, 95% confidence interval [CI]: 0.69-1.32; P = 0.80), and donor HBcAb+ (HR = 0.91, 95% CI: 0.68-1.22; P = 0.53) were not associated with increased overall mortality in the entire TT cohort, with similar results for each individual transplant cohort. Unadjusted survival analysis using Kaplan-Meier curves in individual transplant cohorts did not show significant differences between HBsAg+ and HBsAg- recipients. No statistically significant differences were found between causes of mortality in the 2 groups. HBsAg+ status of recipients or HBcAb+ status of donors does not significantly affect overall survival of TT recipients. These data add to the scant literature on this subject and could potentially increase the donor and recipient pools. © 2014 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  11. Predicting response to HBV vaccination in people with positive anti-HBc but negative HBsAg and anti-HBs.

    Science.gov (United States)

    Kabir, Ali; Keshvari, Maryam; Kashani, Amir Hossein Faghihi; Alavian, Seyed-Moayed

    2008-01-01

    There are 5.1-6.5% of people with positive anti-HBc in Iran. The aim of this study was to assess the predicting factors of response to hepatitis B vaccination in anti-HBc positive subjects. Total response rate to vaccination was 79.8% (75 cases) and 67.9% (38 cases) in cases and controls, respectively. Nineteen persons (20.2%) in cases and 18 persons (32.1%) of controls had negative anti-HBs even after three doses of HB vaccination. Factor associated with decreased response to vaccination was prior history of being HBsAg positive (OR = 1.3, p = 0.01). In a quasi-experimental study, 94 people with negative HBsAg, negative anti-HBs and positive anti-HBc (cases) and 56 persons with negative HBsAg, anti-HBs and anti-HBc (controls) were vaccinated at zero, one and six months with recombinant hepatitis B vaccine. Successful immunization was defined by anti-HBs antibody titer > or =10 mIU/mL. The rate of response to hepatitis B vaccination is nearly like other studies but somewhat different. Higher percent of married cases together with higher percent of positive HBsAg in spouses may explain the slight difference in the response to vaccination in cases in comparison with controls as a result of booster like effect that seldom happens because of recurrent contacts between the subjects and the HBsAg positive spouses spontaneously.

  12. Quantificação de antígenos HLA classe I solúveis pela técnica de ELISA - DOI: 10.4025/actascihealthsci.v31i2.6758 Quantification of soluble HLA class I antigens by ELISA assay- DOI: 10.4025/actascihealthsci.v31i2.6758

    Directory of Open Access Journals (Sweden)

    Marciele Coan Boian

    2009-09-01

    Full Text Available As moléculas HLA (Human Leucocyte Antigens são consideradas, principalmente, estruturas de superfície celular envolvidas em uma variedade de reações imunes associadas com transplante, infecções e doenças autoimunes. Os antígenos HLA também podem ser encontrados, em forma solúvel, no soro e em diferentes fluidos do organismo humano. Este trabalho teve como objetivo desenvolver a técnica imunoenzimática (ELISA para quantificar os níveis séricos de antígenos HLA classe I, específicos e totais, em indivíduos normais e em pacientes renais. A técnica de ELISA foi desenvolvida para demonstrar a presença, no soro, de antígenos HLA classe I totais (sHLA-I e as especificidades HLA-A2 (sHLA-A2 e HLA-B7 (sHLA-B7. Oitenta e oito amostras de soro foram envolvidas neste estudo, sendo 61 amostras provenientes de indivíduos sadios cadastrados no Hemocentro Regional de Maringá, Estado do Paraná, e 27 pacientes renais, provenientes dos centros de diálise da cidade de Maringá, Estado do Paraná. As concentrações médias de sHLA para as especificidades -A2 e -B7, detectadas somente em indivíduos sadios, foram 504.06 ng mL-1 ± 142.10 e 427.33 ng mL-1 ± 140.73, respectivamente. Resultados preliminares mostraram que sHLA-I, em indivíduos sadios, foi de 253,77 ng mL-1 e, em indivíduos renais em diálise, de 381,67 ng mL-1. A técnica de ELISA para detecção de antígenos HLA solúveis poderá ser útil em estudos comparativos, em diferentes populações saudáveis, diferentes patologias e no monitoramento das rejeições em transplantes.HLA (Human Leucocyte Antigens molecules are regarded mainly as cell surface structures involved in several immune reactions associated with transplants, infections and auto-immune diseases. HLA antigens can be also found in soluble form in serum and in different fluids of the human body. The aim of this work was to develop the immunoenzymatic assay (ELISA to quantify serum levels of specific and total

  13. Characterisation of Sarcoptes scabiei antigens.

    Science.gov (United States)

    Hejduk, Gloria; Hofstätter, Katja; Löwenstein, Michael; Peschke, Roman; Miller, Ingrid; Joachim, Anja

    2011-02-01

    In pig herds, the status of Sarcoptes scabiei infections is routinely monitored by serodiagnosis. Crude antigen for ELISA is usually prepared from S. scabiei var. canis or other variations and may lead to variations in the outcome of different tests, making assay standardisation difficult. This study was performed to investigate the antigen profiles of S. scabiei, including differences between hydrophilic and more hydrophobic protein fractions, by Western blotting with sera from pigs with defined infection status. Potential cross-reactivity among S. scabiei (var. canis, suis and bovis), Dermatophagoides farinae and Tyrophagus putrescentiae was also analysed. Hydrophobic S. scabiei antigens were detectable in the range of 40-50 kDa, whilst the hydrophilic fraction showed no specific antigenicity. In the hydrophobic fractions of D. farinae and T. putrescentiae, two major protein fractions in a similar size range could be identified, but no cross-reactivity with Sarcoptes-positive sera was detectable. However, examination of the hydrophilic fractions revealed cross-reactivity between Sarcoptes-positive sera and both the house dust mite and the storage mite in the range of 115 and 28/38 kDa. Specific bands in the same range (42 and 48 kDa) could be detected in blots from hydrophobic fractions of all three tested variations of S. scabiei (var. canis, bovis and suis). These results show that there are considerable differences in mange antibody reactivity, including reactions with proteins from free-living mites, which may interfere with tests based on hydrophilic antigens. Further refinement of antigen and the use of specific hydrophobic proteins could improve ELISA performance and standardisation.

  14. Evaluation of risk factors for false-negative results with an antigen-specific peripheral blood-based quantitative T cell assay (T-SPOT®. TB) in the diagnosis of active tuberculosis: A large-scale retrospective study in China.

    Science.gov (United States)

    Yang, Chi; Zhang, Shaojun; Yao, Lan; Fan, Lin

    2018-01-01

    Objective To investigate the diagnostic efficacy of an interferon-γ release assay, T-SPOT ® . TB, for diagnosing active tuberculosis (TB) and to identify risk factors for false-negative results. Methods This retrospective study enrolled consecutive patients with active TB and with non-TB respiratory diseases to evaluate the risk factors for false-negative results when using the T-SPOT ® . TB assay for the diagnosis of active TB. Patients with active TB were categorized as having confirmed pulmonary TB, clinically diagnosed pulmonary TB or extrapulmonary TB (EPTB). Results This study analysed 4964 consecutive patients; 2425 with active TB and 2539 with non-TB respiratory diseases. Multivariate logistic regression analyses identified the following five factors that were all associated with an increased false-negative rate with the T-SPOT ® . TB assay: increased age (odds ratio [OR] 1.018; 95% confidence interval [CI] 1.013, 1.024); decreased CD8+ count (OR 0.307; 95% CI 0.117, 0.803); negative sputum acid-fast bacilli (AFB) smear staining (OR 1.821; 95% CI 1.338, 2.477); negative mycobacterial cultures (OR 1.379; 95% CI 1.043, 1.824); and absence of EPTB (OR 1.291; 95% CI 1.026, 1.623). Conclusions Increased age, decreased CD8+ count, negative sputum AFB smear results, negative sputum mycobacterial cultures and absence of EPTB might lead to an increased false-negative rate when using the T-SPOT ® . TB assay.

  15. A lateral electrophoretic flow diagnostic assay

    OpenAIRE

    Lin, R; Skandarajah, A; Gerver, RE; Neira, HD; Fletcher, DA; Herr, AE

    2015-01-01

    © 2015 The Royal Society of Chemistry. Immunochromatographic assays are a cornerstone tool in disease screening. To complement existing lateral flow assays (based on wicking flow) we introduce a lateral flow format that employs directed electrophoretic transport. The format is termed a "lateral e-flow assay" and is designed to support multiplexed detection using immobilized reaction volumes of capture antigen. To fabricate the lateral e-flow device, we employ mask-based UV photopatterning to ...

  16. 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.

  17. [Antigenic relations of several strains of Naegleria].

    Science.gov (United States)

    Zubiaur, E; Alonso, P

    1987-02-01

    In previous papers different aspects of one strain of Naegleria lovaniensis (Aq/9/1/45D) and two strains of N. gruberi (1518/le and 1518/lf) have been studied. From the results obtained it can be concluded that each strain behaves differently; no more similarities have been found between both N. gruberi strains, than between each of these and N. lovaniensis. Such an event has prompted us to characterize their antigenic relationships by means of an immunoprecipitation assay (double diffusion in plate). Each antiserum was tested against the different antigenic extracts. For N. lovaniensis, besides the whole extract, two fractions (particulate and soluble) and their respective antisera were assayed separately. No reaction occurred between any of the anti-N. lovaniensis sera and either of the two N. gruberi extracts. The antiserum to N. gruberi 1518/lf reacted only with its homologue and with N. lovaniensis antigens. Both N. lovaniensis fractions share some antigenic components being more complex the antigenic structure of the soluble fraction. Therefore no more similarities occur between both N. gruberi strains than between each one and N. lovaniensis, rather N. gruberi 1518/le exhibits more antigenic relationships with N. lovaniensis than with 1518/lf strains. In view of such results the species N. gruberi should be taxonomically reconsidered, criterium shared by other authors.

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

    CERN Document Server

    Garcia, 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.

  19. 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

  20. Bayesian nonparametric clustering in phylogenetics: modeling antigenic evolution in influenza.

    Science.gov (United States)

    Cybis, Gabriela B; Sinsheimer, Janet S; Bedford, Trevor; Rambaut, Andrew; Lemey, Philippe; Suchard, Marc A

    2018-01-30

    Influenza is responsible for up to 500,000 deaths every year, and antigenic variability represents much of its epidemiological burden. To visualize antigenic differences across many viral strains, antigenic cartography methods use multidimensional scaling on binding assay data to map influenza antigenicity onto a low-dimensional space. Analysis of such assay data ideally leads to natural clustering of influenza strains of similar antigenicity that correlate with sequence evolution. To understand the dynamics of these antigenic groups, we present a framework that jointly models genetic and antigenic evolution by combining multidimensional scaling of binding assay data, Bayesian phylogenetic machinery and nonparametric clustering methods. We propose a phylogenetic Chinese restaurant process that extends the current process to incorporate the phylogenetic dependency structure between strains in the modeling of antigenic clusters. With this method, we are able to use the genetic information to better understand the evolution of antigenicity throughout epidemics, as shown in applications of this model to H1N1 influenza. Copyright © 2017 John Wiley & Sons, Ltd. Copyright © 2017 John Wiley & Sons, Ltd.

  1. Comparison of Measurements of Autoantibodies to Glutamic Acid Decarboxylase and Islet Antigen-2 in Whole Blood Eluates from Dried Blood Spots Using the RSR-Enzyme Linked Immunosorbent Assay Kits and In-House Radioimmunoassays

    Directory of Open Access Journals (Sweden)

    Anders Persson

    2010-01-01

    Full Text Available To evaluate the performance of dried blood spots (DBSs with subsequent analyses of glutamic acid decarboxylase (GADA and islet antigen-2 (IA-2A with the RSR-ELISAs, we selected 80 children newly diagnosed with type 1 diabetes and 120 healthy women. DBSs from patients and controls were used for RSR-ELISAs while patients samples were analysed also with in-house RIAs. The RSR-ELISA-GADA performed well with a specificity of 100%, albeit sensitivity (46% was lower compared to in RIA (56%; P=.008. No prozone effect was observed after dilution of discrepant samples. RSR-ELISA-IA-2A achieved specificity of 69% and sensitivity was lower (59% compared with RIA (66%; P<.001. Negative or low positive patients and control samples in the RSR-ELISA-IA-2A increased after dilution. Eluates from DBS can readily be used to analyse GADA with the RSR-ELISA, even if low levels of autoantibodies were not detected. Some factor could disturb RSR-ELISA-IA-2A analyses.

  2. Clinical characteristics of patients with HBsAg(+ versus HBsAg(-/HBcAb(+ primary hepatic carcinoma treated by hepatectomy: a comparative analysis

    Directory of Open Access Journals (Sweden)

    YANG Keli

    2015-06-01

    Full Text Available ObjectiveTo explore the differences in clinical characteristics between patients with HBsAg(+ and HBsAg(-/HBcAb(+ primary hepatic carcinoma (PHC treated by hepatectomy. MethodsForty-three HBsAg(+ and 18 HBsAg(-/HBcAb(+ patients who underwent liver resection against PHC from October 2009 to November 2014 in Guangzhou 8th People′s Hospital were selected for the study. The clinical data of the subjects, including sex, age, histological differentiation, intravascular tumor thrombi, and hepatic cirrhosis, were compared, using t test for continuous data, chi-square test for categorical data, and Mann-Whitney U test for non-parametric data. ResultsNo significant differences existed between patients with HBsAg(+ and HBsAg(-/HBcAb(+ PHC in terms of the age of onset (50.77±12.93 years vs 54.28±9.89 years, t=-1.031, P>0.05, the incidence of cholangiocarcinoma (2.3% vs 167%, χ2=2.24, P>0.05, the incidence of hepatic cirrhosis (62.8% vs 44.4%, χ2=1.746, P>0.05, alpha-fetoprotein level (3638±7869 ng/ml vs 3577±9628 ng/ml, t=0.026, P>0.05, histological differentiation (Z=-1.085, P>0.05, and the rate of intravascular tumor thrombi (34.9% vs 22.2%, χ2=0.949, P>0.05. ConclusionThere are no significant differences in the age of onset and progression of disease between patients with HBsAg(+ and HBsAg(-/HBcAb(+ PHC treated by hepatectomy. However, given the possibility of occult hepatitis B virus infection, it is necessary to monitor hepatic carcinoma even post HBsAg seroconversion

  3. Hormone assay

    International Nuclear Information System (INIS)

    Eisentraut, A.M.

    1977-01-01

    An improved radioimmunoassay is described for measuring total triiodothyronine or total thyroxine levels in a sample of serum containing free endogenous thyroid hormone and endogenous thyroid hormone bound to thyroid hormone binding protein. The thyroid hormone is released from the protein by adding hydrochloric acid to the serum. The pH of the separated thyroid hormone and thyroid hormone binding protein is raised in the absence of a blocking agent without interference from the endogenous protein. 125 I-labelled thyroid hormone and thyroid hormone antibodies are added to the mixture, allowing the labelled and unlabelled thyroid hormone and the thyroid hormone antibody to bind competitively. This results in free thyroid hormone being separated from antibody bound thyroid hormone and thus the unknown quantity of thyroid hormone may be determined. A thyroid hormone test assay kit is described for this radioimmunoassay. It provides a 'single tube' assay which does not require blocking agents for endogenous protein interference nor an external solid phase sorption step for the separation of bound and free hormone after the competitive binding step; it also requires a minimum number of manipulative steps. Examples of the assay are given to illustrate the reproducibility, linearity and specificity of the assay. (UK)

  4. Disposable immunoassay for hepatitis B surface antigen based on a graphene paste electrode functionalized with gold nanoparticles and a Nafion-cysteine conjugate

    International Nuclear Information System (INIS)

    Huang, K.-J.; Li, J.; Liu, Y.-M.; Yu, S.; Yu, M.; Cao, X.

    2012-01-01

    We report on the modification of a graphene paste electrode with gold nanoparticles (AuNPs) and a Nafion-L-cysteine composite film, and how this electrode can serve as a platform for the construction of a novel electrochemical immunosensor for the detection of hepatitis B surface antigen (HBsAg). To obtain the immunosensor, an antibody against HBsAg was immobilized on the surface of the electrode, and this process was followed by cyclic voltammetry and electrochemical impedance spectroscopy. The peak currents of a hexacyanoferrate redox system decreased on formation of the antibody-antigen complex on the surface of the electrode. Then increased electrochemical response is thought to result from a combination of beneficial effects including the biocompatibility and large surface area of the AuNPs, the high conductivity of the graphene paste electrode, the synergistic effects of composite film, and the increased quantity of HBsAb adsorbed on the electrode surface. The differential pulse voltammetric responses of the hexacyanoferrate redox pair are proportional to the concentration of HBsAg in the range from 0. 5-800 ng mL -1 , and the detection limit is 0.1 ng mL -1 (at an S/N of 3). The immunosensor is sensitive and stable. (author)

  5. 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.

  6. Specific binding-adsorbent assay method and test means

    International Nuclear Information System (INIS)

    1981-01-01

    A description is given of an improved specific binding assay method and test means employing a nonspecific adsorbent for the substance to be determined, particularly hepatitis B surface (HBsub(s)) antigen, in its free state or additionally in the form of its immune complex. The invention is illustrated by 1) the radioimmunoadsorbent assay for HBsub(s) antigen, 2) the radioimmunoadsorbent assay for HBsub(s) antigen in the form of immune complex with antibody, 3) a study of adsorption characteristics of various anion exchange materials for HBsub(s) antigen, 4) the use of hydrophobic adsorbents in a radioimmunoadsorbent assay for HBsub(s) antigen and 5) the radioimmunoadsorbent assay for antibody to HBsub(s) antigen. The advantages of the present method for detecting HBsub(s) antigen compared to previous methods include the manufacturing advantages of eliminating the need for insolubilised anti-HBsub(s) and the advantages of a single incubation step, fewer manipulations, storability of adsorbent materials, increased sensitivity and versatility of detecting HBsub(s) antigen in the form of its immune complex if desired. (U.K.)

  7. Assessing stability and assembly of the hepatitis B surface antigen into virus-like particles during down-stream processing.

    Science.gov (United States)

    Zahid, Maria; Lünsdorf, Heinrich; Rinas, Ursula

    2015-07-17

    The hepatitis B surface antigen (HBsAg) is a recombinant protein-based vaccine being able to form virus-like particles (VLPs). HBsAg is mainly produced using yeast-based expression systems, however, recent results strongly suggest that VLPs are not formed within the yeast cells during the cultivation but are formed in a gradual manner during the following down-stream procedures. VLPs are also not detectable during the first down-stream steps including mechanical and EDTA/detergent-assisted cell destruction. Moreover, VLPs are not detectable in the cell lysate treated with polyethylene glycol and colloidal silica. The first VLP resembling structures appear after elution of HBsAg from colloidal silica to which it binds through hydrophobic interaction. These first VLP resembling structures are non-symmetrical as well as heterodisperse and exhibit a high tendency toward cluster formation presumably because of surface exposed hydrophobic patches. More symmetrical and monodisperse VLPs appear after the following ion-exchange and size-exclusion chromatography most likely as the result of buffer changes during these purification steps (toward more neutral pH and less salt). Final treatment of the VLPs with the denaturant KSCN at moderate concentrations with following KSCN removal by dialysis does not cause unfolding and VLP disassembly but results in a re- and fine-structuring of the VLP surface topology. Copyright © 2015 Elsevier Ltd. All rights reserved.

  8. Identification of an immunodominant epitope in glycoproteins B and G of herpes simplex viruses (HSVs) using synthetic peptides as antigens in assay of antibodies to HSV in herpes simplex encephalitis patients.

    Science.gov (United States)

    Bhullar, S S; Chandak, N H; Baheti, N N; Purohit, H J; Taori, G M; Daginawala, H F; Kashyap, R S

    2014-01-01

    Herpes simplex encephalitis (HSE) is a severe viral infection of the central nervous system (CNS). Assay of antibody response is widely used in diagnostics of HSE. The aim of this study was to identify an immunodominant epitope determining the antibody response to herpes simplex viruses (HSVs) in cerebrospinal fluid (CSF) of HSE patients. The synthetic peptides that resembled type-common as well as type-specific domains of glycoproteins B (gB) and G (gG) of these viruses were evaluated for binding with IgM and IgG antibodies in CSF samples from HSE and non-HSE patients in ELISA. The QLHDLRF peptide, derived from gB of HSV was found to be an immunodominant epitope in the IgM and IgG antibody response. The patients with confirmed and suspected HSE showed in ELISA against this peptide 26% and 23% positivities for IgM, 43% and 37% positivities for IgG and 17% and 15% for both IgM and IgG antibodies, respectively. The total positivities of 86% and 75% for both IgM and IgG antibodies were obtained in the patients with confirmed and suspected HSE, respectively. These results demonstrate that a synthetic peptide-based diagnostics of HSE can be an efficient and easily accessible alternative. This is the first report describing the use of synthetic peptides derived from HSVs in diagnostics of HSE using patientsʹ CSF samples.

  9. 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.

  10. 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.

  11. A toolbox for tuberculosis (TB diagnosis: an Indian multi-centric study (2006-2008; evaluation of serological assays based on PGL-Tb1 and ESAT-6/CFP10 antigens for TB diagnosis.

    Directory of Open Access Journals (Sweden)

    Philippe H Lagrange

    Full Text Available BACKGROUND: The aim of this multi-centric prospective study in India was to assess the accuracy of a serological test as an additional tool for diagnosing active tuberculosis (ATB. In particular, an assay based on ELISA using a phenolic glycolipid (PGL-Tb1 or a fusion protein (ESAT-6/CFP10 was compared to the tuberculin skin test (TST and the microbiological results according to HIV status. METHODS: Individuals with and without ATB and HIV infection were enrolled. Serology and TST results were analyzed per se and in combination with the microbiological data. RESULTS: Among the 778 ATB patients, 102 were HIV-infected, 316 HIV-uninfected and 360 had an HIV-unknown status. Of the 945 non-ATB subjects, 559 were at low risk (community adults and 386 at high risk of M. tuberculosis exposure. Among those with ATB, the sensitivity of ELISA-PGL-Tb1 for ATB was higher than that of ELISA-ESAT-6/CFP10, both in HIV-infected (72.3% versus 63.7%, p = 0.29 and HIV-uninfected/HIV-unknown groups (40.5% versus 28.6%; p<0.0001, whereas the specificity was around 91% for both tests. Sensitivity for ATB increased when the results of the two ELISA were combined, reaching 75.5% in the HIV-infected and 50.9% in the group of HIV-uninfected/HIV-unknown ATB, with a significant decrease of the global specificity (83.9%. Analyzing the ELISA results with the microbiological results, we observed that the sensitivity of both serology tests was independent of the ATB patients' smear microscopy (SM status and grade. Combining the results of SM with both ELISA, the detection of ATB patients significantly increased (p<0.0001, particularly in those with extrapulmonary TB (up to 45.1% or HIV infection (up to 83.3%. No significant association was observed between TST and serology results. CONCLUSIONS: In this prospective multi-centric study, the combination of two rapid tests, such as SM and serology, might be useful in detecting ATB, especially in HIV-infected patients.

  12. Prevalence of Serologic Hepatitis B Markers in Blood Donors From Puebla, Mexico: The Association of Relatively High Levels of Anti-Core Antibodies With the Detection of Surface Antigen and Genomic DNA.

    Science.gov (United States)

    Sosa-Jurado, Francisca; Hilda Rosas-Murrieta, Nora; Guzman-Flores, Belinda; Perez Zempoaltecalt, Cintia; Patricia Sanchez Torres, Ana; Ramirez Rosete, Leticia; Bernal-Soto, Maribel; Marquez-Dominguez, Luis; Melendez-Mena, Daniel; Angel Mendoza Torres, Miguel; Teresa Lopez Delgado, Maria; Reyes-Leyva, Julio; Vallejo-Ruiz, Veronica; Santos-Lopez, Gerardo

    2016-06-01

    The hepatitis B virus (HBV) causes chronic hepatitis, hepatic cirrhosis, and hepatocellular carcinoma. Surface antigen (HBsAg) detection is a definitive test that can confirm HBV infection, while the presence of antibodies against the core protein (anti-HBc) suggests either a previous or ongoing infection or occult hepatitis B infection (OBI). The aim of the present study was to determine the prevalence of anti-HBc and HBsAg in blood donors. Further, the study aimed to estimate the anti-HBc level at which HBV DNA is detected in putative OBI cases, as well as to search for mutations in the "a" determinant associated with the non-detection of HBsAg in serum. We conducted a cross-sectional study from 2003-2009. The study included 120,552 blood donors from the state of Puebla, Mexico. Different commercial systems based on microparticles (enzymatic (MEIA) or chemiluminescent (CMIA)) were used to determine the HBsAg and anti-HBc levels. For the detection of HBV DNA, a nested polymerase chain reaction (nested PCR) was used and the genotypes were determined using Sanger sequencing. Of the 120,552 blood donors, 1437 (1.19%, 95% CI: 1.12 - 1.26) were reactive to anti-HBc, while 82 (0.066%, 95% CI: 0.053 - 0.079) were reactive to HBsAg. Some 156 plasma samples collected in 2009 from anti-HBc-positive/HBsAg-negative blood donors were submitted for HBV DNA detection in a search for probable OBI. Viral DNA was detected in 27/156 (17.3%, 95% CI: 11.5 - 23.1). Our results show an association between HBV DNA or HBsAg and anti-HBc S/CO levels ≥ 4.0. All DNA samples were identified as genotype H and some "a" determinant mutations were identified, although none corresponded to mutations previously reported to hinder the detection of HBsAg by commercial immunoassays. We observed that as the anti-HBc levels increase, there is a higher prevalence of the viral protein HBsAg in blood donors. Samples testing positive for HBV-DNA were seen to exhibit a ten-fold higher presence of anti

  13. Prevalence of Serologic Hepatitis B Markers in Blood Donors From Puebla, Mexico: The Association of Relatively High Levels of Anti-Core Antibodies With the Detection of Surface Antigen and Genomic DNA

    Science.gov (United States)

    Sosa-Jurado, Francisca; Hilda Rosas-Murrieta, Nora; Guzman-Flores, Belinda; Perez Zempoaltecalt, Cintia; Patricia Sanchez Torres, Ana; Ramirez Rosete, Leticia; Bernal-Soto, Maribel; Marquez-Dominguez, Luis; Melendez-Mena, Daniel; Angel Mendoza Torres, Miguel; Teresa Lopez Delgado, Maria; Reyes-Leyva, Julio; Vallejo-Ruiz, Veronica; Santos-Lopez, Gerardo

    2016-01-01

    Background The hepatitis B virus (HBV) causes chronic hepatitis, hepatic cirrhosis, and hepatocellular carcinoma. Surface antigen (HBsAg) detection is a definitive test that can confirm HBV infection, while the presence of antibodies against the core protein (anti-HBc) suggests either a previous or ongoing infection or occult hepatitis B infection (OBI). Objectives The aim of the present study was to determine the prevalence of anti-HBc and HBsAg in blood donors. Further, the study aimed to estimate the anti-HBc level at which HBV DNA is detected in putative OBI cases, as well as to search for mutations in the “a” determinant associated with the non-detection of HBsAg in serum. Patients and Methods We conducted a cross-sectional study from 2003–2009. The study included 120,552 blood donors from the state of Puebla, Mexico. Different commercial systems based on microparticles (enzymatic (MEIA) or chemiluminescent (CMIA)) were used to determine the HBsAg and anti-HBc levels. For the detection of HBV DNA, a nested polymerase chain reaction (nested PCR) was used and the genotypes were determined using Sanger sequencing. Results Of the 120,552 blood donors, 1437 (1.19%, 95% CI: 1.12 - 1.26) were reactive to anti-HBc, while 82 (0.066%, 95% CI: 0.053 - 0.079) were reactive to HBsAg. Some 156 plasma samples collected in 2009 from anti-HBc-positive/HBsAg-negative blood donors were submitted for HBV DNA detection in a search for probable OBI. Viral DNA was detected in 27/156 (17.3%, 95% CI: 11.5 - 23.1). Our results show an association between HBV DNA or HBsAg and anti-HBc S/CO levels ≥ 4.0. All DNA samples were identified as genotype H and some “a” determinant mutations were identified, although none corresponded to mutations previously reported to hinder the detection of HBsAg by commercial immunoassays. Conclusions We observed that as the anti-HBc levels increase, there is a higher prevalence of the viral protein HBsAg in blood donors. Samples testing positive

  14. AntigenMap 3D: an online antigenic cartography resource.

    Science.gov (United States)

    Barnett, J Lamar; Yang, Jialiang; Cai, Zhipeng; Zhang, Tong; Wan, Xiu-Feng

    2012-05-01

    Antigenic cartography is a useful technique to visualize and minimize errors in immunological data by projecting antigens to 2D or 3D cartography. However, a 2D cartography may not be sufficient to capture the antigenic relationship from high-dimensional immunological data. AntigenMap 3D presents an online, interactive, and robust 3D antigenic cartography construction and visualization resource. AntigenMap 3D can be applied to identify antigenic variants and vaccine strain candidates for pathogens with rapid antigenic variations, such as influenza A virus. http://sysbio.cvm.msstate.edu/AntigenMap3D

  15. Antigens of Streptococcus sanguis

    Science.gov (United States)

    Rosan, Burton

    1973-01-01

    An antigenic analysis of the alpha-hemolytic streptococci isolated from dental plaque was performed by use of antisera against a strain of Streptococcus sanguis (M-5) which was isolated from dental plaque. Immunoelectrophoretic and Ouchterlony tests of Rantz and Randall extracts of 45 strains gave positive reactions with the M-5 antisera. These strains represented 60% of the strains tested. The number of antigens which could be identified in these extracts varied from one to five and were designated a to e. The a antigen was found in 36 of the strains tested, including reference strains of S. sanguis and the group H streptococci. The strains reacting with the M-5 antisera were divided into two majors types: type I consisted of 23 strains in which the a antigen was found alone or with one or more of the c, d, and e antigens; type II consisted of 13 strains in which both the a and b antigens were found with or without one or more of the c, d, and e antigens. The remaining strains contained, either singly or in combination, the b, c, d, and e antigens but not the a antigen. Biochemical tests of representatives of each serotype and reference strains indicated that strains reacting with M-5 antisera were S. sanguis. These findings suggest that S. sanguis strains share common physiological and serological properties. Images PMID:4633291

  16. Radioreceptor assays

    International Nuclear Information System (INIS)

    Lapka, R.

    1985-01-01

    Radioreceptor assay (RRA) is an analytical method using the specific interaction of some pharmaceuticals and endogenic substances (ligands) with specific receptors present in certin tissues of living organisms. RRA uses the principle of isotope dilution. The method is described in detail of the preparation of receptors, samples and radioligands, conditions of incubation, the separation of free and bound radioligand, and the mathematical evaluation of RRA. The sensitivity of RRA is measured in units to tens of pg. The specificity of RRA relates to a group of substances with similar pharmacological effect. RRA may be used for identifying neuroleptics, antidepressants, anxiolytics, ergot alkaloids, beta blockers, anticholinergic drugs, certain hormones and neuropeptides. (M.D.)

  17. Designing of enzyme linked immunosorbent assay (ELISA) kit for ...

    African Journals Online (AJOL)

    The sensitivity of microscopic examination of fecal samples to recognize Giardia parasites is low. In the methods based on antigen scanning of parasites such as enzyme linked immunosorbent assay (ELISA), copro-antigens of parasite will be traced and diagnosed even if the live parasite is absent in the fecal samples.

  18. [Retrospective evaluation of HBsAg, anti-HCV, anti-HIV and syphilis reagin antibody seropositivity in blood donors at the Trabzon Farabi Hospital].

    Science.gov (United States)

    Aydin, Faruk; Cubukçu, Kivanç; Yetişkul, Serpil; Yazici, Yelda; Kaklikkaya, Neşe

    2002-01-01

    Transfusion of blood and blood products is a widely used method for therapy in medicine, however it may result with the transmission of infectious agents from donor to recipient. In order to achieve safe blood transfusions and to minimize post-transfusion infections, several screening tests for infectious agents are routinely done all around the world as well as in our country. In this study, HBsAg, anti-HCV, anti-HIV and syphilis reagin antibody tests results have been retrospectively evaluated for 33.766 blood donors during January 1, 1997 to December 31, 2000 in Blood Center of Farabi Hospital, Black Sea Technical University. Testing for HBsAg, anti-HIV and anti-HCV has been done by using commercially available micro and/or macro enzyme immunoassays, and syphilis reagin antibody test by latex agglutination (RPR) method. The indeterminate results were confirmed by retesting of sera with microparticle enzyme immunoassay and Western blot methods. As a result, in 1331 (3.94%) subjects HBsAg, in 250 (0.74%) subjects anti-HCV, and in 161 (0.47%) subjects RPR were found positive. Twenty samples which have had the results in gray-zone for anti-HIV, have been found negative with the confirmation tests.

  19. New diagnostic antigens for early trichinellosis: the excretory-secretory antigens of Trichinella spiralis intestinal infective larvae.

    Science.gov (United States)

    Sun, Ge Ge; Liu, Ruo Dan; Wang, Zhong Quan; Jiang, Peng; Wang, Li; Liu, Xiao Lin; Liu, Chun Yin; Zhang, Xi; Cui, Jing

    2015-12-01

    The excretory-secretory (ES) antigens from Trichinella spiralis muscle larvae (ML) are the most commonly used diagnostic antigens for trichinellosis, but anti-Trichinella IgG antibodies cannot be detected until 2-3 weeks after infection; there is an obvious window period between Trichinella infection and antibody positivity. Intestinal infective larvae (IIL) are the first invasive stage during Trichinella infection, and their ES antigens are firstly exposed to the immune system and might be the early diagnostic markers of trichinellosis. The aim of this study was to evaluate the early diagnostic values of IIL ES antigens for trichinellosis. The IIL were collected from intestines of infected mice at 6 h postinfection (hpi), and IIL ES antigens were prepared by incubation for 18 h. Anti-Trichinella IgG antibodies in mice infected with 100 ML were detectable by ELISA with IIL ES antigens as soon as 10 days postinfection (dpi), but ELISA with ML ES antigens did not permit detection of infected mice before 12 dpi. When the sera of patients with trichinellosis at 19 dpi were assayed, the sensitivity (100 %) of ELISA with IIL ES antigens was evidently higher than 75 % of ELISA with ML ES antigens (P < 0.05) The specificity (96.86 %) of ELISA with IIL ES antigens was also higher than 89.31 % of ELISA with ML ES antigens (P < 0.05). The IIL ES antigens provided a new source of diagnostic antigens and could be considered as a potential early diagnostic antigen for trichinellosis.

  20. Comparison of Batch Assay and Random Assay Using Automatic Dispenser in Radioimmunoassay

    Energy Technology Data Exchange (ETDEWEB)

    Moon, Seung Hwan; Jang, Su Jin; Kang, Ji Yeon; Lee, Dong Soo; Chung, June Key; Lee, Myung Chul [Seoul Metropolitan Government Seoul National University Boramae Medical Center, Seoul (Korea, Republic of); Lee, Ho Young; Shin, Sun Young; Min, Gyeong Sun; Lee, Hyun Joo [Seoul National University college of Medicine, Seoul (Korea, Republic of)

    2009-08-15

    Radioimmunoassay (RIA) was usually performed by the batch assay. To improve the efficiency of RIA without increase of the cost and time, random assay could be a choice. We investigated the possibility of the random assay using automatic dispenser by assessing the agreement between batch assay and random assay. The experiments were performed with four items; Triiodothyronine (T3), free thyroxine (fT4), Prostate specific antigen (PSA), Carcinoembryonic antigen (CEA). In each item, the sera of twenty patients, the standard, and the control samples were used. The measurements were done 4 times with 3 hour time intervals by random assay and batch assay. The coefficient of variation (CV) of the standard samples and patients' data in T3, fT4, PSA, and CEA were assessed. ICC (Intraclass correlation coefficient) and coefficient of correlation were measured to assessing the agreement between two methods. The CVs (%) of T3, fT4, PSA, and CEA measured by batch assay were 3.2+-1.7%, 3.9+-2.1%, 7.1+-6.2%, 11.2+-7.2%. The CVs by random assay were 2.1+-1.7%, 4.8+-3.1%, 3.6+-4.8%, and 7.4+-6.2%. The ICC between the batch assay and random assay were 0.9968 (T3), 0.9973 (fT4), 0.9996 (PSA), and 0.9901 (CEA). The coefficient of correlation between the batch assay and random assay were 0.9924(T3), 0.9974 (fT4), 0.9994 (PSA), and 0.9989 (CEA) (p<0.05). The results of random assay showed strong agreement with the batch assay in a day. These results suggest that random assay using automatic dispenser could be used in radioimmunoassay

  1. Hepatitis B virus activity in patients with anti-hepatitis C virus antibody positivity and hepatitis B antigen positivity.

    Science.gov (United States)

    Haushofer, Alexander C; Hauer, René; Brunner, Harald; Köller, Ursula; Trubert-Exinger, Doris; Halbmayer, Walter Michael; Haas, Josef; Kessler, Harald H

    2002-12-01

    Co-infection with hepatitis B virus (HBV) and HCV seems to be relatively frequent. There might be a mutual influence on replication activity of HBV and HCV. To determine the HBV activity in patients with serum HCV RNA and HBsAg positivity and in those with confirmed anti-HCV antibody and HBsAg positivity but serum HCV RNA negativity. A total of 1,200 anti-HCV antibody positive samples were investigated. Samples of HCV RNA and HBsAg positive patients were compared with those of confirmed anti-HCV and HBsAg positive but serum HCV RNA negative patients. HBV activity was tested with the quantitative Cobas Amplicor HBV Monitor Test (Roche Diagnostic Systems, Pleasanton, CA). Of all studied patients with chronic hepatitis C (serum HCV RNA positivity) only 1.0% were found to be HBsAg positive. In contrast, of all patients with confirmed anti-HCV positivity but serum HCV RNA negativity, 11.9% tested HBsAg positive. The median of HBV DNA levels of patients with serum HCV RNA positivity and HBeAg seroconversion (4.0 x 10(2) HBV DNA copies per ml) was found to be slightly lower than that of patients with serum HCV RNA negativity and HBeAg seroconversion (2.5 x 10(3) HBV DNA copies per ml; P>0.05). The median of HBV DNA levels of patients with serum HCV RNA positivity but without HBeAg seroconversion (1.1 x 10(4) HBV DNA copies per ml) was found to be significantly lower than that of patients with serum HCV RNA negativity but without HBeAg seroconversion (2.6 x 10(7) HBV DNA copies per ml; P<0.05). A mutual effect on HBV and HCV replication could be observed. The molecular assay for quantification of serum HBV DNA was found to be useful for the routine diagnostic laboratory.

  2. 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.

  3. Eosinofil Sel Penyaji Antigen

    Directory of Open Access Journals (Sweden)

    Safari Wahyu Jatmiko

    2015-04-01

    Full Text Available Sel eosinofil merupakan jenis sel lekosit yang terlibat dalam berbagai patogenesis penyakit. Sel eosinofil pada awalnya dikenal sebagai sel efektor  dari sistem imunitas alamiah. Akan tetapi, kemampuan sel eosinofil dalam memfagositosis patogen menimbulkan dugaan bahwa sel eosinofil ikut berperan sebagai sel penyaji antigen. Hal ini dianalogikan dengan sel makrofag dan sel dendritik yang bisa memfagositosis dan menyajikan antigen sebagai hasil dari degradasi patogen yang difagositosis. Untuk menjawab permasalahan ini, penulis melakukan penelusuran artikel tentang eosinofil sebagai sel penyaji antigen melalui US National Library of Medicine National Institute of Healthdengan kata kunci eoshinophil dan antigen presenting cell. Hasil penelusuran adalah ditemukannya 10 artikel yang relevan dengan topik. Hasil dari sintesis kesepuluh jurnal tersebut adalah sel eosinofil mampu berperan sebagai sel penyaji antigen yang profesional (professionalantigenpresentng cell

  4. Lea blood group antigen on human platelets

    Energy Technology Data Exchange (ETDEWEB)

    Dunstan, R.A.; Simpson, M.B.; Rosse, W.F.

    1985-01-01

    One- and two-stage radioligand assays were used to determine if human platelets possess the Lea antigen. Goat IgG anti-Lea antibody was purified by multiple adsorptions with Le(a-b-) human red blood cells, followed by affinity chromatography with synthetic Lea substance and labeling with /sup 125/I. Human IgG anti-Lea antibody was used either in a two stage radioassay with /sup 125/I-labeled mouse monoclonal IgG anti-human IgG as the second antibody or, alternatively, purified by Staph protein A chromatography, labeled with /sup 125/I, and used in a one-stage radioassay. Platelets from donors of appropriate red blood cell phenotypes were incubated with the antisera, centrifuged through phthalate esters, and assayed in a gamma scintillation counter. Dose response and saturation curve analysis demonstrate the presence of Lewis a antigen on platelets from Lea+ donors. Furthermore, platelets from an Le(a-b-) donor incubated in Le (a+b-) plasma adsorb Lea antigen in a similar manner to red blood cells. The clinical significance of these antigens in platelet transfusion remains undefined.

  5. Antigen-binding radioimmunoassays for human IgG antibodies to bovine ν-lactoglobulin

    International Nuclear Information System (INIS)

    Turner, M.W.; Paganelli, R.; Levinsky, R.J.; Williams, A.

    1983-01-01

    A double antibody antigen-binding assay for the detection of human IgG antibodies to the bovine milk allergen ν-lactoglobulin is described. The levels of such antibodies in patients with established cows' milk protein intolerance were significantly higher than the levels observed in a healthy control group (P<0.01). The assay showed excellent correlation with a solid phase antigen binding assay (rsub(s) = 0.8, P<0.001). (Auth.)

  6. Use of antigenic cartography in vaccine seed strain selection.

    Science.gov (United States)

    Fouchier, Ron A M; Smith, Derek J

    2010-03-01

    Human influenza A viruses are classic examples of antigenically variable pathogens that have a seemingly endless capacity to evade the host's immune response. The viral hemagglutinin (HA) and neuraminidase (NA) proteins are the main targets of our antibody response to combat infections. HA and NA continuously change to escape from humoral immunity, a process known as antigenic drift. As a result of antigenic drift, the human influenza vaccine is updated frequently. The World Health Organization (WHO) coordinates a global influenza surveillance network that, by the hemagglutination inhibition (HI) assay, routinely characterizes the antigenic properties of circulating strains in order to select new seed viruses for such vaccine updates. To facilitate a quantitative interpretation and easy visualization of HI data, a new computational technique called "antigenic cartography" was developed. Since its development, antigenic cartography has been applied routinely to assist the WHO with influenza surveillance activities. Until recently, antigenic variation was not considered a serious issue with influenza vaccines for poultry. However, because of the diversification of the Asian H5N1 lineage since 1996 into multiple genetic clades and subclades, and because of the long-term use of poultry vaccines against H5 in some parts of the world, this issue needs to be re-addressed. The antigenic properties of panels of avian H5N1 viruses were characterized by HI assay, using mammalian or avian antisera, and analyzed using antigenic cartography methods. These analyses revealed antigenic differences between circulating H5N1 viruses and the H5 viruses used in poultry vaccines. Considerable antigenic variation was also observed within and between H5N1 clades. These observations have important implications for the efficacy and long-term use of poultry vaccines.

  7. Urinary tract infection: detection of Escherichia coli antigens in human urine with an ELIEDA immunoenzymatic assay Las infecciones urinarias: detección de antígenos de Escherichia coli en orina humana con un ensayo inmunoenzimático por electrodifusión (ELIEDA

    Directory of Open Access Journals (Sweden)

    Myriam T. N. Campanhã

    1999-08-01

    Full Text Available Escherichia coli is the most common causative agent of urinary tract infection (UTI, and diagnosing this infection usually relies on bacteriologic methods. Nevertheless, screening methods can be useful for a rapid presumptive diagnosis even though some of these screening methods have low sensitivity or are expensive. To investigate a possible new alternative approach, an antigen-based immunoassay-enzyme-linked immunoelectrodiffusion assay (ELIEDA-was standardized for screening for this bacterial infection. Combining counter immunoelectrophoresis with an immunoenzymatic assay, the ELIEDA requires concentrated urine specimens, a cellulose acetate membrane, polyclonal antibodies to E. coli raised in rabbits, and peroxidase-labeled sheep antibodies to rabbit immunoglobulin G (IgG. This ELIEDA technique was evaluated using 244 urine specimens, 76 of them with E. coli, 47 with heterologous bacteria, and 121 without bacteria. In comparison to bacteriologic methods, the sensitivity, specificity, and positive and negative predictive values for the ELIEDA were 93.4%, 98.2%, 95.9%, and 97.1%, respectively. The data obtained suggest that this assay is useful for routine diagnostic screening for UTI caused by E. coli. In addition, since the ELIEDA stained membranes can be stored, this assay makes retrospective studies possible.Escherichia coli es el agente causal más frecuente de las infecciones urinarias (IU, cuyo diagnóstico suele basarse en métodos bacteriológicos. No obstante, los métodos de tamizaje pueden ser útiles para hacer un diagnóstico preliminar con rapidez, pese a que algunos de ellos tienen poca sensibilidad y son caros. Con el fin de investigar la posibilidad de usar otra técnica de diagnóstico, se estandarizó un inmunoensayo de tipo antigénico-ensayo inmunoenzimático por electrodifusión (ELIEDA, por enzyme-linked immunoelectrodiffusion assay-para hacer el tamizaje de este tipo de infección. El ELIEDA, que consiste en el uso

  8. 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

  9. [Enterobacterial antigen in human peripheral blood lymphocytes].

    Science.gov (United States)

    Faure-Fontenla, M A; García-Tamayo, F

    1989-11-01

    The following study has as prior history the research reports which have shown the existence of an antigenic tissue deposit in gram-negative enterobacteria. The antigens of the enterobacteria have also been found in the lymphocytic membranes and cytoplasm. Since intestinal lymphoid tissue cells can recirculate by means of the thoracic duct to the peripheral venous system, it was proposed that the circulating lymphocytes in healthy people could also contain small amounts of a common enterobacterial antigen. The study was carried out in 15 human venous blood samples, of which the lymphocytic population was separated to later be used in the preparation of 15 alcohol soluble extracts. This material was used for inhibiting the immuno-hemolysis assay in three occasions in order to show the presence of antigens shared by different enterobacterias, using as reference a fraction separated from the LPS of Escherichia coli 08. The results showed that the human lymphocytes also had antigenic determinants common to gram-negative bacteria.

  10. Original Research Prevalence of antibody to hepatitis B core antigen ...

    African Journals Online (AJOL)

    In blood banks, screening for HBsAg is carried out routinely to detect current or previous HBV infection. Occult HBV infection is defined as the presence of HBV DNA in blood or liver tissues in patients negative for HBsAg but who may or may not be positive for HBV antibodies.3 Thus, the absence of HBsAg in the blood of.

  11. Low cut-off values increase diagnostic performance of protein S assays

    NARCIS (Netherlands)

    Mulder, Rene; ten Kate, Min Ki; Kluin-Nelemans, Hanneke C.; Mulder, Andre B.

    Conflicting data have been reported on the accuracy of protein S (PS) assays for detection of hereditary PS deficiency. In this study we assessed the diagnostic performance of two total PS antigen assays, four free PS assays and three PS activity assays in a group of 28 heterozygous carriers of

  12. Laboratory Validation of the Sand Fly Fever Virus Antigen Assay

    Science.gov (United States)

    2015-12-01

    2015 14. ABSTRACT Sandfly fever group viruses in the genus Phlebovirus (family Bunyaviridae) are widely distributed across the globe and are a cause ...Sandfly fever group viruses in the genus Phlebovirus (family Bunyaviridae) are widely distributed across the globe and are a cause of disease in... causes sporadic epidemics of Pappataci fevers in humans (Brett-Major and Claborn 1997). Rift Valley fever virus and Arumowot virus are transmitted by

  13. 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.

  14. Reduced prevalence of hepatitis B surface antigen positivity among pregnant women born after the national implementation of immunoprophylaxis for babies born to hepatitis B virus-carrier mothers in Japan.

    Science.gov (United States)

    Sugiyama, Aya; Ohisa, Masayuki; Nagashima, Shintaro; Yamamoto, Chikako; Chuon, Channarena; Fujii, Toshiko; Akita, Tomoyuki; Katayama, Keiko; Kudo, Yoshiki; Tanaka, Junko

    2017-11-01

    We aimed to estimate hepatitis B surface antigen (HBsAg) positivity among birth year-stratified pregnant women in Hiroshima, Japan, and compare prevalence rates between women born before and after implementation of a national immunoprophylactic vaccination program for babies born to hepatitis B virus (HBV) carrier mothers in Japan. Pregnant women who gave birth at all delivery hospitals/clinics in Hiroshima prefecture between 1 April 2010 and 31 March 2011 were eligible. Lists collected from each institution included survey items such as age (pregnant woman's birth year) and HBsAg and hepatitis C virus (HCV) antibody (anti-HCV) test results, which were posted anonymously and non-consolidated from medical records. We calculated the HBsAg and anti-HCV prevalence in our cohort according to the mothers' birth year. In 41 of 58 hospitals/clinics, 15 233 and 15 035 pregnant women underwent HBsAg and anti-HCV testing, corresponding to 59.6% and 58.9% of 25 546 births in the 2010 fiscal year, respectively. The overall HBsAg positive rate was 0.51% (95% confidence interval [CI], 0.40-0.63%), and an extremely low prevalence (0.10%; 95% CI, 0.00-0.25%) was observed among pregnant women born after 1986. However, the prevalence in this study was slightly higher than the nationwide value (0.31%) and the Chugoku region-specific value (0.46%) among first-time blood donors at Japanese Red Cross blood centers between 2001 and 2006. No significant difference in anti-HCV positivity was observed. Only two pregnant women born after the preventive program implementation were HBsAg-positive. Perinatal HBV transmission is estimated to be almost completely inhibited in the next generation. © 2017 The Authors. Hepatology Research published by John Wiley & Sons Australia, Ltd on behalf of Japan Society of Hepatology.

  15. Dysregulated Response of Follicular Helper T cells to Hepatitis B Surface Antigen Promotes HBV Persistence in Mice and Associates With Outcomes of Patients.

    Science.gov (United States)

    Wang, Xiaowen; Dong, Qingyang; Li, Qian; Li, Yuanyuan; Zhao, Dianyuan; Sun, Jinjie; Fu, Junliang; Meng, Fanping; Lin, Hu; Luan, Junjie; Liu, Biao; Wang, Min; Wang, Fusheng; He, Fuchu; Tang, Li

    2018-03-12

    Production of neutralizing antibodies against hepatitis B surface antigen (HBsAg) is dysregulated in patients with persistent hepatitis V virus (HBV) infection. We investigated mechanisms by which this immune response to the virus is disrupted and whether it can be restored to promote clearance of HBV. Immune-competent C57BL/6N and C57BL/6J, as well as mice deficient in follicular helper T cells (Tfh cell-deficient), B cells, or Foxp3 + T-regulatory cells (Treg cell-deficient), were given hydrodynamic injections of pAAV/HBV1.2 plasmids. Some mice were given injections of sorted Tfh cells, pan-B cells, Treg cells, or a blocking antibody against CTLA4. Production of antibodies against HBsAg and clearance of HBV were assessed by flow cytometry, ELISA, PCR and immunohistochemical analyses. We obtained blood samples from patients with HBV infection and isolated Treg cells. We measured the ability of Treg cells to suppress production of interleukin 21 (IL21) in CD4 + T cells. Immune-competent C57BL/6N and C57BL/6J mice transfected with the plasmid encoding HBV had features of viral clearance and viral persistence observed in humans. A Tfh-cell response to HBsAg was required for clearance of HBV and was suppressed by Treg cells in mice with persistent HBV infection. Depletion of Treg cells or inhibition of Treg-cell function (with blocking antibody against CTLA4) restored the Tfh-cell response against HBsAg and clearance of HBV in mice. Impaired Tfh cell response to HBsAg was observed in blood from patients with chronic HBV infection, responsiveness was restored by depletion of Treg cells or blocking antibody against CTLA4. In studies of HBV-infected mice and blood from patients with chronic HBV infection, we found a Tfh-cell response to HBsAg of to be required for HBV clearance, and that this response was blocked by Treg cells. Inhibiting Treg cell activity using neutralizing antibody against CTLA4 restored the ability of Tfh cells to clear HBV infection; this approach

  16. Understanding early serum hepatitis D virus and hepatitis B surface antigen kinetics during pegylated interferon-alpha therapy via mathematical modeling.

    Science.gov (United States)

    Guedj, Jeremie; Rotman, Yaron; Cotler, Scott J; Koh, Christopher; Schmid, Peter; Albrecht, Jeff; Haynes-Williams, Vanessa; Liang, T Jake; Hoofnagle, Jay H; Heller, Theo; Dahari, Harel

    2014-12-01

    There is little information on the early kinetics of hepatitis delta virus (HDV) and hepatitis B surface antigen (HBsAg) during interferon-α therapy. Here a mathematical model was developed and fitted to frequent HDV and HBsAg kinetic data from 10 patients during the first 28 weeks of pegylated-interferon-α2a (peg-IFN) therapy. Three patients achieved a complete virological response (CVR), defined as undetectable HDV 6 months after treatment stopped with loss of HBsAg and anti-HBsAg seroconversion. After initiation of therapy, a median delay of 9 days (interquartile range [IQR]: 5-15) was observed with no significant changes in HDV level. Thereafter, HDV declined in a biphasic manner, where a rapid first phase lasting for 25 days (IQR: 23-58) was followed by a slower or plateau second phase. The model predicts that the main effect of peg-IFN is to reduce HDV production/release with a median effectiveness of 96% (IQR: 93-99.8). Median serum HDV half-life (t1/2 ) was estimated as 2.9 days (IQR: 1.5-5.3) corresponding to a pretreatment production and clearance of about 10(10) (IQR: 10(9.7) -10(10.7) ) virions/day. None of the patients with flat second phase in HDV achieved CVR. HBsAg kinetics of decline paralleled the second phase of HDV decline consistent with HBsAg-productive-infected cells being the main source of production of HDV, with a median t1/2 of 135 days (IQR: 20-460). The interferon lambda-3 polymorphism (rs12979860) was not associated with kinetic parameters. Modeling results provide insights into HDV-host dynamics, the relationship between serum HBsAg levels and HBsAg-infected cells, IFN's mode of action, and its effectiveness. The observation that a flat second phase in HDV and HBsAg kinetics was associated with failure to achieve CVR provides the basis to develop early stopping rules during peg-IFN treatment in HDV-infected patients. © 2014 by the American Association for the Study of Liver Diseases. This article has been contributed to by U

  17. Standardization of an enzyme linked immunosorbent assay (ELISA for detecting circulating toxic venom antigens in patients stung by the scorpion Tityus serrulatus Padronização de um teste imunoenzimático (ELISA para detectar antígenos tóxicos circulantes do veneno em pacientes picados pelo escorpião Tityus serrulatus

    Directory of Open Access Journals (Sweden)

    Nilton Alves de Rezende

    1995-02-01

    Full Text Available The sensitivity and specificity of an enzyme-linked immunosorbent assay (ELISA for the detection of circulating antigens from toxic components of Tityus serrulatus scorpion venom was determined in patients stung by T. serrulatus before antivenom administration. Thirty-seven patients were classified as mild cases and 19 as moderate or severe cases. The control absorbance in the venom assay was provided by serum samples from 100 individuals of same socioeconomic group and geographical area who had never been stung by scorpions or treated with horse antisera. The negative cutoff value (mean + 2 SD corresponded to a venom concentration of 4.8 ng/ml. Three out of the 100 normal sera were positive, resulting in a specificity of 97%. The sensitivity of the ELISA when all cases of scorpion sting were included was 39.3%. When mild cases were excluded, the sensitivity increased to 94.7%. This study showed that this ELISA can be used for the detection of circulating venom toxic antigens in patients with systemic manifestations following. T. serrulatus sting but cannot be used for clinical studies in mild cases of envenoming since the test does not discriminate mild cases from control patients.Neste trabalho foram determinadas a sensibilidade e a especificidade da técnica imunoenzimática (ELISA desenvolvida por CHAVÉZ-OLORTEGUI et al. para detectar antígenos circulantes de veneno em pacientes picados po Tityus serrulatus. A média mais dois desvios padrão da observância do soro de 100 pacientes controles foi utilizada como limite entre teste positivo e teste negativo ("cutoff". A especificidade do ELISA foi igual a 97,0%. A sensibilidade do método, quando incluidos pacientes classificados como casos leves, moderados e graves de escorpionismo, foi de 39,3% e aumentou para 94,7% quando considerados apenas os casos moderados e graves. Estes resultados mostram que o ELISA pode ser utilizado para detecção de antígenos tóxicos circulantes em pacientes

  18. 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.

  19. 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)

  20. Coexistence of hepatitis B surface antigen and antibody to hepatitis B surface may increase the risk of hepatocellular carcinoma in chronic hepatitis B virus infection: a retrospective cohort study.

    Science.gov (United States)

    Seo, Seung In; Choi, Hyeok Soo; Choi, Bo Youn; Kim, Hyoung Su; Kim, Hak Yang; Jang, Myoung Kuk

    2014-01-01

    The simultaneous detection of hepatitis B surface antigen (HBsAg) and antibody to hepatitis B surface (anti-HBs) is unusual in chronic hepatitis B virus (HBV) infection, but may be related with more advanced liver diseases. This retrospective long-term cohort study was aimed to investigate whether coexistence of HBsAg and anti-HBs may increase the risk of hepatocellular carcinoma (HCC) in chronic HBV infection. A total of 1,042 non-HCC patients were recruited and followed up for a median 4.3 years (range 1.0-22 years). Univariate and multivariate analyses were performed to identify the risk factors for HCC development. The prevalence of coexistence of HBsAg and anti-HBs was 7.0% (73/1,042). In univariate analysis, the 5-, 10-, and 15-year cumulative incidences of HCC were significantly higher in coexistence group than in HBsAg only group (12.7%, 23.4%, 69.4% vs. 4.9%, 13%, 20.6%, respectively; P = 0.008). In multivariate analysis, coexistence of HBsAg and anti-HBs [Hazard ratio (HR), 2.001; 95% confidence interval (CI), 1.023-3.912; P = 0.043] as well as male gender [HR, 1.898; 95% CI, 0.31-0.896; P = 0.018], age over 40 years [HR, 14.56; 95% CI, 4.499-47.08; P = 0.0001], and cirrhosis [HR, 7.995; 95% CI, 4.756-13.439; P = 0.0001] was identified as the independent factor for HCC development. Also, the cumulative incidence of HCC increased in proportion to the number of the risk factors. In conclusion, coexistence of HBsAg and anti-HBs may increase independently the risk of HCC development in chronic HBV infection. Therefore, consideration of HCC development is required in patients with coexistence of HBsAg and anti-HBs. © 2013 Wiley Periodicals, Inc.

  1. Serotype determination of Salmonella by xTAG assay.

    Science.gov (United States)

    Zheng, Zhibei; Zheng, Wei; Wang, Haoqiu; Pan, Jincao; Pu, Xiaoying

    2017-10-01

    Currently, no protocols or commercial kits are available to determine the serotypes of Salmonella by using Luminex MAGPIX®. In this study, an xTAG assay for serotype determination of Salmonella suitable for Luminex MAGPIX® is described and 228 Salmonella isolates were serotype determined by this xTAG assay. The xTAG assay consists of two steps: 1) Multiplex PCR to amplify simultaneously O, H and Vi antigen genes of Salmonella, and 2) Magplex-TAG™ microsphere hybridization to identify accurately the specific PCR products of different antigens. Compared with the serotyping results of traditional serum agglutination test, the sensitivity and specificity of the xTAG assay were 95.1% and 100%, respectively. The agreement rate of these two assays was 95.2%. Compared with Luminex xMAP® Salmonella Serotyping Assay (SSA) kit, the advantages of this xTAG assay are: First, the magnetic beads make it applicable to both the Luminex®100/200™ and MAGPIX® systems. Second, only primers rather than both primers and probes are needed in the xTAG assay, and the process of coupling antigen-specific oligonucleotide probes to beads is circumvented, which make the xTAG assay convenient to be utilized by other laboratories. The xTAG assay may serve as a rapid alternative or complementary method for traditional Salmonella serotyping tests, especially for laboratories that utilize the MAGPIX® systems. Copyright © 2017 Elsevier B.V. All rights reserved.

  2. HBsAg and aflatoxins in sera of rural (Igbo-Ora) and urban (Ibadan) populations in Nigeria.

    Science.gov (United States)

    Olubuyide, I O; Maxwell, S M; Akinyinka, O O; Hart, C A; Neal, G E; Hendrickse, R G

    1993-12-01

    The purpose of this study was to screen for the presence of hepatitis B surface antigen and aflatoxins in the sera of 100 non-hospitalized individuals from the rural population of Igbo-Ora and 89 non-hospitalized individuals from the urban population of Ibadan, Nigeria. Hitherto, such a study as this has not been undertaken in this environment. The proportions of hepatitis B surface antigen carriage and serum 'pathologic' levels of aflatoxins were high (47-49%, 8.2-9.0% respectively) but varied very little between the two different populations sampled. These findings indicate that determined efforts should be instituted to reduce or eliminate hepatitis B virus infection and aflatoxin contamination of high risk foodstuffs from this environment.

  3. 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.

  4. Antigen binding characteristics of immunoglobulin free light chains: crosslinking by antigen is essential to induce allergic inflammation.

    Directory of Open Access Journals (Sweden)

    Marco Thio

    Full Text Available Beside the production of complete immunoglobulins IgG, IgE, IgA, IgM and IgD, consisting of tetrameric heterodimers of immunoglobulin heavy and light chains, B cells also secrete immunoglobulin free light chains (Ig-fLC. Previous studies showed that Ig-fLCs are able to induce immediate hypersensitivity reactions. It is apparent that recognition and binding of antigen are crucial steps in the onset of these inflammatory responses. In this study, the binding characteristics of Ig-fLC to antigen were further investigated using various biochemical approaches. In addition, we investigated whether antigen-mediated crosslinking of Ig-fLC is required to initiate allergic skin inflammation in vivo. Our study shows that binding of Ig-fLCs to antigen can be measured with different experimental setups. Surface plasmon resonance analysis showed real-time antigen binding characteristics. Specific antigen binding by Ig-fLCs was further detected using immunoblotting and ELISA. Using the ELISA-based assay, a binding affinity of 76.9±3.8 nM was determined for TNP-specific Ig-fLC. Antigen-induced ear swelling in mice passively sensitized with trinitrophenol-specific Ig-fLC was inhibited when multivalent antigen was combined with excess of monovalent antigen during challenge. We conclude that Ig-fLCs are able to interact with antigen, a prerequisite for antigen-specific cellular activation. In analogy to antigen-specific Fc receptor-induced mast cell activation, crosslinking of Ig-fLCs is necessary to initiate a local allergic response.

  5. Whole blood microculture assay of human lymphocyte function.

    Science.gov (United States)

    Pauly, J L; Han, T

    1976-11-01

    A whole blood microculture assay is described for measuring lymphocyte reactivity to mitogenic and antigenic stimulants. This assay employs heparinized whole blood, serum-free culture medium, microtiter plates, and a Multiple Automated Sample Harvester (MASH). When this assay is compared to other leukocyte assays, its major advantages include (1) the utilization of fewer lymphocytes per microculture, thuus reducing the amount of blood required per test while increasing the number of test agents and replicate cultures which can be employed in any given experiment; (2) the conservation of mitogens, antigens, drugs, enzymes, hormones, lymphokines, and other test agents, some of which are either expensive of difficult to prepare in large quantities; (3) the elimination of lymphocyte isolation and purification procedures which may disrupt the relative proportion of T cells, B cells and antigen-processing cells; and (4) the application of an automated harvester which simplifies and expedites procedures required for processing cells for liquid scintillation counting.

  6. Core I97L mutation in conjunction with P79Q is associated with persistent low HBV DNA and HBs antigen clearance in patients with chronic hepatitis B.

    Science.gov (United States)

    Honda, T; Ishigami, M; Ishizu, Y; Kuzuya, T; Hayashi, K; Ishikawa, T; Murakami, Y; Iwadate, M; Umeyama, H; Toyoda, H; Kumada, T; Katano, Y; Goto, H; Hirooka, Y

    2017-06-01

    When considering treatment for chronic hepatitis B (CHB), it is important to discriminate between patients with persistent low HBV DNA and patients with active hepatitis, who may proceed to cirrhosis. In this study, we sought to identify mutations in patients expected to have persistent low HBV DNA and ultimately exhibit clearance of hepatitis B surface antigen (HBsAg). Serum samples were obtained from 33 CHB genotype C patients, divided based on HBV DNA and alanine aminotransferase (ALT) levels following observation for >2 years: Group A (n=10), transient HBV DNA ≥5.0 log copies/mL and ALT ≥120 IU/L; Group B (n=11), persistent HBV DNA DNA mutation and the additional mutation P79Q. We compared cumulative incidences of persistent low HBV DNA and HBsAg clearance in patients with or without I97L and P79Q by the Kaplan-Meier method. Incidence of Core mutation I97L differed significantly among groups: A, 30% (3/10); B, 36.4% (4/11); C, 83.3% (10/12) (p = 0.021). Cumulative incidences of persistent low HBV DNA and HBsAg clearance were significantly higher in patients with I97L than in those with wild-type I97 (p = 0.003 and p = 0.016, respectively), and even higher in those with P79Q. In patients with CHB, measurement of I97L and additional mutation P79Q would be useful for predicting persistent low HBV DNA, normal ALT, and HBsAg clearance. Copyright © 2016 European Society of Clinical Microbiology and Infectious Diseases. Published by Elsevier Ltd. All rights reserved.

  7. Radioimmune assay of human platelet prostaglandin synthetase

    International Nuclear Information System (INIS)

    Roth, G.J.; Machuga, E.T.

    1982-01-01

    Normal platelet function depends, in part, on platelet PG synthesis. PG synthetase (cyclo-oxygenase) catalyzes the first step in PG synthesis, the formation of PGH 2 from arachidonic acid. Inhibition of the enzyme by ASA results in an abnormality in the platelet release reaction. Patients with pparent congenital abnormalities in the enzyme have been described, and the effects have been referred to as ''aspirin-like'' defects of the platelet function. These patients lack platelet PG synthetase activity, but the actual content of PG synthetase protein in these individuals' platelets is unknown. Therefore an RIA for human platelet PG synthetase would provide new information, useful in assessing the aspirin-like defects of platelet function. An RIA for human platelet PG synthetase is described. The assay utilizes a rabbit antibody directed against the enzyme and [ 125 I]-labelled sheep PG synthetase as antigen. The human platelet enzyme is assayed by its ability to inhibit precipitation of the [ 125 I]antigen. The assay is sensitive to 1 ng of enzyme. By the immune assay, human platelets contain approximately 1200 ng of PG synethetase protein per 1.5 mg of platelet protein (approximately 10 9 platelets). This content corresponds to 10,000 enzyme molecules per platelet. The assay provides a rapid and convenient assay for the human platelet enzyme, and it can be applied to the assessment of patients with apparent platelet PG synthetase (cyclo-oxygenase) deficiency

  8. 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.)

  9. A strategy for identifying serodiagnostically relevant antigens of Leishmania or other pathogens in genetic libraries.

    Science.gov (United States)

    Teixeira, Márcia C A; Oliveira, Geraldo G S; Silvany, Marco A; Alcântara-Neves, Neuza M; Soares, Milena B P; Ribeiro-Dos-Santos, Ricardo; Jerônimo, Selma M B; Costa, Carlos H; dos-Santos, Washington L C; Eichinger, Daniel; Pontes-de-Carvalho, Lain

    2007-03-01

    Different individuals, when infected with the same parasite, rarely produce antibodies against the same set of antigens. Indeed, unless a particular antigen happens to be recognized by antibodies in all individuals, the use of a single antigen in the serodiagnosis of parasitic diseases leads, invariably, to false-negative results. A straightforward method for pin-pointing, in genetic libraries, the precise antigens that would increase serodiagnostic assay sensitivities is presented. The method is based on the utilization of sera that produced false-negative results against previously available antigens. Employing this false-negative serum-selection methodology for the identification of new Leishmania infantum recombinant antigens (rAgs), the sensitivity of a dipstick assay for anti-Leishmania antibodies in a panel of sera from patients with visceral leishmaniasis was increased from 83.3% to 98.1%, without affecting its specificity, by the inclusion of a fifth and a sixth L. infantum rAg.

  10. 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.

  11. Antigen test for early diagnosis of active cytomegalo-virus infection in heart-transplant recipients

    NARCIS (Netherlands)

    van der Bij, W; van Dijk, R. B.; van Son, W. J.; Torensma, R; Prenger, K. B.; Prop, J.; Tegzess, A. M.; The, T. H.

    An assay was developed for the detection of cytomegalovirus (CMV) antigens in blood leukocytes and evaluated for its diagnostic significance in six heart transplant recipients. Slides of cytocentrifuged blood leukocytes were prepared at regular intervals during the posttransplantation period and

  12. 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

  13. Immunoglobulin A-specific serodiagnosis of acute human cytomegalovirus infection by using recombinant viral antigens

    NARCIS (Netherlands)

    Vornhagen, R; Hinderer, W; Sonneborn, HH; Bein, G; Matter, L; The, TH; Jahn, G; Plachter, B

    The immunoglobulin A-specific reactivities of recombinant viral proteins from nine different reading frames of human cytomegalovirus were evaluated in enzyme-linked immunosorbent assay experiments. Antigen fragments of reading frames pUL32, pUL44, and pUL57 were identified as preferable antigens for

  14. The role of CD4 in antigen-independent activation of isolated single T lymphocytes

    DEFF Research Database (Denmark)

    Kelso, A; Owens, T

    1988-01-01

    The membrane molecule CD4 (L3T4) is thought to facilitate activation of Class II H-2-restricted T cells by binding to Ia determinants on antigen-presenting cells. Recent reports suggest that CD4 can also contribute to antigen-independent activation by anti-T cell receptor (TCR) antibodies. An assay...

  15. A monkey antigen crossreacting with carcinoembryonic antigen, CEA.

    Science.gov (United States)

    Engvall, E.; Vuento, M.; Ruoslahti, E.

    1976-01-01

    Normal monkey tissues were found to contain an antigen which crossreacts immunologically with the carcinoembryonic antigen (CEA) of the human digestive tract. The monkey antigen reacted with complete or partial identity to the normal crossreacting antigen (NCA) in humans when tested in immunodiffusion against anti-CEA or anti-NCA. Extracts of monkey tissues inhibited in radioimmunoassays measuring human NCA. It is possible that monkey foetuses and colonic tumours contain CEA. Images Fig. 1 PMID:823952

  16. Antigen smuggling in tuberculosis.

    Science.gov (United States)

    Hudrisier, Denis; Neyrolles, Olivier

    2014-06-11

    The importance of CD4 T lymphocytes in immunity to M. tuberculosis is well established; however, how dendritic cells activate T cells in vivo remains obscure. In this issue of Cell Host & Microbe, Srivastava and Ernst (2014) report a mechanism of antigen transfer for efficient activation of antimycobacterial T cells. Copyright © 2014 Elsevier Inc. All rights reserved.

  17. CD antigens 2001

    Czech Academy of Sciences Publication Activity Database

    Mason, D.; Andre, P.; Bensussan, A.; Buckley, C.; Civin, C.; Clark, E.; de Haas, M.; Goyert, S.; Hadam, M.; Hart, D.; Hořejší, Václav; Meuer, S.; Morrissey, J.; Schwartz-Albiez, R.; Shaw, S.; Simmons, D.; Uguccioni, M.; van der Schoot, E.; Vivier, E.; Zola, H.

    2001-01-01

    Roč. 58, č. 6 (2001), s. 425-430 ISSN 0001-2815. [Conference on Human leucocyte differentiation antigens /7./. Harrogate, 20.06.2000-25.06.2000] Institutional research plan: CEZ:AV0Z5052915 Keywords : CD molecules, HLDA Subject RIV: EC - Immunology Impact factor: 2.864, year: 2001

  18. CD antigens 2002

    Czech Academy of Sciences Publication Activity Database

    Mason, D.; Andre, P.; Bensussan, A.; Buckley, C.; Civin, C.; Clark, E.; de Haas, M.; Goyert, S.; Hadam, M.; Hart, D.; Hořejší, Václav; Meuer, S.; Morrissey, J.; Schwartz-Albiez, R.; Shaw, S.; Simmons, D.; Uguccioni, M.; van der Schoot, E.; Vivier, E.; Zola, H.

    2002-01-01

    Roč. 99, č. 10 (2002), s. 3877-3880 ISSN 0006-4971. [Conference on Human leucocyte differentiation antigens /7./. Harrogate, 20.06.2000-25.06.2000] Institutional research plan: CEZ:AV0Z5052915 Keywords : CD molecules, HLDA Subject RIV: EC - Immunology Impact factor: 9.631, year: 2002

  19. CD antigens 2001

    Czech Academy of Sciences Publication Activity Database

    Mason, D.; Andre, P.; Bensussan, A.; Buckley, C.; Civin, C.; Clark, E.; de Haas, M.; Goyert, S.; Hadam, M.; Hart, D.; Hořejší, Václav; Meuer, S.; Morrissey, J.; Schwartz-Albiez, R.; Shaw, S.; Simmons, D.; Uguccioni, M.; van der Schoot, E.; Vivier, E.; Zola, H.

    2002-01-01

    Roč. 168, č. 5 (2002), s. 2083-2086 ISSN 0022-1767. [Conference on Human leucocyte differentiation antigens /7./. Harrogate, 20.06.2000-25.06.2000] Institutional research plan: CEZ:AV0Z5052915 Keywords : CD molecules, HLDA Subject RIV: EC - Immunology Impact factor: 7.014, year: 2002

  20. CD antigens 2001

    Czech Academy of Sciences Publication Activity Database

    Mason, D.; Andre, P.; Bensussan, A.; Buckley, C.; Civin, C.; Clark, E.; de Haas, M.; Goyert, S.; Hadam, M.; Hart, D.; Hořejší, Václav; Meuer, S.; Morrissey, J.; Schwartz-Albiez, R.; Shaw, S.; Simmons, D.; Uguccioni, M.; van der Schoot, E.; Vivier, E.; Zola, H.

    2001-01-01

    Roč. 103, č. 4 (2001), s. 401-406 ISSN 0019-2805 R&D Projects: GA ČR GA310/99/0349 Institutional research plan: CEZ:AV0Z5052915 Keywords : antigen * CD * leukocyte Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 2.656, year: 2001

  1. CD antigens 2001

    Czech Academy of Sciences Publication Activity Database

    Mason, D.; Andre, P.; Bensussan, A.; Buckley, C.; Civin, C.; Clark, E.; de Haas, M.; Goyert, S.; Hadam, M.; Hart, D.; Hořejší, Václav; Meuer, S.; Morrissey, J.; Schwartz-Albiez, R.; Shaw, S.; Simmons, D.; Uguccioni, M.; van der Schoot, E.; Vivier, E.; Zola, H.

    2001-01-01

    Roč. 19, č. 6 (2001), s. 556-562 ISSN 1066-5099 R&D Projects: GA AV ČR IAA7052904 Institutional research plan: CEZ:AV0Z5052915 Keywords : CD * leukocyte antigens Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 2.689, year: 2001

  2. CD antigens 2001

    Czech Academy of Sciences Publication Activity Database

    Mason, D.; Andre, P.; Bensussan, A.; Buckley, C.; Civin, C.; Clark, E.; de Haas, M.; Goyert, S.; Hadam, M.; Hart, D.; Hořejší, Václav; Meuer, S.; Morrissey, J.; Schwartz-Albiez, R.; Shaw, S.; Simmons, D.; Uguccioni, M.; van der Schoot, E.; Vivier, E.; Zola, H.

    2001-01-01

    Roč. 31, č. 10 (2001), s. 2841-2847 ISSN 0014-2980 R&D Projects: GA AV ČR IAA7052904 Keywords : CD * leukocyte antigens Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 4.990, year: 2001

  3. CD antigens 2001

    Czech Academy of Sciences Publication Activity Database

    Mason, D.; Andre, P.; Bensussan, A.; Buckley, C.; Civin, C.; Clark, E.; de Haas, M.; Goyert, S.; Hadam, M.; Hart, D.; Hořejší, Václav; Meuer, S.; Morrissey, J.; Schwartz-Albiez, R.; Shaw, S.; Simmons, D.; Uguccioni, M.; van der Schoot, E.; Vivier, E.; Zola, H.

    2001-01-01

    Roč. 211, č. 2 (2001), s. 81-85 ISSN 0008-8749 R&D Projects: GA ČR GA310/99/0349 Institutional research plan: CEZ:AV0Z5052915 Keywords : antigen * CD * leukocyte Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 2.604, year: 2001

  4. CD antigens 2001

    Czech Academy of Sciences Publication Activity Database

    Mason, D.; Andre, P.; Bensussan, A.; Buckley, C.; Civin, C.; Clark, E.; de Haas, M.; Goyert, S.; Hadam, M.; Hart, D.; Hořejší, Václav; Meuer, S.; Morrissey, J.; Schwartz-Albiez, R.; Shaw, S.; Simmons, D.; Uguccioni, M.; van der Schoot, E.; Vivier, E.; Zola, H.

    2002-01-01

    Roč. 15, č. 1 (2002), s. 71-76 ISSN 0893-3952. [Conference on Human leucocyte differentiation antigens /7./. Harrogate, 20.06.2000-25.06.2000] Institutional research plan: CEZ:AV0Z5052915 Keywords : CD molecules, HLDA Subject RIV: EC - Immunology Impact factor: 3.821, year: 2002

  5. CD antigens 2001

    Czech Academy of Sciences Publication Activity Database

    Mason, D.; Andre, P.; Bensussan, A.; Buckley, C.; Civin, C.; Clark, E.; de Haas, M.; Goyert, S.; Hadam, M.; Hart, D.; Hořejší, Václav; Meuer, S.; Morrissey, J.; Schwartz-Albiez, R.; Shaw, S.; Simmons, D.; Uguccioni, M.; van der Schoot, E.; Vivier, E.; Zola, H.

    2001-01-01

    Roč. 70, č. 5 (2001), s. 685-690 ISSN 0741-5400 R&D Projects: GA AV ČR IAA7052904 Institutional research plan: CEZ:AV0Z5052915 Keywords : CD * leukocyte antigens Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 4.516, year: 2001

  6. CD antigens 2001

    Czech Academy of Sciences Publication Activity Database

    Mason, D.; Andre, P.; Bensussan, A.; Buckley, C.; Civin, C.; Clark, E.; de Haas, M.; Goyert, S.; Hadam, M.; Hart, D.; Hořejší, Václav; Meuer, S.; Morrissey, J.; Schwartz-Albiez, R.; Shaw, S.; Simmons, D.; Uguccioni, M.; van der Schoot, E.; Vivier, E.; Zola, H.

    2001-01-01

    Roč. 13, č. 9 (2001), s. 1095-1098 ISSN 0953-8178 R&D Projects: GA ČR GA310/99/0349 Institutional research plan: CEZ:AV0Z5052915 Keywords : antigen * CD * leukocyte Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 3.611, year: 2001

  7. β-endorphin antigen

    International Nuclear Information System (INIS)

    1981-01-01

    This invention relates to the production of antigens comprising β-endorphin, βsub(h)-endorphin, or βsub(c)-endorphin, in covalent conjugation with human gammaglobulin as immunogenic carrier material, and an antibody having the property of specifically binding β-endorphin or fragments thereof, containing the (6-15) residue sequence. (U.K.)

  8. Mathematical Model of Serodiagnostic Immunochromatographic Assay.

    Science.gov (United States)

    Sotnikov, Dmitriy V; Zherdev, Anatoly V; Dzantiev, Boris B

    2017-04-18

    This article describes the mathematical model for an immunochromatographic assay for the detection of specific immunoglobulins against a target antigen (antibodies) in blood/serum (serodiagnosis). The model utilizes an analytical (non-numerical) approach and allows the calculation of the kinetics of immune complexes' formation in a continuous-flow system using commonly available software, such as Microsoft Excel. The developed model could identify the nature of the influence of immunochemical interaction constants and reagent concentrations on the kinetics of the formation of the detected target complex. On the basis of the model, recommendations are developed to decrease the detection limit for an immunochromatographic assay of specific immunoglobulins.

  9. Comparative application of antigen detection enzyme-linked ...

    African Journals Online (AJOL)

    Antigen-detection enzyme-linked immunosorbent assay (Ag-ELISA) and buffy coat parasitological technique (BCT) were employed for the diagnosis of bovine trypanosomiosis in trade cattle slaughtered at the Bodija Municipal abattoir in Ibadan, Oyo State, between March and November, 2002 and in some sedentary herds ...

  10. Immunochemical Investigations of Cell Surface Antigens of Anaerobic Bacteria.

    Science.gov (United States)

    1976-01-15

    has also been visulalized . With use of a radioactive anti’qen bindinq assay, antibody to this capsularpolysaccharide has been demonstrated in anti- sera...With many bacteria, serogrouning is based on cansular oolysaccharide antigens. Serogrouping has led to much valuable epidemiologic information

  11. (ELISA) kit for diagnosis copro-antigens of Giardia lamblia

    African Journals Online (AJOL)

    STORAGESEVER

    2010-08-02

    Aug 2, 2010 ... methods based on antigen scanning of parasites such as enzyme linked immunosorbent assay (ELISA), ... samples. To design this method, a pure antibody against parasite as well as an antibody conjugated to a ..... school children in Santiago, Chile by capture ELISA for the detection of fecal Giardia ...

  12. Antigenic Relationships among Human Pathogenic Orientia tsutsugamushi Isolates from Thailand.

    Directory of Open Access Journals (Sweden)

    Sarah L James

    2016-06-01

    Full Text Available Scrub typhus is a common cause of undiagnosed febrile illness in certain tropical regions, but can be easily treated with antibiotics. The causative agent, Orientia tsutsugamushi, is antigenically variable which complicates diagnosis and efforts towards vaccine development.This study aimed to dissect the antigenic and genetic relatedness of O. tsutsugamushi strains and investigate sero-diagnostic reactivities by titrating individual patient sera against their O. tsutsugamushi isolates (whole-cell antigen preparation, in homologous and heterologous serum-isolate pairs from the same endemic region in NE Thailand. The indirect immunofluorescence assay was used to titrate Orientia tsutsugamushi isolates and human sera, and a mathematical technique, antigenic cartography, was applied to these data to visualise the antigenic differences and cross-reactivity between strains and sera. No functional or antigen-specific analyses were performed. The antigenic variation found in clinical isolates was much less pronounced than the genetic differences found in the 56kDa type-specific antigen genes. The Karp-like sera were more broadly reactive than the Gilliam-like sera.Antigenic cartography worked well with scrub typhus indirect immunofluorescence titres. The data from humoral responses suggest that a Karp-like strain would provide broader antibody cross-reactivity than a Gilliam-like strain. Although previous exposure to O. tsutsugamushi could not be ruled out, scrub typhus patient serum antibody responses were characterised by strong homologous, but weak heterologous antibody titres, with little evidence for cross-reactivity by Gilliam-like sera, but a broader response from some Karp-like sera. This work highlights the importance of antigenic variation in O. tsutsugamushi diagnosis and determination of new serotypes.

  13. Contamination of passenger trains with Dermatophagoides (Acari: Pyroglyphidae) mite antigen in Japan.

    Science.gov (United States)

    Uehara, K; Toyoda, Y; Konishi, E

    2000-01-01

    Passenger trains were surveyed for contamination with Dermatophagoides farinae Hughes and Dermatophagoides pteronyssinus (Trouesart) mites in Japan. A total of 492 dust samples were collected from upholstered seats in six commuter trains, one long-distance express train and three night trains in October, 1996 and January, April, and July, 1997. Mite antigen levels contained in fine dust fractions of these samples were measured by an enzyme-linked immunosorbent assay. Most samples obtained from commuter trains showed relatively high mite antigen levels of > 10 microgm(-2) (corresponding to > 100 mites). Express and night trains showed lower antigen levels per square meter, but higher mite antigen levels per gram of fine dust than commuter trains, indicating relatively high mite antigen densities. Seasonal comparisons indicated that commuter trains showed the highest mean antigen level per square meter in winter (January), whereas the highest antigen level per gram of fine dust was observed in summer (July) in express and night trains.

  14. Impact of the thimerosal controversy on hepatitis B vaccine coverage of infants born to women of unknown hepatitis B surface antigen status in Michigan.

    Science.gov (United States)

    Biroscak, Brian J; Fiore, Anthony E; Fasano, Nancy; Fineis, Patrick; Collins, Michael P; Stoltman, Gillian

    2003-06-01

    Hepatitis B vaccine is recommended for all infants, and the series may be started during the delivery admission. For infants who are born either to women who are positive for hepatitis B surface antigen (HBsAg) or to women whose HBsAg status is unknown, vaccination should be started within 12 hours of birth to prevent perinatal and early childhood hepatitis B virus infection. Because of concerns about mercury exposures from vaccines that contain thimerosal, the United States Public Health Service (USPHS) and the American Academy of Pediatrics (AAP) recommended in July 1999 that the first dose of hepatitis B vaccine be deferred until 2-6 months of age but only for infants who are born to HBsAg-negative women. To assess the impact on birth-dose vaccine coverage for infants who are born to women with unknown HBsAg status, we measured coverage before and after July 1999. A sample of Michigan infants who were born to women whose HBsAg status was either unknown or missing were identified by reviewing newborn screening cards for infants who were born during 1) March-April 1999 (before recommendation changes [T1]); 2) July 15-September 15, 1999 (immediately after recommendation changes [T2]); and 3) March-April 2000 (6 months after resumption of pre-1999 practices were recommended [T3]). We verified maternal HBsAg screening and newborn hepatitis B vaccination by reviewing infant and maternal hospital records. Of 1201 infants who were born to women whose HBsAg status was indicated as unknown or missing on the newborn screening card during the 3 time periods, 216 (18%) were born to women whose status was truly unknown at the time of delivery, as determined by medical record review. During T1, 53% of these 216 infants received hepatitis B vaccine before hospital discharge, compared with 7% of infants who were born during T2 and 57% of infants who were born during T3. During T1, 19% of these infants received hepatitis B vaccine within 12 hours of birth compared with 1% of

  15. [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 HBV DNA, 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.

  16. The line blot assay: problems with titrating first and second antibodies for Western blot and immunohistochemistry assays?

    Science.gov (United States)

    Rojas-Espinosa, O; Silva-Miranda, M; Wek-Rodriguez, K; Arce-Paredes, P

    2006-01-01

    We describe a technique designed to assess the optimal dilution of primary and secondary antibodies, to be used in Western blot, dot blot, the multi-antigen print immunoassay (MAPIA) and immunohistochemistry assays. The method that we call "line blot" is not an alternative but a practical, complementary tool for the above techniques that assures definitive results are obtained from single assays, so there is no need to repeat the assay. As with most immunoenzymatic assays, the line blot assay is very sensitive, allowing the detection of absolute amounts of antigen as low as 2.5 ng in the 0.5 cm-long segment line (see Results), depending on the strength of the secondary, enzyme-labelled antibody.

  17. Antigen microarrays: descriptive chemistry or functional immunomics?

    Science.gov (United States)

    Prechl, József; Papp, Krisztián; Erdei, Anna

    2010-04-01

    Advances in protein microarray technology allow the generation of high content, reliable information about complex, multilevel protein interaction networks. Yet antigen arrays are used mostly only as devices for parallel immune assays describing multitudes of individual binding events. We propose here that the huge amount of immunological information hidden in the plasma of an individual could be better revealed by combining the characterization of antibody binding to target epitopes with improved estimation of effector functions triggered by these binding events. Furthermore, we could generate functional immune profiles characterizing general immune responsiveness of the individual by designing arrays incorporating epitope collections from diverse subsets of antibody targets. Copyright 2010 Elsevier Ltd. All rights reserved.

  18. Detection of poliovirus antigen by enzyme immunoassay.

    OpenAIRE

    Ukkonen, P; Huovilainen, A; Hovi, T

    1986-01-01

    A solid-phase enzyme immunoassay (EIA) was developed for the detection of poliovirus antigen. Rabbit and guinea pig antisera for the assay were raised against purified poliovirus type 3/Fin (strain 3/Fin/K) isolated from a fecal specimen from a meningitis patient during an outbreak of poliomyelitis in Finland in 1984. The EIA was highly specific for poliovirus type 3, and it was about 30 times more sensitive for strain 3/Fin/K than for strain 3/Saukett used in the inactivated poliovirus vacci...

  19. Development of multiplex serological assay for the detection of human African trypanosomiasis.

    Science.gov (United States)

    Nzou, Samson Muuo; Fujii, Yoshito; Miura, Masashi; Mwau, Matilu; Mwangi, Anne Wanjiru; Itoh, Makoto; Salam, Md Abdus; Hamano, Shinjiro; Hirayama, Kenji; Kaneko, Satoshi

    2016-04-01

    Human African trypanosomiasis (HAT) is a disease caused by Kinetoplastid infection. Serological tests are useful for epidemiological surveillance. The aim of this study was to develop a multiplex serological assay for HAT to assess the diagnostic value of selected HAT antigens for sero-epidemiological surveillance. We cloned loci encoding eight antigens from Trypanosoma brucei gambiense, expressed the genes in bacterial systems, and purified the resulting proteins. Antigens were subjected to Luminex multiplex assays using sera from HAT and VL patients to assess the antigens' immunodiagnostic potential. Among T. b. gambiense antigens, the 64-kDa and 65-kDa invariant surface glycoproteins (ISGs) and flagellar calcium binding protein (FCaBP) had high sensitivity for sera from T. b. gambiense patients, yielding AUC values of 0.871, 0.737 and 0.858 respectively in receiver operating characteristics (ROC) analysis. The ISG64, ISG65, and FCaBP antigens were partially cross-reactive to sera from Trypanosoma brucei rhodesiense patients. The GM6 antigen was cross-reactive to sera from T. b. rhodesiense patients as well as to sera from VL patients. Furthermore, heterogeneous antibody responses to each individual HAT antigen were observed. Testing for multiple HAT antigens in the same panel allowed specific and sensitive detection. Our results demonstrate the utility of applying multiplex assays for development and evaluation of HAT antigens for use in sero-epidemiological surveillance. Copyright © 2015 The Authors. Published by Elsevier Ireland Ltd.. All rights reserved.

  20. 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.

  1. Isotopic methods or immuno diagnosis: The Radioimmunoassay and immunoradiometric assay

    International Nuclear Information System (INIS)

    Caso, R.

    1997-01-01

    This work offers an explanation about the more used isotopic techniques for immuno diagnosis: the radioimmunoassay (RIA) and immunoradiometric assay (IRMA). It describes the basic principles of these assays, the antigen-antibody reaction, the radioiodination methods with I-125 for antigens and antibodies, the purification and characterization of labelled compounds. On the order hand they present work gives a review of the methods for separate the bound and free fractions. At the end it offers the principles of the quality control of immunoassay and the future lines of research in the field of RIA and IRMA

  2. Human platelet antigens - 2013.

    Science.gov (United States)

    Curtis, B R; McFarland, J G

    2014-02-01

    To date, 33 human platelet alloantigens (HPAs) have been identified on six functionally important platelet glycoprotein (GP) complexes and have been implicated in alloimmune platelet disorders including foetal and neonatal alloimmune thrombocytopenia (FNAIT), posttransfusion purpura (PTP) and multitransfusion platelet refractoriness (MPR). The greatest number of recognized HPA (20 of 33) resides on the GPIIb/IIIa complex, which serves as the receptor for ligands important in mediating haemostasis and inflammation. These include HPA-1a, the most commonly implicated HPA in FNAIT and PTP in Caucasian populations. Other platelet GP complexes, GPIb/V/IX, GPIa/IIa and CD109, express the remaining 13 HPAs. Of the recognized HPAs, 12 occur as six serologically and genetically defined biallelic 'systems' where the -a form designates the higher frequency allele and the -b form, the lower. Twenty-one other HPAs are low-frequency or rare antigens for which postulated higher frequency -a alleles have not yet been identified as antibody specificities. In addition to the HPA markers, platelets also express ABO and human leucocyte antigen (HLA) antigens; antibodies directed at the former are occasionally important in FNAIT, and to the latter, in MPR. © 2013 International Society of Blood Transfusion.

  3. Effect of a novel saponin adjuvant derived from Quillaja saponaria on the immune response to recombinant hepatitis B surface antigen.

    Science.gov (United States)

    So, H S; Yoon, H S; Choi, D Y; Kwon, Y S; Sung, J H; Lee, T G; Park, E S; Cho, H S; Lee, B M; Cho, J M; Ryu, W S

    1997-04-30

    Adjuvant activity of saponins extracted from the South American tree Quillaja saponaria has been demonstrated with many antigens. Recently, four saponin fractions (designated as QS-7, QS-17, QS-18, and QS-21) with adjuvant activity were purified by reverse phase chromatography. In particular, efficacy of the less toxic QS-21 fraction has been demonstrated with several recombinant viral antigens including HIV gp120. Here, we report a novel saponin fraction (designated as QS-L1) derived from Quillaja saponaria. Unlike previously identified saponins, QS-L1 had a different chemical structure and showed adjuvant activity only when administered in the presence of alum-precipitated antigen. Interestingly, the QS-L1 greatly increased not only a humoral immune response but also cellular immune response to recombinant hepatitis B virus surface antigen (HBsAg). Furthermore, QS-L1 showed lower toxicity in vivo and in vitro than the previously identified saponin fraction, QS-21. Finally, we examined the chemical structure of the QS-L1 using mass spectroscopic analysis, carbohydrate composition analysis and NMR spectroscopic analysis. Thus, our results indicated that this novel QS-L1 saponin fraction had several desirable properties required for an effective adjuvant.

  4. 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.

    Directory of Open Access Journals (Sweden)

    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.

  5. 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

    -2d-restricted cytotoxic T lymphocyte (CTL) epitope. In an attempt to improve the immunogenicity of V3 in DNA vaccines, a plasmid expressing MN V3 as a fusion protein with the highly immunogenic middle (pre-S2+S) surface antigen of hepatitis B virus (HBsAg) was constructed. Epidermal inoculation...... by gene gun was used for genetic immunization in a mouse model. Antibody and CTL responses to MN V3 and HBsAg were measured and compared with the immune responses obtained after vaccination with plasmids encoding the complete HIV-1 MN gp160 and HBsAg (pre-S2+S), respectively. DNA vaccination with the HIV...... MN gp160 envelope plasmid induced a slow and low titred anti-MN V3 antibody response at 12 weeks post-inoculation (p.i.) and a late appearing (7 weeks), weak and variable CTL response. In contrast, DNA vaccination with the HBsAg-encoding plasmid induced a rapid and high titred anti-HBsAg antibody...

  6. Characterization of entamoeba histolytica antigens in circulating immune complexes in sera of patients with amoebiasis.

    Science.gov (United States)

    Sengupta, K; Ghosh, P K; Ganguly, S; Das, P; Maitra, T K; Jalan, K N

    2002-09-01

    Isolated circulating immune complexes (CICs) from sera of patients with amoebiasis were characterized to determine Entamoeba histolytica antigens that participate in the disease process. In total, 116 serum samples were collected before starting anti-amoebic therapy, and their CICs were isolated by differential polyethylene glycol precipitation. The presence of amoeba-specific antigens in CICs was detected by antigen capture enzyme-linked immunosorbent assay (ELISA) and by immunoblot assay. Antigen capture ELISA showed significantly higher optical density (p amoebiasis than in the normal healthy controls and patients of non-amoebic hepatic disorder. Immunoblot assay detected amoeba-specific CICs in all 18 patients (100%) with confirmed amoebic liver abscess, 28 (80%) of 35 patients with clinically-suspected amoebic liver abscess, and 18 (78.26%) of 23 patients with amoebic colitis. No patients with non-amoebic hepatic disorders and healthy control subjects had any detectable level of amoebic antigens in CICs. Immunoblot assay revealed E. histolytica antigens of relative molecular masses of 35, 56, 70, and 90 kDa present in CICs of 64 of 76 patients with amoebiasis. The 35-kDa polypeptide was observed in 52 patients (81.25%). The results of the study suggest that the 35-kDa polypeptide antigen can be a diagnostic marker in active amoebiasis.

  7. Single-step colony assay for screening antibody libraries.

    Science.gov (United States)

    Kato, Mieko; Hanyu, Yoshiro

    2017-08-10

    We describe a method, single-step colony assay, for simple and rapid screening of single-chain Fv fragment (scFv) libraries. Colonies of Escherichia coli expressing the scFv library are formed on a hydrophilic filter that is positioned in contact with a membrane coated with an antigen. scFv expression is triggered upon treatment of colonies with an induction reagent, following which scFvs are secreted from the cells and diffused to the antigen-coated membrane. scFvs that exhibit binding affinity for the antigen are captured by the membrane-immobilized antigen. Lastly, detection of scFv binding of the antigen on the membrane allows identification of the clones on the filter that express antigen-specific scFvs. We tested this methodology by using an anti-rabbit IgG scFv, scFv(A10B), and a rat immune scFv library. Experiments conducted using scFv(A10B) revealed that this method improves scFv expression during the colony assay. By using our method to screen an immune library of 3×10 3 scFv clones, we established several clones exhibiting affinity for the antigen. Moreover, we tested 7 other antigens, including peptides, and successfully identified positive clones. We believe that this simple procedure and controlled scFv expression of the single-step colony assay could make the antibody screening both rapid and reliable and lead to successful isolation of positive clones from antibody libraries. Copyright © 2017 Elsevier B.V. All rights reserved.

  8. Role of Quantiferon TB gold assays in monitoring the efficacy of antituberculosis therapy

    Directory of Open Access Journals (Sweden)

    N. Helmy

    2012-10-01

    Conclusion: The analysis of QFT-G assay results showed that in the majority of our TB patients there was a correlation between clinical treatment outcome and changes of IFN-γ response to M. tuberculosis-specific antigens.

  9. Evaluation of an Antigen-Antibody “Combination” Enzyme Linked ...

    African Journals Online (AJOL)

    Conclusion: We conclude that although this assay depicts high sensitivity and specificity in detecting antibodies to HCV, it seems not to add further benefit in our study population to detect HCV infections by enhanced sensitivity due the potential contingency to trace viral capsid antigens. Keywords: Ag-Ab Combination assay ...

  10. 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.

  11. Efficacy of antigen dosage on the hepatitis B vaccine response in infants born to hepatitis B-uninfected and hepatitis B-infected mothers.

    Science.gov (United States)

    Kang, Guodong; Ma, Fubao; Chen, Haiping; Yang, Yunkai; Guo, Shaohong; Wang, Zhiguo; Liang, Xiaofeng; Li, Li; Cui, Fuqiang; Zhang, Longhua

    2015-08-07

    To compare the safety and immunogenicity of two dosages of recombinant hepatitis B (HB) vaccine administered to infants born to HB-uninfected and HB-infected mothers. A phase III, controlled, single-blinded clinical trial was conducted with 506 healthy newborns. The newborns were assigned to three groups based on maternal levels of HB surface antigen (HBsAg) and HB e antigen (HBeAg): Group A, HBsAg negative; Group B, HBsAg positive and HBeAg negative; and Group C, HBsAg positive and HBeAg positive. Three doses of 10 or 5 μg recombinant HB vaccine were randomly administered by 1:1 within 24 h after birth, at 1 month and at 6 months. Safety data and pre- and postvaccination blood samples were collected. A total of 326, 93, and 87 subjects were included in Groups A, B, and C, respectively. Both dosages of HB vaccine were well tolerated by all subjects. The most common injection-site adverse reactions (ARs) and systemic ARs were pain and fever. After 1 month of the third dose, the Group A infants who received the 10 μg HB vaccine achieved a higher geometric mean concentration (GMC) of HB surface antibody (anti-HBs) than those who received the 5 μg dosage. Maternal anti-HBs serostatus did not influence HB vaccine immunogenicity at either dosage. In contrast, there was no significant difference in the anti-HBs seroconversion rate, GMCs, or estimated vaccine efficacy (EVE) against perinatal transmission between Groups B and C, regardless of dosage. However, the seroconversion rate and EVE of the 5 μg HB vaccine was lower in Group C than in Group B. Both dosages of the HB vaccine were well tolerated and elicited a good immune response in infants of Group A, regardless of the maternal anti-HBs serostatus. EVE did not significantly differ between Groups B and C. Clinicaltrials.gov identifier: NCT02152709. Copyright © 2015 Elsevier Ltd. All rights reserved.

  12. Detection by enzyme-linked immunosorbent assay of Aujeszky's disease virus in tissues of infected pigs.

    OpenAIRE

    Qvist, P; Meyling, A; Hoff-Jørgensen, R

    1990-01-01

    An enzyme-linked immunosorbent assay was developed for the detection of Aujeszky's disease virus antigen in tissue extracts and in nasal swabs. The enzyme-linked immunosorbent assay is based on two different monoclonal antibodies with specificity for the gII glycoprotein of Aujeszky's disease virus. Viral antigen was detected in 81 of 93 tissue extracts prepared from virus-infected organs. Fifteen outbreaks of Aujeszky's disease were analyzed in this study, and they were all identified by the...

  13. Cancer testis antigen and immunotherapy

    Directory of Open Access Journals (Sweden)

    Krishnadas DK

    2013-04-01

    Full Text Available Deepa Kolaseri Krishnadas, Fanqi Bai, Kenneth G Lucas Department of Pediatrics, Division of Hematology/Oncology, University of Louisville, KY, USA Abstract: The identification of cancer testis (CT antigens has been an important advance in determining potential targets for cancer immunotherapy. Multiple previous studies have shown that CT antigen vaccines, using both peptides and dendritic cell vaccines, can elicit clinical and immunologic responses in several different tumors. This review details the expression of melanoma antigen family A, 1 (MAGE-A1, melanoma antigen family A, 3 (MAGE-A3, and New York esophageal squamous cell carcinoma-1 (NY-ESO-1 in various malignancies, and presents our current understanding of CT antigen based immunotherapy. Keywords: cancer testis antigens, immunotherapy, vaccine

  14. Specificity of antigens on UV radiation-induced antigenic tumor cell variants measured in vitro and in vivo

    International Nuclear Information System (INIS)

    Hostetler, L.W.; Romerdahl, C.A.; Kripke, M.L.

    1989-01-01

    The purpose of this study was to determine whether antigenic variants cross-react immunologically with the parental tumor and whether the UVR-associated antigen unique to UVR-induced tumors is also present on the variants. Antigenic (regressor) variants and nonimmunogenic (progressor) clones derived from UV-irradiated cultures of the C3H K1735 melanoma and SF19 spontaneous fibrosarcoma cell lines were used to address these questions. In an in vivo immunization and challenge assay, the antigenic variants did not induce cross-protection among themselves, but each induced immunity against the immunizing variant, the parent tumor cells, and nonimmunogenic clones derived from UV-irradiated parent cultures. Therefore, the variants can be used to induce in mice a protective immunity that prevents the growth of the parent tumor and nonimmunogenic clones, but not other antigenic variants. In contrast, immunization with cells of the parental tumor or the nonimmunogenic clones induced no protective immunity against challenge with any of the cell lines. Utilizing the K1735 melanoma-derived cell lines in vitro, T-helper (Th) cells isolated from tumor-immunized mice were tested for cross-reactivity by their ability to collaborate with trinitrophenyl-primed B-cells in the presence of trinitrophenyl-conjugated tumor cells. Also, the cross-reactivity of cytotoxic T-lymphocytes from tumor-immunized mice was assessed by a 4-h 51Cr-release assay. Antigenic variants induced cytotoxic T-lymphocytes and Th activity that was higher than that induced by the parent tumor and nonimmunogenic clones from the UVR-exposed parent tumor and cross-reacted with the parental tumor cells and nonimmunogenic clones, but not with other antigenic variants

  15. Crude Antigen Cystisercus Taenia Saginata Isolat Bali untuk Deteksi Sistiserkosis pada Sapi

    Directory of Open Access Journals (Sweden)

    Hertati Anriani Lubis

    2015-06-01

    Full Text Available The purpose of this study was to evaluate Taenia saginata cystisercus antigen for the detection of bovine cysticercosis. Taenia saginata cysticercus antigen was derived from local isolates, obtained from the experimental infection of Taenia saginata tape worms from Bali. The research was done by ELISA (Enzyme Linked Immunosorbent Assay optimized by determining the optimal concentration of antigen, the optimal dilutions of serum and the optimal dilutions of conjugate. The results showed that Taenia saginata cysticercus crude antigen (Bali isolate are antigenic and can be used to detect cattle cysticercosis. Optimal concentration of antigen: 2 ug/ml, optimal dilutions of serum: 1:80 and optimal dilution of conjugate: 1:4000.

  16. Validation of a KHV antibody enzyme-linked immunosorbent assay (ELISA)

    DEFF Research Database (Denmark)

    Bergmann, S M; Wang, Q; Zeng, W

    2017-01-01

    fully validated for KHV. Therefore, it was developed and validated an enzyme-linked immunosorbent assay (ELISA) to detect KHV antibodies. The assay was optimized with respect to plates, buffers, antigens and assay conditions. It demonstrated high diagnostic and analytical sensitivity and specificity...... and was particularly useful at the pond or farm levels. Considering the scale of the carp and koi industry worldwide, this assay represents an important practical tool for the indirect detection of KHV, also in the absence of clinical signs....

  17. 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

  18. Evaluation of the Procleix Ultrio Plus ID NAT assay for detection of HIV 1, HBV and HCV in blood donors

    Directory of Open Access Journals (Sweden)

    Raj Nath Makroo

    2015-01-01

    Full Text Available Introduction: The Procleix Ultrio Plusassay is a new-generation qualitative in vitro nucleic acid amplification test used to screen for human immunodeficiency virus type 1 (HIV-1 RNA, hepatitis C virus (HCV RNA and hepatitis B virus (HBV DNA in blood donors. This study was performed to compare the Procleix Ultrio assay with the new-generation Procleix Ultrio Plus Nucleic Acid Test (NAT assays. Materials and Methods: Ten thousand three hundred and two donor samples were run in parallel for ID NAT using the Procleix Ultrio and the Procleix Ultrio Plus assay. Simultaneously, enzyme-linked immunosorbent assay testing was performed on an EVOLIS Walk away System for HIV, HCV, HBsAg and anti-HBc. Reactive samples were confirmed using polymerase chain reaction. Results: In the 10,302 samples tested during the study period, we identified 15 NAT yields, and all these revealed HBV DNA in the discriminatory assays. Eight of these were exclusive yields from the Ultrio Plus assay and the remaining seven cases were determined as HBV NAT yield, both by the Procleix Ultrio as well as the Ultrio Plus assays, i.e. "Combined" yields. No HCV or HIV 1 yields were detected during the study period by either of two assays. Conclusion: With an overall yield rate of 1 in 687 and an exclusive yield rate of 1 in 1287, the Procleix Ultrio Plus assay proved to be highly sensitive in detecting occult HBV infections.

  19. Comparison of antigen-specific T-cell responses of tuberculosis patients using complex or single antigens of Mycobacterium tuberculosis

    DEFF Research Database (Denmark)

    Mustafa, A S; Amoudy, H A; Wiker, H G

    1998-01-01

    We have screened peripheral blood mononuclear cells (PBMC) from tuberculosis (TB) patients for proliferative reactivity and interferon-gamma (IFN-gamma) secretion against a panel of purified recombinant (r) and natural (n) culture filtrate (rESAT-6, nMPT59, nMPT64 and nMPB70) and somatic-derived (r......GroES, rPstS, rGroEL and rDnaK) antigens of Mycobacterium tuberculosis. The responses of PBMC to these defined antigens were compared with the corresponding results obtained with complex antigens, such as whole-cell M. tuberculosis, M. tuberculosis culture filtrate (MT-CF) and cell wall antigens, as well...... as the vaccine strain, Mycobacterium bovis bacillus Calmette-Guerin (BCG). In addition, M. tuberculosis and MT-CF-induced T-cell lines were tested in the same assays against the panel of purified and complex antigens. The compiled data from PBMC and T-cell lines tested for antigen-induced proliferation and IFN...

  20. Application of bead array technology to simultaneous detection of human leucocyte antigen and human platelet antigen antibodies.

    Science.gov (United States)

    Fujiwara, K; Shimano, K; Tanaka, H; Sekine, M; Kashiwase, K; Uchikawa, M; Satake, M; Nakajima, K

    2009-04-01

    Detection of antibodies against human leucocyte antigens (HLA) and human platelet antigens (HPA) is crucial for patients refractory to platelet transfusion therapy. However, a reliable and high-throughput method for HLA cross-matching and detecting HPA antibodies has not yet been described. Immunocomplex capture fluorescence analysis (ICFA) was developed for high-throughput, simultaneous detection of HLA and HPA antibodies. Microarray beads were separately coupled with monoclonal antibodies specific for CD36, CD41, CD42b, CD49b, CD61 and HLA class I antigens. Platelets reacting with patient serum were lysed and the lysates were incubated with the bead mixture to specifically capture antigen-antibody complexes via the epitopes on platelet glycoproteins or HLA antigens. The beads capturing immunocomplexes were then subjected to flow cytometric analysis. Immunocomplex capture fluorescence analysis was validated using 50 serum samples containing HLA antibodies and 20 serum samples containing HPA antibodies. The method enabled the detection of all the HLA antibodies with a sensitivity comparable to that of the purified HLA antigen-coated pooled-bead assay (FlowPRA, One Lambda, Canoga Park, CA, USA). The method also enabled the detection of all the HPA antibodies with a sensitivity higher than that of the mixed passive haemagglutination. In this study, we developed a rapid, simple and reliable method for the simultaneous analysis of HLA and HPA antibodies. ICFA can also be used as an alternative to the lymphocyte cytotoxicity test for HLA cross-matching.

  1. 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 and maltose), although residual glucose accumulation in the mid-exponential phase reduced HBsAg production. HBsAg production in starchbased cultures may be improved further by optimization of the rates of starch hydrolysis by glucoamylase and subsequent... in cultivation significantly affected HBsAg production levels through induction of the glucoamylase promoter. The highest specific HBsAg production was observed during growth on inducing substrates of starch and its degradation products (maltodextrin...

  2. 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)

    Vanz, Ana Leticia; Lünsdorf, Heinrich; Adnan, Ahmad; Nimtz, Manfred; Gurramkonda, Chandrasekhar; Khanna, Navin; Rinas, Ursula

    2012-08-08

    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. 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 proceed via the

  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. Enzyme linked immunosorbent assay for rubella antibodies: a simple method of antigen production. A preliminary report Reação imunoenzimática (ELISA para detecção de anticorpos contra o vírus da Rubéola: um método simples de produção de antígeno. Nota prévia

    Directory of Open Access Journals (Sweden)

    Vanda Akico Ueda Fick de Souza

    1995-08-01

    Full Text Available A simple method of rubella antigen production by treatment with sodium desoxycholate for use in enzyme immunoassay (IMT-ELISA is presented. When this assay was compared with a commercial test (Enzygnost-Rubella, Behring, in the study of 108 sera and 118 filter paper blood samples, 96.9% (219/226 overall agreement and correlation coefficient of 0.90 between absorbances were observed. Seven samples showed discordant results, negative by the commercial kit and positive by our test. Four of those 7 samples were available, being 3 positive by HI.Um método simples de produção de antígeno de vírus da rubéola, por extração com desoxicolato de sódio para aplicação no ensaio imunoenzimático, IMT-ELISA, é apresentado. Este ensaio comparado com ELISA comercial (Enzygnost-Rubella, Behring, no estudo de 108 soros e 118 amostras de papel de filtro apresentou 96,9% (219/226 de concordância e um coeficiente de correlação de 0,90 entre as absorbâncias. Sete amostras apresentaram resultados discordantes, negativos pelo ensaio comercial e positivos pelo IMT-ELISA. Destas, 4 foram testadas por RIH, observando-se positividade em 3.

  5. Baseline hepatitis B surface antigen quantitation can predict virologic response in entecavir-treated chronic hepatitis B patients.

    Science.gov (United States)

    Wang, Chia-Chi; Tseng, Tai-Chung; Wang, Pin-Chao; Lin, Hans Hsienhong; Kao, Jia-Horng

    2014-11-01

    Several anti-viral drugs are approved for the treatment of hepatitis B virus (HBV) infection. However, whether quantitative hepatitis B surface antigen (qHBsAg) can predict the therapeutic response during long-term entecavir treatment remains unclear. Fifty-five chronic hepatitis B (CHB) patients who received entecavir for more than 2 years were enrolled. The serum qHBsAg level was measured by HBsAg II quant immunoassay. A significant decline in the qHBsAg level was defined as > 1 log reduction from baseline to 6 months of entecavir treatment. Of the 55 patients (41 males and 14 females with a mean age of 48.3 ± 11.4 years), 23 patients were positive for hepatitis B e antigen (HBeAg). The median treatment period was 34 months, and ranged from 26 months to 43 months. A total of 288 serum samples were used to determine the qHBsAg levels. At year 3 of entecavir therapy, one (1.8%) patient had HBsAg seroclearance. A high qHBsAg level was defined as greater than 10,000 IU/mL. Patients with a high baseline qHBsAg level had a lower rate of virologic response at year 1 (37.5% vs. 89.7%, p response in all patients. The baseline serum qHBsAg level can predict virologic response in entecavir-treated CHB patients. However, a significant decline in the qHBsAg level cannot predict serologic or virologic response of entecavir treatment. Copyright © 2013. Published by Elsevier B.V.

  6. Associations between antibody to hepatitis B core antigen positivity and outcomes in hepatocellular carcinoma patients undergoing hepatic resection.

    Science.gov (United States)

    Itoh, Shinji; Yoshizumi, Tomoharu; Tomino, Takahiro; Nagatsu, Akihisa; Motomura, Takashi; Harada, Noboru; Harimoto, Norifumi; Ikegami, Toru; Soejima, Yuji; Maehara, Yoshihiko

    2018-02-01

    We aimed to evaluate the effect of antibody to hepatitis B core antigen (HBcAb) positivity on clinical outcomes after hepatic resection in hepatocellular carcinoma (HCC) patients with negative hepatitis B surface antigen (HBsAg) and hepatitis C virus antibody (HCVAb), termed non-B, non-C HCC (NBNC-HCC), or with HCV-related HCC. Two hundred and sixty-three patients who underwent hepatic resection for HCC and measurements of HBsAg, HCVAb, and HBcAb were enrolled in this study. The percentages of HBcAb positivity were 52.3% (n = 57) and 56.9% (n = 66) in patients with NBNC- and HCV-related HCC, respectively. The proportion of multiple NBNC-HCCs was significantly greater in patients with HBcAb positivity compared to HBcAb negativity (P = 0.028). There were no significant differences in the recurrence-free and overall survival rates between NBNC-HCC patients with HBcAb positivity versus negativity (P = 0.461 and P = 0.190, respectively). Furthermore, for HCV-related HCC patients, there were no significant differences in the baseline factors between patients with positive versus negative HBcAb. The proportion of patients with HBcAb-positive HCV-related HCC who underwent anatomical resection of the liver was significantly greater than that of HBcAb-negative patients, whereas the recurrence-free and overall survival rates were not significantly different (P = 0.158 and P = 0.191, respectively). In our study, the presence of HBcAb had no impact on surgical outcomes after hepatic resection in patients with NBNB- and HCV-related HCC. Occult HBV infection might be associated with hepatocarcinogenesis in patients with NBNC-related HCC. © 2017 The Japan Society of Hepatology.

  7. Increased prevalence of Dirofilaria immitis antigen in canine samples after heat treatment.

    Science.gov (United States)

    Velasquez, Luisa; Blagburn, Byron L; Duncan-Decoq, Rebecca; Johnson, Eileen M; Allen, Kelly E; Meinkoth, James; Gruntmeir, Jeff; Little, Susan E

    2014-11-15

    Canine serum samples may contain factors that prevent detection of antigen of Dirofilaria immitis on commercial assays, precluding accurate diagnosis. To determine the degree to which the presence of blocking antibodies or other inhibitors of antigen detection may interfere with our ability to detect circulating antigen in canine samples, archived plasma and serum samples (n=165) collected from dogs in animal shelters were tested for D. immitis antigen before and after heat treatment. Negative samples were also evaluated for their ability to block detection of D. immitis antigen in a sample from a positive dog. All 165 samples were negative prior to heating, but 11/154 (7.1%) became positive after heat treatment, a conversion that was documented and quantified on spectrophotometric plate assays, and 7/165 (4.2%) samples decreased detection of antigen when mixed with a known positive sample, suggesting some blocking ability was present. An additional 103 plasma and serum samples that tested positive prior to heating also were evaluated; the optical density of 14/101 (13.9%) increased by ≥50%, and one sample by as much as 15-fold, after heat treatment. Our results suggest that canine serum and plasma samples from dogs in the southeastern United States can contain inhibitors of D. immitis antigen detection, and that prevalence estimates of heartworm infection based on these assays would benefit from heat treatment of samples prior to testing. Copyright © 2014 Elsevier B.V. All rights reserved.

  8. Effective detection of toxigenic Clostridium difficile by a two-step algorithm including tests for antigen and cytotoxin.

    Science.gov (United States)

    Ticehurst, John R; Aird, Deborah Z; Dam, Lisa M; Borek, Anita P; Hargrove, John T; Carroll, Karen C

    2006-03-01

    We evaluated a two-step algorithm for detecting toxigenic Clostridium difficile: an enzyme immunoassay for glutamate dehydrogenase antigen (Ag-EIA) and then, for antigen-positive specimens, a concurrent cell culture cytotoxicity neutralization assay (CCNA). Antigen-negative results were > or = 99% predictive of CCNA negativity. Because the Ag-EIA reduced cell culture workload by approximately 75 to 80% and two-step testing was complete in CCNA alone had been performed on all 5,887 specimens.

  9. El ensayo inmunoenzimatico en microgotas sobre nitrocelulosa (Dot-ELISA en el diagnostico de la enfermedad de Chagas: I. Estudio comparativo de dos preparaciones antigenicos de Trypanosoma cruzi The Dot-Enzyme linked immunosorbent assay (Dot-ELISA in the diagnosis of Chagas-disease: I. Comparative study of two antigenic preparations of Trypanosoma cruzi

    Directory of Open Access Journals (Sweden)

    Rosa M. de Hubsch

    1988-09-01

    Full Text Available Se estudia el Ensayo Inmunoenzimático en Microgotas sobre Nitrocelulosa (Dot-ELISAcomparando dos preparados antigénicos de formas epimastigotas de cultivo de T. cruzi: 1 la fracción citoplasmática (antígeno citoplasmático y 2 el parásito total fijado previamente con formaldehido (antígeno integral. Se usaron sueros de: 95 pacientes chagásicos con serología convencional positiva, cardiopatía crónica y algunos con xenodiagnóstico positivo; 42 personas sanas y 32 con miocardipatía crónica con serología negativa y 74 pacientes con diferentes patologías incluyendo: sífilis, toxoplasmosis, lupus eritematoso diseminado, con factor reumatoide, leishmaniasis visceral, y leishmaniasis cutánea. Definidos los títulos diagnósticos (cut-off de 1:512 con antígeno citoplasmático y de 1: 128 con antígeno integral, la especificidad fue 96% para el primero y de 100% para el segundo; mientras que la sensibilidad fue de 100% para ambas. En el estudio comparativo con las pruebas serológicas convencionales examinando 147 sueros tomados de personas referidas al laboratório, Dot-ELISA con antígeno citoplasmático presentó índices deco-positividad de 1,0, co-negatividad de 0,989 y eficiencia 0,993. Dot-ELIS con antígeno integral dió 1,0, 0,979 y 0,986 respectivamente. De acuerdo con esta evaluación, la técnica Dot-ELISA con antígeno integral se presenta como una alternativa práctica para el diagnóstico serológico de la enfermedad de Chagas.Using the Dot-ELISA technique, two antigenic preparations of Trypanosoma cruzi epimastigote forms have been compared for the diagnosis of Chagas' disease: (1 The citoplasmic fraction (citoplasmic antigen and (2 whole fixed epimastigotes (integral antigen. There was been used sera from 95 chagasic patients with chronic cadiomyopathy, positive conventional serology and either positive or negative xenodiagnosis; 74 subjects with negative conventional serology, and either clinically normal or presenting

  10. Specific Antibodies Reacting with SV40 Large T Antigen Mimotopes in Serum Samples of Healthy Subjects.

    Directory of Open Access Journals (Sweden)

    Mauro Tognon

    Full Text Available Simian Virus 40, experimentally assayed in vitro in different animal and human cells and in vivo in rodents, was classified as a small DNA tumor virus. In previous studies, many groups identified Simian Virus 40 sequences in healthy individuals and cancer patients using PCR techniques, whereas others failed to detect the viral sequences in human specimens. These conflicting results prompted us to develop a novel indirect ELISA with synthetic peptides, mimicking Simian Virus 40 capsid viral protein antigens, named mimotopes. This immunologic assay allowed us to investigate the presence of serum antibodies against Simian Virus 40 and to verify whether Simian Virus 40 is circulating in humans. In this investigation two mimotopes from Simian Virus 40 large T antigen, the viral replication protein and oncoprotein, were employed to analyze for specific reactions to human sera antibodies. This indirect ELISA with synthetic peptides from Simian Virus 40 large T antigen was used to assay a new collection of serum samples from healthy subjects. This novel assay revealed that serum antibodies against Simian Virus 40 large T antigen mimotopes are detectable, at low titer, in healthy subjects aged from 18-65 years old. The overall prevalence of reactivity with the two Simian Virus 40 large T antigen peptides was 20%. This new ELISA with two mimotopes of the early viral regions is able to detect in a specific manner Simian Virus 40 large T antigen-antibody responses.

  11. Antigen antibody interactions

    CERN Document Server

    DeLisi, Charles

    1976-01-01

    1. 1 Organization of the Immune System One of the most important survival mechanisms of vertebrates is their ability to recognize and respond to the onslaught of pathogenic microbes to which they are conti- ously exposed. The collection of host cells and molecules involved in this recognition­ 12 response function constitutes its immune system. In man, it comprises about 10 cells 20 (lymphocytes) and 10 molecules (immunoglobulins). Its ontogenic development is c- strained by the requirement that it be capable of responding to an almost limitless variety of molecular configurations on foreign substances, while simultaneously remaining inert to those on self components. It has thus evolved to discriminate, with exquisite precision, between molecular patterns. The foreign substances which induce a response, called antigens, are typically large molecules such as proteins and polysaccharides. The portions of these with which immunoglobulins interact are called epitopes or determinants. A typical protein epitope m...

  12. Antigenic maps of influenza A(H3N2) produced with human antisera obtained after primary infection

    NARCIS (Netherlands)

    J.M. Fonville (Judith); P.L.A. Fraaij (Pieter); G. de Mutsert (Gerrie); S. Wilks; R. van Beek (Ruud); R.A.M. Fouchier (Ron); G.F. Rimmelzwaan (Guus)

    2016-01-01

    textabstractBackground Antigenic characterization of influenza viruses is typically based on hemagglutination inhibition (HI) assay data for viral isolates tested against strain-specific postinfection ferret antisera. Here, similar virus characterizations were performed using serological data from

  13. Cancer antigen 125 and prognosis

    DEFF Research Database (Denmark)

    Høgdall, Estrid Vilma Solyom

    2008-01-01

    cancer antigen 125 determination may be implemented into clinical practice, cut-off levels must be evaluated and internationally defined. Studies examining serum cancer antigen 125 levels after surgery but before, during, or after treatment confirmed that changes in serum levels are of prognostic value...

  14. Increased detection of Dirofilaria immitis antigen in cats after heat pretreatment of samples.

    Science.gov (United States)

    Gruntmeir, Jeff M; Adolph, Chris B; Thomas, Jennifer E; Reichard, Mason V; Blagburn, Byron L; Little, Susan E

    2017-10-01

    Objectives To determine whether pretreating diagnostic samples with heat increases the detection of Dirofilaria immitis antigen in adult cats, we evaluated feline serum and plasma samples collected in heartworm-endemic areas of the southern United States. Methods Commercial microtiter well assays for detection of D immitis antigen were used to evaluate serum or plasma samples from 385 shelter and free-roaming cats from the southcentral and southeastern United States before and after heat treatment; commercial antibody tests were performed on a subset of samples. Results Prior to sample heat treatment, 1/220 (0.5%) shelter cats and 4/165 (2.4%) free-roaming cats had detectable D immitis antigen. After heat pretreatment, the detection rate increased to 13/220 (5.9%) and 13/165 (7.9%), respectively. Antibody reactive to D immitis was significantly more common ( P cats that were antigen positive after heat treatment (10/13; 76.9%) than serum from cats that remained antigen negative after heat treatment (22/163; 13.5%). Conclusions and relevance Heat pretreatment of feline samples increased antigen detection by commercial assays for D immitis and improved overall concordance of antigen and antibody test results in antigen-positive samples in this population. Although further work to investigate the specificity of D immitis antigen assays when using pre-treated samples is warranted, this approach may be useful in the diagnosis of heartworm infection in individual cats and may increase the accuracy of surveys based on antigen detection.

  15. Antigenic differences between bovine viral diarrhea viruses and HoBi virus: Possible impacts on diagnosis and control

    Science.gov (United States)

    Compare antigenic differences between HoBi virus and BVDV strains that might impact on diagnostics and control. Eighteen non-cytopathic isolates of pestiviruses including the 5 genotypic groups (BVDV1a-c, BVDV2, BDV) and HoBi virus, were tested using antigen capture enzyme-linked immunosorbent assay...

  16. Assessment of a serum tumour marker for carcinoma of the pancreas: the carbohydrate antigen C.A. 19-9

    International Nuclear Information System (INIS)

    Vincent, D.; Venot, J.; Catanzano, G.; Clement, M.N.; Piquet, M.F.; Veyriras, E.; Beck, C.

    1985-01-01

    A radio-immunological assay with monoclonal antibodies was used to measure the C 19-9 antigen in 51 patients to determine its diagnostic value in cancer of the pancreas. The results show that the C 19-9 antigen is a good marker for carcinoma of the pancreas and that it can be commonly used [fr

  17. 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

  18. Radiation and chemical effects on viral transformation and tumor antigen expression. Annual progress report, August 1, 1978--May 1, 1979

    International Nuclear Information System (INIS)

    Coggin, J.H. Jr.

    1979-01-01

    Studies aimed at the biological, biochemical, and immunologic characterization of fetal antigens (EA) in hamsters and mice and locating and determining the distribution of fetal antigens in tumor tissues and in developing fetuses have been underway for several months. Progress has been made in isolating embryonic or fetal antigens from fetuses and from tumor cells. We have developed and reported a reliable lymphocyte transformation assay (LTA) which meets our needs in routinely assaying cell free tumor associated antigen (TAA) preparations from fetal and tumor cells. The assay correlated with transplantation resistance assays and has appropriate specificity. We have also developed the staph-A protein binding assay utilizing anti-serum derived against embryonic antigens present on SV40 tumor cells. In other studies, we have reported increases and perturbations in thymocytes during viral and chemical oncogenesis in hamsters, have developed a simple technique for preserving functional lymphocytes sensitized against TAA by freezing for use in our model system work, have reported the cross-reactivity of tranplantation resistance antigen on a spectrum of chemically induced tumors previously believed to only contain individually specific TSTAs and have recently reported the cross-reactivity of papovavirus induced transplantation resistance antigen in sarcoma cells induced by different viruses. We have concluded our studies of glycosyltransferases in the membranes of developing fetuses and noted no differences in their levels with advancing days of gestation using whold embryo cell populations

  19. Assay for methadone

    International Nuclear Information System (INIS)

    1980-01-01

    An improved radioimmunoassay for methadone is described using a novel antigen, antibody and labelled methadone derivatives. The preparation of a hemi-ester antigen is described by reacting a methadone derivative with succinic anhydride or glutaric anhydride; this hapten is then covalently bonded through the carboxyl group to bovine serum albumin. An antibody specific to methadone is produced by inoculating a host animal with the above antigen. The unknown amount of methadone in a sample is then determined by mixing the sample with a known amount of radiolabelled methadone derivative and the above antibody and comparing the degree of binding to a standard curve obtained by mixing the antibody with known amounts of methadone and fixed amounts of labelled methadone derivative. The radioimmunoassay was used to measure methadone levels in urine from individuals attending a methadone clinic. (U.K.)

  20. Radioreceptor opioid assay

    International Nuclear Information System (INIS)

    Miller, R.J.; Chang, K.-J.

    1981-01-01

    A radioreceptor assay is described for assaying opioid drugs in biological fluids. The method enables the assay of total opioid activity, being specific for opioids as a class but lacking specificity within the class. A radio-iodinated opioid and the liquid test sample are incubated with an opiate receptor material. The percentage inhibition of the binding of the radio-iodinated compound to the opiate receptor is calculated and the opioid activity of the test liquid determined from a standard curve. Examples of preparing radio-iodinated opioids and assaying opioid activity are given. A test kit for the assay is described. Compared to other methods, this assay is cheap, easy and rapid. (U.K.)

  1. 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.

  2. Absolute nuclear material assay

    Science.gov (United States)

    Prasad, Manoj K [Pleasanton, CA; Snyderman, Neal J [Berkeley, CA; Rowland, Mark S [Alamo, CA

    2010-07-13

    A method of absolute nuclear material assay of an unknown source comprising counting neutrons from the unknown source and providing an absolute nuclear material assay utilizing a model to optimally compare to the measured count distributions. In one embodiment, the step of providing an absolute nuclear material assay comprises utilizing a random sampling of analytically computed fission chain distributions to generate a continuous time-evolving sequence of event-counts by spreading the fission chain distribution in time.

  3. Absolute nuclear material assay

    Science.gov (United States)

    Prasad, Manoj K [Pleasanton, CA; Snyderman, Neal J [Berkeley, CA; Rowland, Mark S [Alamo, CA

    2012-05-15

    A method of absolute nuclear material assay of an unknown source comprising counting neutrons from the unknown source and providing an absolute nuclear material assay utilizing a model to optimally compare to the measured count distributions. In one embodiment, the step of providing an absolute nuclear material assay comprises utilizing a random sampling of analytically computed fission chain distributions to generate a continuous time-evolving sequence of event-counts by spreading the fission chain distribution in time.

  4. Tricyclic antidepressant radioreceptor assay

    International Nuclear Information System (INIS)

    Innis, R.B.; Tune, L.; Rock, R.; Depaulo, R.; U'Prichard, D.C.; Snyder, S.M.

    1979-01-01

    A receptor assay for tricyclic antidepressants described here is based on the ability of these drugs to compete with [ 3 H]-3-guinuclidnyl benzilate ( 3 H-QNB) for binding to muscarinic cholinergic receptors in rat brain membranes. The assay is sensitive, in that it can detect, for example, 2ng/ml nortriptyline in plasma. Seven plasma samples from depressed patients treated with nortriptyline were assayed with the radioreceptor and gas liquid chromatographic methods, and the results from these two methods were almost identical. This assay should be used cautiously, if at all, in patients treated with other drugs that have potent anticholinergic effects. (Auth.)

  5. COLONOSCOPY AND CARCINOEMBRYONIC ANTIGEN VARIATIONS

    Directory of Open Access Journals (Sweden)

    Rita G SOUSA

    2014-03-01

    Full Text Available Context Colonoscopy is essential for synchronous and metachronous cancer detection. Carcinoembryonic antigen is a colorectal cancer tumor marker, important as a follow-up tool in patients with previous colorectal cancer. False-positive carcinoembryonic antigen elevation results in multiples exams and in patient anxiety. In literature, there is reference to transient carcinoembryonic antigen increase with colonoscopy. Objective To evaluate the influence of bowel preparation and colonoscopy in carcinoembryonic antigen blood levels. Methods We prospectively studied subjects that underwent routine colonoscopy in our institution. Blood samples were collected (1 before bowel cleaning, (2 before colonoscopy and (3 immediately after colonoscopy. Blood carcinoembryonic antigen levels were determined by “Sandwich” immunoassay. The statistical methods used were the paired t-test and ANOVA. Results Thirty-seven patients (22M/15F were included; age range 28-84 (mean 56 years. Mean carcinoembryonic antigen values were 1.9, 2 and 1.8 for (1, (2 and (3, respectively. An increase in value (2 compared with (1 was observed in 20/37 patients (P = 0.018, mainly in younger patients and in patients requiring more endoluminal interventions. In 29/37 patients, the CEA value decreased from (2 to (3 (P = 1.3x10-7. Conclusions A trend for carcinoembryonic antigen increase after bowel cleaning was observed, especially in younger patients and in patients with more endoluminal interventions, but without clinical meaning.

  6. Colonoscopy and carcinoembryonic antigen variations.

    Science.gov (United States)

    Sousa, Rita G; Nunes, Ana; Meira, Tânia; Carreira, Olga; Pires, Ana M; Freitas, João

    2014-01-01

    Colonoscopy is essential for synchronous and metachronous cancer detection. Carcinoembryonic antigen is a colorectal cancer tumor marker, important as a follow-up tool in patients with previous colorectal cancer. False-positive carcinoembryonic antigen elevation results in multiples exams and in patient anxiety. In literature, there is reference to transient carcinoembryonic antigen increase with colonoscopy. To evaluate the influence of bowel preparation and colonoscopy in carcinoembryonic antigen blood levels. We prospectively studied subjects that underwent routine colonoscopy in our institution. Blood samples were collected (1) before bowel cleaning, (2) before colonoscopy and (3) immediately after colonoscopy. Blood carcinoembryonic antigen levels were determined by "Sandwich" immunoassay. The statistical methods used were the paired t-test and ANOVA. Thirty-seven patients (22M/15F) were included; age range 28-84 (mean 56 years). Mean carcinoembryonic antigen values were 1.9, 2 and 1.8 for (1), (2) and (3), respectively. An increase in value (2) compared with (1) was observed in 20/37 patients (P = 0.018), mainly in younger patients and in patients requiring more endoluminal interventions. In 29/37 patients, the CEA value decreased from (2) to (3) (P = 1.3x10-7). A trend for carcinoembryonic antigen increase after bowel cleaning was observed, especially in younger patients and in patients with more endoluminal interventions, but without clinical meaning.

  7. [Serological diagnosis of sporotrichosis using an antigen of Sporothrix schenckii sensu stricto mycelium].

    Science.gov (United States)

    Alvarado, Primavera; Ostos, Ana; Franquiz, Nohelys; Roschman-González, Antonio; Zambrano, Edgar A; Mendoza, Mireya

    2015-06-01

    We developed and analyzed an Enzyme-Linked Immunosorbent Assay (ELISA) in order to detect antibodies in sera from sporotrichosis patients. We used a crude antigen of Sporothrix schenckii sensu stricto, obtained from the mycelial phase of the fungi. Positive sera were analyzed by other serological techniques such as double immunodiffusion (IGG) and counterimmunoelectrophoresis (CIE). The assay was validated by using sera from patients with other pathologies such as: histoplasmosis, paracoccidioidomycosis, tuberculosis, leishmaniasis, lupus and healthy individuals as negative controls. For the Sporothrix schenckii sensu stricto antigen, we found a 100% of specificity by every technique and sensitivity higher than 98% with IDD, CIE and ELISA. Our results show a high sensitivity and specificity for the Sporothrix schenckii sensu stricto antigen, so it can be used for IDD, CIE and ELISA. The results suggest that this antigen could be used in conjunction with other conventional tests for differential diagnosis and may be useful for monitoring the disease progression and response to treatment.

  8. Pre-treatment with heat facilitates detection of antigen of Dirofilaria immitis in canine samples.

    Science.gov (United States)

    Little, Susan E; Munzing, Candace; Heise, Steph R; Allen, Kelly E; Starkey, Lindsay A; Johnson, Eileen M; Meinkoth, James; Reichard, Mason V

    2014-06-16

    Diagnosis of Dirofilaria immitis infection in dogs is largely dependent on detection of antigen in canine serum, plasma, or whole blood, but antigen may be bound in immune complexes and thus not detected. To develop a model for antigen blocking, we mixed serum from a microfilaremic, antigen-positive dog with that of a hypergammaglobulinemic dog not currently infected with D. immitis and converted the positive sample to antigen-negative; detection of antigen was restored when the mixed sample was heat-treated, presumably due to disruption of antigen/antibody complexes. A blood sample was also evaluated from a dog that was microfilaremic and for which microfilariae were identified as D. immitis by morphologic examination. Antigen of D. immitis was not detected in this sample prior to heating but the sample was strongly positive after heat treatment of whole blood. Taken together, our results indicate that blood samples from some dogs may contain factors that inhibit detection of antigen of D. immitis, and that heat treatment of these samples prior to testing could improve the sensitivity of these assays in some patients. Copyright © 2014 Elsevier B.V. All rights reserved.

  9. A Model System for Concurrent Detection of Antigen and Antibody Based on Immunological Fluorescent Method

    Directory of Open Access Journals (Sweden)

    Yuan-Cheng Cao

    2015-01-01

    Full Text Available This paper describes a combined antigen/antibody immunoassay implemented in a 96-well plate using fluorescent spectroscopic method. First, goat anti-human IgG was used to capture human IgG (model antigen; goat anti-human IgG (Cy3 or FITC was used to detect the model antigen; a saturating level of model antigen was then added followed by unlabelled goat anti-human IgG (model antibody; finally, Cy3 labelled rabbit anti-goat IgG was used to detect the model antibody. Two approaches were applied to the concomitant assay to analyze the feasibility. The first approach applied FITC and Cy3 when both targets were present at the same time, resulting in 50 ng/mL of the antibody detection limit and 10 ng/mL of antigen detection limit in the quantitative measurements of target concentration, taking the consideration of FRET efficiency of 68% between donor and acceptor. The sequential approach tended to lower the signal/noise (S/N ratio and the detection of the model antigen (lower than 1 ng/mL had better sensitivity than the model antibody (lower than 50 ng/mL. This combined antigen/antibody method might be useful for combined detection of antigens and antibodies. It will be helpful to screen for both antigen and antibody particularly in the situations of the multiserotype and high-frequency mutant virus infections.

  10. Lymphoid cell blastogenesis as an in vitro indicator of cellular immunity to Legionella pneumophila antigens.

    OpenAIRE

    Friedman, F; Widen, R; Klein, T; Friedman, H

    1984-01-01

    The lymphocyte blastogenic transformation assay was adapted to study responsiveness of lymphoid cells from animals and humans to Legionella pneumophila antigens in vitro. Spleen cells from guinea pigs after active immunization with Legionella vaccine, but not from normal animals, responded by blast cell transformation when stimulated in vitro with killed Legionella whole-cell vaccine, sonic extracts thereof, or a purified somatic antigen. The response was dose dependent. Similar lymphocyte bl...

  11. 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

  12. Endogenous Locus Reporter Assays.

    Science.gov (United States)

    Liu, Yaping; Hermes, Jeffrey; Li, Jing; Tudor, Matthew

    2018-01-01

    Reporter gene assays are widely used in high-throughput screening (HTS) to identify compounds that modulate gene expression. Traditionally a reporter gene assay is built by cloning an endogenous promoter sequence or synthetic response elements in the regulatory region of a reporter gene to monitor transcriptional activity of a specific biological process (exogenous reporter assay). In contrast, an endogenous locus reporter has a reporter gene inserted in the endogenous gene locus that allows the reporter gene to be expressed under the control of the same regulatory elements as the endogenous gene, thus more accurately reflecting the changes seen in the regulation of the actual gene. In this chapter, we introduce some of the considerations behind building a reporter gene assay for high-throughput compound screening and describe the methods we have utilized to establish 1536-well format endogenous locus reporter and exogenous reporter assays for the screening of compounds that modulate Myc pathway activity.

  13. Determinação da infecção por Entamoeba histolytica em residentes da área metropolitana de Belém, Pará, Brasil, utilizando ensaio imunoenzimático (ELISA para detecção de antígenos Determination of Entamoeba histolytica infection in patients from Greater Metropolitan Belém, Pará, Brazil, by enzyme-linked immunosorbent assay (ELISA for antigen detection

    Directory of Open Access Journals (Sweden)

    Mônica Cristina de Moraes Silva

    2005-06-01

    Full Text Available O status epidemiológico da amebíase está sendo reavaliado desde que a Entamoeba histolytica (patogênica foi considerada espécie distinta de Entamoeba dispar (não patogênica. Em nosso estudo, realizamos pesquisa de antígenos de E. histolytica em amostras fecais de pacientes residentes na cidade de Belém, Pará, Brasil, utilizando ensaio imunoenzimático (E. histolytica Test, TechLab Inc., Blacksburg, Estados Unidos disponível comercialmente. Foram analisadas 845 amostras, com positividade em 248 (29,35%. A infecção por E. histolytica foi maior no grupo etário acima de 14 anos (30,36% que no grupo de 0-14 anos (28,28%, porém sem significância estatística (p The epidemiological status of amebiasis has been reevaluated since Entamoeba histolytica (pathogenic was considered a distinct species from Entamoeba dispar (non-pathogenic. We investigated E. histolytica antigens in stool samples from residents of Belém, Pará State, Brazil, with commercially available enzyme-linked immunosorbent assay (E. histolytica Test, TechLab Inc., Blacksburg, USA. A total of 845 samples were analyzed, of which 248 were positive (29.35%. E. histolytica infection was more frequent in the over-14-year age group (30.36% than in the 0-14-year group (28.28%, but the difference was not statistically significant (p < 0.05. Of all the samples, 334 were also submitted to parasitological methods (direct, Hoffman, and Faust et al.. There were discordant results between ELISA and parasitological methods in 83 samples (24.85%, with more positive results using ELISA. Our results thus suggest that intestinal amebiasis is an important public health problem in Greater Metropolitan Belém.

  14. ELISA for the detection of venom antigens in experimental and clinical envenoming by Loxosceles intermedia spiders.

    Science.gov (United States)

    Chávez-Olórtegui, C; Zanetti, V C; Ferreira, A P; Minozzo, J C; Mangili, O C; Gubert, I C

    1998-04-01

    Enzyme linked immunosorbent assays (ELISA) were developed to detect antigens from Loxosceles intermedia spider venom. Hyperimmune horse anti-Loxosceles intermedia IgGs were prepared by immunoaffinity chromatography and used to set up a sandwich-type ELISA. The specificity of the assay was demonstrated by its capacity to correctly discriminate the circulating antigens in mice that were experimentally inoculated with L. intermedia venom from those inoculated with L. gaucho, L. laeta, and Phoneutria nigriventer spider venoms, Tityus serrulatus scorpion venom and Bothrops jararaca, Crotalus durissus terrificus, Lachesis muta muta and Micrurus frontalis snake venoms. Measurable absorbance signals were obtained with 0.8 ng of venom per assay. The ELISA also detected antigens in the sera of patients envenomed by L. intermedia. Therefore, after standardization for clinical use this ELISA may be a valuable tool for clinicians and epidemiologists.

  15. KIR content genotypes associate with carriage of hepatitis B surface antigen, e antigen and HBV viral load in Gambians.

    Directory of Open Access Journals (Sweden)

    Louis-Marie Yindom

    Full Text Available Hepatocellular carcinoma (HCC causes over 800,000 deaths worldwide annually, mainly in low income countries, and incidence is rising rapidly in the developed world with the spread of hepatitis B (HBV and C (HCV viruses. Natural Killer (NK cells protect against viral infections and tumours by killing abnormal cells recognised by Killer-cell Immunoglobulin-like Receptors (KIR. Thus genes and haplotypes encoding these receptors may be important in determining both outcome of initial hepatitis infection and subsequent chronic liver disease and tumour formation. HBV is highly prevalent in The Gambia and the commonest cause of liver disease. The Gambia Liver Cancer Study was a matched case-control study conducted between September 1997 and January 2001 where cases with liver disease were identified in three tertiary referral hospitals and matched with out-patient controls with no clinical evidence of liver disease.We typed 15 KIR genes using the polymerase chain reaction with sequence specific primers (PCR-SSP in 279 adult Gambians, 136 with liver disease (HCC or Cirrhosis and 143 matched controls. We investigated effects of KIR genotypes and haplotypes on HBV infection and associations with cirrhosis and HCC.Homozygosity for KIR group A gene-content haplotype was associated with HBsAg carriage (OR 3.7, 95% CI 1.4-10.0 whilst telomeric A genotype (t-AA was associated with reduced risk of e antigenaemia (OR 0.2, 95% CI 0.0-0.6 and lower viral loads (mean log viral load 5.2 vs. 6.9, pc = 0.022. One novel telomeric B genotype (t-ABx2 containing KIR3DS1 (which is rare in West Africa was also linked to e antigenaemia (OR 8.8, 95% CI 1.3-60.5. There were no associations with cirrhosis or HCC.Certain KIR profiles may promote clearance of hepatitis B surface antigen whilst others predispose to e antigen carriage and high viral load. Larger studies are necessary to quantify the effects of individual KIR genes, haplotypes and KIR/HLA combinations on long

  16. KIR content genotypes associate with carriage of hepatitis B surface antigen, e antigen and HBV viral load in Gambians.

    Science.gov (United States)

    Yindom, Louis-Marie; Mendy, Maimuna; Bodimeade, Christopher; Chambion, Caroline; Aka, Peter; Whittle, Hilton C; Rowland-Jones, Sarah L; Walton, Robert

    2017-01-01

    Hepatocellular carcinoma (HCC) causes over 800,000 deaths worldwide annually, mainly in low income countries, and incidence is rising rapidly in the developed world with the spread of hepatitis B (HBV) and C (HCV) viruses. Natural Killer (NK) cells protect against viral infections and tumours by killing abnormal cells recognised by Killer-cell Immunoglobulin-like Receptors (KIR). Thus genes and haplotypes encoding these receptors may be important in determining both outcome of initial hepatitis infection and subsequent chronic liver disease and tumour formation. HBV is highly prevalent in The Gambia and the commonest cause of liver disease. The Gambia Liver Cancer Study was a matched case-control study conducted between September 1997 and January 2001 where cases with liver disease were identified in three tertiary referral hospitals and matched with out-patient controls with no clinical evidence of liver disease. We typed 15 KIR genes using the polymerase chain reaction with sequence specific primers (PCR-SSP) in 279 adult Gambians, 136 with liver disease (HCC or Cirrhosis) and 143 matched controls. We investigated effects of KIR genotypes and haplotypes on HBV infection and associations with cirrhosis and HCC. Homozygosity for KIR group A gene-content haplotype was associated with HBsAg carriage (OR 3.7, 95% CI 1.4-10.0) whilst telomeric A genotype (t-AA) was associated with reduced risk of e antigenaemia (OR 0.2, 95% CI 0.0-0.6) and lower viral loads (mean log viral load 5.2 vs. 6.9, pc = 0.022). One novel telomeric B genotype (t-ABx2) containing KIR3DS1 (which is rare in West Africa) was also linked to e antigenaemia (OR 8.8, 95% CI 1.3-60.5). There were no associations with cirrhosis or HCC. Certain KIR profiles may promote clearance of hepatitis B surface antigen whilst others predispose to e antigen carriage and high viral load. Larger studies are necessary to quantify the effects of individual KIR genes, haplotypes and KIR/HLA combinations on long

  17. Penggunaan Crude Antigen Cysticercus cellulosae Isolat Bali Untuk Optimalisasi Uji ELISA

    Directory of Open Access Journals (Sweden)

    Inti Sari Pati R U Sianturi

    2017-01-01

    Full Text Available Sistiserkosis merupakan penyakit parasitik yang disebabkan oleh larva stadium metacestoda dari cacing pita yang disebut Cysticercus.  Cysticercus yang ditemukan pada babi adalah Cysticercus cellulosae yang merupakan larva dari cacing pita Taenia solium. Penelitian ini dilakukan dengan tujuan mengevaluasi antigen crude Cysticercus cellulosae untuk mendeteksi sistiserkosis pada babi. Cysticercus celllulosae yang digunakan adalah isolat lokal yang diperoleh dari babi terinfeksi Taenia solium asal Karangasem-Bali. Penelitian dilakukan untuk optimalisasi ELISA (Enzyme Linked Immunosorbent Assay terhadap antigen, serum, dan konjugat dengan cara mencari konsentrasi optimal dari antigen, pengenceran optimal serum, dan pengenceran optimal konjugat. Hasil penelitian didapatkan bahwa crude antigen Cysticercus cellulosae isolat Bali bersifat antigenik dan dapat digunakan untuk mendeteksi sistiserkosis pada babi dengan konsentrasi optimal antigen 0,3125 µg/ml, pengenceran optimal serum 1:50, dan pengenceran konjugat 1:2000.

  18. Antigenic relationships among four herpesviruses.

    Science.gov (United States)

    Blue, W T; Plummer, G

    1973-06-01

    Common viral antigens were detected, by fluorescent-antibody studies, in cells infected with herpes simplex virus 1, squirrel monkey herpesvirus 1, bovine rhinotracheitis, and equine abortion viruses. The two primate viruses showed slight cross-neutralization.

  19. HLA-B27 antigen

    Science.gov (United States)

    Human leukocyte antigen B27; Ankylosing spondylitis-HLA; Psoriatic arthritis-HLA; Reactive arthritis-HLA ... Erythrocyte sedimentation rate ( ESR ) Rheumatoid factor X-rays HLA testing is also used to match donated tissue ...

  20. 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