Validation of an ELISA for the concurrent detection of total antibodies (IgM and IgG to Rift Valley fever virus

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Charlotte E. Ellis

2014-05-01

Full Text Available Rift Valley fever virus (RVFV infects humans and livestock, causing haemorrhaging andabortions in animals. Three major RVF epizootics have occurred in South Africa since the1950s and the outbreak in 2010 had a mortality rate of 10.7% in humans. Accurate and earlydetection is therefore essential for management of this zoonotic disease. Enzyme-linkedimmunosorbent assays (ELISAs have been developed for the detection of either IgM or IgGantibodies to RVFV in animal sera. In this study, data are presented on the validation of adouble-antigen ELISA for the simultaneous detection of both classes of antibodies to RVFV ina single test. ELISA plates were coated with a recombinant nucleoprotein. The nucleoprotein,conjugated to horseradish peroxidase, was used as the detecting reagent. A total of 534 serafrom sheep and cattle were used in the validation. The sheep sera were collected during a RVFpathogenesis study at the Agricultural Research Council (ARC – Onderstepoort VeterinaryInstitute and the cattle sera were collected during an outbreak of RVF in 2008 at the ARC –Animal Production Institute in Irene, Pretoria. The ELISA had a diagnostic sensitivity of 98.4%and a specificity of 100% when compared to a commercial cELISA. This convenient and fastassay is suitable for use in serological surveys or monitoring immune responses in vaccinatedanimals.

Validation of an IgM antibody capture ELISA based on a recombinant nucleoprotein for identification of domestic ruminants infected with Rift Valley fever virus.

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Williams, Roy; Ellis, Charlotte Elizabeth; Smith, Shirley Jacqueline; Potgieter, Christiaan Abraham; Wallace, David; Mareledwane, Vuyokazi Epipodia; Majiwa, Phelix Antipas Ochola

2011-11-01

The presence of competent vectors in some countries currently free of Rift Valley fever (RVF) and global changes in climate, travel and trade have increased the risk of RVF spreading to new regions and have emphasised the need for accurate and reliable diagnostic tools for early diagnosis during RVF outbreaks. Highly sensitive viral detection systems like PCR have a limited use during outbreaks because of the short duration of viraemia, whereas antibodies like specific IgM which are serological indicators of acute infection, can be detected for up to 50 days after infection. Using the highly conserved and immunogenic recombinant nucleoprotein of RVF virus in an IgM capture ELISA, the risk of laboratory infection associated with traditional serological methods is avoided. The use of pre-coated/pre-blocked ELISA plates and the conjugation of the recombinant nucleoprotein with horseradish peroxidase simplified and shortened the assay procedure. Results showed the assay to be highly reproducible with a lower detection limit equal to that of a commercial competition ELISA. By receiver operating characteristic (ROC) curve analysis the area under curve (AUC) index was determined as 1.0 and the diagnostic sensitivity and specificity at a PP cut-off value of 4.1 as 100% and 99.78% respectively. The results of this study demonstrated that the IgM capture ELISA is a safe, reliable and highly accurate diagnostic tool which can be used on its own or in parallel with other methods for the early diagnosis of RVF virus infection and also for monitoring of immune responses in vaccinated domestic ruminants. Copyright © 2011 Elsevier B.V. All rights reserved.

IgM rheumatoid factor removal and performance of the FTA-ABS (IgM) test in congenital syphilis.

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Meyer, M P; Roditi, D; Louw, S

1992-08-01

To determine the performance of the FTA-ABS (IgM) test in congenital syphilis after eliminating interference by IgM rheumatoid factor (RF) and preventing competitive inhibition by IgG. The FTA-ABS (IgM) test was carried out before and after RF removal (achieved by immunoprecipitation of the IgG) in infants with congenital syphilis and controls. Newborns delivered in the Peninsula Maternal and Neonatal Services in Cape Town and infants presenting at Red Cross War Memorial Children's Hospital. Infants with congenital syphilis aged 0-4 months were divided into those with clinical signs at presentation and those who were asymptomatic at delivery. In addition, patients without congenital syphilis but with similar clinical signs at presentation were investigated as were control infants. The diagnosis of congenital syphilis was based on the criteria suggested by Kaufman et al (1977). Amongst symptomatic infants with congenital syphilis the FTA-ABS (IgM) test was positive in 34 (92%) of 37 cases prior to abolishing the RF effect and in 29 (78.4%) of 37 cases afterwards (p = 0.19). In 12 cases of congenital syphilis who were asymptomatic at birth, 10 had positive FTA-ABS (IgM) tests before RF removal and only three had positive tests afterwards (p = 0.006). False positive tests were not found amongst 15 symptomatic infants whose clinical features mimicked those of the infants with congenital syphilis. Among 51 healthy infants the test had a false-positive rate of 2% in newborns and 13% in older infants. The false positive reactions were eradicated by IgG precipitation. Following IgG and RF removal there was an improvement in the specificity of the FTA-ABS (IgM) test but this was at the expense of a loss of sensitivity, particularly in asymptomatic newborns. For newborns, if the FTA-ABS (IgM) test was positive, the patient was likely to require treatment for congenital syphilis, regardless of whether the result was due to the presence of RF or specific IgM.

Utility of loop-mediated isothermal amplification assay, polymerase chain reaction, and elisa for diagnosis of leptospirosis in South Indian patients

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Mallika Sengupta

2017-01-01

Full Text Available Background: Leptospirosis is a zoonotic disease which requires laboratory diagnosis for confirmation. Materials and Methods: In this study serum samples from adults with acute undifferentiated fever (duration ≤15 days were tested for IgM antibodies to Leptospira by ELISA, PCR for rrs gene and loop-mediated isothermal amplification (LAMP assay for LipL32 and LipL41. Results: Among the 150 sera tested, three were positive by PCR, LAMP and IgM ELISA/modified Faines' criteria, two by only PCR; seven only by LAMP assay and forty fulfilled modified Faine's criteria (illness clinically compatible and IgM ELISA positive for leptospirosis. Clinical correlation revealed renal compromise, low platelet count and severe jaundice were significantly related to leptospirosis (P < 0.05. Conclusion: This study suggests that LAMP assay could be useful for diagnosis of leptospirosis during the 1st week of illness whereas IgM ELISA forms the mainstay of diagnosis from the 2nd week onward. Further studies especially community based, comparing ELISA, PCR, LAMP, culture and microscopic agglutination test are required to evaluate the veracity of these findings.

Evaluation of Two Enzyme-Linked Immunosorbent Assay Kits for Chikungunya Virus IgM Using Samples from Deceased Organ and Tissue Donors

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Altrich, Michelle L.; Nowicki, Marek J.

2016-01-01

The identification of nearly 3,500 cases of chikungunya virus (CHIKV) infection in U.S. residents returning in 2014 and 2015 from areas in which it is endemic has raised concerns within the transplant community that, should recently infected individuals become organ and/or tissue donors, CHIKV would be transmitted to transplant recipients. Thus, tests designed to detect recent CHIKV infection among U.S. organ and tissue donors may become necessary in the future. Accordingly, we evaluated 2 enzyme-linked immunosorbent assays (ELISAs) for CHIKV IgM readily available in the United States using 1,000 deidentified serum or plasma specimens collected from donors between November 2014 and March 2015. The Euroimmun indirect ELISA identified 38 reactive specimens; however, all 38 were negative for CHIKV IgG and IgM in immunofluorescence assays (IFAs) conducted at a reference laboratory and, thus, were falsely reactive in the Euroimmun CHIKV IgM assay. The InBios IgM-capture ELISA identified 26 reactive samples, and one was still reactive (index ≥ 1.00) when retested using the InBios kit with a background subtraction modification to identify false reactivity. This reactive specimen was CHIKV IgM negative but IgG positive by IFAs at two reference laboratories; plaque reduction neutralization testing (PRNT) demonstrated CHIKV-specific reactivity. The IgG and PRNT findings strongly suggest that the InBios CHIKV IgM-reactive result represents true reactivity, even though the IgM IFA result was negative. If testing organ/tissue donors for CHIKV IgM becomes necessary, the limitations of the currently available CHIKV IgM ELISAs and options for their optimization must be understood to avoid organ/tissue wastage due to falsely reactive results. PMID:27535838

IgM rheumatoid factor removal and performance of the FTA-ABS (IgM) test in congenital syphilis.

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Meyer, M P; Roditi, D; Louw, S

1992-01-01

OBJECTIVE--To determine the performance of the FTA-ABS (IgM) test in congenital syphilis after eliminating interference by IgM rheumatoid factor (RF) and preventing competitive inhibition by IgG. DESIGN--The FTA-ABS (IgM) test was carried out before and after RF removal (achieved by immunoprecipitation of the IgG) in infants with congenital syphilis and controls. SETTING--Newborns delivered in the Peninsula Maternal and Neonatal Services in Cape Town and infants presenting at Red Cross War Me...

New ELISA Kits using C3 Binding Glycoprotein from Cuscuta europea Detect Mainly IgM CIC in Rheumatoid Arthritis and Progressive Systemic Sclerosis, but not in Systemic Lupus Erythematosus

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Spaska Angelova Stanilova

2003-01-01

Full Text Available Elevated levels of circulating immune complexes (CIC, containing IgG, IgM or IgA antibodies were detected in the sera of patients with autoimmune diseases. This might indicate a different biological meaning of the three isotypes of immunoglobulin (Ig in the CIC. Each CIC assay detected only certain classes and subclasses of Ig in CIC material or fixed complement protein. In this study, a new method based on C3binding glycoprotein named CIF-ELISA and a well-known method ANTI-C3 ELISA, were used for quantitative assessment of IgM-CIC, IgG-CIC and IgA-CIC levels in human sera. A modified CIF-ELISA and ANTI-C3 ELISA for simultaneous detection of CIC, containing IgG, IgM and IgA, (stCIC, were also performed. The assays were evaluated on the same specially prepared samples: 55 normal sera, 99 sera from rheumatoid arthritis (RA, 88 sera from systemic lupus erythematosus (SLE, and 27 sera from progressive systemic sclerosis (PSS. We found that the sensitivity of the tests used varied depending on the diseases studied. CIF-ELISA displayed higher sensitivity of IgM-CIC when compared to ANTI-C3 ELISA in RA patients (40.0 and 20.95%, respectively and PSS (44.43 and 37.04%, respectively. Results for the sensitivity of IgA-CIC were in adverse direction in the RA group (14.28 and 19.05% and PSS (14.81 and 25.93% by both methods. It was also established that the concordance of IgM-CIC positives by both methods was 48.84% in RA and 46.67% in PSS, while in SLE it was 18.78%. These results are most probably due to the different assay abilities to detect antibody isotype of the CIC material and help to explain what specific role each Ig isotype in CIC has in the course of the disease.

Development of an enzyme-linked immunosorbent assay for detection of IgM antibodies to Babesia bigemina in cattle

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Ruiz Patrícia M Gonçalves

2001-01-01

Full Text Available A crude antigenic preparation of Babesia bigemina was used to develop an ELISA for the detection of IgM antibodies. Optimal dilutions of the antigen, using positive and negative reference sera, were determined by checkerboard titrations. Negative sera from cattle imported from tick-free areas, serum samples collected from infected B. bigemina cattle were used to validate the test. The specificity was 94% and sensitivity of the Elisa 87.5%. Sera from 385 cattle deriving from areas free from tick-borne diseases, which were submitted to a preimmunization process, were screened by this technique. The Elisa detected seroconversion on the 14th day post-inoculation in animals either infested with Boophilus microplus ticks (infected with B. bigemina, or inoculated with B. bigemina infected blood. Antibody titers decreased after day 33; however, all animals remained positive until the end of the experiment (124 days. The ELISA described may prove to be an appropriate serological test for the detection of IgM antibodies against B. bigemina.

Comparison of dot-ELISA and standard ELISA for detection of Neisseria meningitidis outer membrane complex-specific antibodies

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Elza FT Belo

Full Text Available Dot-ELISA using the outer membrane complex antigens of Neisseria meningitidis as a target was standardized for rapid detection of meningococcal-specific antibodies in human serum. We investigated the level of meningococcal-specific IgG, IgA, and IgM in serum using dot-ELISA with outer membrane antigens prepared from Neisseria meningitidis serotype B:4.19:P1.15,3,7,9 (a strain isolated from a Brazilian epidemic. The dot-ELISA is based on the same principles as the standard ELISA and is useful for detection of anti-N. meningitidis B antibodies in serum of patients with meningococcal infections. For the assay, outer membrane complexes (OMCs were absorbed by nitrocellulose membrane and blocked with a 5% skim milk solution. Serum samples were drawn upon hospital admission and during convalescence from patients with meningococcal septicemia, and single samples were drawn from uninfected controls. We retrospectively examined a total of 57 serum samples: 35 from patients infected with N. meningitidis B, 12 from patients infected with Haemophilus influenzae b, and 10 from health individuals. When performed at room temperature, dot-ELISA took approximately four hours to perform, and the optimum antigen concentration was 0.42 µg per dot. The specificity of IgG, IgM, and IgA demonstrates that dot-ELISA using OMCs from N. meningitidis B as a target is suitable for serologic verification of clinically suspected meningococcal disease in patients and for titer determination of antibodies produced during different phases of natural infection. Furthermore, the sensitivity of dot-ELISA was comparable to that of standard ELISA. Overall, dot-ELISA is simple to perform, rapid, and low cost. Further validation of the test as a screening tool is required.

Detection of koi herpesvirus (KHV) using a monoclonal antibody against Cyprinus carpio IgM.

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Li, Yingying; Zheng, Shucheng; Wang, Qing; Bergmann, Sven M; Zeng, Weiwei; Wang, Yingying; Liu, Chun; Shi, Cunbin

2017-08-01

Koi herpesvirus disease (KHVD) is associated with high mortality in both common carp and koi carp (Cyprinus carpio L.) worldwide. The indirect detection of fish viruses based on the identification of antibodies has emerged as a practical and reliable means of diagnosis. Thus, it is important to create monoclonal antibodies (MAbs) against carp IgM. By using hybridoma-monoclonal antibody technology, one hybridoma cell line secreting MAbs against IgM from carp was established. In western blot analysis, the secreted MAb from cell line A5-E10 recognized the heavy chain of IgM from common carp or koi but did not react with immunoglobulins from three different fish species: grass carp (Ctenopharyngodon idella), tilapia (Oreochromis mossambicus) and Mandarin fish (Siniperca chuatsi). These results demonstrated that this MAb is highly specific for the IgM of carp and suggested that it can be used for monitoring the immunity level of carp, for example for indirect KHV diagnosis by antibody ELISA. We therefore established an indirect ELISA, which was tested using 200 serum samples from koi from three farms. The final results showed that 147 (73.5%) samples were confirmed to be KHV antibody negative and 53 (26.5%) were definitely positive, containing antibodies against KHV.

Usefulness of a single-assay chemiluminescence test (Tularaemia VIRCLIA IgG + IgM monotest) for the diagnosis of human tularemia. Comparison of five serological tests.

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Cubero, África; Durántez, Carlos; Almaraz, Ana; Fernández-Lago, Luis; Gutiérrez, María P; Castro, María J; Bratos, Miguel A; Simarro, María; March, Gabriel A; Orduña, Antonio

2018-04-01

The aim of this work was to ascertain the usefulness of a new commercially-available single-assay chemiluminescence test (CHT) for the diagnosis of human tularemia (Tularaemia VIRCLIA IgG + IgM monotest, Vircell, Santa Fe, Granada, Spain). A total of 773 sera from 773 patients including 364 initial sera from patients with diagnosed tularemia, patients with suspected tularemia not confirmed (100), healthy people (152), patients with serology positive to Brucella (97), patients diagnosed with other infectious diseases (30), and patients diagnosed with autoimmune diseases (30) were included. All sera were tested by CHT, "in-house" microagglutination test (MAT), immunochromatographic test (ICT) (Virapid Tularaemia, Vircell, Santa Fe Granada, Spain), and "in-house" ELISA IgG, and ELISA IgM. Of the total initial sera, 334 (sensitivity 91.8%) were positive in the CHT, 332 (sensitivity 91.2%) in the MAT, 330 (sensitivity 90.7%) in the ICT, and 328 (sensitivity 90.1%) in the ELISA IgG and ELISA IgM tests. The specificity of the CHT was 96.7%; of the MAT, 100%; of the ICT, 98.7%; and of the ELISA IgG and ELISA IgM, 97.4%. In the group of patients with serology positive to Brucella, at least 12.4% of sera were positive in tularemia tests (12.4% in ELISA IgM, 13.4% in MAT, 14.4% in ICT, and 15.5% in CHT and ELISA IgG). In conclusion, CHT presents a sensitivity and specificity in early diagnosis of human tularemia, similar to MAT, ICT, and ELISA IgG and ELISA IgM. Its single assay design allows lower costs, especially in areas of low endemicity or inter-epidemic periods.

Generation of a novel high-affinity monoclonal antibody with conformational recognition epitope on human IgM.

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Sarikhani, Sina; Mirshahi, Manouchehr; Gharaati, Mohammad Reza; Mirshahi, Tooran

2010-11-01

As IgM is the first isotype of antibody which appears in blood after initial exposure to a foreign antigen in the pattern of primary response, detection, and quantification of this molecule in blood seems invaluable. To approach these goals, generation, and characterization of a highly specific mAb (monoclonal antibody) against human IgM were investigated. Human IgM immunoglobulins were used to immunize Balb/c mice. Spleen cells taken from the immunized animals were fused with SP2/O myeloma cells using PEG (polyethylene glycol, MW 1450) as fusogen. The hybridomas were cultured in HAT containing medium and supernatants from the growing hybrids were screened by enzyme-linked immunosorbent assay (ELISA) using plates coated with pure human IgM and the positive wells were then cloned at limiting dilutions. The best clone designated as MAN-1, was injected intraperitoneally to some Pristane-injected mice. Anti-IgM mAb was purified from the animals' ascitic fluid by protein-G sepharose followed by DEAE-cellulose ion exchange chromatography. MAN-1 interacted with human IgM with a very high specificity and affinity. The purity of the sample was tested by SDS-PAGE and the affinity constant was measured (K(a) = 3.5 x 10(9)M(-1). Immunoblotting and competitive ELISA were done and the results showed that the harvested antibody recognizes a conformational epitope on the mu chain of human IgM and there was no cross-reactivity with other subclasses of immunoglobulins. Furthermore, isotyping test was done and the results showed the subclass of the obtained mAb which was IgG(1)kappa.

[Diagnosis for human parvovirus B19-polyarthritis: usefulness of empty particle B19.ELISA and B19-DNA.PCR].

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Hatakeyama, Y; Ishii, K; Murai, C; Sugamura, K; Mitomo, N; Saitoh, T; Rikimaru, Y; Okazaki, T; Sasaki, T

1998-10-01

To evaluate the usefulness of new ELISA for human parvovirus B19 (B19) antibodies and PCR for the diagnosis of acute onset of B19 polyarthritis. We evaluated the reproducibility and sensitivity on the detection of anti-B19 antibody by ELISA using recombinant VP-1 and VP-2 (empty particle), and then studied for the prevalence of IgM and IgG B19 antibody in 125 samples for anti-B19 tests. The random study on anti-B19 antibody assay as well as PCR for B19-DNA was also performed in 130 cases with acute onset of arthritis excluding those with known origins, 224 with rheumatoid arthritis and 149 with other categories. The results by using B19-empty particle ELISA were reproducible and showed the assay was a sensitive way for clinical use. IgM anti-B19 antibodies were positive not only in all samples from erythema infectiosum, but also often in those from hemolytic anemia, pure red cell aplasia, fetal hydrops, hepatic injury, fever of unknown origin. Among 130 with acute onset of arthritis, 21 showed positive tests for IgM anti-B19 antibody and/or B19 DNA. On the other hand, 4 among 224 patients with rheumatoid arthritis were positive for IgM anti-B19 antibody, but all of 149 in control group were negative for IgM anti-B19 antibodies and for B19 DNA. Anti-B19 ELISA using B19-empty particle which has been introduced as a routine test system, is a useful tool for the diagnosis of acute onset of B19 arthritis. An additional examination using PCR for B19 DNA may contribute for understanding persistent B19 polyarthritis or reactivation of B19 infection.

Retrospective analysis of dengue specific IgM reactive serum samples

OpenAIRE

Nemai Bhattacharya; Bhaswati Bandyopadhyay; Indranil Bhattacharjee; Hiranmoy Mukherjee; Srabani Talukdar; Ruby Mondal; Netai Pramanick; Goutam Chandra; Amiya K. Hati

2013-01-01

Objective: To conduct a retrospective analysis of dengue cases in Kolkata, on the basis of presence of anti-dengue IgM in their sera and presence or absence of anti-dengue IgG and dengue specific Non structural 1 (NS1) antigen in each of the serum sample. Methods: Sample was tested quantitatively employing ELISA technique, using Biorad test kits, with a view to get a more comprehensive picture of dengue in an urban endemic area and also to evaluate individual cases. Results: Th...

Comparison of a New and Rapid Method: Brucella Coombs Gel Test With Other Diagnostic Tests.

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Kalem, Fatma; Ergün, Ayşe Gül; Durmaz, Süleyman; Doğan, Metin; Ertuğrul, Ömür; Gündem, Seval

2016-09-01

The aim of this study was to detect reliability of Brucella Coombs gel test (BCGT) by comparing with with ELISA (IgG + IgM), Standard agglutination test, and Brucella immunocapture agglutination methods in serological diagnosis of brucellosis. Brucella Coombs gel test (BCGT), Brucella ELISA (IgG + IgM), Standard agglutination test, and Brucella immunocapture agglutination tests of 78 patients with presumptive diagnosis of brucellosis which were sent to Microbiology Laboratory of Konya Numune Hospital from various regions of Konya were studied. Of 78 patients with ELISA IgG and IgM, STA, BICA and BCGT; 26, 21, 10, 12 and 12 were positive. When compared with BICA, the sensitivity and specifity of BCGT were 100% and 100%, respectively. According to results BCGT can be used as a diagnostic test in routine laboratories after more comprehensive studies in control groups and patients. © 2016 Wiley Periodicals, Inc.

Simultaneous use of serum IgG and IgM for risk scoring of suspected early Lyme borreliosis: graphical and bivariate analyses

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Dessau, Ram B; Ejlertsen, Tove; Hilden, Jørgen

2010-01-01

The laboratory diagnosis of early disseminated Lyme borreliosis (LB) rests on IgM and IgG antibodies in serum. The purpose of this study was to refine the statistical interpretation of IgM and IgG by combining the diagnostic evidence provided by the two immunoglobulins and exploiting the whole...... range of the quantitative variation in test values. ELISA assays based on purified flagella antigen were performed on sera from 815 healthy Danish blood donors as negative controls and 117 consecutive patients with confirmed neuroborreliosis (NB). A logistic regression model combining the standardized...... units of the IgM and IgG ELISA assays was constructed and the resulting disease risks graphically evaluated by receiver operating characteristic and 'predictiveness' curves. The combined model improves the discrimination between NB patients and blood donors. Hence, it is possible to report a predicted...

IMPROVEMENT OF THE QUALITY CONTROL OF ELISA TESTING FOR THE LABORATORY CONFIRMATION OF MEASLES AND RUBELLA INFECTIONS AT THE STAGE OF THE MEASLES/ RUBELLA ELIMINATION PROGRAM

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T. A. Mamaeva

2017-01-01

�.u. (р < 0.05 in EcoLab and Siemens ELISA test-systems correspondently. In the studies when the ILC working solution parameters for ELISA of “capture” and “indirect” formats were evaluated the statistic reliability and high information capability of the mathematic models of the OD value changes vs. the degree of dilution of the initial ILC were determined. For the “capture” and “indirect” formats the determination coefficient (R2 consisted 97.34 and 99.29 correspondently, the Fisher criteria (F — 219.62 and 556.55 correspondently, the significance level (p — < 0.05 for both formats. The evaluated optimal working dilution degrees of the IgM-containing ILC make possible to exclude the influence of the IgG antibodies as the non-target marker in the ILC. On the other hand, taking into account the format of the used ELISA kit the optimal working dilution degrees give the possibility to obtain the desirable 2–3 “cut-off” values of the specific marker. Moreover, the issue of the target marker quantitative content in ILC is discussed in the study. In order to improve the quality of the commercial MRV IgM and IgG ELISA test-systems the joint studies with those who develop and produce these systems are desirable to be organized.

Detection of anti-Toxoplasma gondii antibodies in experimentally and naturally infected non-human primates by Indirect Fluorescence Assay (IFA and indirect ELISA Detecção de anticorpos anti-Toxoplasma gondii por meio das técnicas de Imunofluorescência Indireta e ELISA Indireto em primatas experimentalmente e naturalmente infectados

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Andréa Bouer

2010-03-01

Full Text Available The Indirect Fluorescence Assay (IFA and the indirect ELISA were comparatively used to detect IgG and IgM antibodies for Toxoplasma gondii in experimentally and naturally infected primates. In the experimentally infected group, antibodies of diagnostic value were detected at day 9 post-infection (PI with the IFA (IgG and IgM and with IgG-ELISA. IgM-ELISA detected antibodies for T. gondii starting at day 3 PI until the end of the experiment (102 days PI. Of the 209 naturally infected sera tested, from many zoos of State of Sao Paulo, 64.59 and 67.94% were positive in the IgG-IFA test and IgG-ELISA respectively. IgM-ELISA test detected seropositivity in 52.63% of the sera although IgM-IFA test detected it in only in 0.96% of the samples. The differential toxoplasmosis diagnosis was accomplished with Neospora caninum by IFA, observing 61 (29.2% seropositive animals for this parasite and 149 (70.8% negative. Sixty animals were positive for both T. gondii and N. caninum. Pneumonia, splenomegaly, and intestinal ulcers were macroscopically observed. Unremarkable interstitial pneumonia, enteritis, colitis, splenitis, and glomerulitis were microscopically observed. The immunohistochemical stain could not detect the presence of T. gondii in the tissues of the animals infected experimentally.Detectou-se anticorpos das classes IgG e IgM anti-Toxoplasma gondii em primatas experimentalmente e naturalmente infectados, utilizando-se como técnicas comparativas a RIFI e o ELISA-teste. No grupo dos primatas experimentalmente infectados, anticorpos de valor diagnóstico foram detectados a partir do 9º dia de infecção tanto na RIFI (IgG e IgM como no ELISA-IgG. O ELISA IgM detectou anticorpos a partir do 3º dia de infecção até o final do experimento (102 dias pós-infecção. Dos 209 soros dos primatas naturalmente infectados, de diversos zoológicos do Estado de São Paulo, 64,59 e 67,94% mostraram-se positivos na RIFI-IgG e no ELISA-IgG, respectivamente. O

IgM response to a human Pneumocystis carinii surface antigen in HIV-infected patients with pulmonary symptoms

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Lundgren, Bettina; Kovacs, J A; Mathiesen, Lars Reinhardt

1993-01-01

We have developed an ELISA to detect IgM antibodies to a major human Pneumocystis carinii surface antigen (gp95), and investigated the IgM response in 128 HIV-infected patients who underwent bronchoscopy for evaluation of pulmonary symptoms. Only 5 (4%) patients had IgM antibodies to P. carinii g...

In Vivo-Expressed Proteins of Virulent Leptospira interrogans Serovar Autumnalis N2 Elicit Strong IgM Responses of Value in Conclusive Diagnosis.

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Raja, Veerapandian; Shanmughapriya, Santhanam; Kanagavel, Murugesan; Artiushin, Sergey C; Velineni, Sridhar; Timoney, John F; Natarajaseenivasan, Kalimuthusamy

2016-01-01

Leptospirosis is a serious zoonosis that is underdiagnosed because of limited access to laboratory facilities in Southeast Asia, Central and South America, and Oceania. Timely diagnosis of locally distributed serovars of high virulence is crucial for successful care and outbreak management. Using pooled patient sera, an expression gene library of a virulent Leptospira interrogans serovar Autumnalis strain N2 isolated in South India was screened. The identified genes were characterized, and the purified recombinant proteins were used as antigens in IgM enzyme-linked immunosorbent assay (ELISA) either singly or in combination. Sera (n = 118) from cases of acute leptospirosis along with sera (n = 58) from healthy subjects were tested for reactivity with the identified proteins in an ELISA designed to detect specific IgM responses. We have identified nine immunoreactive proteins, ArgC, RecA, GlpF, FliD, TrmD, RplS, RnhB, Lp28.6, and Lrr44.9, which were found to be highly conserved among pathogenic leptospires. Apparently, the proteins ArgC, RecA, GlpF, FliD, TrmD, and Lrr44.9 are expressed during natural infection of the host and undetectable in in vitro cultures. Among all the recombinant proteins used as antigens in IgM ELISA, ArgC had the highest sensitivity and specificity, 89.8% and 95.5%, respectively, for the conclusive diagnosis of leptospirosis. The use of ArgC and RecA in combination for IgM ELISA increased the sensitivity and specificity to 95.7% and 94.9%, respectively. ArgC and RecA thus elicited specific IgM responses and were therefore effective in laboratory confirmation of Leptospira infection. Copyright © 2016, American Society for Microbiology. All Rights Reserved.

Frequency of antiphospholipid antibodies in patients with infectious diseases using three different ELISA methods Freqüência de anticorpos antifosfolípides em pacientes com doenças infecciosas usando três diferentes testes de ELISA

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Mittermayer Barreto Santiago

2006-02-01

Full Text Available OBJECTIVE: The standard enzyme-linked immunosorbent assay (ELISA for anticardiolipin (aCL antibodies is the most important test for the diagnosis of antiphospholipid syndrome (APS. However, the test is also positive in some infectious diseases and other non-related syndromes. It has been suggested that the detection of antibodies to a mixture of phospholipids or to beta2-glycoprotein I (beta2-GP I has higher specificity for APS than the standard aCL ELISA. The aim of the present work is to compare the diagnostic specificity of three different antiphospholipid (aPL assays in patients with infectious diseases. METHODS: Antiphospholipid antibodies were searched by three ELISA techniques, namely standard aCL, APhL® ELISA kit and anti-beta2-GP I, in sera of patients with infectious diseases, including syphilis (69, leptospirosis (33 and visceral leishmaniasis (30. RESULTS: The frequency of positivity of IgG aPL in patients with syphilis, leptospirosis and Kala-azar was 13/69 (19%, 9/33 (27% and 2/30 (6%, respectively, using standard ELISA, versus only 1/69 (1.4%, 0/33 (0% and 0/30 (0% positivity by the APhL® ELISA kit. The positivity of the isotype IgM aPL was 10/69 (14%, 4/33 (12% and 1/30 (3%, respectively, by the standard ELISA, and 1/69 (1.4%, 0/33 (0% and 0/30 (0% by the APhL® ELISA kit. The presence of significant levels of IgG anti-beta2GPI was observed in 14/69 cases of syphilis (20%, 6/33 cases of leptospirosis (18% and 16/30 cases of Kala-azar (53%. The APhL® ELISA kit had superior performance showing the highest specificity: 97% (95% CI: 92%-99% for IgG compared to 81% (95% CI: 74%-87% for standard ELISA and 72% (95% CI: 64%-79% for anti-beta2 GPI assay. CONCLUSIONS: The APhL® ELISA kit proved to be significantly more specific than the aCL standard ELISA and the anti-beta2GPI ELISA, and it should be used to help in the diagnosis and confirmation of APS.OBJETIVO: O ensaio de enzyme-linked immunosorbent assay (ELISA para a pesquisa de

Purification, characterization and ELISA detection of mink immunoglobulins

DEFF Research Database (Denmark)

Martel, Cyril Jean-Marie; Aasted, Bent

2008-01-01

the estimated molecular weights of the immunoglobulin gamma, alpha and mu heavy chains were found to be 54 kDa, 69 kDa and 83 kDa respectively. The purities of purified IgG, IgM and IgA were estimated by immunoglobulin class specific ELISAs to be more than 90% for IgG and IgM, and more than 80% for IgA....

Comparison between DOT EIA IgM and Widal Test as early diagnosis of typhoid fever.

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Begum, Z; Hossain, M A; Musa, A K; Shamsuzzaman, A K; Mahmud, M C; Ahsan, M M; Sumona, A A; Ahmed, S; Jahan, N A; Alam, M; Begum, A

2009-01-01

A recently developed DOT enzyme immunoassay known as "Typhidot" for detecting IgM antibody against 50 KDa OMP antigen of Salmonella typhi, was evaluated on 100 clinically suspected typhoid fever cases and 40 age-sex matched controls, in the Department of Microbiology, Mymensingh Medical College during, the period from June 2006 to July 2007. Blood culture, Widal test, and DOT EIA for IgM test were performed in all patients. Among 100 clinically suspected typhoid fever cases, 35 were subsequently confirmed on the basis of positive blood culture for S. typhi and/or significant rising titre of Widal test. The DOT EIA IgM test could produce results within 1 hour. The result of the DOT EIA IgM test showed a good diagnostic value for typhoid fever. The sensitivity, specificity, positive and negative predictive value of the test was found as 91.42%, 90.00%, 88.88% and 92.30% respectively. On the other hand corresponding values for Widal test were of 42.85%, 85.00%, 71.42% and 62.96% respectively. Thus, The DOT EIA IgM seems to be a practical alternative to Widal test for early diagnosis of typhoid fever.

[Use of new immunoglobulin isotype-specific ELISA-systems to detect Salmonella infections in pigs].

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Ehlers, Joachim; Alt, Michael; Trepnau, Daniela; Lehmann, Jörg

2006-01-01

In Germany, the program for controlling salmonella infections in pigs is based on tests detecting salmonella-lipopolysaccharide (LPS) induced antibodies in meat-juice or blood. These conventional tests which are based on the technology of enzyme-linked immunosorbent assay (ELISA) detect exclusively or mainly immunoglobulin(lg)G antibodies. Meanwhile, novel ELISA systems (WCE-ELISA, 3-Isotype-Screening-ELISA) have been developed, which additionally detect the antibody classes IgM and IgA.This fact enables the registration of fresh salmonella infections (starting with day 5 p.i.) and thus, the distinction between early and older infections. The results show that animals with early salmonella infections appear significantly more often in herds with a high than with a low prevalence. With the newly developed tests this group of animals can be detected much more efficiently and precisely than with the tests used so far. Due to their clearly improved sensitivity the application of the WCE-ELISA and the 3-Isotype-Screening-ELISA in terms of the QS-Salmonella-Monitoring program can therefore significantly improve the selection of farms with potential salmonella excretors. Additionally, the WCE-ELISA can be applied very suitable for the examination of individual animals.

Imunodiagnóstico da leptospirose humana através do teste ELISA-IgM, empregando-se diferentes preparações antigênicas a partir de sorotipos prevalentes de Leptospira interrogans Immunodiagnostic of human leptospirosis by ELISA-IgM, employing: different antigenic preparations as from prevalent serovars of Leptospira interrogans

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Marcos Vinicius da Silva

1990-08-01

Full Text Available Realizou-se estudo comparativo de diferentes sorotipos de Leptospira interrogans utilizados na preparação de antígenos empregados no teste ELISA, para a detecção de anticorpos da classe IgM, em amostras de soro na fase precoce e tardia da leptospirose humana. Foram utilizados dez sorotipos, escolhidos entre os que apresentaram maior reatividade na soroaglutinação microscópica (SAM, na cidade de São Paulo. Os cinco sorotipos que apresentaram melhores resultados individualmente no teste ELISA-IgM (canicola, hebdomadis, icterohaemorrhagiae, cynopteri e brasiliensis, foram também estudados em mistura antigênica. Os antígenos não tratados apresentaram maior reatividade do que os antígenos tratados com Triton X - 100 (4% à temperatura de 50ºC, durante 4 horas. O teste ELISA-IgM empregando os sorotipos não tratados, isoladamente, e em mistura antigênica, mostrou-se altamente sensível, podendo ser empregado como teste de triagem para o diagnóstico precoce da leptospirose humana. Outra aplicação do teste é permitir a detecção do início de situações epidêmicas ou de surtos, possibilitando acionar medidas de vigilância epidemiológica.A comparative study among different serovars of Leptospira interrogans was performed in order to prepare antigens to detect IgM antibodies by ELISA in early and late phase of human leptospirosis. Ten serovars were chosen among the most prevalent detected by microscopic seroagglutination (SAM in São Paulo city. Using ELISA-IgM five of them showed better results (canicola, hebdomadis, icterohaemorrhagiae, cynopteri and brasiliensis. These ones were also studied in a pool. The non-treated antigens showed higher reactivity than the Triton X-100 (4%/50ºC/4h. ELISA-IgM using individually or pool of non treated antigens proved to be reliable with high sensitivity and should be used for an earlier diagnosis of leptospirosis, as a trial test. Faster diagnostic elucidation can be useful to detect

Performance of an ELISA and Indirect Immunofluorescence Assay in Serological Diagnosis of Zoonotic Cutaneous Leishmaniasis in Iran

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Bahador Sarkari

2014-01-01

Full Text Available Serological assays have been extensively evaluated for diagnosis of visceral leishmaniasis (VL and considered as a routine method for diagnosis of VL while these methods are not properly evaluated for diagnosis of cutaneous leishmaniasis (CL. This study aimed to assess the performance of indirect immunofluorescent-antibody test (IFA and enzyme-linked immunosorbent assay (ELISA for serodiagnosis of cutaneous leishmaniasis in Iran. Sixty-one sera samples from parasitologically confirmed CL patients and 50 sera from healthy controls along with 50 sera from non-CL patients were collected. Antigen was prepared from promastigotes and amastigotes of Leishmania major. IFA was used to detect anti-Leishmania IgG while ELISA was used to detect anti-Leishmania IgM, total IgG, or IgG subclasses (IgG1 and 4. ELISA, for detection of total IgG and IgM, showed sensitivity of 83.6% and 84.7% and specificity of 62.7% and 54.6%, respectively. Sensitivity and specificity of ELISA for detecting IgG1 and IgG4 were 64%, 75% and 85%, 49%, respectively. Sensitivity and specificity of IFA were 91.6% and 81%. Conclusion. Findings of this study demonstrated that serological test, especially IFA, can be used for proper diagnosis of CL.

IgM response to a human Pneumocystis carinii surface antigen in HIV-infected patients with pulmonary symptoms

DEFF Research Database (Denmark)

Lundgren, Bettina; Kovacs, J A; Mathiesen, Lars Reinhardt

1993-01-01

We have developed an ELISA to detect IgM antibodies to a major human Pneumocystis carinii surface antigen (gp95), and investigated the IgM response in 128 HIV-infected patients who underwent bronchoscopy for evaluation of pulmonary symptoms. Only 5 (4%) patients had IgM antibodies to P. carinii gp...... response to gp95. These patients also showed an increase in IgG antibodies to gp95 and had microbiologically proven PCP. Prior to the development of the IgM response, IgG antibodies to gp95 were detectable in all 3 patients. Thus, HIV-infected patients with PCP seldom produce IgM antibodies to the major...

Evaluation of ID-PaGIA syphilis antibody test.

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Naaber, Paul; Makoid, Ene; Aus, Anneli; Loivukene, Krista; Poder, Airi

2009-01-01

Laboratory diagnosis of syphilis is usually accomplished by serology. There are currently a large number of different commercial treponemal tests available that vary in format, sensitivity and specificity. To evaluate the ID-PaGIA Syphilis Antibody Test as an alternative to other specific treponemal tests for primary screening or confirmation of diagnosis. Serum samples from healthy adults (n = 100) were used for detection of specificity of ID-PaGIA. To evaluate sensitivity of ID-PaGIA serum samples (n = 101) from patients with confirmed or suspected syphilis were tested for syphilis antibodies with FTA-Abs IgM, ID-PaGIA, ELISA IgM and TPHA tests. No false-positive results were found with ID-PaGIA. Sensitivity of various treponemal tests was the following: FTA-Abs IgM: 95.5%, ID-PaGIA and ELISA IgM: 94%, and TPHA 75%. The positive and negative predictive values of ID-PaGIA were 100 and 89.5%, respectively. Compared with other treponemal tests ID-PaGIA has excellent sensitivity and specificity.

Detection of Anti-Leptospira IgM Antibody in Serum Samples of Suspected Patients Visiting National Public Health Laboratory, Teku, Kathmandu

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Krishna Prasad Dahal

2016-01-01

Full Text Available Leptospirosis is a globally distributed zoonosis with varied clinical outcomes and multiorgan involvement in humans. In this study conducted from July 2011 to December 2011, 178 serum samples from patients suspected of leptospirosis were tested by Panbio IgM ELISA at National Public Health Laboratory, Kathmandu, out of which 51 (28.65% were positive for anti-Leptospira IgM antibody. Leptospirosis was more common in people in their 2nd and 3rd decades of their life which together comprised 56.86% of the total positive cases. Most of those tested positive were farmers followed by students and housewives. Both animal contact and water contact seemed to play significant roles in disease transmission. Symptoms were vague with the most common being fever, headache, myalgia, abdominal pain, vomiting, jaundice, and diarrhoea. Life style heavily dominated by agronomical and farming activities in Nepal is conducive to leptospirosis transmission. Leptospirosis seems to be a significant public health problem in Nepal but is underestimated. In resource poor countries like Nepal where laboratories performing MAT or maintaining cultures are rarely available, serological test like ELISA could well depict the scenario of the disease prevalence.

Evaluation of SD BIOLINE H. pylori Ag rapid test against double ELISA with SD H. pylori Ag ELISA and EZ-STEP H. pylori Ag ELISA tests.

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Negash, Markos; Kassu, Afework; Amare, Bemnet; Yismaw, Gizachew; Moges, Beyene

2018-01-01

Helicobacter pylori antibody titters fall very slowly even after successful treatment. Therefore, tests detecting H. pylori antibody lack specificity and sensitivity. On the other hand, H. pylori stool antigen tests are reported as an alternative assay because of their reliability and simplicity. However, the comparative performance of H. pylori stool antigen tests for detecting the presence of the bacterium in clinical specimens in the study area is not assessed. Therefore, in this study we evaluated the performance of SD BIOLINE H. pylori Ag rapid test with reference to the commercially available EZ- STEP ELISA and SD BIOLINE H. pylori Ag ELISA tests. Stool samples were collected to analyse the diagnostic performance of SD BIOLINE H. pylori Ag rapid test kit using SD H. pylori Ag ELISA kit and EZ- STEP ELISA tests as a gold standard. Serum samples were also collected from each patient to test for the presence of H. pylori antibodies using dBest H. pylori Test Disk. Sensitivity, specificity, predictive values and kappa value are assessed. P values H. pylori Ag rapid test were: 95.6% (95% CI, 88.8-98.8), 92.5% (95%CI, 89-94.1%), 86.7% (95% CI, 80.5-89.6), and 97.6% (95% CI, 993.9-99.3) respectively. The performance of SD BIOLINE H. pylori Ag rapid test was better than the currently available antibody test in study area. Therefore, the SD BIOLINE Ag rapid stool test could replace and be used to diagnose active H. pylori infection before the commencement of therapy among dyspeptic patients.

A standard screening test for the early and rapid diagnosis of leptospirosis

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Chandrasekaran S

2004-01-01

Full Text Available PURPOSE : To perform dark field microscopy (DFM for detection of Leptospira and to validate the results using Leptospira IgM antibody SERION ELISA test. METHODS : After differential centrifugation of Ruys, DFM was done to demonstrate Leptospira in the blood and SERION ELISA was done for Leptospira IgM antibody in single or paired serum samples. One hundred and eleven cases (39 adults and 72 children of suspected leptospirosis were included in the study. RESULTS : Anicteric cases accounted for 66.7% (26/39 of adults and complications involving brain, liver, kidney and eyes were seen in 33.3% (13/39. In children, 90.3% (65/72 were anicteric and involvement of brain and liver was seen in 9.7% (7/72 cases. On testing 60 single samples of blood from 23 adults and 37 children, DFM exhibited greater sensitivity of 93.3% (56/60 than that of SERION ELISA for Leptospira IgM antibody (33.3%, 20/60. It was observed that the positivity of DFM decreased from 100% (15/15 to 90.9% (10/11 with increase in the duration of infection for more than one week. ELISA for Leptospira IgM, done on 51 paired blood samples, was positive in 64.7% (33/51 cases when both (first and second samples were tested while in 45.1% (23/51 cases was positive with first sample alone. 58.8%(30/51 cases were positive by testing second sample. DFM results on paired blood samples showed persistence of Leptospira in 92.9% of cases. CONCLUSION : This study shows the validation of DFM results by SERION ELISA for Leptospira IgM antibody, based on which we recommend that DFM can serve as a standard screening test for early and rapid diagnosis of leptospirosis.

Evaluation of In-House and Commercial Serological Tests for Diagnosis of Human Tularemia

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Yanes, Hadjila; Hennebique, Aurélie; Pelloux, Isabelle; Boisset, Sandrine; Bicout, Dominique J.; Caspar, Yvan

2017-01-01

ABSTRACT Tularemia is a zoonosis caused by the bacterium Francisella tularensis. Its specific diagnosis remains based on serological methods, while F. tularensis is rarely detected in clinical samples by culture or PCR. The aim of the present study was to evaluate the performance of the Serion enzyme-linked immunosorbent assay (ELISA) classic Francisella tularensis IgG and IgM tests (Virion/Serion GmbH Institute, Würzburg, Germany) and the VIRapid tularemia immunochromatographic test (ICT) (Vircell, Granada, Spain) compared to that of the in-house microagglutination test (MAT) and indirect immunofluorescence assay (IFA) currently used at the French National Reference Center for Francisella. We evaluated 256 consecutive sera from 208 patients, including 51 confirmed and 23 probable tularemia cases, and 134 control patients not infected with F. tularensis. The IFA tests displayed 72.5% sensitivity for IgM (cutoff titer ≥80) and 74.5% for IgG (cutoff titer ≥160), and 99.3% specificity for both IgM and IgG. Using cutoffs advocated by the manufacturer, the Serion ELISAs displayed 88.2% sensitivity for IgM and 86.3% for IgG antibodies; specificity was 94.8% for IgM and 95.5% for IgG. Compared to MAT and IFA tests, the Serion ELISAs allowed earlier detection of specific antibodies (1 to 2 weeks versus 2 to 3 weeks after the onset of symptoms). The ICT sensitivity and specificity were 90% and 83.6%, respectively, when considering the cutoff advocated by the manufacturer. In conclusion, the Serion ELISAs are useful as screening tests for tularemia diagnosis, but additional confirmatory tests (such as MAT and IFA) are needed, especially in areas of low endemicity. PMID:29118164

Diagnostic performance of serological tests to detect antibodies against acute scrub typhus infection in central India

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Kiran Pote

2018-01-01

Full Text Available Background: Differentiating scrub typhus from other acute febrile illness is difficult due to non specificity of clinical symptoms and relative absence of eschar in Indian population. The diagnosis thus relies mainly on laboratory tests. Antibody based serological tests are mainstay of scrub typhus diagnosis. Here, we evaluated the diagnostic performance of IgM ELISA, IgM IFA and ICT to detect antibodies against O. tsutsugamushi in acute serum of febrile patients. Methodology: The serum samples from 600 randomly selected patients suffering from acute undifferentiated fever were tested by all the three tests mentioned above. We used latent class analysis to generate unbiased results as all the tests for scrub typhus diagnosis are imperfect and none of them can be considered as reference standard. Results: We found that IgM ELISA with cutoff titer 0.5 OD has high diagnostic accuracy (sensitivity 99.9% and specificity 99.15 than IgM IFA (sensitivity 96.8% and specificity 99.7% for scrub typhus diagnosis. ICT used in our study had very high specificity 100% but low sensitivity (38% which would limit its use for acute serum samples. ICT being a screening or point of care test, has to be more sensitive while some compromise with specificity is affordable. Hence, optimal cutoff for ICT should be evaluated under different settings. Conclusion: IgM ELISA being simple and affordable could be an alternative diagnostic test to IgM IFA which is subjective and costly.

Diagnostic performance of serological tests to detect antibodies against acute scrub typhus infection in central India.

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Pote, Kiran; Narang, Rahul; Deshmukh, Pradeep

2018-01-01

Differentiating scrub typhus from other acute febrile illness is difficult due to non specificity of clinical symptoms and relative absence of eschar in Indian population. The diagnosis thus relies mainly on laboratory tests. Antibody based serological tests are mainstay of scrub typhus diagnosis. Here, we evaluated the diagnostic performance of IgM ELISA, IgM IFA and ICT to detect antibodies against O. tsutsugamushi in acute serum of febrile patients. The serum samples from 600 randomly selected patients suffering from acute undifferentiated fever were tested by all the three tests mentioned above. We used latent class analysis to generate unbiased results as all the tests for scrub typhus diagnosis are imperfect and none of them can be considered as reference standard. We found that IgM ELISA with cutoff titer 0.5 OD has high diagnostic accuracy (sensitivity 99.9% and specificity 99.15) than IgM IFA (sensitivity 96.8% and specificity 99.7%) for scrub typhus diagnosis. ICT used in our study had very high specificity 100% but low sensitivity (38%) which would limit its use for acute serum samples. ICT being a screening or point of care test, has to be more sensitive while some compromise with specificity is affordable. Hence, optimal cutoff for ICT should be evaluated under different settings. IgM ELISA being simple and affordable could be an alternative diagnostic test to IgM IFA which is subjective and costly.

Development and evaluation of a Sarcocystis neurona-specific IgM capture enzyme-linked immunosorbent assay.

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Murphy, J E; Marsh, A E; Reed, S M; Meadows, C; Bolten, K; Saville, W J A

2006-01-01

Equine protozoal myeloencephalitis (EPM) is a serious neurologic disease of horses caused primarily by the protozoal parasite Sarcocystis neurona. Currently available antemortem diagnostic testing has low specificity. The hypothesis of this study was that serum and cerebrospinal fluid (CSF) of horses experimentally challenged with S neurona would have an increased S neurona-specific IgM (Sn-IgM) concentration after infection, as determined by an IgM capture enzyme linked immunoassay (ELISA). The ELISA was based on the S neurona low molecular weight protein SNUCD-1 antigen and the monoclonal antibody 2G5 labeled with horseradish peroxidase. The test was evaluated using serum and CSF from 12 horses experimentally infected with 1.5 million S neurona sporocysts and 16 horses experimentally infected with varying doses (100 to 100,000) of S neurona sporocysts, for which results of histopathologic examination of the central nervous system were available. For horses challenged with 1.5 million sporocysts, there was a significant increase in serum Sn-IgM concentrations compared with values before infection at weeks 2-6 after inoculation (P neurona, there were significant increases in serum Sn-IgM concentration at various points in time after inoculation, depending on the challenge dose (P < .01). In addition, there was a significant increase between the CSF Sn-IgM concentrations before and after inoculation (P < .0001). These results support further evaluation of the assay as a diagnostic test during the acute phase of EPM.

Comparative evaluation of competitive ELISA test in Colombian cattle

International Nuclear Information System (INIS)

Marino, O.; Rueda, E.; Sedano, L.; Zuniga, I.; Calderon, C.; Ortega, A.; Puentes, A.

1998-01-01

In order to contribute to the definition of the best ELISA test for screening and differential diagnosis of Brucella abortus to be applied for control programmes, a total of 2971 sera from Colombian cattle were tested for brucellosis. Conventional agglutination tests, Buffered Plate antigen test (BPAT) and Rose Bengal (RB) as well as Complement Fixation test (CFT) (Alton, et al. 1988) were used comparatively. Radial immunodiffusion test (RID) was also performed to all sera. The sera were also tested using four different ELISAs: indirect ELISA from FAO/IAEA and the indirect ELISA modified by Nielsen, et al. 1992 as well as two competitive ELISAs: one competitive ELISA used B. abortus O-polysaccharide antigen and an enzyme conjugated monoclonal to the O-polysaccharide for competition and detection. The second competitive ELISA used lipopolysaccharide (sLPS) antigen, a different monoclonal antibody for competition but also specific for the O-polysaccharide and a commercially available goat anti-mouse IgG enzyme conjugate for detection. The sera were analyzed based on its population status, 987 positive obtained from Brucella abortus infected herds based on clinical and/or bacteriological evidence and a high prevalence of brucellosis, CFT percentage of positive animals in the herd was greater than 5%. Eight hundred sixty six (866) negative sera from non-vaccinated cattle from a brucellosis free area and 1118 negative sera obtained from reglamentary vaccinated areas under a free herd program. Initial cut-off values were derived using negative serum samples. The diagnostic sensitivity and specificity was defined from frequency histograms based on this cut-off values and using 2x2 tables, corresponding confidence limits (95%) were calculated. The data were also analysed using signal detection analysis (ROC). Kappa statistics was determined for all tests and populations, accuracy was used as index of comparison to evaluate different assays. The data support the initial

Pros and Cons of serological testing in syphilis diagnosis and follow up

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Gino Ciarrocchi

2010-03-01

Full Text Available Since a proper diagnosis of syphilis is often difficult due to the wide variability of both clinical picture and laboratory test results, early recognition of infection caused by Treponema pallidum is crucial for a timely and effective treatment. In most cases, definitive diagnosis relies upon serological testing. A screening ELISA test, coupled with a quantitative RPR test and specific IgM antibodies detection, is currently regarded as the basic diagnostic procedure. In addition, a quantitative particle agglutination TP-PA test, FTA-abs IgG test and, eventually, a western-blot IgG and IgM test, allow to achieve a whole serological pattern for each patient at the time of first diagnosis. In this study, a group of serum samples (n=107 and cerebro-spinal fluid (n=3 were retrospectively analyzed using the above mentioned tests. A population of 19 patients whose clinical picture was unremarkable for syphilis, showed border-line values at screening and negative results on confirmation tests. Thirty-three out of 91 luetic patients were diagnosed as primary or early secondary syphilis, 36 as latent syphilis, 3 as neurosyphilis, and 3 were neonates with passive specific immunization. Quantitative RPR test and detection of specific IgM antibodies exhibited extremely high values in all 33 primary syphilis patients; a whole positive luetic pattern was also obtained by confirmation tests. Searching for IgM antibodies, a capture elisa test compared with a single device rapid elisa test showed an overall concordance of 98.1%. In luetic patients other than primary syphilis, quantitative RPR test and detection of specific IgM antibodies provided less relevant values and a low prevalence pattern, whereas TP-PA and FTA-abs tests showed persistent positives results. In the follow up of 19 initially treated patients, quantitative RPR values and specific IgM antibodies index showed a slow, progressive decrease until negative. Conclusion: a comprehensive initial

Performance of commercial dengue NS1 ELISA and molecular analysis of NS1 gene of dengue viruses obtained during surveillance in Indonesia.

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Aryati, Aryati; Trimarsanto, Hidayat; Yohan, Benediktus; Wardhani, Puspa; Fahri, Sukmal; Sasmono, R Tedjo

2013-12-29

Early diagnosis of dengue infection is crucial for better management of the disease. Diagnostic tests based on the detection of dengue virus (DENV) Non Structural Protein 1 (NS1) antigen are commercially available with different sensitivities and specificities observed in various settings. Dengue is endemic in Indonesia and clinicians are increasingly using the NS1 detection for dengue confirmation. This study described the performance of Panbio Dengue Early NS1 and IgM Capture ELISA assays for dengue detection during our surveillance in eight cities in Indonesia as well as the genetic diversity of DENV NS1 genes and its relationship with the NS1 detection. The NS1 and IgM/IgG ELISA assays were used for screening and confirmation of dengue infection during surveillance in 2010-2012. Collected serum samples (n = 440) were subjected to RT-PCR and virus isolation, in which 188 samples were confirmed for dengue infection. The positivity of the ELISA assays were correlated with the RT-PCR results to obtain the sensitivity of the assays. The NS1 genes of 48 Indonesian virus isolates were sequenced and their genetic characteristics were studied. Using molecular data as gold standard, the sensitivity of NS1 ELISA assay for samples from Indonesia was 56.4% while IgM ELISA was 73.7%. When both NS1 and IgM results were combined, the sensitivity increased to 89.4%. The NS1 sensitivity varied when correlated with city/geographical origins and DENV serotype, in which the lowest sensitivity was observed for DENV-4 (19.0%). NS1 sensitivity was higher in primary (67.6%) compared to secondary infection (48.2%). The specificity of NS1 assay for non-dengue samples were 100%. The NS1 gene sequence analysis of 48 isolates revealed the presence of polymorphisms of the NS1 genes which apparently did not influence the NS1 sensitivity. We observed a relatively low sensitivity of NS1 ELISA for dengue detection on RT-PCR-positive dengue samples. The detection rate increased significantly

Distribution of anti-HAV IgM positivity according to age and months of a year in Van region,Turkey

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Mehmet Parlak

2012-09-01

Full Text Available Objectives: In this study we investigated the anti-HAVIgM positivity rates and their distribution according to ageand season of a year in Van region of Turkey.Materials and methods: During five-year period between2006-2010, the presence of anti-HAV IgM weredetermined in the serum samples sent to our laboratorythat have prediagnosis of hepatitis A by ELISA test, usingAxSYM (Abbott Diagnostics, Germany and i2000SR Architect(Abbott Diagnostics, Germany analyzers. For statisticalanalyze of Anti-HAV IgM positivity rates, patients’age and gender and time of year when specimen wasobtain were compared.Results: The presence of anti-HAV IgM was investigatedin a total of 8851 patients, including 5303 (60% childrenand 3548 (40% adults. Anti-HAV IgM in children and adultpatients were determined as 9.8% and 2.6%, respectively,and this difference was found statistically significant (p<0.01. Anti-HAV IgM positivity rate began to rise in August,reached the highest level in November-Decemberand decreased to the initial level in January. The highestfrequency detected during the November-December periodwas statistically significantly higher than rates foundduring other months.Conclusions: The prevalence of Hepatitis A was found tobe similar with previous studies performed in our country.The prevalence of disease was significantly increased especiallybetween November and December.Key words: Anti-HAV IgM, seasonal distribution, seroprevalence,age

Human anti-HIV IgM detection by the OraQuick ADVANCE® Rapid HIV 1/2 Antibody Test.

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Guillon, Geraldine; Yearwood, Graham; Snipes, Casey; Boschi, Daniel; Reed, Michael R

2018-01-01

The Centers for Disease Control and Prevention (CDC) and many public health jurisdictions continue to advocate for the most sensitive rapid HIV test that is available. Currently, the recommendation is to utilize tests that can detect HIV infection biomarkers within 30 days of infection, when initial immune responses are mounted. The infected patient's IgM response is often used to detect acute infection within a 20-25 days window after infection. This requirement applies to lab-based testing with automated analyzers and rapid, point of care (POC) testing used for screening in a non-clinical setting. A recent study has demonstrated that POC tests using a Protein A-based detection system can detect samples with predominantly HIV-1 IgM reactivity (Moshgabadi et al., 2015). The OraQuick ADVANCE ® Rapid HIV-1/2 Antibody Test (OraQuick ADVANCE ®) also uses Protein A as the detection protein in the antibody-binding colloidal gold conjugate, so it is expected that the OraQuick ADVANCE ® Test will also detect samples with predominantly IgM reactivity. This report definitively demonstrates that the OraQuick ADVANCE ® Test can detect IgM antibodies during an acute infection window period of approximately 20-25 days after infection, and is therefore suitable for use in testing environments requiring adherence to current CDC recommendations.

Detection of IgM and IgG antibodies to Chlamydophila pneumoniae in pediatric community-acquired lower respiratory tract infections

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Surinder Kumar

2011-01-01

Full Text Available Context: Chlamydophila pneumoniae (C. pneumoniae is an emerging infectious agent with a spectrum of clinical manifestations including lower and upper respiratory tract infections. Aims: To investigate the role of C. pneumoniae in community-acquired lower respiratory tract infections (LRTIs in children using serological tests. Settings and Design: Two hundred children, age 2 months to 12 years, hospitalized for community-acquired LRTIs were investigated for C. pneumoniae etiology. Materials and Methods: We investigated 200 children hospitalized for community-acquired LRTIs, using ELISA for detecting anti-C. pneumoniae IgM and IgG antibodies. The demographic, clinical and radiological findings for C. pneumoniae antibody positive and C. pneumoniae antibody negative cases were compared. Statistical Analysis Used: Data analysis was performed by Chi-square test and Fisher′s exact tests using Epi Info (2002. Results: Clinical and radiological findings in both the groups were comparable. Serological evidence of C. pneumoniae infection was observed in 12 (6% patients; specific IgM antibodies were detected in 11 (91.67%; specific IgG antibodies in 1 (8.33% patients, while 4-fold rise in C. pneumoniae IgG antibody titers were noted in none of the patients. Conclusions: C. pneumoniae has a role in community-acquired LRTIs, even in children aged < 5 years. Serological detection using ELISA would enable pediatricians in better management of C. pneumoniae infections.

Pesquisa de anticorpos IgM anti-Toxoplasma gondii por meio de técnica imunoenzimática reversa

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José Roberto Mineo

1986-02-01

Full Text Available Um teste imunoenzimático reverso foi padronizado utilizando-se como fase sólida, microplacas de polivinil sensibilizadas com anticorpos anti-IgM.7 Estas foram incubadas seqüencialmente com alíquotas de soros de pacientes com suspeita de toxoplasmose aguda, antígeno solúvel de Toxoplasma gondii, conjugado peroxidase F (ab'2 anti-toxoplasma e substrato enzimático. A atividade enzimática foi determinada por leitura espectrofotométrica, considerando-se como títulos dos soros a máxima diluição fornecendo valores de absorbância maiores que os obtidos com a menor diluição do soro padrão não-reativo. Em 69 amostras de soros de pacientes com toxoplasmose aguda, a média geométrica dos títulos no teste ELISA-Reverso IgM foi superior à de todos os outros testes para anticorpos IgM, não se observando resultados negativos falsos devidos a altos títulos de IgG específica. Não foi encontrada, também, reatividade cruzada em nenhuma das 104 amostras de soros de pacientes com outras patologias, inclusive em amostras contendo fator reumatóide IgM.

Retrospective analysis of dengue specific IgM reactive serum samples

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Nemai Bhattacharya

2013-04-01

Full Text Available Objective: To conduct a retrospective analysis of dengue cases in Kolkata, on the basis of presence of anti-dengue IgM in their sera and presence or absence of anti-dengue IgG and dengue specific Non structural 1 (NS1 antigen in each of the serum sample. Methods: Sample was tested quantitatively employing ELISA technique, using Biorad test kits, with a view to get a more comprehensive picture of dengue in an urban endemic area and also to evaluate individual cases. Results: This reconstructed study revealed that of those 91 dengue cases, 70.3% (64 and 29.7% (27 were suffering from secondary and primary dengue respectively, showing that number of secondary dengue cases were much more than that of primary dengue cases with a possibility of emergence of DHF. A small proportion of cases 18.7% (17 were reactive for NS1. The duration of fever in NS1 antigen positive cases varied between 5 and 7 days. Of 17 NS1 reactive cases, 10 (10.9% and 7 (7.7% were suffering from secondary and primary dengue respectively. Conclusions: Early detection of primary and secondary dengue cases would be facilitated by utilizing all three parameters (NS1 antigen, anti-dengue IgM and IgG helping to evaluate, monitor and treat a dengue case effectively.

An ELISA test for the detection of antibodies to Legionella pneumophila.

OpenAIRE

Wreghitt, T G; Nagington, J; Gray, J

1982-01-01

An enzyme-linked immunosorbent assay (ELISA) test has been developed to detect antibodies to Legionella pneumophila serogroup 1. There is good correlation between indirect fluorescent antibody (IFA) and ELISA titres but ELISA is more sensitive.

The use of ELISAs for monitoring exposure of pig herds to Brachyspira hyodysenteriae

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Song Yong

2012-01-01

Full Text Available Abstract Background Swine dysentery (SD, a mucohaemorrhagic diarrhoeal disease of pigs, results from infection of the large intestine with the spirochaete Brachyspira hyodysenteriae. ELISA systems using whole spirochaete cells (WC and the B. hyodysenteriae outer membrane lipoprotein Bhlp29.7 previously have been established as potential diagnostic tools for SD. However, their true value in identifying infected herds remains unclear. The present study aimed to compare the performance of whole-cell and Bhlp29.7 based ELISAs in detecting specific immunoglobulin class IgG and IgM to B. hyodysenteriae in growing pigs, and additionally evaluated whether meat juice could serve as a source of specific antibodies. Results Levels of circulating IgG and IgM reacting with WC spirochaete preparations and recombinant Bhlp29.7 peaked 4-6 weeks post-infection in the experimentally challenged pigs, and remained elevated in the present study. In a cohort of pigs on an infected farm levels of antibody directed against both antigens showed a progressive increase with time. However, other than for the level of IgG against WC antigen, a significant increase in antibody levels also was observed in a cohort of pigs on a non-infected farm. In addition, assays using meat juice had 100% specificity and equivalent sensitivity to those based on serum, and likewise the best performance was achieved using the WC IgG ELISA. Conclusions IgG ELISAs using either WC or Bhlp29.7 as plate-coating antigens were shown to be useful for monitoring the dynamics of B. hyodysenteriae infection in grower pigs. Of the two antigens, the WC preparation tended to give better discrimination between pigs from infected and non-infected farms. Testing of meat juice was shown to have potential for identifying infected herds.

Reatividade do anticorpo IgM anti-Treponema pallidum na soroconversão e na resposta sorológica ao tratamento de sífilis IgM antibody reactivity to Treponema pallidum in seroconversion and in the serologic response to syphilis treatment

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Neuza Satomi Sato

2012-12-01

Full Text Available INTRODUÇÃO: A utilidade da detecção de anticorpos da imunoglobulina da classe M (IgM no diagnóstico da sífilis tem sido discutida há tempos. OBJETIVO: No presente estudo foi analisada a ocorrência de anticorpo IgM anti-T. pallidum (Tp-IgMAc nas amostras de pacientes com sífilis recente, na fase de soroconversão e no monitoramento da resposta sorológica pós-tratamento. MÉTODOS: Amostras séricas de 11 indivíduos. RESULTADOS: Na soroconversão, o Tp-IgMAc foi detectado nas amostras de 10 indivíduos, e em um paciente a reatividade IgM ocorreu anteriormente ao Venereal Disease Research Laboratory (VDRL. A sororreversão foi evidenciada nas amostras de três pacientes com sífilis secundária tratada, e em um indivíduo com reinfecção. CONCLUSÃO: A detecção de Tp-IgMAc mostrou ser um potencial marcador diagnóstico de sífilis ativa e o desempenho do ensaio imunoenzimático de captura de IgM (ELISA-IgM para o monitoramento pós-tratamento foi similar ao da VDRL.INTRODUCTION: The appropriateness of IgM antibody detection in the diagnosis of syphilis has been extensively discussed. OBJECTIVE: This study aimed at assessing the detection of anti-T. pallidum IgM antibody (TP-IgMAb in serum samples from patients with recent syphilis in seroconversion and in the monitoring of post-treatment serological response. METHODS: Serum samples from 11 individuals. RESULTS: At seroconversion, positive Tp-IgMAb was detected in 10 samples and IgM reactivity previous to Venereal Disease Research Laboratory (VDRL was detected in one sample. Seroreversion was found in samples from three treated patients with secondary syphilis and in one individual with reinfection. CONCLUSION: Tp-IgMAb detection proved to be a potential diagnostic marker for active syphilis, and IgM capture enzyme linked immunosorbent assay (ELISA-IgM performance was similar to VDRL in post-treatment monitoring.

Comparing validation of four ELISA-systems for detection of Salmonella derby- and Salmonella infantis-infected pigs.

Science.gov (United States)

Roesler, Uwe; Szabo, Istvan; Matthies, Claudia; Albrecht, Kerstin; Leffler, Martin; Scherer, Kathrin; Nöckler, Karsten; Lehmann, Jörg; Methner, Ulrich; Hensel, Andreas; Truyen, Uwe

2011-01-01

The objective of this study was the comparative evaluation of four indirect Salmonella ELISA tests at study time approved in Germany to detect Salmonella infection in pigs.Three tests are based on a LPS-antigen mix and directed against specific IgG antibodies. The fourth test is based on a purified S. Typhimurium whole-cell lysate antigen and discriminates between Salmonella-specific IgM-, IgA-, and IgG- antibodies. In a longitudinal study, two groups of six weeks old hybrid piglets were orally infected with a porcine S. Infantis or S. Derby strain. Clinical and bacteriological parameters were monitored weekly during an observation period of 130 days after infection and serum samples were investigated in parallel with the respective ELISAs. Apparently, the LPS-based ELISA systems used in this study failed to recognize S. Infantis-infected pigs although those animals shed the pathogen in high amounts throughout the study until day 81 post infection (p. i.). In contrast, the isotype-specific Salmonella Typhimurium whole-cell-lysate based ELISA was capable of detecting Salmonella-infected pigs from day ten p. i. at all tested serotypes and revealed the highest sensitivity in detection of S. Infantis-infected pigs. Furthermore, it became apparent that the often used surveillance cut-off value of 40 OD% is not appropriate for intra-vitam detection of S. Infantis- and S. Derby-infected pigs. In contrast, the cut-off values of the ELISAs given by the suppliers result in considerable higher detection rates.

Diagnosis of acute toxoplasmosis in pregnant women referred to therapeutic centers of Alborz Province (Iran using immunoglobulin G avidity ELISA technique

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Lame Akhlaghi

2016-11-01

Full Text Available Objective: To evaluate immunoglobulin G (IgG avidity as a useful and reliable technique in diagnosing toxoplasmosis in pregnant women referring to therapeutic centers of Alborz Province (Iran in 2014, against two other tests, IgG and immunoglobulin G (IgM antiToxoplasma. Methods: Serum samples (468 in total were obtained from different therapeutic centers in Karaj City. ELISA method was used to test the anti-Toxoplasma avidity of IgG, IgM and IgG. The data were analyzed by descriptive statistical methods and Chi-square test (P < 0.05 using SPSS 17.0. Results: Anti-Toxoplasma tests of IgM and IgG were positive in 9 and 86 samples respectively. Also, a borderline IgM was detected in 2 suspected samples. In addition, among all positive and suspected samples, 79 cases indicated high titers of IgG avidity, 7 cases were of low titers and 1 case was of a borderline titer. The prevalence of anti-Toxoplasma antibodies was 20%. The sera which showed high avidity index was obtained from patients at chronic phase of infection (92% while those which showed low avidity levels were from patients at acute toxoplasmosis (77.7%. Conclusions: This study clearly showed that acute and chronic phases of toxoplasmosis could be differentiated with the aid of IgG avidity test. This test may also assist in recognizing old and newly acquired infections.

Antibodies recognizing both IgM isotypes in Atlantic salmon

DEFF Research Database (Denmark)

Hedfors, Ida Aagård; Bakke, Hege; Skjødt, Karsten

2012-01-01

these molecules. The present study aimed at identifying tools to separate IgM positive (IgM(+)) B cells from IgM negative (IgM(-)) non-B cell populations using flow cytometry. Several monoclonal antibodies (mAbs), and one polyclonal antibody (pAb) to both rainbow trout (Oncorhynchus mykiss) and Atlantic salmon...... (Salmo salar) IgM, either commercially available or locally produced were tested for their recognition of Atlantic salmon IgM(+) cells. Leukocytes were isolated from peripheral blood (PB), spleen (S) and head kidney (HK) and stained with all mAbs and the pAb, to possibly verify the approximate number...... of IgM(+) cells in the respective tissues in salmon. To our surprise, this seemingly simple task did not reveal similar staining patterns for all antibodies as expected, but rather large differences in the number of positively stained cells were discovered. In short, positively stained cells by each...

Development of an LPS-based ELISA for diagnosis of Yersinia enterocolitica O:3 infections in Danish patients: a follow-up study.

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Dalby, Tine; Rasmussen, Eva; Schiellerup, Peter; Krogfelt, Karen Angeliki

2017-05-25

The bacterium Yersinia enterocolitica causes gastroenteritis in humans. The study aimed to develop a diagnostic enzyme-linked immunosorbent assay (ELISA) for detection of Yersinia enterocolitica O:3 LPS antibodies in sera from Danish patients with suspected Yersinia enterocolitica O:3 gastrointestinal infection. As a part of this, antibody decay profiles after culture confirmed Yersinia enteritis were studied. An ELISA using Yersinia enterocolitica O:3 LPS as the coating antigen was developed for measuring IgA, IgG and IgM specific antibodies. A longitudinal collection of 220 sera drawn between 20 and 1053 days after onset of symptoms from 85 adult Danish patients with verified Yersinia enteritis were examined. A control group of 100 sera from healthy Danish blood-donors were analysed in order to determine the cut-off for interpretation of results. Serum samples from 62 out of 81 patients who delivered either the first or the second sample were found positive for specific antibodies against Yersinia enterocolitica O:3 LPS (77%). For samples collected within 60 days after onset of symptoms (n = 48) sensitivities of 58%, 42% and 79% for IgA, IgG and IgM antibodies were found. A sensitivity of 81% was found for these samples when using the definition of a positive result in either IgA, IgG or IgM as a combined positive. All samples received up to 36 days after onset of symptoms (n = 10) were found to be positive using this definition. For the period 61 to 90 days after onset of symptoms (n = 32), a combined sensitivity of 63% was found. The antibody levels as well as decay profiles for the three different immunoglobulin classes for the individual patients exhibited a large degree of variation. Using a definition of positive as a positive result for either IgA, IgG or IgM antibodies, a diagnostic sensitivity of 81% was achieved for samples received within 60 days after onset of symptoms. In particular, the levels of specific IgM antibodies were elevated. In

Development of ELISAs for diagnosis of acute typhoid fever in Nigerian children.

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Jiin Felgner

2017-06-01

Full Text Available Improved serodiagnostic tests for typhoid fever (TF are needed for surveillance, to facilitate patient management, curb antibiotic resistance, and inform public health programs. To address this need, IgA, IgM and IgG ELISAs using Salmonella enterica serovar Typhi (S. Typhi lipopolysaccharide (LPS and hemolysin E (t1477 protein were conducted on 86 Nigerian pediatric TF and 29 non-typhoidal Salmonella (NTS cases, 178 culture-negative febrile cases, 28 "other" (i.e., non-Salmonella pediatric infections, and 48 healthy Nigerian children. The best discrimination was achieved between TF and healthy children. LPS-specific IgA and IgM provided receiver operator characteristic areas under the curve (ROC AUC values of 0.963 and 0.968, respectively, and 0.978 for IgA+M combined. Similar performance was achieved with t1477-specific IgA and IgM (0.968 and 0.968, respectively; 0.976 combined. IgG against LPS and t1477 was less accurate for discriminating these groups, possibly as a consequence of previous exposure, although ROC AUC values were still high (0.928 and 0.932, respectively. Importantly, discrimination between TF and children with other infections was maintained by LPS-specific IgA and IgM (AUC = 0.903 and 0.934, respectively; 0.938 combined, and slightly reduced for IgG (0.909, while t1477-specific IgG performed best (0.914. A similar pattern was seen when comparing TF with other infections from outside Nigeria. The t1477 may be recognized by cross-reactive antibodies from other acute infections, although a robust IgG response may provide some diagnostic utility in populations where incidence of other infections is low, such as in children. The data are consistent with IgA and IgM against S. Typhi LPS being specific markers of acute TF.

Diagnostic validation of selected serological tests for detecting scrub typhus.

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Koraluru, Munegowda; Bairy, Indira; Varma, Muralidhar; Vidyasagar, Sudha

2015-07-01

Clinical diagnosis of scrub typhus is often difficult because the symptoms are very similar to those of other febrile illness such as dengue, leptospirosis, malaria and other viral hemorrhagic fevers. Though better diagnostic tests are available for rickettsial diseases and scrub typhus elsewhere, the Weil-Felix test is still commonly used in India, mainly because microimmunofluorescence assays (M-IFA) were not available in India till recently and relevant staff had insufficient training. The present study was performed to investigate the performance of M-IFA, IgM ELISA, and Weil-Felix test on 546 non-repeated serum samples from subjects suspected of having scrub typhus. One hundred and forty-three of these 546 samples were positive by M-IFA; these cases were also confirmed clinically to have scrub typhus based on their dramatic responses to doxycycline therapy. IgM ELISA was positive in 122 of the 143 M-IFA positive cases and the Weil-Felix test in 96. Though the Weil-Felix test is a heterophile agglutination test, it was found in this study to have good specificity but far too little sensitivity to use as a routine diagnostic test. IgM ELISA can be a good substitute for M-IFA. Incorporation of multiple prototype antigens on M-IFA slides is likely one of the reasons for its superior performance. As newer and better diagnostic assays become available for scrub typhus diagnosis in developed countries, it will be imperative to also use such tests in other endemic countries to prevent over- or under-diagnosis of scrub typhus. © 2015 The Societies and Wiley Publishing Asia Pty Ltd.

Enterovirus IgM detection

International Nuclear Information System (INIS)

Frisk, G.; Nilsson, E.; Diderholm, H.

1989-01-01

A predominantly type-specific L-capture radio-immunoassay (RIA) of IgM antibodies to Coxsackie B1-B5 (CB1-CB5) viruses was previously described. The present study is concerned with the specificity of this assay, using as antigen different strains of one serotype (CB5) and procapsids of two serotypes (CB3 and CB5). Eight strains of CB5 virions were tested against acute and/or convalescent sera from 10 patients from whom CB5 had been isolated. It is concluded that the choice of strain is important if a high frequency of homotypic titres with no or only a few heterotypic reactions is to be obtained. When procapsids were used as antigen, both homotypic and heterotypic titres were seen to a large extent. All patients with homotypic IgM against CB3 or CB5 virions showed IgM against the CB3 or the CB5 procapsids, respectively. It is concluded that the use of two or more procapsids in combination is of value for the diagnosis of a recent or current enterovirus infection (author). 18 refs.; 2 figs.; 4 tabs

KAtex antigen-detection test as a diagnostic tool for latent visceral ...

African Journals Online (AJOL)

SERVER

2008-04-03

Apr 3, 2008 ... Urine samples were tested by kAtex kit to detect VL antigen. All sera .... IFA, and ELISA-IgG and IgM) to finding of agreement and validity and reliability .... Animal inoculation is not usually employed as a diag- nostic test, since ...

Intrathecal IgM index correlates with a severe disease course in multiple sclerosis: Clinical and MRI results.

Science.gov (United States)

Ozakbas, Serkan; Cinar, Bilge Piri; Özcelik, Pinar; Baser, Hatice; Kosehasanoğullari, Gorkem

2017-09-01

Intrathecally synthesized IgM can be seen not only in the cerebrospinal fluid (CSF) in infectious and inflammatory diseases of the central nervous system, but also in that of patients with multiple sclerosis (MS). Intrathecal IgM synthesis in MS seems to be correlated with an unfavorable disease course. In one cross-sectional study, intrathecal synthesis of IgM (IgM index) was found to be correlated with cranial magnetic resonance imaging (MRI) parameters. The purpose of this study was to determine the possible relationship between the IgM index and MRI and clinical parameters. Eighty-one patients with MS (58 female) undergoing lumbar puncture were included in the study. Fifty-one patients had a relapsing-remitting (RR) disease course, while 30 cases were secondary progressive MS (SPMS). IgM was detected in paired CSF and serum specimens using ELISA. The IgM index was calculated using the formula CSF IgM/serum IgM: CSF albumin/serum albumin. IgM indexes higher than 0.1 were considered "increased". All patients underwent brain and whole spinal cord MRI. The IgM index was normal in 43 of the 81 patients (53.1%) and increased in 38 (46.9%). A significant correlation was determined between the IgM index and Expanded Disability Status Scale (EDSS) (r=0.638, p=0.001). Most of the subjects with increased IgM indexes were SPMS patients, 28 having a SPMS course and 10 a RRMS course. Only two patients with SPMS courses had normal IgM indexes. EDSS scores were significantly higher in patients with increased IgM indexes (EDSS 4.3 vs EDSS 2.8, p=0.000). All patients with EDSS >3 had increased IgM indexes. All patients with IgM index values higher than 0.2 IgM had SPMS courses and EDSS >6. Time to onset of the secondary progressive phase of the disease was correlated with IgM index values (p=0.004). IgM index values were also correlated with T1 hypointense lesions (r=0.0431, p=0.008) and Gd enhancing lesions (r=0.0396, p=0.006). Patients with increased IgM indexes also had more

Inadequacy of IgM antibody tests for diagnosis of Rocky Mountain Spotted Fever.

Science.gov (United States)

McQuiston, Jennifer H; Wiedeman, Caleb; Singleton, Joseph; Carpenter, L Rand; McElroy, Kristina; Mosites, Emily; Chung, Ida; Kato, Cecilia; Morris, Kevin; Moncayo, Abelardo C; Porter, Susan; Dunn, John

2014-10-01

Among 13 suspected Rocky Mountain spotted fever (RMSF) cases identified through an enhanced surveillance program in Tennessee, antibodies to Rickettsia rickettsii were detected in 10 (77%) patients using a standard indirect immunofluorescent antibody (IFA) assay. Immunoglobulin M (IgM) antibodies were observed for 6 of 13 patients (46%) without a corresponding development of IgG, and for 3 of 10 patients (30%) at least 1 year post-onset. However, recent infection with a spotted fever group rickettsiae could not be confirmed for any patient, based on a lack of rising antibody titers in properly timed acute and convalescent serologic specimens, and negative findings by polymerase chain reaction testing. Case definitions used in national surveillance programs lack specificity and may capture cases that do not represent current rickettsial infections. Use of IgM antibodies should be reconsidered as a basis for diagnosis and public health reporting of RMSF and other spotted fever group rickettsiae in the United States. © The American Society of Tropical Medicine and Hygiene.

A point-of-care test for measles diagnosis: detection of measles-specific IgM antibodies and viral nucleic acid.

Science.gov (United States)

Warrener, Lenesha; Slibinskas, Rimantas; Chua, Kaw Bing; Nigatu, Wondatir; Brown, Kevin E; Sasnauskas, Kestutis; Samuel, Dhanraj; Brown, David

2011-09-01

To evaluate the performance of a newly developed point-of-care test (POCT) for the detection of measles-specific IgM antibodies in serum and oral fluid specimens and to assess if measles virus nucleic acid could be recovered from used POCT strips. The POCT was used to test 170 serum specimens collected through measles surveillance or vaccination programmes in Ethiopia, Malaysia and the Russian Federation: 69 were positive for measles immunoglobulin M (IgM) antibodies, 74 were positive for rubella IgM antibodies and 7 were positive for both. Also tested were 282 oral fluid specimens from the measles, mumps and rubella (MMR) surveillance programme of the United Kingdom of Great Britain and Northern Ireland. The Microimmune measles IgM capture enzyme immunoassay was the gold standard for comparison. A panel of 24 oral fluids was used to investigate if measles virus haemagglutinin (H) and nucleocapsid (N) genes could be amplified by polymerase chain reaction directly from used POCT strips. With serum POCT showed a sensitivity and specificity of 90.8% (69/76) and 93.6% (88/94), respectively; with oral fluids, sensitivity and specificity were 90.0% (63/70) and 96.2% (200/208), respectively. Both H and N genes were reliably detected in POCT strips and the N genes could be sequenced for genotyping. Measles virus genes could be recovered from POCT strips after storage for 5 weeks at 20-25 °C. The POCT has the sensitivity and specificity required of a field-based test for measles diagnosis. However, its role in global measles control programmes requires further evaluation.

Determination of Antibodies (IgG, IgM against Toxoplasma gondii in Patients with Cancer

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M Pedram

2007-08-01

Full Text Available Background: The aim of this study was determination of antibodies (IgG, IgM against Toxoplasma in malignant patients in order to refer the patients on time to the physician for treatment.Methods: This study was carried out on 252 malignant patients and 252 healthy normal subjects (as control obtained from Shafa Hospital and Medical Diagnostic Laboratory (Iran-Zamin, in Ahwaz city. Patient's information was recorded in a questionnaire before sampling. Serum samples of patients were examined for IgG and IgM antibodies by ELISA technique using Trinity kits. Results: The results of this study revealed the presence of Toxoplasma antibodies in 114 (45.2% cases of patients who were positive for Toxoplasma IgG antibodies, and 26 (10.3% cases were confirmed to be positive for Toxoplasma IgM antibodies and also 17 (6.7% of cases had both IgG and IgM antibodies against Toxoplasma gondii. In control group 92 (36.5% cases and 15 (6% cases revealed seropositive for IgG and IgM antibodies, respectively. There were no significant differences between sex, close contact with cat, living region, chemotherapy, and seropositivity rate of toxoplasmosis in patients. Comparing the age groups, the highest seropositive rate showed in the age of 51 years or higher, and their rates had tendency to increase with age in both groups. No seropositivity significant relationship was found between patients and control group.Conclusion: According to the prevalence of positive cases in these patients, it is necessary to examine the patients for toxoplasmosis before, during and after chemotherapy.

Evaluation of the LDBIO point of care test for the combined detection of toxoplasmic IgG and IgM.

Science.gov (United States)

Chapey, Emmanuelle; Wallon, Martine; Peyron, François

2017-01-01

The toxoplasma ICT IgG-IgM rapid diagnostic test for the simultaneous detection of specific toxoplasmic immunoglobulin (Ig) G and IgM was compared with the Architect fully automated chemiluminescence test. Four hundred sera were included, among which 248 scored negative in Architect. The cassettes were easily read with the naked eye. Diagnostic sensitivity and specificity were 97% and 96%, respectively. The test scored 8 false-positive IgG and yielded negative results in 3 sera displaying unspecific IgM in Architect. The LDBIO appears to be a reliable first line test, although the false-positive results for IgG deserve further investigation. Such an easily performed test could be used advantageously for screening for toxoplasmosis in pregnant women. Copyright © 2016 Elsevier B.V. All rights reserved.

Estimating the true accuracy of diagnostic tests for dengue infection using bayesian latent class models.

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Wirichada Pan-ngum

Full Text Available Accuracy of rapid diagnostic tests for dengue infection has been repeatedly estimated by comparing those tests with reference assays. We hypothesized that those estimates might be inaccurate if the accuracy of the reference assays is not perfect. Here, we investigated this using statistical modeling.Data from a cohort study of 549 patients suspected of dengue infection presenting at Colombo North Teaching Hospital, Ragama, Sri Lanka, that described the application of our reference assay (a combination of Dengue IgM antibody capture ELISA and IgG antibody capture ELISA and of three rapid diagnostic tests (Panbio NS1 antigen, IgM antibody and IgG antibody rapid immunochromatographic cassette tests were re-evaluated using bayesian latent class models (LCMs. The estimated sensitivity and specificity of the reference assay were 62.0% and 99.6%, respectively. Prevalence of dengue infection (24.3%, and sensitivities and specificities of the Panbio NS1 (45.9% and 97.9%, IgM (54.5% and 95.5% and IgG (62.1% and 84.5% estimated by bayesian LCMs were significantly different from those estimated by assuming that the reference assay was perfect. Sensitivity, specificity, PPV and NPV for a combination of NS1, IgM and IgG cassette tests on admission samples were 87.0%, 82.8%, 62.0% and 95.2%, respectively.Our reference assay is an imperfect gold standard. In our setting, the combination of NS1, IgM and IgG rapid diagnostic tests could be used on admission to rule out dengue infection with a high level of accuracy (NPV 95.2%. Further evaluation of rapid diagnostic tests for dengue infection should include the use of appropriate statistical models.

Evaluation of dengue NS1 antigen rapid tests and ELISA kits using clinical samples.

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Subhamoy Pal

Full Text Available Early diagnosis of dengue virus (DENV infection can improve clinical outcomes by ensuring close follow-up, initiating appropriate supportive therapies and raising awareness to the potential of hemorrhage or shock. Non-structural glycoprotein-1 (NS1 has proven to be a useful biomarker for early diagnosis of dengue. A number of rapid diagnostic tests (RDTs and enzyme-linked immunosorbent assays (ELISAs targeting NS1 antigen (Ag are now commercially available. Here we evaluated these tests using a well-characterized panel of clinical samples to determine their effectiveness for early diagnosis.Retrospective samples from South America were used to evaluate the following tests: (i "Dengue NS1 Ag STRIP" and (ii "Platelia Dengue NS1 Ag ELISA" (Bio-Rad, France, (iii "Dengue NS1 Detect Rapid Test (1st Generation" and (iv "DENV Detect NS1 ELISA" (InBios International, United States, (v "Panbio Dengue Early Rapid (1st generation" (vi "Panbio Dengue Early ELISA (2nd generation" and (vii "SD Bioline Dengue NS1 Ag Rapid Test" (Alere, United States. Overall, the sensitivity of the RDTs ranged from 71.9%-79.1% while the sensitivity of the ELISAs varied between 85.6-95.9%, using virus isolation as the reference method. Most tests had lower sensitivity for DENV-4 relative to the other three serotypes, were less sensitive in detecting secondary infections, and appeared to be most sensitive on Day 3-4 post symptom onset. The specificity of all evaluated tests ranged from 95%-100%.ELISAs had greater overall sensitivity than RDTs. In conjunction with other parameters, the performance data can help determine which dengue diagnostics should be used during the first few days of illness, when the patients are most likely to present to a clinic seeking care.

Construction of an optical test-bed for eLISA

International Nuclear Information System (INIS)

Lieser, Maike; Isleif, K-S; Schuster, S; Tröbs, M; Veith, S; Heinzel, G; Danzmann, K; Fitzsimons, E; Killow, C; Perreur-Lloyd, M; Robertson, D; Ward, H

2016-01-01

In the planned eLISA mission a key part of the system is the optical bench that holds the interferometers for reading out the inter-spacecraft distance and the test mass position. We report on ongoing technology development for the eLISA optical system like the back-link between the optical benches and the science interferometer where the local beam is interfered with the received beam from the distant spacecraft. The focus will be on a setup to investigate the tilt-to-pathlength coupling in the science interferometer. To test the science interferometer in the lab a second bench providing a laser beam and a reference interferometer is needed. We present a setup with two ultra-stable low expansion glass benches and bonded optics. To suppress the tilt-to-pathlength coupling to the required level (few μm/rad) imaging optics are placed in front of the interferometer photo diodes. (paper)

Generation and characterisation of murine monoclonal antibodies specific for cervine immunoglobulin light chain, IgM and IgG

International Nuclear Information System (INIS)

Hibma, M.; Griffin, J.F.T.

1992-01-01

Monoclonal antibodies (mAb) which react with cervine immunoglobulin (Ig) light chain, IgM and IgG were produced using conventional cell fusion technology. Hybridoma supernatants were initially screened for specificity against cervine Ig using an enzyme-linked immunosorbent assay (ELISA). The specificity of supernatants against size-fractionated cervine Ig was further determined. Supernatants were characterised using western blotting and autoradiographic techniques. The mAb OU1G, OU2G and OU3G were specific for cervine gamma-chain of IgG, whereas OU1L was specific for light chain of Ig. A further mAb (OU1M) bound IgM and not IgG. These mAb were found to have varying cross-reactivity against Ig from other species

ELISA Cut-off Point for the Diagnosis of Human Brucellosis; a Comparison with Serum Agglutination Test

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Anahita Sanaei Dashti

2012-03-01

Full Text Available Background: Brucellosis is a world-wide disease, which has a diverse clinical manifestation, and its diagnosis has to be proven by laboratory data. Serum agglutination test (SAT is the most-widely used test for diagnosing brucellosis. The enzyme linked immunosorbent assay (ELISA can also determine specific antibody classes against brucella. It is a sensitive, simple and rapid test, which could be an acceptable alternative to SAT with fewer limitations, however, like any other new test it should be further evaluated and standardized for various populations. This study was planned to determine an optimal cut-off point, for ELISA which would offer maximum sensitivity and specificity for the test when compared to SAT.Methods: Four hundred and seven patients with fever and other compatible symptoms of brucellosis were enrolled in the study. Serum agglutination test, 2-Mercaptoethanol test, and ELISA were performed on their sera. Results: The cut-off point of 53 IU/ml of ELISA-IgG yielded the maximal sensitivity and specificity comparing to the other levels of ELISA-IgG, and was considered the best cut off-point of ELISA-IgG to diagnose acute brucellosis. At this cut-off, the sensitivity, specificity, positive predictive value, negative predictive value, positive likelihood ratio, and negative likelihood ratio were 84.09%, 85.38%, 62.20, 94.90, 5.75, 0.18, respectively.Conclusion: The best cut-off point of ELISA-IgG is 53 IU/ml, which yields the maximal sensitivity and specificity to diagnose acute brucellosis.

Comparison of three commercial fecal calprotectin ELISA test kits used in patients with Inflammatory Bowel Disease

DEFF Research Database (Denmark)

Mirsepasi-Lauridsen, Hengameh Chloé; Bachmann Holmetoft, Ulla; Halkjær, Sofie Ingdam

2016-01-01

OBJECTIVE: Fecal calprotectin is a noninvasive marker of intestinal inflammation used to distinguish between functional and organic bowel diseases and to evaluate disease activity among patients with Inflammatory Bowel Disease (IBD). The goal of this study was to compare three different ELISA tests...... and 18 to 67 years, respectively. Disease activity in the patients was established using the following clinical activity indices: the Simple Clinical Colitis Activity Index (SCCAI), the Harvey Bradshaw Index (HBI) and the Modified Pouchitis Disease Activity Index (MPDAI). Three ELISA calprotectin tests...... (EK-CAL, CALPRO and HK325) were performed on fecal specimens and results compared. RESULTS: The CALPRO calprotectin ELISA test was shown to have the best specificity of 96% compared to the HK325 and the EK-CAL calprotectin ELISA tests with 28% specificity and 74% specificity, respectively...

Assessment of the diagnostic performance of the IDS-iSYS tests for toxo IgG, toxo IgM and avidity.

Science.gov (United States)

Levigne, Pauline; Peyron, François; Wallon, Martine

2016-10-01

When acquired during pregnancy toxoplasmosis can have devastating consequences on the fetus. As maternal infection is in the majority of cases subclinical, the diagnosis of toxoplasmosis relies on serological tests for the detection of IgG, IGM and the mesure of IgG avidity. We evaluated the performance of IDS-iSYS a new automatized instrument based on chemiluminescence for the diagnosis of the disease. Our study was based on non-selected samples received in our laboratory either for the determination of serological status or for distinguishing acute from chronic infection. Seven hundred eighty three samples were enrolled in the study. Compared with Architect IgG and IgM assays, the sensitivity and specificity were respectively 99% and 99% for IgG, and 75% and 97% for IgM. We observed higher remaining titers for IDS iSYS IgG, which could reduce the proportions of patients who have to be retested because of doubtful titers. IgM detection and avidity scored equivalent performance with both methods. This automate appears to be a reliable and easy-to-use tool for diagnosing toxoplasmosis in different clinical settings. Copyright © 2016 Elsevier Inc. All rights reserved.

Evaluation of the Abbott ARCHITECT Toxo IgM assay.

Science.gov (United States)

Sickinger, Eva; Braun, Hans-Bertram; Praast, Gerald; Stieler, Myriam; Gundlach, Cordelia; Birkenbach, Claudia; Prostko, John; Palafox, Mary Ann; Frias, Edwin; Hsu, Stephen; Matias, Matthew; Pucci, Dominick; Hausmann, Michael; Sagel, Ulrich; Smith, Darwin

2009-07-01

Development of the ARCHITECT Toxo IgM assay has been done to assist the clinician in acute Toxoplasma gondii infection detection, especially in pregnant women. Its use, in conjunction with ARCHITECT Toxo IgG and Toxo Avidity assays, will provide an array of assays particularly useful in the monitoring of pregnant females to determine the risk of maternal transmission of the parasite. Specificity results from 2 testing sites, using populations of pregnant females, hospital patients, and blood donors, demonstrated that the assay has an overall resolved relative specificity of 99.89% (confidence interval, 99.68-99.98%). Relative specificity for pregnant female specimens was 99.95% (n = 2031). Excellent seroconversion sensitivity was observed for the ARCHITECT Toxo IgM assay, which was similar to the Abbott AxSYM Toxo IgM assay (Abbott Laboratories, Abbott Park, IL). In more than 90% of the panels tested, the 1st bleed detected in the serial bleeds was the same for both assays.

Salivary anti-PGL-1 IgM may indicate active transmission of Mycobacterium leprae among young people under 16 years of age.

Science.gov (United States)

Macedo, Alexandre Casimiro de; Cunha, José Evandro; Yaochite, Juliana Navarro Ueda; Tavares, Clodis Maria; Nagao-Dias, Aparecida Tiemi

Considering that the main route of Mycobacterium leprae transmission is the upper respiratory tract, detection of salivary antibodies can be a useful tool for diagnosing early infection. The study aimed to analyze salivary anti-PGL-1 IgA and IgM antibodies in 169 children aged 4-16 years old, who lived nearby or inside the house of multibacillary or paucibacillary leprosy patients in two endemic cities in Alagoas State - Brazil. Salivary anti-PGL-1 antibodies were quantified by modified ELISA method. The frequency of contact and clinical form of the index case were significantly associated with salivary antibody levels. High frequency of IgM positivity strongly suggests active transmission of M. leprae in these communities. We suggest in the present work that salivary anti-PGL IgA and IgM are important biomarkers to be used for identifying communities with probable active transmission of M. leprae. Copyright © 2017 Sociedade Brasileira de Infectologia. Published by Elsevier Editora Ltda. All rights reserved.

Antibody class capture assay (ACCA) for rubella-specific IgM antibody.

Science.gov (United States)

Isaac, M; Payne, R A

1982-01-01

Enzyme-linked immunosorbent assays for IgM antirubella were carried out on 1,546 sera, using an IgM capture method with a F (ab')2 conjugate (ACCA). Under the conditions described, sera containing IgM antirubella bound up to 15 times as much enzyme activity as negative specimens. Paired serum specimens from 27 patients, serial serum specimens from 6 patients, and single serum specimens from 15 patients who had had recent rubella were examined by the haemagglutination inhibition test (HAI) in the presence and absence of 2-mercaptoethanol following sucrose density gradient centrifugation (SDGC). ACCA confirmed all the results found with HAI following SDGC. Specimens were examined from ten patients with congenital rubella; ACCA confirmed the results found with both immunofluorescence following SDGC and radioimmunoassay. Pre- and post-vaccination specimens from 123 patients who had been vaccinated against rubella were examined. An IgM response could only be demonstrated in the 57 cases when IgG was absent in the first specimen. The specificity of the assay was confirmed by testing 31 serum specimens from rubella immune patients that also contained rheumatoid factor, 163 serum specimens from patients with acute infections other than rubella, and 12 serum specimens from infants with miscellaneous neonatal abnormalities other than congenital rubella. The ACCA proved a simple, sensitive, and specific test for IgM antirubella and the results compared favourably with those obtained by the SDGC technique.

An experiment to test in-field pointing for Elisa

Science.gov (United States)

Brugger, Christina; Broll, Bernhard; Fitzsimons, Ewan; Johann, Ulrich; Jonke, Wouter; Lucarelli, Stefano; Nikolov, Susanne; Voert, Martijn; Weise, Dennis; Witvoet, Gert

2017-11-01

The evolved Laser Interferometer Space Antenna (eLISA) Mission is being developed to detect and characterise gravitational waves by measuring pathlength changes between free flying inertial test masses over a baseline of order 1 Gm. Here the observed astrophysical events and objects lie in a frequency range between 30 μHz and 1 Hz (the LISA measurement band, LMB).

Polymerase chain reaction and blood culture in blood donors screened by ELISA test for Chagas' disease

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Andréa Tieko Kinoshita-Yanaga

2011-03-01

Full Text Available The objective of this study was to evaluate, through blood culture and PCR, the results of the ELISA for Chagas' disease in the screening of blood donors in the public blood-supply network of the state of Paraná, Brazil, and to map the epidemiological profile of the donors with respect to their risk of infection by Trypanosoma cruzi. The negative and positive results of the ELISA were confirmed by blood culture and PCR for 190/191 individuals (99.5%. For one individual (0.5%, the ELISA was inconclusive, blood culture and IIF were negative, and IHA and PCR positive. Three individuals (1.6% were positive for T. cruzi on all the tests. Donors were predominantly female, and natives of Paraná, of rural origin, had observed or been informed of the presence of the vector in the municipalities where they resided, had never received a blood transfusion, had donated blood 1 to 4 times, and reported no cases of Chagas' disease in their families. We concluded that PCR and blood culturing have excellent potential for confirming the results of the ELISA, and that candidate blood donors with negative or positive tests have a similar risk of infection by T. cruzi, indicating that the ELISA test is sufficiently safe for screening blood prior to use.O objetivo deste estudo foi avaliar, pela hemocultura e PCR, os resultados do teste ELISA utilizado para doença de Chagas na triagem de doadores de sangue na rede pública do Estado do Paraná, Brasil, e traçar o perfil epidemiológico dos doadores quanto ao risco de infecção pelo Trypanosoma cruzi. Os resultados negativos e positivos do ELISA foram confirmados pela hemocultura e PCR em 190/191 indivíduos (99,5%. Para um indivíduo (0,5%, o teste de ELISA foi inconclusivo, hemocultura e IFI foram negativas, HAI e PCR foram positivas. Três indivíduos (1,6% foram positivos para T. cruzi em todos os testes. A maioria dos doadores era do sexo feminino, oriundos do Estado do Paraná, de origem rural, tinham

Detecção de imunoglobulinas IgG, IgM e IgA anti-Toxoplasma gondii no soro, líquor e saliva de pacientes com síndrome da imunodeficiência adquirida e neurotoxoplasmose Detection of anti-Toxoplasma gondii IgG, IgM and IgA immunoglobulins in the serum, cerebrospinal fluid and saliva of patients with acquired immunodeficiency syndrome and neurotoxoplasmosis

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Aercio Sebastião Borges

2004-12-01

Full Text Available Estudamos 55 pacientes com sindrome da imunodeficiência adquirida (SIDA e neurotoxoplasmose (grupo 1; 37 pacientes com SIDA e comprometimento neurológico por outra etiologia (grupo 2 e 18 indivíduos anti-HIV negativos com manifestações neurológicas (grupo 3, pesquisando IgG, IgA e IgM anti-Toxoplasma gondii, no soro, líquor e saliva, utilizando teste ELISA, para fins diagnósticos. O valor preditivo negativo do teste para o encontro de IgG no soro foi 100% e no líquor, 92,4%. Não houve diferença entre os três grupos quanto aos anticorpos IgA neste material. Para IgA, no líquor, o teste alcançou 72,7% de especificidade (pWe studied 55 patients with acquired immunodeficiency syndrome (AIDS and neurotoxoplasmosis (group 1, 37 patients with AIDS and neurological involvement due to another etiology (group 2 and 18 anti-HIV-negative individuals with neurological manifestations, by searching for anti-T. gondii IgG, IgA and IgM immunoglobulins in serum, cerebrospinal fluid (CSFand saliva, using ELISA. The negative predictive value of the test for IgG in serum was 100% and in CSF, 92.4%. There was no difference among the three groups studied regarding IgA in serum. For IgA, in CSF the test reached 72.7% specificity (p<0.05. In saliva, only the detection of IgG was found to be correlated with a diagnosis of neurotoxoplasmosis. We emphasize that the absence of anti-T. gondii IgG antibodies in serum and CSF strongly indicates the absence of a diagnosis of neurotoxoplasmosis and that specific IgA immunoglobulins in CSF and IgG in saliva may represent two auxiliary markers for the differential diagnosis of toxoplasmic encephalitis in AIDS.

Radioimmunoassay for detection of IgM domains

Energy Technology Data Exchange (ETDEWEB)

Shimizu, A [Osaka Univ. (Japan); Watanabe, S; Kiyotaki, C; Yamamura, Y

1979-09-01

IgM from two macroglobulinemia patients was digested with trypsin, and Fab monomer, Fab dimer and Fc fragments of the IgM were isolated. Using these fragments as antigens and rabbit antisera prepared against another IgM from a macroglobulinemia patient, a radioimmunoassay system for the C..mu..1, C..mu..2 and Fc..mu.. was established. This system can be used as a tool for immunochemical characterization of IgM present on the surface of lymphoid cells.

Field trial of brucellosis competitive ELISA

International Nuclear Information System (INIS)

Perez, B.; Rojas, M.

1998-01-01

2990 sera samples from cattle were tested for antibodies to Brucella abortus using 8 serological tests for. The tests used were Rose Bengal (RBT), Buffer Plate Agglutination Test (BPAT), Complement Fixation (CFT), 2 Indirect and 2 Competitive Enzyme Linked Immunosorbent Assays (ELISA). Bacteriological evaluation from milk was done also. All tests were compared with respect to diagnostic specificity in vaccinated herds which were considered to be Brucella-free. The diagnostic specificity of the Indirect and Competitive ELISA was greater than 99,8%. Estimates of relative sensitivity were obtained from infected herds. The diagnostic sensitivity of the Indirect ELISA was greater than 95,8% and for the Competitive ELISA between 98,8 and 100 %, the last value refers to the Competitive ELISA Prototype II (SLPS antigen/M84 Mab), which was found highly suitable to differentiate vaccinated from brucella-infected cattle. The use of C-ELISA II for monitoring bovine populations under an eradication programme is recommended. (author)

Role of Natural IgM Autoantibodies (IgM-NAA) and IgM Anti-Leukocyte Antibodies (IgM-ALA) in Regulating Inflammation.

Science.gov (United States)

Lobo, Peter I

2017-01-01

Natural IgM autoantibodies (IgM-NAA) are rapidly produced to inhibit pathogens and abrogate inflammation mediated by invading microorganisms and host neoantigens. IgM-NAA achieve this difficult task by being polyreactive with low binding affinity but with high avidity, characteristics that allow these antibodies to bind antigenic determinants shared by pathogens and neoantigens. Hence the same clones of natural IgM can bind and mask host neoantigens as well as inhibit microorganisms. In addition, IgM-NAA regulate the inflammatory response via mechanisms involving binding of IgM to apoptotic cells to enhance their removal and binding of IgM to live leukocytes to regulate their function. Secondly, we review how natural IgM prevents autoimmune disorders arising from pathogenic IgG autoantibodies as well as by autoreactive B and T cells that have escaped tolerance mechanisms. Thirdly, using IgM knockout mice, we show that regulatory B and T cells require IgM to effectively regulate inflammation mediated by innate, adaptive and autoimmune mechanisms. It is therefore not surprising why the host positively selects such autoreactive B1 cells that generate protective IgM-NAA, which are also evolutionarily conserved. Fourthly, we show that IgM anti-leukocyte autoantibodies (IgM-ALA) levels and their repertoire can vary in normal humans and disease states and this variation may partly explain the observed differences in the inflammatory response after infection, ischemic injury or after a transplant. Finally we also show how protective IgM-NAA can be rendered pathogenic under non-physiological conditions. IgM-NAA have therapeutic potential. Polyclonal IgM infusions can be used to abrogate ongoing inflammation. Additionally, inflammation arising after ischemic kidney injury, e.g., during high-risk elective cardiac surgery or after allograft transplantation, can be prevented by pre-emptively infusing polyclonal IgM, or DC pretreated ex vivo with IgM, or by increasing in vivo IgM

A novel indirect ELISA for diagnosis of dengue fever

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Rohan Narayan

2016-01-01

Full Text Available Background & objectives: Dengue fever (DF is associated with significant morbidity and mortality in the tropical and sub-tropical regions of the world. Since there are no effective antiviral drugs for treatment, clinicians often rely on the accurate diagnosis of dengue fever to begin supportive therapy at early stages of the illness. The objective of this study was to develop an in-house dengue virus serotype 2 (DENV-2 non-structural protein- 5 (NS5 based indirect ELISA. Methods: DENV-2 was raised in Vero cells and the viral proteins were separated and subsequently the NS5 protein was eluted. Serum samples from primary and secondary dengue fever patients; and acute and convalescent samples from Japanese encephalitis (JE and West Nile virus (WNV cases were used to validate the ELISA. Results: The assay was found to be 100 per cent specific in detecting DENV-2 specific antibodies from patient′s serum. However, in terms of sensitivity, the assay could detect IgM antibodies only from 90 per cent of the primary dengue samples. The IgM/IgG ratio of the primary and secondary samples was 7.24 and 0.64, respectively. Interpretation & conclusions: The results indicate that the DENV-2 NS5 ELISA is dengue group specific and can be used to differentiate dengue infection from other circulating Flavivirus infections. This NS5 ELISA can also be used to distinguish between primary and secondary dengue fever on the basis of IgM/IgG ratios. Further studies with larger sample sizes and different DENV serotypes are required to validate the ELISA.

Cellphone-based hand-held microplate reader for point-of-care ELISA testing (Conference Presentation)

Science.gov (United States)

Berg, Brandon; Cortazar, Bingen; Tseng, Derek; Ozkan, Haydar; Feng, Steve; Wei, Qingshan; Chan, Raymond Y.; Burbano, Jordi; Farooqui, Qamar; Lewinski, Michael; Di Carlo, Dino; Garner, Omai B.; Ozcan, Aydogan

2016-03-01

Enzyme-linked immunosorbent assay (ELISA) in a microplate format has been a gold standard first-line clinical test for diagnosis of various diseases including infectious diseases. However, this technology requires a relatively large and expensive multi-well scanning spectrophotometer to read and quantify the signal from each well, hindering its implementation in resource-limited-settings. Here, we demonstrate a cost-effective and handheld smartphone-based colorimetric microplate reader for rapid digitization and quantification of immunoserology-related ELISA tests in a conventional 96-well plate format at the point of care (POC). This device consists of a bundle of 96 optical fibers to collect the transmitted light from each well of the microplate and direct all the transmission signals from the wells onto the camera of the mobile-phone. Captured images are then transmitted to a remote server through a custom-designed app, and both quantitative and qualitative diagnostic results are returned back to the user within ~1 minute per 96-well plate by using a machine learning algorithm. We tested this mobile-phone based micro-plate reader in a clinical microbiology lab using FDA-approved mumps IgG, measles IgG, and herpes simplex virus IgG (HSV-1 and HSV-2) ELISA tests on 1138 remnant patient samples (roughly 50% training and 50% testing), and achieved an overall accuracy of ~99% or higher for each ELISA test. This handheld and cost-effective platform could be immediately useful for large-scale vaccination monitoring in low-infrastructure settings, and also for other high-throughput disease screening applications at POC.

Teste de ELISA indireto para o diagnóstico sorológico de pitiose Indirect ELISA for the serodiagnostic of pythiosis

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Janio M. Santurio

2006-03-01

Full Text Available A pitiose, doença granulomatosa de eqüinos causada pelo oomiceto Pythium insidiosum, tem como característica a evolução rápida seguida de morte dos animais. Estas mortes muitas vezes são causadas por diagnósticos errôneos ou demorados quando os doentes já não respondem ao tratamento. Este trabalho teve por objetivo a padronização do ensaio imunoenzimático indireto (ELISA para diagnóstico sorológico de pitiose em eqüinos e coelhos, visando a diminuição de erros e de tempo necessário para o diagnóstico. Para o desenvolvimento e validação do teste foram utilizadas 72 amostras de soro de eqüinos saudáveis e 44 soros de eqüinos com pitiose confirmada. Os resultados da validação do ELISA para eqüinos foram: sensibilidade 97,72%, especificidade 90,27%, valor preditivo positivo 86%, valor preditivo negativo 98,4% e eficiência de 93,1%. Para coelhos, o teste foi padronizado com 48 amostras de soro de animais saudáveis e 24 amostras de coelhos imunizados com antígenos de P. insidiosum. Os resultados foram: sensibilidade 91,66%, especificidade 95,83%, valor preditivo positivo 91,66%, valor preditivo negativo 95,83% e eficiência de 94,44%. Os resultados deste trabalho demonstram que o ensaio imunoenzimático indireto é um método seguro e eficaz para o diagnóstico sorológico da pitiose.Pythiosis is a granulomatous disease caused by the oomycete Pythium insidiosum that affects humans and animals, especially horses. Deaths are very often the consequence of incorrect or late diagnosis when animals no longer respond to treatment. This study aimed standardization of the ELISA assay for the serodiagnostic of pythiosis in horses and rabbits, in order to minimize errors and delays in the diagnosis of the disease. Sera of 72 healthy and 44 of by pythiosis affected horses were used for development and evaluation of the test. The ELISA for equine diagnostic showed 97.72% sensitivity, 90.27% specificity, 86% positive predictive value

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

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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.

The impact of milk handling procedures on Ostertagia ostertagi antibody ELISA test results.

Science.gov (United States)

Vanderstichel, Raphaël; Dohoo, Ian; Stryhn, Henrik

2010-04-19

The impact of various milk handling stressors were analyzed using a commercially available enzyme-linked immunosorbent assay (ELISA) test measuring Ostertagia ostertagi antibodies in milk from dairy cattle (Svanovir). An indirect ELISA has the ability to determine the amount of milk production losses related to intestinal parasitism. The ELISA test recommends fresh defatted milk, however, milk collected from Dairy Herd Improvement (DHI) programs in North America undergo many stressors, including, heating, freezing and are not defatted. Normalized optical density ratios (ODRs) were compared between fresh defatted milk and milk subjected to one or more stressors with a linear mixed model accounting for differences in variation between the fresh and the frozen samples. Concordance correlation coefficients were also analyzed for comparisons to other similar studies. After accounting for random cow and container effects, the treatment factors interacted with each other (p<0.001). Biologically interesting contrasts were created to explain the interaction. The estimated difference in ODR between the milk samples handled according to recommendations of the manufacturers of Svanovir and the whole milk samples that were subjected to the most extreme treatment (heated, frozen, thawed, and re-frozen for 4 weeks) was 0.062 (p<0.001). This difference represented less than 5% of the range, and was thus considered biologically negligible. Frozen whole milk processed by DHI programs, the most likely method of collecting on-farm samples in North America, will likely yield reliable results for the indirect ELISA tests, particularly, Svanovir.

Diagnosis of Lyme-associated uveitis: value of serological testing in a tertiary centre.

Science.gov (United States)

Bernard, Alexia; Kodjikian, Laurent; Abukhashabh, Amro; Roure-Sobas, Chantal; Boibieux, Andre; Denis, Philippe; Broussolle, Christiane; Seve, Pascal

2018-03-01

To determine the frequency and clinical presentation of Lyme disease in patients with uveitis and to assess the value of Borrelia burgdorferi serological testing. Retrospective study on all patients with uveitis who were referred to our tertiary hospital were serologically tested for Lyme in our laboratory between 2003 and 2016. Screening consisted of determining B. burgdorferi serum IgG and IgM by ELISA method. The patient's serology was considered as positive if the ELISA-positive result in IgM and/or IgG was confirmed by an immunoblot positive in IgM and/or IgG. Lyme-associated uveitis was diagnosed based on serological results as well as response to antibiotics and exclusion of other diagnosis. Of the 430 patients with uveitis (60% women, mean age 49 years) fulfilling inclusion criteria, 63 (14.7%) had an ELISA-positive serology, confirmed by immunoblot for 34 patients (7.9%). The diagnosis of Lyme-associated uveitis was finally retained in seven patients (1.6%). These patients reported either a previous exposure including tick bite or forest walks (n=5), symptoms suggestive of Lyme disease (n=5) and resistance to local and/or systemic steroids (n=7). Among the remaining 27 positive patients, 22 had other established aetiologies and 5 other were unclassified. The seroprevalence of B. burgdorferi among our patients with uveitis was 7.9% compared with 6 to 8.5% in the general French population which leads to a low predictive value of serological testing. Its use should be reserved for patients with unexplained uveitis, an exposure history, systemic findings suggestive of Lyme disease and steroids resistance. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2018. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

Bayesian estimation of sensitivity and specificity of Coxiella burnetii antibody ELISA tests in bovine blood and milk

DEFF Research Database (Denmark)

Paul, Suman; Toft, Nils; Agerholm, Jørgen S.

2013-01-01

Serological tests for Coxiella burnetii (the causative agent of Q fever) antibodies are usually based on enzyme linked immunosorbent assay (ELISA) although this method is not thoroughly evaluated. The objective of this study was to determine the sensitivity and specificity of an ELISA for detection...... lactating cows is relatively easy, non-invasive and inexpensive and hence milk ELISA may be a better option for screening lactating cows. But, blood ELISA is an option for screening non-lactating cattle....

Performance of immunochromatographic and ELISA tests for detecting fallow deer infected with Mycobacterium bovis.

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Boadella, M; Barasona, J A; Diaz-Sanchez, S; Lyashchenko, K P; Greenwald, R; Esfandiari, J; Gortazar, C

2012-04-01

Fallow deer (Dama dama) are widely distributed as natural or naturalised populations, as well as in game parks and deer farms. We used 157 fallow deer sampled in populations considered to be Mycobacterium tuberculosis complex (MTC) free and 73 Mycobacterium bovis-infected fallow deer confirmed postmortem by culture to evaluate the diagnostic performance of two tests for the detection of anti-mycobacterial antibodies: the dual path platform (DPP) VetTB assay and the bovine purified protein derivative (bPPD) ELISA. We also compared their sensitivity with that of the skin test, analyzed the effect of haemolysis degree on the antibody detection and described the relationship between the test readings and presence/absence of gross tuberculosis (TB) compatible lesions. Sensitivity of bPPD ELISA was 51% at a specificity of 96%. Depending on the cut-off value selected, the sensitivity of DPP VetTB ranged from 62 to 71%, while its specificity was 88-95%. In the subgroup of M. bovis-infected deer for which the skin test data were available (33 of 73); this method detected 76% of culture-positive animals, although the specificity of the intradermal test was not determined in this study. When the DPP VetTB and skin test data were combined, the resulting sensitivity obtained in this sub-group of M. bovis-infected deer increased to 97%. Gross pathology identified TB compatible lesions (TBL) in 89% culture-confirmed fallow deer. The infected animals with visible lesions had significantly higher readings in the DPP VetTB, but not in the bPPD ELISA. Only high levels of haemolysis decreased antibody test sensitivity and this effect was more evident for the bPPD ELISA. The results allowed inferring a number of management recommendations for rapid detection of MTC infection in live fallow deer and in surveys on hunter-harvested cervids. Copyright © 2011 Elsevier B.V. All rights reserved.

[Clinical manifestation of Lyme borreliosis in children with positive and negatiwe western blot results].

Science.gov (United States)

Ołdak, Elzbieta; Rozkiewicz, Doroto; Sulik, Artur

2008-01-01

In the afforested area of North-Eastern Poland the risk of Borrelia burgdorferi infection seems to be higher compared to the other regions. Because of unspecific clinical manifestation of Lyme borreliosis in children the positive ELISA IgM results should be confirmed with Western blot IgM tests. Retrospective analysis of clinical signs and symptoms of Lyme borreliosis in children with positive ELISA IgM and positive Western blot IgM results and in children with positive ELISA IgM and negative Western blot IgM results. The study included 20 children reactive with ELISA IgM (Bellco Biomedica, Austria), hospitalized in Pediatric Infectious Diseases Clinic in 2007 due to probable diagnosis of Lyme disease. All children were tested with B. burgdorferi Western blot IgM and/or IgG assay (DRG, Diagnostics, Germany) as a second-step diagnosis. In 10 (50% females, 50% males) out of 20 children the results were positive (borreliosis) and in other 10 (80% females, 20% males) the results were negative (controls). In both groups of patients the retrospective analysis of signs and symptoms was done. The most often clinical manifestation of Lyme borreliosis in children was neuroborreliosis. Children presented Lyme meningitis (30%), facial nerve palsy (10%) and chronic or recurrent headaches (40%), associated with vertigo (20%), weakness (30%), fever (40%), and fatigue syndrome (30%). One patient presented Lyme arthritis. Children of control group presented with unspecific symptoms like isolated headaches (40%), arthralgias (70%), myalgias (10%) and abdomen pain (20%) (1) The most frequent clinical presentation of Lyme borreliosis in analyzed children was neuroborreliosis; (2) Isolated arthralgias in children reactive with B. burgdorferi ELISA IgM need to be confirmed with Western blot assay before implementing the antibiotic therapy.

An ELISA-inhibition test using monoclonal antibody for the serology of leprosy

NARCIS (Netherlands)

Klatser, P. R.; de Wit, M. Y.; Kolk, A. H.

1985-01-01

In this study a mouse monoclonal antibody (47-9) is described, which recognized an epitope on the 36 kD protein antigen of M. leprae. The monoclonal antibody showed specificity for M. leprae. An ELISA-inhibition test based on the competitive inhibition by antibodies from human test sera of the

The role of laboratory diagnostic of boreliose in the environment of forest workers

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Patryk Matuszek

2013-12-01

Full Text Available Background: The laboratory diagnostics of boreliose is based on detection of specific IgG and IgM antibodies by ELISA test followed by confirmation test of Line-blot. Material and methods: Testing of the presence of specific anti-Borrelia antibodies was performed in the group of 568 forest workers. The ELISA tests were performed in serum, saliva, and dry spot of blood. The confirmation tests Line blot were performed in serum then the prevalence of particular antibodies against Borrelia was calculated. The ELISA test consists complete extract from Borrelia whereas the Line-blot test consists antigens from B. afzelii, B. burdorferi, and B. garinii. Results: The samples from 201 (35% forest workers have revealed the positive results in ELISA in IgG class and 171 (30 results from this group were confirmed by Line-blot. Only in 40 (7 samples have revealed the positive results in Line-blot but were negative in ELISA tests. The main antigen was VIsE (77% in IgG class. It has been shown that 119 (21% samples have revealed positive results in the IgM class in ELISA tests, and from this group 59 (10% cases were confirmed by Line-blot. Antibody against antigen OspC revealed the highest prevalence (71% in IgM class. The correlation between samples from sera and mucosal transudate have shown r40.736 in the case of IgG and r40.162 in the case of IgM. Conclusion: The frequency, of anti-Borrelia antibodies occurrence was very high and appeared in 42% of forest workers. It has revealed that the correlation of results between serum and mucosal transudate was not satisfactory in the case of ELISA test. In contrary, the correlation of results between serum and dry spot of blood was very high and should be consider as alternative material for boreliose diagnosis.

Radioimmunoassay of IgM, IgG, and IgA brucella antibodies

International Nuclear Information System (INIS)

Parrett, D.; Nielson, K.H.; White, R.G.; Payne, D.J.H.

1977-01-01

A radioimmunoassay (R.I.A.) has been devised to measure the serum antibody against Brucella abortus in each of the immunoglobulin classes IgM, IgG, and IgA. This test was applied to 46 sera from individuals with various clinical types of brucellosis, and the results were compared with the results of conventional direct and indirect agglutination and complement-fixation tests. The R.I.A. provided a highly sensitive primary-type assay which avoided the difficulties with blocking or non-agglutinating antibody, and thus has many advantages in the diagnosis of acute and chronic stages of brucella infection in man. The R.I.A. was successful in detection of antibody in many instances in which conventional serological tests were negative, and such antibody could (if IgM) be associated with acute or (if IgG or IgA) with chronic cases of brucellosis. One case in which B.abortus was isolated by blood culture but which failed to yield antibody by conventional tests, nevertheless showed substantial levels of IgM and IgG antibody by R.I.A. In other cases the R.I.A. test helped to eliminate the diagnosis of brucellosis by revealing absent or low antibody levels. (author)

Multicountry Prospective Clinical Evaluation of Two Enzyme-Linked Immunosorbent Assays and Two Rapid Diagnostic Tests for Diagnosing Dengue Fever

Science.gov (United States)

Dauner, Allison L.; Valks, Andrea; Forshey, Brett M.; Long, Kanya C.; Thaisomboonsuk, Butsaya; Sierra, Gloria; Picos, Victor; Talmage, Sara; Morrison, Amy C.; Halsey, Eric S.; Comach, Guillermo; Yasuda, Chadwick; Loeffelholz, Michael; Jarman, Richard G.; Fernandez, Stefan; An, Ung Sam; Kochel, Tadeusz J.; Jasper, Louis E.; Wu, Shuenn-Jue L.

2015-01-01

We evaluated four dengue diagnostic devices from Alere, including the SD Bioline Dengue Duo (nonstructural [NS] 1 Ag and IgG/IgM), the Panbio Dengue Duo Cassette (IgM/IgG) rapid diagnostic tests (RDTs), and the Panbio dengue IgM and IgG capture enzyme-linked immunosorbent assays (ELISAs) in a prospective, controlled, multicenter study in Peru, Venezuela, Cambodia, and the United States, using samples from 1,021 febrile individuals. Archived, well-characterized samples from an additional 135 febrile individuals from Thailand were also used. Reference testing was performed on all samples using an algorithm involving virus isolation, in-house IgM and IgG capture ELISAs, and plaque reduction neutralization tests (PRNT) to determine the infection status of the individual. The primary endpoints were the clinical sensitivities and specificities of these devices. The SD Bioline Dengue Duo had an overall sensitivity of 87.3% (95% confidence interval [CI], 84.1 to 90.2%) and specificity of 86.8% (95% CI, 83.9 to 89.3%) during the first 14 days post-symptom onset (p.s.o.). The Panbio Dengue Duo Cassette demonstrated a sensitivity of 92.1% (87.8 to 95.2%) and specificity of 62.2% (54.5 to 69.5%) during days 4 to 14 p.s.o. The Panbio IgM capture ELISA had a sensitivity of 87.6% (82.7 to 91.4%) and specificity of 88.1% (82.2 to 92.6%) during days 4 to 14 p.s.o. Finally, the Panbio IgG capture ELISA had a sensitivity of 69.6% (62.1 to 76.4%) and a specificity of 88.4% (82.6 to 92.8%) during days 4 to 14 p.s.o. for identification of secondary dengue infections. This multicountry prospective study resulted in reliable real-world performance data that will facilitate data-driven laboratory test choices for managing patient care during dengue outbreaks. PMID:25588659

Immune Dysfunction in Rett Syndrome Patients Revealed by High Levels of Serum Anti-N(Glc IgM Antibody Fraction

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Anna Maria Papini

2014-01-01

Full Text Available Rett syndrome (RTT, a neurodevelopmental disorder affecting exclusively (99% female infants, is associated with loss-of-function mutations in the gene encoding methyl-CpG binding protein 2 (MECP2 and, more rarely, cyclin-dependent kinase-like 5 (CDKL5 and forkhead box protein G1 (FOXG1. In this study, we aimed to evaluate the function of the immune system by measuring serum immunoglobulins (IgG and IgM in RTT patients (n=53 and, by comparison, in age-matched children affected by non-RTT pervasive developmental disorders (non-RTT PDD (n=82 and healthy age-matched controls (n=29. To determine immunoglobulins we used both a conventional agglutination assay and a novel ELISA based on antibody recognition by a surrogate antigen probe, CSF114(Glc, a synthetic N-glucosylated peptide. Both assays provided evidence for an increase in IgM titer, but not in IgG, in RTT patients relative to both healthy controls and non-RTT PDD patients. The significant difference in IgM titers between RTT patients and healthy subjects in the CSF114(Glc assay (P=0.001 suggests that this procedure specifically detects a fraction of IgM antibodies likely to be relevant for the RTT disease. These findings offer a new insight into the mechanism underlying the Rett disease as they unveil the possible involvement of the immune system in this pathology.

A peptide extension dictates IgM assembly.

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Pasalic, Dzana; Weber, Benedikt; Giannone, Chiara; Anelli, Tiziana; Müller, Roger; Fagioli, Claudio; Felkl, Manuel; John, Christine; Mossuto, Maria Francesca; Becker, Christian F W; Sitia, Roberto; Buchner, Johannes

2017-10-10

Professional secretory cells can produce large amounts of high-quality complex molecules, including IgM antibodies. Owing to their multivalency, polymeric IgM antibodies provide an efficient first-line of defense against pathogens. To decipher the mechanisms of IgM assembly, we investigated its biosynthesis in living cells and faithfully reconstituted the underlying processes in vitro. We find that a conserved peptide extension at the C-terminal end of the IgM heavy (Ig-μ) chains, termed the tailpiece, is necessary and sufficient to establish the correct geometry. Alanine scanning revealed that hydrophobic amino acids in the first half of the tailpiece contain essential information for generating the correct topology. Assembly is triggered by the formation of a disulfide bond linking two tailpieces. This induces conformational changes in the tailpiece and the adjacent domain, which drive further polymerization. Thus, the biogenesis of large and topologically challenging IgM complexes is dictated by a local conformational switch in a peptide extension.

Jatobal virus antigenic characterization by ELISA and neutralization test using EIA as indicator, on tissue culture

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Luiz Tadeu M. Figueiredo

1988-06-01

Full Text Available A virus antigenic characterization methodology using an indirect method of antibody detection ELISA with virus-infected cultured cells as antigen and a micro virus neutralisation test using EIA (NT-EIA as an aid to reading were used for antigenic characterization of Jatobal (BeAn 423380. Jatobal virus was characterized as a Bunyaviridae, Bunyavirus genus, Simbu serogroup virus. ELISA using infected cultured cells as antigen is a sensitive and reliable method for identification of viruses and has many advantages over conventional antibody capture ELISA's and other tests: it eliminates solid phase coating with virus and laborious antigen preparation; it permits screening of large numbers of virus antisera faster and more easily than by CF, HAI, or plaque reduction NT. ELISA and NT using EIA as an aid to reading can be applicable to viruses which do not produce cytopathogenic effect. Both techniques are applicable to identification of viruses which grow in mosquito cells.A caracterização antigênica do vírus Jatobal (BeAn 423380 foi efetuada utilizando uma técnica de ELISA para deteccão de anticorpos que utiliza culturas celulares infectadas como antígeno e um micro teste de neutralização para vírus que utiliza o método imunoenzimático como auxiliar para a leitura dos resultados (NT-EIA. O vírus Jatobal foi caracterizado como um Bunyaviridae, gênero Bunyavirus, pertencente ao sorogrupo Simbu. A técnica de ELISA, utilizando culturas celulares infectadas como antígeno, trata-se de método sensível e confiável na identificação de agentes virais, possuindo muitas vantagens sobre ELISA convencionais e outros testes: elimina a preparação laboriosa de antígenos para o revestimento em fase sólida; permite que se teste de forma mais rápida e fácil que por CF, HAI e neutralização por redução de plaques um grande número de antisoros de vírus. ELISA e NT-EIA podem ser utilizados para a classificação de vírus que não produzem

Usefulness of in-house obtained recombinant proteins Yop of Yersinia enterocolitica as highly specific antigens in ELISA and recom-dot performed in the serodiagnosis of yersiniosis.

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Rastawicki, Waldemar; Smietafiska, Karolina; Chrost, Anna; Wolkowicz, Tomasz; Rokosz-Chudziak, Natalia

Proper analysis of the human immune response is crucial in the laboratory diagnosis of many bacterial infections-The current serological diagnosis of yersiniosis often is carried out using ELISA with native antigens. However, recombinant proteins increase the specificity of the serological assays, particularly in patients with chronic, non- specific infections. The aim of the present study was to evaluate the usefulness of in-house obtained recombinant proteins Yop of Yersinia enterocolitica as highly specific antigens in ELISA and recom-dot performed in the serodiagnosis of yersiniosis. Recombinant YopD, YopB, YopE and V-Ag proteins of Y enterocolitica were expressing in E. coli BL21 (DE3) using the pET-30 Ek/LIC expression vector (Novagen). Purification was accomplished by immobilized metal (Ni2) affinity column chromatography (His-trap). The proteins were used as antigens in standard ELISA and recom-dot assay, which was performed on nitrocellulose strips. The study population, used for characterization of the humoral immune response to the recombinant proteins, consisted of 74 patients suspected for Y enterocolitica infection and 41 clinically healthy blood donors. Some of the results obtained by ELISA and recom-dot were compared with results obtained by commercial western-blot Yersinia (Virotech). In the group of patients suspected for yersiniosis in clinical investigation the most positive results were obtained in ELISA with the recombinant protein YopD (IgA respectively 25 (42.4%), IgG 41 (69.5%), IgM 24 (40.7%). The percentage ofpositive results in the group of blood donors did not exceed 10.0% in IgG and 5.0% in IgA/IgM classes of immunoglobulin. The results obtained in the recom-dot assay showed that among 74 tested serum samples obtained from individuals suspected of yersiniosis the most common IgA, IgG and IgM antibodies were found for recombinant protein YopD (respectively IgG in 60.8%, IgA in 37.8% and IgM in 33.8% of serum samples). IgG antibodies to

Diagnostic Value of ELISA Tests for the Detection of Specific Antibodies in Cats and Rabbits with Dermatophytosis

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Marinka Drobnič-Košorok

2002-01-01

Full Text Available Two indirect ELISA tests developed for the detection of specific IgG in cats and rabbits, infected with M. canis and T. mentagrophytes, respectively, were evaluated and compared. The levels of specific antibodies were determined in sera of 20 cats and 25 rabbits naturally infected with M. canis and T. mentagrophytes, respectively. Infection was confirmed by the results of fungal culture. Blood samples from 12 cats and 17 rabbits, previously unexposed to dermatophytes, served as negative controls. A significant increase in the level of specific antibodies in groups of infected animals was demonstrated. Sensitivity, specificity and predictive values of a positive and a negative test were determined to evaluate the diagnostic potential. ELISA for the detection of specific antibodies in cats infected with M. canis (ELISA-cats test exhibited 75.0 % of sensitivity at 91.7 % of specificity, whereas the test for the detection of specific antibodies in rabbits, infected with T. mentagrophytes (ELISA-rabbits test is highly sensitive (96.0 % and highly specific (94.1 %, confirming its encouraging diagnostic potential. The cross-reactivity of fungal antigens was tested by performing the assays with antigens M. canis, T. mentagrophytes, M. pachydermatis and A. fumigatus. There were no significant indications of cross-reactions in the test T. mentagrophytes-rabbits, whereas strong cross-reaction between dermatophyte antigens was observed in the test M. canis-cats.

DEPIVIH 2: Use of three HIV testing methods in French primary care settings - ELISA laboratory screening versus two rapid point-of-care HIV tests.

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Papadima, D; Gauthier, R; Prévoteau du Clary, F; Bouée, S; Conort, G; Livrozet, J-M; Taulera, O; Wajsbrot, A; Majerholc, C; Peter, J-M; Aubert, J-P

2018-03-01

The primary endpoint was to evaluate the use of HIV testing methods by French primary care providers: Elisa laboratory screening, instant result HIV diagnostic test and rapid result HIV diagnostic test. The secondary endpoints were the population screening rate of unknown HIV status consulting during the study period, reasons for screening and for choosing the specific screening method, the investigators' satisfaction with the rapid diagnostic test (RDT) and problems encountered. National prospective interventional study with French family physicians (FP) from December 2013 to December 2014. FPs enrolled all consenting adults consulting for an HIV screening test during a 6-month period: the choice was an Elisa laboratory test or one of the two RDTs. During the study period, 43 FPs included 981 patients. HIV screening was performed for the first time for 31.6% of patients; 767 (78.2%) Elisa laboratory test prescriptions and 214 (21.8%) RDTs were performed, leading to a screening rate of 1.3%. For 120 (15.7%) of the Elisa laboratory tests, the result was not reported and six RDTs were not valid. Nine patients were diagnosed as HIV-infected (0.9%): five with Elisa laboratory test and four with RDT. Almost 90% of FPs were willing to keep on using RDTs in their daily practice. In general practice, RDTs may be an important additional tool to traditional HIV screening. They could account for one in five tests prescribed in this context. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

Protective roles of natural IgM antibodies

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Caroline eGrönwall

2012-04-01

Full Text Available Antibodies are a vital part of the armentarium of the adaptive immune system for the fine-tuning of the recognition and response to foreign threats. However, in health there are some types of antibodies that instead recognize self-antigens for the enhancement of primitive innate functions. The repertoire of natural IgM antibodies is postulated to have been selected during immune evolution for their contributions to critical immunoregulatory and housekeeping properties. The clearance of dying cells is one of the most essential responsibilities of the immune system, which is essential to prevent uncontrolled inflammation and autoimmunity. In the murine immune system, natural IgM antibodies that recognize apoptotic cells have been shown to enhance the phagocytic clearance of dead and dying cells and to suppress innate immune signaling pathways. In the mouse, natural IgM are often the products of B-1 cell clones that arise during immune development without an absolute requirement for exogenous antigenic stimulation. In patients with systemic lupus erythemtosus, IgM autoantibodies, which bind to neo-epitopes on apoptotic cells, have been demonstrated to be present at significantly higher levels in patients with lower disease activity and with less severe organ damage. While certain specificities of IgM autoantibodies correlate with protection from lupus renal disease, others may convey protective properties from lupus-associated atherosclerotic cardiovascular disease. New unexpected insights into the functional roles of IgM antibodies are still emerging, especially regarding the functions of natural antibodies. Herein, we review recent progress in our understanding of the potential roles of natural IgM autoantibodies in the regulation of immune homeostasis and for protection from autoimmune and inflammatory diseases.

Screening assays to find out late latent syphilis cases – which is the ...

African Journals Online (AJOL)

non-treponemal) such as Rapid Plasma Reagin (RPR), and specific (treponemal) such as Treponema pallidum hemagglutination test (TPHA) and Enzyme-linked immunosorbent assay IgG, IgM (ELISA IgG, IgM) tests. The aim of this ...

Hyper IgM Syndrome with low IgM and thrombocytosis: an unusual case of immunodeficiency.

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Yousef, Ejaz; Arshad Alvi, M

2016-09-01

We report a 5 years old male child with low serum IgG, IgA and IgM levels, who presented with recurrent perianal and oral ulcers, intermittent fever, and protracted diarrhea. Despite the lack of typical respiratory symptoms, low serum IgM level and persistent thrombocytosis, an X-linked hyper-IgM syndrome (X-HIGM) was considered. Laboratory investigations revealed a diagnosis of hyper-IgM syndrome caused by CD40L deficiency.

Dot-ELISA-IgM in saliva for the diagnosis of human leptospirosis using polyester fabric-resin as support (Preliminary Report Dot-ELISA-IgM em saliva para diagnóstico da leptospirose humana, empregando como suporte tecido de poliéster-resina (Nota Prévia

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Marcos Vinicius da Silva

1994-10-01

Full Text Available In order to improve the diagnosis of human leptospirosis, we standardized the dot-ELISA for the search of specific IgM antibodies in saliva. Saliva and serum samples were collected simultaneously from 20 patients with the icterohemorrhagic form of the disease, from 10 patients with other pathologies and from 5 negative controls. Leptospires of serovars icterohaemorrhagiae, canicola, hebdomadis, brasiliensis and cynopteri grown in EMJH medium and mixed together in equal volumes, were used as antigen at individual protein concentration of 0.2 µg/µl. In the solid phase of the test we used polyester fabric impregnated with N-methylolacrylamide resin. The antigen volume for each test was 1µl, the saliva volume was 8 µl, and the volume of peroxidase-labelled anti-human IgM conjugate was 30 µl. A visual reading was taken after development in freshly prepared chromogen solution. In contrast to the classic nitrocellulose membrane support, the fabric support is easy to obtain and to handle. Saliva can be collected directly onto the support, a fact that facilitates the method and reduces the expenses and risks related to blood processing.Com a finalidade de melhorar o diagnóstico da leptospirose humana, padronizou-se o teste dot-ELISA para a pesquisa de anticorpos específicos da classe IgM na saliva. Empregaram-se amostras de saliva e soro coletadas simultaneamente de 20 pacientes com a forma ictero-hemorrágica da doença, de 10 pacientes com outras patologias e 5 controles negativos. Culturas de Leptos-pira em meio EMJH, dos sorovares: icterohaemorrhagiae, canicola, hebdomadis, brasiliensis e cynopteri, foram utilizadas como antígeno, na concentração proteica individual de 0,2 µg/µl, misturadas em volumes iguais. Na fase sólida do teste empregou-se tecido de po-liéster impregnado com resina de N-metilol-acrilamida. O volume do antígeno para cada teste foi de 1µl, o de saliva 8µl, o de conjugado anti-IgM humana marcada com peroxidase, de

Primary cytomegalovirus infection in pregnant Egyptian women confirmed by cytomegalovirus IgG avidity testing.

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Kamel, N; Metwally, L; Gomaa, N; Sayed Ahmed, W A; Lotfi, M; Younis, S

2014-01-01

To determine the frequency of primary cytomegalovirus (CMV) infection in pregnant Egyptian women using CMV IgG avidity testing. A cross-sectional study was conducted at Suez Canal University Hospital, Ismailia, Egypt. A total of 546 pregnant women, presenting for routine antenatal screening, were tested for CMV IgG and IgM using a commercially available enzyme-linked immunosorbent assay (ELISA). Sera from CMV IgM-positive women were tested by CMV IgG avidity assay. All the 546 pregnant women were seropositive for anti-CMV IgG. Of the 546 women, 40 (7.3%) were positive or equivocal for IgM antibodies. All sera from the 40 women (IgG+/IgM+) showed a high or intermediate CMV IgG avidity index. Of the 40 women, 23 (57.5%) were in the second or third trimesters of pregnancy and had their first-trimester blood retrieved, and the tested CMV IgG avidity assay showed a high avidity index. Women who were IgM positive had no primary CMV infection in the index pregnancy as evidenced by the high CMV IgG avidity testing. © 2013 S. Karger AG, Basel.

Human Secretory IgM Antibodies Activate Human Complement and Offer Protection at Mucosal Surface.

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Michaelsen, T E; Emilsen, S; Sandin, R H; Granerud, B K; Bratlie, D; Ihle, O; Sandlie, I

2017-01-01

IgM molecules circulate in serum as large polymers, mainly pentamers, which can be transported by the poly-Ig receptor (pIgR) across epithelial cells to mucosal surfaces and released as secretory IgM (SIgM). The mucosal SIgM molecules have non-covalently attached secretory component (SC), which is the extracellular part of pIgR which is cleaved from the epithelial cell membrane. Serum IgM antibodies do not contain SC and have previously been shown to make a conformational change from 'a star' to a 'staple' conformation upon reaction with antigens on a cell surface, enabling them to activate complement. However, it is not clear whether SIgM similarly can induce complement activation. To clarify this issue, we constructed recombinant chimeric (mouse/human) IgM antibodies against hapten 5-iodo-4-hydroxy-3-nitro-phenacetyl (NIP) and in addition studied polyclonal IgM formed after immunization with a meningococcal group B vaccine. The monoclonal and polyclonal IgM molecules were purified by affinity chromatography on a column containing human SC in order to isolate joining-chain (J-chain) containing IgM, followed by addition of excess amounts of soluble SC to create SIgM (IgM J+ SC+). These SIgM preparations were tested for complement activation ability and shown to be nearly as active as the parental IgM J+ molecules. Thus, SIgM may offer protection against pathogens at mucosal surface by complement-mediated cell lysis or by phagocytosis mediated by complement receptors present on effector cells on mucosa. © 2016 The Foundation for the Scandinavian Journal of Immunology.

Autoimmunity related to IgM monoclonal gammopathy of undetermined significance. Peripheral neuropathy and connective tissue sensibilization caused by IgM M-proteins

DEFF Research Database (Denmark)

Jønsson, V; Schrøder, H D; Nolsøe, C

1988-01-01

of them, including two siblings with a demyelinating peripheral neuropathy, the IgM was bound to the myelin-associated glycoprotein (MAG) of peripheral nerves. One had axonal neuropathy with IgM activity against the peri- and endoneurium, while another case with post-infectious neuritis had IgM activity......In eight of 10 consecutive cases of IgM monoclonal gammopathy of undetermined significance (MGUS), the M-protein had specificity towards various tissues as estimated by direct and indirect immunofluorescence studies of skin and/or sural nerve biopsies. Five of the cases had neuropathy. In three...

Unreliability of three commercial Coxiella burnetii phase II IgM ELISA kits for the seroscreening of acute Q fever in human cases

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Selvaraj Stephen

2017-01-01

Interpretation & conclusions: The three different ELISA kits exhibited poor agreement amongst them and unacceptable level of false positivity. IFA remains to be the only option for diagnosing acute QF. Discrepancy between the clinical findings and IFA/ELISA results needs confirmation by C. burnetii DNA detection in real-time polymerase chain reaction.

Influence of the cerebrospinal fluid laboratory parameters in the ELISA test for neurocysticercosis using a total cysticerci antigen Influência dos parâmetros laboratoriais do líquido cefalorraquidiano no teste ELISA para neurocisticercose utilizando antígeno total de cisticerco

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Cristiane S. Casanova

2006-03-01

Full Text Available To evaluate if the cerebrospinal fluid (CSF parameters may influence the cysticercosis immunoreactivity response in the CSF. CSF samples of 109 patients were analyzed and classified in three groups, according to the neurological manifestations and the reactivity in antibody-enzyme linked immunosorbent assay (Ab-ELISA testing in CSF for neurocysticercosis (NC: group A, 18 patients with neurological disorders compatible with NC and reactive Ab-ELISA in CSF for NC; group B, 50 patients with neurological disorders non-compatible with NC and reactive Ab-ELISA for NC; group C, 41 patients with neurological disorders non-compatible with NC and non-reactive Ab-ELISA in CSF for NC. The CSF analysis in group A was compatible with NC. The group B in comparison to the groups A and C presents higher frequency and intensity of hypercytosis, presence of red blood cells in CSF, protein concentration and immunological reactive test for other etiological agents (pAvaliar se os parâmetros do líquido cefalorraquidiano (LCR podem influenciar na reatividade da resposta imune específica do LCR na neurocisticercose (NC. Amostras de LCR de 109 pacientes foram analisadas e classificadas em três grupos, de acordo com as manifestações neurológicas e reatividade do teste de Ab-ELISA para NC no LCR. Grupo A, 18 pacientes com enfermidades neurológicas compatíveis com NC e reatividade do teste Ab-ELISA para NC no LCR; grupo B, 50 pacientes com enfermidades neurológicas não compatíveis com NC e reatividade do teste Ab-ELISA para NC no LCR; grupo C, 41 pacientes com enfermidades neurológicas não compatíveis com NC e na ausência de reatividade do teste de Ab-ELISA para NC no LCR. A análise do LCR do grupo A foi compatível com NC. O grupo B apresentou maior freqüência e intensidade da pleocitose, da presença de hemácias no LCR, hiperproteinorraquia, reatividade imune para outros agentes etiológicos em comparação aos grupos A e C (p<0.05. Os dados indicam

[Detection of cerebrospinal fluid anti-enterovirus 71 IgM in children with severe hand, food and mouth disease induced by enterovirus 71 infection and its clinical significance].

Science.gov (United States)

Wu, Yidong; Chen, Dong; Zhou, Jun; Wang, Jie; Zhao, Shiyong; Shao, Qimin; Wei, Yi

2015-05-01

To detect the anti-enterovirus 71 (EV71) IgM level in cerebrospinal fluid (CSF) of children with severe hand, foot and mouth disease (HFMD) induced by EV71 and then analyze the relationships among the IgM antibody levels, CSF routine examination and patients' clinical features, and thus to evaluate the clinical significance of anti-EV71 IgM as a new indicator for early diagnosis of children with severe HFMD induced by EV71. A total of 294 laboratory-confirmed cases of children with severe HFMD infected with EV71 were enrolled into the research group from March 2014 to June 2014, consisting of 53 fatal cases and 241 severe cases, and their CSF samples underwent enzyme-linked immunosorbent assay (ELISA) for anti-EV71 IgM levels, CSF routine and biochemical tests. Forty-one cases of children with severe HFMD induced by other enteroviruses were collected as antibody-testing control group during the same period. In the research group, the total positive rate of anti-EV71 IgM in 294 CSF samples of children with severe HFMD infected by EV71 was 60.2% (177/294); the positive rate of anti-EV71 IgM in the fatal HFMD subgroup was 62.3% (33/53); the positive rate of anti-EV71 IgM in the severe HFMD subgroup was 59.8% (144/241). In the control group, the results of CSF anti-EV71 IgM tests were all negative (0/41). In the research group, patients in antibody-positive subgroup (2.5±1.2) years old were younger than those in antibody-negative subgroup (2.9±1.1) years old (t=2.595, P=0.010). And within the antibody-positive subgroup, the patients ((1.9±0.7) years old) with fatal type disease were younger than those ((2.6±1.2) years old) with severe type disease (t=3.150, P=0.002). The CSF nucleated cells count and positive rates (105 (56,180) ×10(6) /L; 97.7% (173/177)) in antibody-positive subgroup were higher than those (62(30,150) ×10(6) /L; 83.8% (98/117)) in antibody-negative subgroup (Z=3.663, P=0.000; χ(2)=19.089, P=0.000). In antibody-positive subgroup, the percentage

Bulk tank milk ELISA for detection of antibodies to Mycobacterium avium subsp paratuberculosis: Correlation between repeated tests and within-herd antibody-prevalence

DEFF Research Database (Denmark)

Nielsen, Søren Saxmose; Toft, Nils

2014-01-01

Detection of bulk tank milk (BTM) antibodies using ELISA (BTM-ELISA) may constitute an inexpensive test for surveillance of Mycobacterium avium subsp. paratuberculosis (MAP) infection in dairy cattle herds provided that the test is accurate and consistent. The objectives of this study were...... Danish Holstein herds over a period of one year. All samples were tested using a commercial indirect ELISA for detection of MAP specific antibodies. The individual cow's results were dichotomised and used to estimate the within-herd antibody prevalence at each test-date. These prevalences were...... to 0.60 when corrected for the within-herd antibody prevalence. Although the test-results were relatively consistent and correlated with the within-herd prevalence, the magnitude of the test-values makes it difficult to use the BTM-ELISA for surveillance of MAP infections in practice....

Comparison of the Hemagglutination Inhibition Test and IgG ELISA in Categorizing Primary and Secondary Dengue Infections Based on the Plaque Reduction Neutralization Test

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Nurhayati Lukman

2016-01-01

Full Text Available Secondary dengue infection by heterotypic serotypes is associated with severe manifestations of disease, that is, dengue hemorrhagic fever (DHF and dengue shock syndrome (DSS. The World Health Organization (WHO has recommended criteria based on the hemagglutination inhibition (HI test to distinguish between primary and secondary dengue infections. Since the HI test has practical limitations and disadvantages, we evaluated the accuracy of WHO HI criteria and compared it with criteria based on an IgG enzyme-linked immunosorbent assay (ELISA using a plaque reduction neutralization test (PRNT as the gold standard. Both WHO HI criteria and IgG ELISA criteria performed strongly (16/16 in determining primary infection. However, to determine secondary infection, the IgG ELISA criteria performed better (72/73 compared to the WHO HI criteria (23/73.

Determination of cutoff of ELISA and immunofluorescence assay for scrub typhus

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Nitin Gupta

2016-01-01

Full Text Available Background: The most common method employed for diagnosis of scrub typhus is serology. It is widely known that demonstration of ≥4-fold rise in titers of antibody in paired sera is required for diagnosis. However, for guidance of initial treatment, there is a need for rapid diagnosis at the time of admission. Therefore, there is a need for standardized region specific cutoff titers at the time of admission. Materials and Methods: A total of 258 patients of all age groups with clinically suspected scrub typhus over a period of 24 months (October 2013-October 2015 were enrolled. Serum samples of these patients were subjected to immunofluorescent antibody (IFA for immunoglobulin M (IgM (Fuller Labs, USA with dilutions of 1:64, 1:128, 1:256, and 1:512. Serum samples of all 258 patients were subjected to IgM ELISA (Inbios Inc., USA. Any patient with response to antibiotics within 48 h accompanied by either presence of an eschar or positivity by polymerase chain reaction was taken as positive. Receiver operating characteristic (ROC curve was drawn to generate cutoff for these tests. Results: A total of 20 patients were diagnosed as cases of scrub typhus. The ROC curve analysis revealed a cutoff optical density value of 0.87 with sensitivity and specificity of 100% and 94.12%, respectively. ROC curve analysis of IFA revealed sensitivity and specificity of 100% and 93.5%, respectively at 1:64 dilution. Conclusion: Considering cost constraints, centers in and around New Delhi region can use the cutoffs we determined for the diagnosis of scrub typhus.

Direct Competitive Enzyme-Linked Immunosorbent Assay (ELISA).

Science.gov (United States)

Kohl, Thomas O; Ascoli, Carl A

2017-07-05

The competitive enzyme-linked immunosorbent assay (ELISA) (cELISA; also called an inhibition ELISA) is designed so that purified antigen competes with antigen in the test sample for binding to an antibody that has been immobilized in microtiter plate wells. The same concept works if the immobilized molecule is antigen and the competing molecules are purified labeled antibody versus antibody in a test sample. Direct cELISAs incorporate labeled antigen or antibody, whereas indirect assay configurations use reporter-labeled secondary antibodies. The cELISA is very useful for determining the concentration of small-molecule antigens in complex sample mixtures. In the direct cELISA, antigen-specific capture antibody is adsorbed onto the microtiter plate before incubation with either known standards or unknown test samples. Enzyme-linked antigen (i.e., labeled antigen) is also added, which can bind to the capture antibody only when the antibody's binding site is not occupied by either the antigen standard or antigen in the test samples. Unbound labeled and unlabeled antigens are washed away and substrate is added. The amount of antigen in the standard or the test sample determines the amount of reporter-labeled antigen bound to antibody, yielding a signal that is inversely proportional to antigen concentration within the sample. Thus, the higher the antigen concentration in the test sample, the less labeled antigen is bound to the capture antibody, and hence the weaker is the resultant signal. © 2017 Cold Spring Harbor Laboratory Press.

Application of anti-leptospira ELISA-lgM for the etiologic elucidation of meningitis Aplicação do ELISA-IgM anti-leptospira na elucidação etiológica das meningites

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Marcos V Silva

1996-04-01

Full Text Available Leptospirosis is one of the causes of meningitis, although its importance is not well known. In the present study we contributed to this knowledge by demonstrating specific IgM class anti-leptospira antibodies by the immunoenzymatic method ELISA in 14.6% of cerebrospinal fluid (CSF samples from 171 patients with meningitis considered to be of indeterminate etiology. The frequencies of positivity were similar in cases with predominance of polymorphonuclear or lymphomononuclear leucocytes in the CSF. Age distribution showed a predominance of the 5 to 15 year age range (72%, and sex distribution showed a predominance of males (68%. The authors discuss the contribution of this method to the etiologic elucidation of meningitis.A Leptospirose é uma das causas de meningite, embora sua importância seja pouco conhecida. O presente estudo contribui para este conhecimento ao demonstrar anticorpos específicos da classe IgM anti-Leptospira pelo método imunoenzimático (ELISA, em 14,6% das amostras de líqüido cefalorraquianos (LCR de 171 pacientes com meningite considerada de etiología indeterminada. As freqüências de positividade foram parecidas nos casos com predomínio no LCR de leucócitos polimorfonucleares ou linfomononucleares. A distribuição por idade mostrou predomínio na faixa etária entre 5 e 15 anos (72% e por sexo o predomínio do masculino (68%. Os autores discutem a contribuição desse método na elucidação etiológica das meningites.

Presence of Mycoplasma fermentans in the bloodstream of Mexican patients with rheumatoid arthritis and IgM and IgG antibodies against whole microorganism

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Salinas Salvador

2009-08-01

Full Text Available Abstract Background Increasing evidence incriminates bacteria, especially Mycoplasma fermentans, as possible arthritogenic agents in humans. The purpose of this study was to investigate M. fermentans in the bloodstream of patients with rheumatoid arthritis. Methods Two hundred and nineteen blood samples from patients with rheumatoid arthritis, systemic lupus erythematosus, antiphospholipid syndrome, and healthy individuals were screened by bacterial culture and direct PCR in order to detect mycoplasmas; IgM and IgG against M. fermentans PG18 were also detected by ELISA and Immunoblotting assays in patients with rheumatoid arthritis and healthy individuals. Results Blood samples from patients with antiphospholipid syndrome and healthy individuals were negative for mycoplasma by culture or direct PCR. In blood samples from patients with systemic lupus erythematosus were detected by direct PCR M. fermentans in 2/50 (2%, M. hominis in 2/50 (2% and U. urealyticum in 1/50 (0.5%. In patients with RA M. fermentans was detected by culture in 13/87 blood samples and in 13/87 by direct PCR, however, there was only concordance between culture and direct PCR in six samples, so M. fermentans was detected in 20/87(23% of the blood samples from patients with RA by either culture or PCR. Antibody-specific ELISA assay to M. fermentans PG18 was done, IgM was detected in sera from 40/87 patients with RA and in sera of 7/67 control individuals, IgG was detected in sera from 48/87 RA patients and in sera from 7/67 healthy individuals. Antibody-specific immunoblotting to M. fermentans PG18 showed IgM in sera from 35/87 patients with RA and in sera from 4/67 healthy individuals, IgG was detected in sera from 34/87 patients and in sera from 5/67 healthy individuals. Conclusion Our findings show that only M. fermentans produce bacteremia in a high percentage of patients with RA. This finding is similar to those reported in the literature. IgM and IgG against M

Comparison of Rubazyme-M and MACRIA for the detection of rubella-specific IgM

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Best, J.M.; Palmer, S.J.; Morgan-Capner, P.; Hodgson, J. (Saint Thomas' Hospital, London (UK))

1984-02-01

One hundred and eighty-six carefully selected sera were tested for rubella-specific IgM by Rubazyme-M (Abbott Diagnostics) and an M-antibody capture radioimmunoassay (MACRIA). Eleven of these sera were from cases of infectious mononucleosis, six of which gave positive results in MACRIA, while one gave a positive result in Rubazyme-M. Of the remaining 175 sera, 158 gave concordant results whilst 17 sera gave discordant results; these 17 were also tested by serum fractionation. Problems were encountered with all assay systems used. It is therefore recommended that the results of all tests for rubella-specific IgM should be interpreted with caution.

Interpolation of the magnetic field at the test masses in eLISA

International Nuclear Information System (INIS)

Mateos, I; Díaz-Aguiló, M; Ramos-Castro, J; García-Berro, E; Lobo, A

2015-01-01

A feasible design for a magnetic diagnostics subsystem for eLISA will be based on that of its precursor mission, LISA Pathfinder. Previous experience indicates that magnetic field estimation at the positions of the test masses has certain complications. This is due to two reasons. The first is that magnetometers usually back-act due to their measurement principles (i.e., they also create their own magnetic fields), while the second is that the sensors selected for LISA Pathfinder have a large size, which conflicts with space resolution and with the possibility of having a sufficient number of them to properly map the magnetic field around the test masses. However, high-sensitivity and small-sized sensors that significantly mitigate the two aforementioned limitations exist, and have been proposed to overcome these problems. Thus, these sensors will be likely selected for the magnetic diagnostics subsystem of eLISA. Here we perform a quantitative analysis of the new magnetic subsystem, as it is currently conceived, and assess the feasibility of selecting these sensors in the final configuration of the magnetic diagnostic subsystem. (paper)

Diagnosis of gastritis caused by Helicobacter pylori in children by means of an ELISA.

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Czinn, S J; Carr, H S; Speck, W T

1991-01-01

In this study, the systemic immune response to bacterial cell sonicates of Helicobacter pylori was characterized in children with symptomatic gastroduodenal disease. Isotype-specific antibodies to H. pylori in samples of serum from 16 children with culture-proven disease caused by H. pylori and from 19 controls with negative cultures were measured by ELISA with bacterial cell lysates. The levels in serum of IgA antibody to cell sonicates of H. pylori were significantly higher in the patients with positive cultures than in the controls. Only 45% of patients were infected when the established optical density cutoff was used to discriminate between patients infected and not infected with H. pylori. Levels of IgM antibody in serum were not significantly higher in patients who were infected with H. pylori. On the basis of this survey and of previous work conducted in our laboratory, we conclude that at a serum dilution of 1:800, IgG but not IgA or IgM antibody to H. pylori is useful in the rapid screening of symptomatic children for the presence of H. pylori.

Effect of irradiation on T-cell suppression of ELISA-determined Ig production by human blood B-cells in vitro

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Wasserman, J; Stedingk, L.V. von; Biberfeld, G; Petrini, B; Blomgren, H; Baral, E [Central Microbiologcal Lab. of Stockholm County Council (Sweden)

1979-11-01

Human blood B-lymphocytes were co-cultured with in vitro irradiated allogeneic or autologous T-lymphocytes in the presence of pokeweed mitogen (PWM). The production of IgG, IgM and IgA, as assessed by the enzyme-linked immunosorbent assay (ELISA) was increased 2-7 times, as compared to values obtained with non-irradiated T-lymphocytes. It was suggested that the increase of Ig production was due to the selective radiosensitivity of T-lymphocytes with suppressor function. (author).

Toxoplasmosis serology: an efficient hemagglutination procedure to detect IgG and IgM antibodies

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M.E. Camargo

1989-08-01

Full Text Available In search of an efficient but simple, low cost procedure for the serodiagnosis of Toxoplasmosis, especially suited for routine laboratories facing technical and budget limitations as in less developed countries, the diagnostic capability of Hematoxo® , an hemagglutination test for toxoplasmosis, was evaluated in relation to a battery of tests including IgG- and IgM-immunofluorescence tests, hemagglutination and an IgM-capture enzymatic assay. Detecting a little as 5 I.U. of IgG antitoxoplasma antibodies, Hematoxo® showed a straight agreement as to reactivity and non-reactivity for the 443 non-reactive and the 387 reactive serum samples, included in this study. In 23 cases presenting a serological pattern of acute toxoplasmosis and showing IgM antibodies, Hematoxo® could detect IgM antibodies in 18, indicated by negativation or a significant decrease in titers as a result of treating samples with 2-mercapto-ethanol. However, a neat increase in sensitivity for IgM specific antibodies could be achieved by previously removing IgG from the sample, as demonstrated in a series of acute toxoplasmosis sera. A simple procedure was developed for this purpose, by reconstituting a lyophilized suspension of Protein A - rich Staphylococcus with the lowest serum dilution to be tested. Of low cost and easy to perform, Hematoxo® affords not only a practical qualitative procedure for screening reactors and non-reactors, as in prenatal services, but also quantitative assays that permit to titrate antibodies as well as to identify IgM antibodies.

Pre-cut Filter Paper for Detecting Anti-Japanese Encephalitis Virus IgM from Dried Cerebrospinal Fluid Spots.

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Bharucha, Tehmina; Chanthongthip, Anisone; Phuangpanom, Soumphou; Phonemixay, Ooyanong; Sengvilaipaseuth, Onanong; Vongsouvath, Manivanh; Lee, Sue; Newton, Paul N; Dubot-Pérès, Audrey

2016-03-01

The use of filter paper as a simple, inexpensive tool for storage and transportation of blood, 'Dried Blood Spots' or Guthrie cards, for diagnostic assays is well-established. In contrast, there are a paucity of diagnostic evaluations of dried cerebrospinal fluid (CSF) spots. These have potential applications in low-resource settings, such as Laos, where laboratory facilities for central nervous system (CNS) diagnostics are only available in Vientiane. In Laos, a major cause of CNS infection is Japanese encephalitis virus (JEV). We aimed to develop a dried CSF spot protocol and to evaluate its diagnostic performance using the World Health Organisation recommended anti-JEV IgM antibody capture enzyme-linked immunosorbent assay (JEV MAC-ELISA). Sample volumes, spotting techniques and filter paper type were evaluated using a CSF-substitute of anti-JEV IgM positive serum diluted in Phosphate Buffer Solution (PBS) to end-limits of detection by JEV MAC-ELISA. A conventional protocol, involving eluting one paper punch in 200 μl PBS, did not detect the end-dilution, nor did multiple punches utilising diverse spotting techniques. However, pre-cut filter paper enabled saturation with five times the volume of CSF-substitute, sufficiently improving sensitivity to detect the end-dilution. The diagnostic accuracy of this optimised protocol was compared with routine, neat CSF in a pilot, retrospective study of JEV MAC-ELISA on consecutive CSF samples, collected 2009-15, from three Lao hospitals. In comparison to neat CSF, 132 CSF samples stored as dried CSF spots for one month at 25-30 °C showed 81.6% (65.7-92.3 95%CI) positive agreement, 96.8% (91.0-99.3 95%CI) negative agreement, with a kappa coefficient of 0.81 (0.70-0.92 95%CI). The novel design of pre-cut filter paper saturated with CSF could provide a useful tool for JEV diagnostics in settings with limited laboratory access. It has the potential to improve national JEV surveillance and inform vaccination policies. The

Pre-cut Filter Paper for Detecting Anti-Japanese Encephalitis Virus IgM from Dried Cerebrospinal Fluid Spots.

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Tehmina Bharucha

2016-03-01

Full Text Available The use of filter paper as a simple, inexpensive tool for storage and transportation of blood, 'Dried Blood Spots' or Guthrie cards, for diagnostic assays is well-established. In contrast, there are a paucity of diagnostic evaluations of dried cerebrospinal fluid (CSF spots. These have potential applications in low-resource settings, such as Laos, where laboratory facilities for central nervous system (CNS diagnostics are only available in Vientiane. In Laos, a major cause of CNS infection is Japanese encephalitis virus (JEV. We aimed to develop a dried CSF spot protocol and to evaluate its diagnostic performance using the World Health Organisation recommended anti-JEV IgM antibody capture enzyme-linked immunosorbent assay (JEV MAC-ELISA.Sample volumes, spotting techniques and filter paper type were evaluated using a CSF-substitute of anti-JEV IgM positive serum diluted in Phosphate Buffer Solution (PBS to end-limits of detection by JEV MAC-ELISA. A conventional protocol, involving eluting one paper punch in 200 μl PBS, did not detect the end-dilution, nor did multiple punches utilising diverse spotting techniques. However, pre-cut filter paper enabled saturation with five times the volume of CSF-substitute, sufficiently improving sensitivity to detect the end-dilution. The diagnostic accuracy of this optimised protocol was compared with routine, neat CSF in a pilot, retrospective study of JEV MAC-ELISA on consecutive CSF samples, collected 2009-15, from three Lao hospitals. In comparison to neat CSF, 132 CSF samples stored as dried CSF spots for one month at 25-30 °C showed 81.6% (65.7-92.3 95%CI positive agreement, 96.8% (91.0-99.3 95%CI negative agreement, with a kappa coefficient of 0.81 (0.70-0.92 95%CI.The novel design of pre-cut filter paper saturated with CSF could provide a useful tool for JEV diagnostics in settings with limited laboratory access. It has the potential to improve national JEV surveillance and inform vaccination

Evaluation of Selected Borrelia burgdorferi lp54 Plasmid-Encoded Gene Products Expressed during Mammalian Infection as Antigens To Improve Serodiagnostic Testing for Early Lyme Disease

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Weiner, Zachary P.; Crew, Rebecca M.; Brandt, Kevin S.; Ullmann, Amy J.; Schriefer, Martin E.; Molins, Claudia R.

2015-01-01

Laboratory testing for the diagnosis of Lyme disease is performed primarily by serologic assays and is accurate for detection beyond the acute stage of the infection. Serodiagnostic assays to detect the early stages of infection, however, are limited in their sensitivity, and improvement is warranted. We analyzed a series of Borrelia burgdorferi proteins known to be induced within feeding ticks and/or during mammalian infection for their utility as serodiagnostic markers against a comprehensive panel of Lyme disease patient serum samples. The antigens were assayed for IgM and IgG reactivity in line immunoblots and separately by enzyme-linked immunosorbent assay (ELISA), with a focus on reactivity against early Lyme disease with erythema migrans (EM), early disseminated Lyme neuroborreliosis, and early Lyme carditis patient serum samples. By IgM immunoblotting, we found that recombinant proteins BBA65, BBA70, and BBA73 reacted with early Lyme EM samples at levels comparable to those of the OspC antigen used in the current IgM blotting criteria. Additionally, these proteins reacted with serum samples from patients with early neuroborreliosis and early carditis, suggesting value in detecting early stages of this disease progression. We also found serological reactivity against recombinant proteins BBA69 and BBA73 with early-Lyme-disease samples using IgG immunoblotting and ELISA. Significantly, some samples that had been scored negative by the Centers for Disease Control and Prevention-recommended 2-tiered testing algorithm demonstrated positive reactivity to one or more of the antigens by IgM/IgG immunoblot and ELISA. These results suggest that incorporating additional in vivo-expressed antigens into the current IgM/IgG immunoblotting tier in a recombinant protein platform assay may improve the performance of early-Lyme-disease serologic testing. PMID:26376927

Evaluation of Selected Borrelia burgdorferi lp54 Plasmid-Encoded Gene Products Expressed during Mammalian Infection as Antigens To Improve Serodiagnostic Testing for Early Lyme Disease.

Science.gov (United States)

Weiner, Zachary P; Crew, Rebecca M; Brandt, Kevin S; Ullmann, Amy J; Schriefer, Martin E; Molins, Claudia R; Gilmore, Robert D

2015-11-01

Laboratory testing for the diagnosis of Lyme disease is performed primarily by serologic assays and is accurate for detection beyond the acute stage of the infection. Serodiagnostic assays to detect the early stages of infection, however, are limited in their sensitivity, and improvement is warranted. We analyzed a series of Borrelia burgdorferi proteins known to be induced within feeding ticks and/or during mammalian infection for their utility as serodiagnostic markers against a comprehensive panel of Lyme disease patient serum samples. The antigens were assayed for IgM and IgG reactivity in line immunoblots and separately by enzyme-linked immunosorbent assay (ELISA), with a focus on reactivity against early Lyme disease with erythema migrans (EM), early disseminated Lyme neuroborreliosis, and early Lyme carditis patient serum samples. By IgM immunoblotting, we found that recombinant proteins BBA65, BBA70, and BBA73 reacted with early Lyme EM samples at levels comparable to those of the OspC antigen used in the current IgM blotting criteria. Additionally, these proteins reacted with serum samples from patients with early neuroborreliosis and early carditis, suggesting value in detecting early stages of this disease progression. We also found serological reactivity against recombinant proteins BBA69 and BBA73 with early-Lyme-disease samples using IgG immunoblotting and ELISA. Significantly, some samples that had been scored negative by the Centers for Disease Control and Prevention-recommended 2-tiered testing algorithm demonstrated positive reactivity to one or more of the antigens by IgM/IgG immunoblot and ELISA. These results suggest that incorporating additional in vivo-expressed antigens into the current IgM/IgG immunoblotting tier in a recombinant protein platform assay may improve the performance of early-Lyme-disease serologic testing. Copyright © 2015, American Society for Microbiology. All Rights Reserved.

Catalytic properties of IgMs with amylolytic activity isolated from patients with multiple sclerosis.

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Ivanen, Dina R; Kulminskaya, Anna A; Shabalin, Konstantin A; Isaeva-Ivanova, Luydmila V; Ershova, Nadezhda A; Saveliev, Andrew N; Nevinsky, Gregory A; Neustroev, Kirill N

2004-08-01

Recently, amylolytic activity was detected in IgMs isolated from the sera of the patients with multiple sclerosis. All purified samples of IgM were electrophoretically homogenous and did not contain any co-purified a-amylase and a-glucosidase activities, in accordance with a set of criteria developed for abzymes. The amylolytic activity of abzymes was studied in the hydrolysis of p-nitrophenyl a-D-maltooligosaccharides with different degrees of polymerization from 1 to 8 by TLC and reverse-phase HPLC techniques. All IgM samples isolated from 54 patients with clinically definite multiple sclerosis demonstrated hydrolytic activity towards the above artificial substrates. The Michaelis constant values (Km) in the hydrolysis of p-nitrophenyl a-D-maltoheptaoside were in the range of 10 p-nitrophenyl or p-nitrophenyl a-D-glucosides, thus indicating the presence of an a-D-glucosidase activity. For a number of the investigated samples, specific amylolytic activity increased depending on the length of substrates (from p-nitrophenyl maltopentaoside to p-nitrophenyl maltohexaoside); for other IgMs, the opposite dependence was observed. All IgMs studied did not exhibit any other glycoside hydrolase activities toward p-nitrophenyl glycoside substrates. Abzyme fractions from different donors demonstrated catalytic heterogeneity in Michaelis-Menten parameters and different modes of action in the hydrolysis of p-nitrophenyl maltooligosaccharides. Enzymatic properties of the IgMs tested varied from human a-amylases. All investigated abzyme samples did not show transglycosylating ability.

A comparison of Rubazyme-M and MACRIA for the detection of rubella-specific IgM

International Nuclear Information System (INIS)

Best, J.M.; Palmer, S.J.; Morgan-Capner, P.; Hodgson, J.

1984-01-01

One hundred and eighty-six carefully selected sera were tested for rubella-specific IgM by Rubazyme-M (Abbott Diagnostics) and an M-antibody capture radioimmunoassay (MACRIA). Eleven of these sera were from cases of infectious mononucleosis, six of which gave positive results in MACRIA, while one gave a positive result in Rubazyme-M. Of the remaining 175 sera, 158 gave concordant results whilst 17 sera gave discordant results; these 17 were also tested by serum fractionation. Problems were encountered with all assay systems used. It is therefore recommended that the results of all tests for rubella-specific IgM should be interpreted with caution. (Auth.)

Teste de ELISA indireto para diagnóstico sorológico de leishmaniose visceral em canídeos silvestres Indirect ELISA for the serological diagnosis of visceral leishmaniasis in wild canids

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Paulo R.B. Ferreira

2013-04-01

Full Text Available Na América do Sul, alguns canídeos silvestres são considerados reservatórios naturais da Leishmania chagasi. A resposta imunológica desses animais à Leishmania é pouco conhecida, havendo a necessidade de métodos diagnósticos adequados para esse fim. No presente estudo, é descrita a padronização do ensaio imunoenzimático indireto (ELISA para o diagnóstico sorológico de leishmaniose visceral em canídeos silvestres brasileiros. Foram estudadas amostras de soro e plasma de 12 canídeos cativos: sete lobos-guará (Chrysocyon brachyurus, três raposinhas (Lycalopex vetulus e dois cachorros-do-mato (Cerdocyon thous. As amostras de um C. brachyurus e uma L. vetulus, cativos em área endêmica para LV, que apresentavam doença clínica e positividade em testes de Imunofluorescência Indireta e Reação em Cadeia de Polimerase, foram utilizadas como controles positivos. Foram comparados os conjugados anti-IgG de cão e proteína A, ambos ligados a peroxidase, cujos testes detectaram quatro (04/12 e três (03/12 C. brachyurus soropositivos para anticorpos anti-Leishmania sp., respectivamente. As médias das densidades ópticas (DOs das amostras negativas foram nitidamente mais baixas do que as médias das DOs dos positivos tanto no ELISA com anti-IgG de cão (4,8 vezes como com proteína A (15,5 vezes. Os soros de três C. brachyurus positivos no ELISA indireto foram avaliados por Western blotting e identificaram 22 bandas, sendo imunodominantes as de peso molecular de 19, 22, 24, 45 e 66 kDa. Os testes ELISA com a proteína A e o conjugado anti-IgG de cão apresentaram respectivamente concordância excelente (Kappa = 1; pIn South America, some wild canids are considered natural reservoirs of Leishmania chagasi. The immunological response of wild canids to Leishmania is not well understood, and the development of diagnostic methods is necessary for such purpose. In the present study, the standardization of an enzyme-linked immunosorbent

Elisa Miller | NREL

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Elisa Miller Photo of Elisa Miller Elisa Link-Miller Researcher III-Chemistry Elisa.Miller@nrel.gov | 303-384-6777 Dr. Elisa Miller-Link studies the surface of semiconductors that are applicable for , and other nanocrystalline films. Elisa came to NREL in 2013 as an NREL Director's Fellowship recipient

Detection of toxoplasma-specific immunoglobulin G in human sera: performance comparison of in house Dot-ELISA with ECLIA and ELISA.

Science.gov (United States)

Teimouri, Aref; Modarressi, Mohammad Hossein; Shojaee, Saeedeh; Mohebali, Mehdi; Zouei, Nima; Rezaian, Mostafa; Keshavarz, Hossein

2018-05-08

In the current study, performance of electrochemiluminescence immunoassay (ECLIA) in detection of anti-toxoplasma IgG in human sera was compared with that of enzyme-linked immunosorbent assay (ELISA). Furthermore, performance of an in house Dot-ELISA in detection of anti-toxoplasma IgG was compared with that of ECLIA and ELISA. In total, 219 human sera were tested to detect anti-toxoplasma IgG using Dynex DS2® and Roche Cobas® e411 Automated Analyzers. Discordant results rechecked using immunofluorescence assay (IFA). Then, sera were used in an in house Dot-ELISA to assess toxoplasma-specific IgG. Of the 219 samples, two samples were found undetermined using ECLIA but reactive using ELISA. Using IFA, the two sera were reported unreactive. Furthermore, two samples were found reactive using ECLIA and unreactive using ELISA. These samples were reported reactive using IFA. The overall agreement for the two former methods was 98% (rZ0.98.1; P house Dot-ELISA included sensitivity of 79.5, specificity of 78.2, and accuracy of 78.9%, compared to ECLIA and ELISA. Positive and negative predictive values included 82.9 and 74.2%, respectively. A 100% sensitivity was found in in house Dot-ELISA for highly reactive sera in ECLIA and ELISA. ECLIA is appropriate for the first-line serological screening tests and can replace ELISA due to high speed, sensitivity, and specificity, particularly in large laboratories. Dot-ELISA is a rapid, sensitive, specific, cost-effective, user-friendly, and field-portable technique and hence can be used for screening toxoplasmosis, especially in rural fields or less equipped laboratories.

Comparison between an immunochromatographic test with an amplified ELISA for detecting e antigen and anti-e antigen antibodies in chronic Hepatitis B

International Nuclear Information System (INIS)

Mainet Gonzalez, Damian; Palenzuela Gardon, Daniel O; Aguilar Rubido; Julio C

2009-01-01

The disappearance of the e antigen and the appearance of anti-e antigen antibodies are two biomarkers that indicate favorable prognosis in Hepatitis B. In this study the Advanced QualityTM immunochromatographic test for detecting those biomarkers was compared to the Vidas semi-quantitative ELISA test. Our hypothesis was that it is possible to use these biomarkers measured in a rapid and simple Advanced QualityTM immunochromatographic test for evaluating the therapeutic response in clinical trials with chronic hepatitis B patients. The two methods were done following the manufacturer's instructions. The sera were taken from 69 patients with chronic hepatitis B of the clinical trial of the CIGB 440 therapeutic candidate. The immunochromatographic test and ELISA for detecting e antigen and anti-e antigen antibodies presented from substantial to almost perfect agreement in the evaluation of the sera of chronic Hepatitis B patients in a clinical trial. The immunochromatographic test for detecting e antigen had a low positive average agreement and a high negative average agreement compared to the ELISA. Nevertheless, the immunochromatographic test for detecting anti-e antigen antibodies had a high negative and positive average agreement in comparison to the ELISA. The immunochromagraphic test for the e antigen had a lower positive average agreement compared to the ELISA and some patients infected with Hepatitis B virus could not be detected by the former assay. The immunochromatographic test for anti-e antigen antibodies showed a similar performance to that of ELISA and could therefore be used in clinical trials for chronic Hepatitis B in health institutions without the need of a highly qualified lab technician. (author)

Splenectomy Associated Changes in IgM Memory B Cells in an Adult Spleen Registry Cohort

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Cameron, Paul U.; Jones, Penelope; Gorniak, Malgorzata; Dunster, Kate; Paul, Eldho; Lewin, Sharon; Woolley, Ian; Spelman, Denis

2011-01-01

Asplenic patients have a lifelong risk of overwhelming post-splenectomy infection and have been reported to have low numbers of peripheral blood IgM memory B cells. The clinical value of quantitation of memory B cells as an indicator of splenic abnormality or risk of infection has been unclear. To assess changes in B cell sub-populations after splenectomy we studied patients recruited to a spleen registry (n = 591). A subset of 209 adult asplenic or hyposplenic subjects, and normal controls (n = 140) were tested for IgM memory B cells. We also determined a) changes in IgM memory B cells with time after splenectomy using the cross-sectional data from patients on the registry and b) the kinetics of changes in haematological markers associated with splenectomy(n = 45). Total B cells in splenectomy patients did not differ from controls, but memory B cells, IgM memory B cells and switched B cells were significantly (psplenectomy. Changes of asplenia in routine blood films including presence of Howell-Jolly bodies (HJB), occurred early (median 25 days) and splenectomy associated thrombocytosis and lymphocytosis peaked by 50 days. There was a more gradual decrease in IgM memory B cells reaching a stable level within 6 months after splenectomy. IgM memory B cells as proportion of B cells was the best discriminator between splenectomized patients and normal controls and at the optimal cut-off of 4.53, showed a true positive rate of 95% and false positive rate of 20%. In a survey of 152 registry patients stratified by IgM memory B cells around this cut-off there was no association with minor infections and no registry patients experienced OPSI during the study. Despite significant changes after splenectomy, conventional measures of IgM memory cells have limited clinical utility in this population. PMID:21829713

Exposure to ticks and seroprevalence of [i]Borrelia burgdorferi [/i]among a healthy young population living in the area of southern Podlasie, Poland

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Anna Pańczuk

2014-09-01

Full Text Available [b]Objectives[/b]. The objective of the study was assessment of risk of infection with [i]Borrelia burgdorferi[/i] in the area of southern Podlasie in Poland, near the border with Belarus, by analysis of post-exposure procedure, and evaluation of asymptomatic infection in adolescents bitten by a tick, confirmed by serologic tests. [b]Material and methods[/b]. The study was conducted among 128 healthy individuals aged 16–20 who declared being bitten by a tick. The level of IgM and IgG class antibodies was determined using the immunoenzymatic test (Borrelia 14 kD + OspC IgM ELISA and Borrelia IgG + VlsE ELISA, DRG Diagnostics. Positive and doubtful results were confirmed using the Western blot method (EUROLINE-WB, EUROIMMUN. [b]Results[/b]. In the study group, the largest number of respondents (59.4% declared tick bite in the region of the lower extremities, most often in the knee pit. Among the methods for removing the tick the largest number of respondents indicated removing it with the use of tweezers, with a simple, swift steady movement (29.7%, and pulling it out with the fingers (22.7%. In the ELISA test, a positive or doubtful result in at least one class was observed in 25.0% of respondents (n=32/128: in IgM class – 23.4% (n=30/128, and in IgG class – 4.7% (n=6/128. After verification with the Western blot test, infection was confirmed in 5.5% of respondents (n=7/128: in IgM class – 1.6% (n=2/128, in IgG class – 3.9% (n=5/128. In IgM class antibodies, the Western blot test confirmed positive or doubtful results of the ELISA test in 6.7%, while in IgG class antibodies in 83.3%. [b]Conclusion[/b]. Evaluation of the actual infection with [i]Borrelia spp.[/i] using serologic tests is difficult due to a certain non-specificity of the ELISA test, especially in IgM class antibodies, and difficulties with performance of a wide scope of specific Western blot tests. The variety of methods of tick removal declared by adolescents suggests

[IgM class antibodies against hepatitis A viruses in the differentiation of viral hepatitis].

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Zivanović-Marinković, V; Stanković, D; Parabucki, S; Lazarov, A; Marinković, V; Krstić, L; Letica, Z

1982-01-01

The sera of 64 patients with acute viral hepatitis which were previously HbsAG negative by rPHA were tested by RIA methods for the presence of HBsAG and anti-HBc, by EIA method for HBc and anti-HBc and also by RIA method for the presence of IgM antibodies against hepatitis A virus. The pairs of sera were tested also for the presence of antibodies against cytomegalovirus and EB viruses. Of the total of 64 patients, markers of fresh HB viral infection were proved in 5 patients, sera positive to IgM antibodies to hepatitis A virus were found in 51 and no positive tests to any of the tested viruses were found in 8. The authors consider that they belonged to "non-A, non-B" viral hepatitis.

Evaluation of a Commercial IgE ELISA in Comparison with IgA and IgM ELISAs, IgG Avidity Assay and Complement Fixation for the Diagnosis of Acute Toxoplasmosis

Czech Academy of Sciences Publication Activity Database

Kodym, P.; Machala, L.; Roháčová, H.; Širocká, B.; Malý, Marek

2007-01-01

Roč. 13, č. 1 (2007), s. 40-47 ISSN 1198-743X Source of funding: V - iné verejné zdroje Keywords : acute infection * diagnosis * IgE ELISA * lymphadenopathy * serology * toxoplasmosis Subject RIV: BB - Applied Statistics, Operational Research Impact factor: 2.980, year: 2007

E.L.I.S.A. en coccidioidomicosis humana E.L.I.S.A. in human coccidioidomycosis

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Iris Nora Tiraboschi

1991-08-01

Full Text Available Se realizó E.L.I.S.A. con exoantígeno de Coccidioides immitis para la detectión de anticuerpos, en 67 sueros humanos diluidos 1/1000, 1/2000, 1/4000 y 1/8000. De los 18 sueros de enfermos de coccidioidomicosis comprobada por examen directo, cultivo y/o histología, 5 fueron negativos, en otros 13 fueron positivos en una o varias diluciones. 3/26 sueros de personas sanas, coccidioidino positivas, fueron positivos en títulos de 1/1000 y el resto no tuvo anticuerpos detectables. No presentaron reacciones positivas ninguno de los sueros controles de personas sanas, pero sí lo hicieron 4/8 pacientes con otras micosis. Se concluye que E.L.I.S.A. es útil para la detección de mínimas cantidades de anticuerpos o en sueros que no pueden ser procesados por fijación de complemento. No es recomendable el uso de la técnica en forma aislada por al presencia de reacciones cruzadas.An E.L.I.S.A. test for antibody detection, with an exo-antigen of Coccidioides immitis was standardized in 67 humans sera diluited in 1/1000, 1/2000, 1/4000 and 1/8000. Eightheen sera from mycologically proved cases of coccidioidomycosis were studied: 5 were negative and 13 were positive in some dilutions. 3/26 sera of healthy persons who presented positive skin tests with coccidioidin were positive and the other 23 sera did not have positive reactions. None of the 15 sera of healthy human exhibited positive E.L.I.S.A. Serum samples of 8 patients suffering other deep mycosis were studied, 4 of them presented cross-reactions in E.L.I.S.A. tests. E.L.I.S.A. test seems to be a useful Serologic technique for antibody detection in anticomplementary serum samples or when a low concentration of antibodies should be detected. As it is very sensitive, cross-reactions with other mycoses are frequent, thus the use other more specific serologic technique together E.L.I.S.A. is recommended.

Kinetics of hemolytic plaque formation. IV. IgM plaque inhibition

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DeLisi, C

1975-01-01

An analysis of the inhibition of hemolytic plaques formed against IgM antibodies is presented. The starting point is the equations of DeLisi and Bell (1974) which describe the kinetics of plaque growth, and DeLisi and Goldstein (1975) which describe inhibition of IgG plaques. However, the physical chemical models which were used previously to describe IgG inhibition data are shown to be inadequate for describing the characteristics of IgM inhibition curves. Moreover, it is shown that the experimental results place severe restrictions on the possible choices of physical chemical models for IgM upon which to base the calculations. It is argued that in order to account even qualitatively for all the data, one must assume (1) a very restricted motion of IgMs about the Fab hinge region and (2) a very narrow secretion rate distribution of IgM by antibody secreting cells. (auth)

DETECTION OF HUMAN ANTI-ZIKA VIRUS IgG BY ELISA USING AN ANTIGEN FROM in vitro INFECTED VERO CELLS: PRELIMINARY RESULTS

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Laura Masami SUMITA

Full Text Available SUMMARY Zika virus (ZKV infection is a huge public health problem in Brazil because of the increased incidence of microcephaly in neonates from infected mothers. Detection of specific IgG antibodies in maternal serum samples constitutes an important approach for diagnosing ZKV infection and evaluating its relationship with neonatal microcephaly. However, as there is no serological test produced in Brazil to detect IgM and IgG antibodies against ZKV, we sought to examine specific IgG in serum samples from patients or suspected mothers to detect previous infection and to test for specificity with regard to flaviviral infections occurring in the same area. Brazilian Zika virus native antigens were obtained from infected Vero cell layers or free virions in the culture medium and then used in ELISA. We tested sera from eight ZKV RNA-diagnosed infected patients (ZKVR, seven neonates with microcephaly and their mothers after delivery (MM, 140 dengue virus IgM-positive (DM and IgG (DG-positive patients, and 100 yellow fever (YF-vaccinated patients. According to the ELISA, ZKVR samples were mostly positive (7/8, and all the MM serum samples were positive for ZKV IgG (7/7. In contrast, cross-reactions for dengue or yellow fever-vaccinated patients were observed, including DM (48/95, DG (10/45 or YF (3/100 serum samples; however, these cross-reactions exhibited low antigen avidity so that 6 M urea largely removed this cross-reactivity, with only a few cross-reacting samples remaining (8/140. ELISA based on extracted virions was much more specific, with all ZKVR (8/8 and MM sera being positive for ZKV IgG (7/7 and only borderline cross-reactivity found for DM (6/95, DG (3/45 or YF (4/100-vaccinated serum samples. This technique (ELISA can identify specific IgG in ZKV-infected patients and may be helpful in diagnosing congenital infetions after maternal RNA virus clearance or in epidemiological studies.

Development and validation of a quantitative competitive ELISA for potency testing of equine anti rabies sera with other potential use.

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Korimbocus, Jehanara; Dehay, Nicolas; Tordo, Noël; Cano, François; Morgeaux, Sylvie

2016-06-14

In case of a bite by a rabies infected animal, the World Health Organisation recommends a prophylactic treatment including the administration of Human Rabies Immunoglobulins (HRIGs) or highly purified F(ab')2 fragments produced from Equine Rabies Immunoglobulin (F(ab')2 - ERIGs). According to international regulation, quality control of F(ab')2 - ERIGs lots requires potency testing by the in vivo Mouse Neutralisation Test (MNT) prior marketing. However, the strategy of the 3Rs (Reduce, Refine, Replace) for animal testing required by the European Directive encourages the replacement of the in vivo potency test by an in vitro assay. In this context, a competitive ELISA method (c-ELISA) has been developed by the Agence Nationale de Sécurité du Médicament et des Produits de Santé where F(ab')2 - ERIGs are in competition with a monoclonal antibody recognizing the trimeric native form of the rabies glycoprotein. After a full validation study, the c-ELISA has been applied to commercial batches of F(ab')2 - ERIGs. A correlation study with the MNT demonstrated a similarity between the two methods (r=0.751). Moreover, the c-ELISA method which does not need any species specific reagent has been applied to HRIGs potency testing as an alternative method to Rapid Fluorescent Focus Inhibition Test (RFFIT), thus avoiding the handling of live rabies virus in BSL3 containment. In conclusion, the c-ELISA has shown its potential to replace MNT and possibly RFFIT for the quantification of rabies immunoglobulin. After optimisation it may be used for the quantification of rabies immunoglobulin in any animal species, notably for rabies immunogenicity assay in mice. Copyright © 2016 Elsevier Ltd. All rights reserved.

Comparison of Rose Bengal Plate Agglutination, Standard tube agglutination and Indirect ELISA tests for detection of Brucella antibodies in Cows and Buffaloes

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S. N. Ghodasara

2010-04-01

Full Text Available A total of 180 serum samples (107 cows, 73 buffaloes from cases of abortion and various reproductive disorders were collected for detection of Brucella antibody by Rose Bengal Plate Agglutination Test (RBPT, Serum Tube Agglutination Test (STAT and indirect- ELISA (i-ELISA. The overall prevalence of brucellosis by RBPT, STAT and i-ELISA were 11.21%, 16.00% and 24.30% in cows 9.59%, 12.33% and 26.03% in buffaloes respectively. Overall seroprevalence of Brucellosis in cases of abortion, R.O.P. by RBPT, STAT and i-ELISA were 11.32%, 16.04% and 32.08% respectively. When three serological tests were compared, seropositivity was found highest by i-ELISA (25%, followed by STAT (14.45% and RBPT (10.56%. The results shows higher prevalence of brucellosis in cases of abortion and R.O.P., while at lower level from various reproductive disorders as detected serologically indicating endemicity of the infection in villages around Anand city, Gujarat. [Vet. World 2010; 3(2.000: 61-64

Diagnostic value of a Rec-ELISA using Toxoplasma gondii recombinant SporoSAG, BAG1, and GRA1 proteins in murine models infected orally with tissue cysts and oocysts.

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Mert Döşkaya

Full Text Available Toxoplasma gondii causes congenital toxoplasmosis in newborns resulting with fetal anomalies. Determining the initiation time of infection is very important for pregnant women and current serological assays have drawbacks in distinguishing the recently acute toxoplasmosis. Diagnosis of recently acute infection may be improved by using stage specific antigens in serological assays. In the present study, the diagnostic value of sporozoite specific SporoSAG, bradyzoite specific BAG1 proteins and GRA1 protein expressed by all forms of the parasite have been evaluated ELISA using sera systematically collected from mice administered orally with tissue cyst and oocysts. The anti-SporoSAG IgM antibodies in sera obtained from mice infected with oocysts peaked significantly at days 1, 10, and 15 (P<0.01. The anti-BAG1 IgM antibodies in sera obtained from mice infected with tissue cysts peaked significantly at days 15, 40, and 120 (P<0.05. The anti-GRA1 IgM antibodies in sera obtained from mice infected with oocysts peaked significantly at days 2, 10, and 40 (P<0.01. The anti-GRA1 IgM antibodies in sera obtained from mice infected with tissue cysts peaked significantly only at day 40 (P<0.05. The anti-SporoSAG, anti-BAG1, and anti-GRA1 IgG titers of mice showed significant increases at day 40 (P<0.05 and decrement started for only anti-GRA1 IgG at day 120. The presence of anti-SporoSAG IgM and IgG antibodies can be interpreted as recently acute infection between days 10-40 because IgM decreases at day 40. Similarly, presence of anti-BAG1 IgM and absence of IgG can be evaluated as a recently acute infection that occurred 40 days before because IgG peaks at day 40. A peak in anti-GRA1 antibody level at first testing and reduction in consecutive sample can be considered as an infection approximately around day 40 or prior. Overall, recombinant SporoSAG, BAG1 and GRA1 proteins can be accepted as valuable diagnostic markers of recently acute toxoplasmosis.

Evaluation of a serological test (indirect ELISA) for the diagnosis of sarcoptic mange in red foxes (Vulpes vulpes).

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Bornstein, Set; Frössling, Jenny; Näslund, Katarina; Zakrisson, Göran; Mörner, Torsten

2006-12-01

Sarcoptic mange occurs in many parts of the world and is common in populations of domestic and wild canids, including red foxes (Vulpes vulpes). In recent years, an indirect antibody enzyme-linked immunosorbent assay (ELISA), with higher sensitivity and specificity than traditional diagnostic methods, has been successfully applied in the diagnosis of sarcoptic mange in dogs. The same ELISA has also demonstrated specific antibodies to Sarcoptes scabiei in experimentally infected red foxes. The aim of this study was to evaluate the indirect ELISA when used to detect antibodies to S. scabiei in field sera from Swedish red foxes. One cohort of both infected and non-infected red foxes (cohort 1; n = 88), and one cohort of apparently non-infected foxes (cohort 2; n = 67) were examined for skin lesions and presence of S. scabiei by thorough visual examination at autopsy and skin scrapings. Samples of blood-tinted body liquid from the abdomen or thorax cavity were collected and analysed by the indirect ELISA. The relative sensitivity and specificity of the ELISA at different cut-offs (OD values) were estimated by comparing the test results to the infection status as determined by examination and skin scrapings. The highest combination of relative sensitivity and specificity, calculated based on cohort 1, was 95.4 and 100.0%, respectively. These estimates were constant for cut-offs 0.150-0.225, which included the cut-off based on the mean plus three standard deviations of test results from cohort 2 (0.165). It is concluded that this test can be useful in diagnosis and epidemiological studies of S. scabiei infection in red foxes.

Specificity of Toxocara ELISA in tropical populations.

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Lynch, N R; Wilkes, L K; Hodgen, A N; Turner, K J

1988-05-01

The diagnosis of human infection by Toxocara canis relies heavily upon serological tests, the specificity of which can be inadequate in regions of endemic helminthiasis. When different population groups of tropical Venezuela were evaluated using ELISA based upon Toxocara excretory-secretory antigen (TcESA), solid-phase adsorption of the sera with extracts of a wide variety of non-homologous parasites revealed the existence of significant cross-reactivity. This was effectively and conveniently overcome when the test sera were incubated in the presence of the soluble parasite extracts in a competitive inhibition ELISA. The mean reduction of ELISA values caused by pre-adsorption of the sera tested was 32.2%, and that caused by competitive inhibition was 42.3%, the effects of these two procedures being strongly correlated (r = 0.83). The magnitude of the reduction was inversely proportional to the actual ELISA value (r = -0.55), and ranged from a mean of 68.0% in sera from apparently healthy individuals of medium-high socio-economic level, down to 28.1% in heavily parasitized Amazon indians. Ascaris showed the greatest degree of cross-reactivity in these tests, although under conditions of competitive inhibition even sera with high levels of antibody against this parasite could be negative in Toxocara ELISA. Western blotting revealed a major 81,400 D component that was shared between Ascaris and TcESA. Our results indicate that the competitive inhibition of cross-reactivity by soluble non-homologous parasite extracts provides a convenient and economical means of increasing the specificity of ELISA for the determination of the seroprevalence of toxocariasis in tropical populations.

Comparative study of three screening tests, two microbiological tube tests, and a multi-sulphonamide ELISA kit for the detection of antimicrobial and sulphonamide residues in eggs.

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Gaudin, V; Hedou, C; Rault, A; Sanders, P; Verdon, E

2009-04-01

The screening of antimicrobial residues in eggs is an especially important subject. Three different commercial kits for the screening of sulphonamides and other antimicrobials in eggs were validated in accordance with Decision 2002/657/EC: one enzyme-linked immunoabsorbant assay (ELISA) kit multi-sulphonamides (from RAISIO Diagnostics) and two microbiological tests (a Premi test from DSM and an Explorer kit from Zeu-Inmunotec). The false-positive rates were lower than 2% for all kits. The detection capabilities (CCbeta) have to be as low as possible for banned substances and lower than the maximum residue limit (MRL) when MRLs have been set. The sensitivity of the Premi test was better than that of the Explorer test, probably because of the dilution of the eggs before the Explorer test was used. The CCbeta values towards most of the tested sulphonamides were satisfactory with the Premi test (amoxicillin, neomycin, tylosin and erythromycin were lower than their respective MRLs. Detection capabilities for sulphonamides were much lower for the ELISA kit than for microbiological tests. The ELISA kit could be recommended for the targeted screening of sulphonamides in eggs. On the other hand, the Explorer and Premi tests could be used as wide screening tests allowing the detection of most of the antimicrobial families.

Splenectomy associated changes in IgM memory B cells in an adult spleen registry cohort.

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Paul U Cameron

Full Text Available Asplenic patients have a lifelong risk of overwhelming post-splenectomy infection and have been reported to have low numbers of peripheral blood IgM memory B cells. The clinical value of quantitation of memory B cells as an indicator of splenic abnormality or risk of infection has been unclear. To assess changes in B cell sub-populations after splenectomy we studied patients recruited to a spleen registry (n = 591. A subset of 209 adult asplenic or hyposplenic subjects, and normal controls (n = 140 were tested for IgM memory B cells. We also determined a changes in IgM memory B cells with time after splenectomy using the cross-sectional data from patients on the registry and b the kinetics of changes in haematological markers associated with splenectomy(n = 45. Total B cells in splenectomy patients did not differ from controls, but memory B cells, IgM memory B cells and switched B cells were significantly (p<0.001 reduced. The reduction was similar for different indications for splenectomy. Changes of asplenia in routine blood films including presence of Howell-Jolly bodies (HJB, occurred early (median 25 days and splenectomy associated thrombocytosis and lymphocytosis peaked by 50 days. There was a more gradual decrease in IgM memory B cells reaching a stable level within 6 months after splenectomy. IgM memory B cells as proportion of B cells was the best discriminator between splenectomized patients and normal controls and at the optimal cut-off of 4.53, showed a true positive rate of 95% and false positive rate of 20%. In a survey of 152 registry patients stratified by IgM memory B cells around this cut-off there was no association with minor infections and no registry patients experienced OPSI during the study. Despite significant changes after splenectomy, conventional measures of IgM memory cells have limited clinical utility in this population.

Salivary IgA against sporozoite-specific embryogenesis-related protein (TgERP) in the study of horizontally transmitted toxoplasmosis via T. gondii oocysts in endemic settings

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The prevalence of toxoplasmosis was investigated in endemic settings in Brazil, and calculated by measuring antibodies in two ELISA systems: 1) IgG and IgM from sera tested by commercial conventional ELISA, and 2) IgA, from saliva, and IgG from sera samples tested against a sporozoite-specific prote...

Bayesian modelling to estimate the test characteristics of coprology, coproantigen ELISA and a novel real-time PCR for the diagnosis of taeniasis.

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Praet, Nicolas; Verweij, Jaco J; Mwape, Kabemba E; Phiri, Isaac K; Muma, John B; Zulu, Gideon; van Lieshout, Lisette; Rodriguez-Hidalgo, Richar; Benitez-Ortiz, Washington; Dorny, Pierre; Gabriël, Sarah

2013-05-01

To estimate and compare the performances of coprology, copro-Ag ELISA and real-time polymerase chain reaction assay (copro-PCR) for detection of Taenia solium tapeworm carriers. The three diagnostic tests were applied on 817 stool samples collected in two Zambian communities where taeniasis is endemic. A Bayesian approach was used to allow estimation of the test characteristics. Two (0.2%; 95% Confidence Interval (CI): 0-0.8), 67 (8.2%; 95% CI: 6.4-10.3) and 10 (1.2%; 95% CI: 0.5-2.2) samples were positive using coprology, copro-Ag ELISA and copro-PCR, respectively. Specificities of 99.9%, 92.0% and 99.0% were determined for coprology, copro-Ag ELISA and copro-PCR, respectively. Sensitivities of 52.5%, 84.5% and 82.7% were determined for coprology, copro-Ag ELISA and copro-PCR, respectively. We urge for additional studies exploring possible cross-reactions of the copro-Ag ELISA and for the use of more sensitive tests, such as copro-PCR, for the detection of tapeworm carriers, which is a key factor in controlling the parasite in endemic areas. © 2013 Blackwell Publishing Ltd.

IgM, FcµRs, and malarial immune evasion

DEFF Research Database (Denmark)

Czajkowsky, Daniel M; Salanti, Ali; Ditlev, Sisse B

2010-01-01

IgM is an ancestral Ab class found in all jawed vertebrates, from sharks to mammals. This ancient ancestry is shared by malaria parasites (genus Plasmodium) that infect all classes of terrestrial vertebrates with whom they coevolved. IgM, the least studied and most enigmatic of the vertebrate Igs...

¿Es necesario investigar anticuerpos IgM contra el virus de la hepatitis A cuando el enzimograma hepático es normal? Is it necessary to investigate anti-hepatitis A virus (HAV IgM antibodies when the hepatic enzymogram is normal?

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C. Coitinho

2007-09-01

Full Text Available La hepatitis por virus A (VHA es la más frecuente de las hepatitis virales en el mundo, especialmente en los países subdesarrollados. Donde esta enfermedad es endémica, se suelen realizar un gran número de estudios de laboratorio para confirmarla. El objetivo del presente trabajo fue evaluar la utilidad de investigar anticuerpos IgM anti hepatitis A (IgM anti-VHA para el diagnóstico de la VHA en pacientes con niveles séricos normales de aspartato y alanina aminotransferasas (AST/ALT. Todos los pacientes que concurrieron al laboratorio con solicitud de enzimograma hepático y anticuerpos IgM anti-VHA durante el período octubre 2005-marzo 2006 fueron evaluados en este estudio. Los datos clínicos más frecuentes fueron presunción de hepatitis e ictericia (27,5 y 12,7%. La determinación de IgM anti-VHA se realizó por ensayo inmunoenzimático de micropartículas (MEIA; la de enzimas hepáticas en un multianalizador. De los 158 pacientes estudiados, 84 tenían valores elevados de AST/ALT; dentro de este grupo, el 82% fue reactivo para IgM anti-VHA. Los 74 pacientes restantes mostraron niveles normales de AST/ALT y solo 7 de ellos, bajo control de evolución por VHA ya confirmada, fueron reactivos para IgM anti-VHA. El 49% de los pacientes IgM anti-VHA reactivos correspondió a menores de 10 años. De acuerdo con estas observaciones, sugerimos que los estudios de laboratorio para confirmar infección aguda por VHA deberían realizarse en forma secuencial, ya que es innecesaria la determinación de anticuerpos IgM anti-VHA cuando las aminotransferasas séricas son normales.Type A viral Hepatitis (HAV is the most frequent viral hepatitis around the world, especially in low income countries. In order to confirm this disease, a lot of laboratory tests are annually carried out where HAV is endemic. Our objective was to establish the utility of investigating anti-hepatitis A virus (HAV IgM antibodies for HAV diagnosis in patients with normal

A chromogranin A ELISA absent of an apparent high-dose hook effect observed in other chromogranin A ELISAs.

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Erickson, J Alan; Grenache, David G

2016-01-15

Routine testing for chromogranin A (CgA) using an established commercial ELISA revealed an apparent high-dose hook effect in approximately 15% of specimens. Investigations found the same effect in two additional ELISAs. We hypothesized that a CgA derived peptide(s) at high concentrations was responsible but experiments were inconclusive. Here we describe the analytical performance characteristics of the Chromoa™ CgA ELISA that did not display the apparent high-dose hook effect. Performance characteristics of the Chromoa ELISA were assessed. The reference interval was established utilizing healthy volunteers. Specimens producing the apparent high-dose hook effect in other assays were evaluated using the Chromoa ELISA. The limit of detection was 8ng/ml. Linearity was acceptable (slope=1.04, intercept=18.1 and r(2)=0.997). CVs were ≤4.6 and ≤9.3% for repeatability and within-laboratory imprecision, respectively. CgA was stable at ambient and refrigerated temperatures for a minimum of two and 14days, respectively. An upper reference interval limit of 95ng/ml was established. Specimens demonstrating the apparent high-dose hook effect in other ELISAs did not exhibit the phenomenon using the Chromoa ELISA. The Chromoa ELISA demonstrates acceptable performance for quantifying serum CgA. The apparent high-dose hook effect exhibited in other ELISAs was absent using the Chromoa assay. Copyright © 2015 Elsevier B.V. All rights reserved.

Calorimetric features of IgM gammopathies. Implication for patient’s diagnosis and monitoring

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Krumova, Sashka; Todinova, Svetla; Danailova, Avgustina [Institute of Biophysics and Biomedical Engineering, Bulgarian Academy of Sciences, Acad. G. Bonchev Str., bl. 21, 1113 Sofia (Bulgaria); Petkova, Violeta; Dimitrova, Keranka; Gartcheva, Lidia [National Specialized Hospital for Active Treating of Haematological Diseases, Sofia 1756 (Bulgaria); Taneva, Stefka G., E-mail: stefka.germanova@ehu.es [Institute of Biophysics and Biomedical Engineering, Bulgarian Academy of Sciences, Acad. G. Bonchev Str., bl. 21, 1113 Sofia (Bulgaria); Unidad de Biofísica (CSIC-UPV/EHU) and Departamento de Bioquímica y Biología Molecular, Universidad del País Vasco, 48080 Bilbao (Spain)

2015-09-10

Highlights: • DSC reveals distinct calorimetric features for IgM gammopaties. • Calorimetry sets of IgM multiple myeloma and Waldenström’s macroglobulinemia patients. • DSC features correlate with the level of involved IgM heavy/light chains. • DSC and “Heavylite” are complementary methods for patients diagnostics/monitoring. - Abstract: The serum proteome of patients featuring immunoglobulin M (IgM) gammopathy and diagnosed as having IgM multiple myeloma or Waldenström’s macroglobulinemia was characterized by differential scanning calorimetry and HevyLite™ (HLC) assay. The thermodynamic properties of the thermograms and their deviation from the typical healthy thermogram were found to correlate with the monoclonal protein concentration and the level of the involved (monoclonal) IgM heavy/light chains. Patients monitoring during treatment showed that the variations in the shape of the DSC profiles corresponded to fluctuations of the IgM heavy/light chain levels verifying the two parameters as non-invasive markers for disease progression.

Evaluation of ELISA and haemagglutination inhibition as screening tests in serosurveillance for H5/H7 avian influenza in commercial chicken flocks

DEFF Research Database (Denmark)

Arnold, M E; Slomka, M J; Breed, A C

2018-01-01

with an ELISA, which detects antibodies to all subtypes. Sera (n = 1055) from 74 commercial chicken flocks were tested by both methods. A Bayesian approach served to estimate diagnostic test sensitivities and specificities, without assuming any 'gold standard'. Sensitivity and specificity of the ELISA was 97......% and 99.8%, and for H5/H7 HI 43% and 99.8%, respectively, although H5/H7 HI sensitivity varied considerably between infected flocks. ELISA therefore provides superior sensitivity for the screening of chicken flocks as part of an algorithm, which subsequently utilises H5/H7 HI to identify infection...

Comparison of the serological tests ICT and ELISA for the diagnosis of alveolar echinococcosis in France.

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Knapp, Jenny; Sako, Yasuhito; Grenouillet, Frédéric; Bresson-Hadni, Solange; Richou, Carine; Gbaguidi-Haore, Houssein; Ito, Akira; Millon, Laurence

2014-01-01

Serological diagnosis of alveolar echinococcosis (AE) is a key element for efficient patient treatment management. A rapid immunochromatography test kit (ICT) using the recombinant Em18 antigen (rEm18) was recently developed. The aim of our study was to assess this test on a panel of sera from French patients with alveolar echinococcosis and control patients. In a blind test, a total of 112 serum samples were tested including samples of AE (n = 30), cystic echinococcosis [CE] (n = 15), and polycystic echinococcosis [PE] (n = 1). For the comparison, 66 sera from patients with hepatocarcinoma, fascioliasis, toxocariasis, Caroli's disease, or autoimmune chronic active hepatitis were used. The diagnostic test sets we used were the rEm18-ICT and two validated ELISAs with rEm18 and Em2-Em18 antigens, respectively. For the ICT, 27/30 sera from AE patients, 4/15 sera from CE patients and the PE patient serum were positive. One serum from the control panel (toxocariasis) was positive for the ICT. The rEm18-ICT sensitivity (90.0%) and specificity (92.7%) for detection of Em18-specific antibodies confirmed it as a relevant tool for AE diagnosis. The rEm18-ELISA had a sensitivity of 86.7% and specificity of 91.5%, and the Em2-Em18-ELISA had a sensitivity of 96.7% and specificity of 87.8%. However, when AE patient sera are recorded as weak in intensity with the ICT, we recommend a double reading and use of a reference sample if the ICT is used for patient follow-up. © J. Knapp et al., published by EDP Sciences, 2014.

Mobile phone based ELISA (MELISA).

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Zhdanov, Arsenii; Keefe, Jordan; Franco-Waite, Luis; Konnaiyan, Karthik Raj; Pyayt, Anna

2018-04-30

Enzyme-linked immunosorbent assay (ELISA) is one of the most important technologies for biochemical analysis critical for diagnosis and monitoring of many diseases. Traditional systems for ELISA incubation and reading are expensive and bulky, thus cannot be used at point-of-care or in the field. Here, we propose and demonstrate a new miniature mobile phone based system for ELISA (MELISA). This system can be used to complete all steps of the assay, including incubation and reading. It weighs just 1 pound, can be fabricated at low cost, portable, and can transfer test results via mobile phone. We successfully demonstrated how MELISA can be calibrated for accurate measurements of progesterone and demonstrated successful measurements with the calibrated system. Copyright © 2017 Elsevier B.V. All rights reserved.

Detection of anti-dsDNA by IgG ELISA test using two different sources of antigens: calf thymus versus E.coli

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Mohammadi M

2009-04-01

Full Text Available "nBackground: Anti-dsDNA antibodies frequently found in the sera Systemic Lupus Erythematosus patients, particularly in active disease stage. Nowadays exploit different eukaryotic and prokaryotic dsDNA as antigen source and different reagents as binder. The aim of this study to compared two dsDNA different sources and tow different kinds of reagents for binder in ELISA test. "nMethods: In this study bacterial genomic DNA from E.coli (ATCC 25922 and genomic DNA from calf thymus extracted with high purity and were used as antigens for IgG anti-dsDNA detection by ELISA. To coat dsDNA in microtiter wells, tow different kinds of reagents including methylated -BSA and poly-l-lysine (for pre-coating are used. Sera from systemic lupus erythematosus patients and from normal blood donors are used to assess sensitivity and specificity of our ELISA test in compared with IF test and commercial kits. "nResults: Our results displayed pre-coating of microtiter plates with methylated -BSA reduce nonspecific binding reaction and the relative sensitivity and specificity of ELISA increased when calf thymus DNA is employed as antigenic source in compared with IF test and commercial kits 80%, 88% and 100%, 98% respectively, but when E.coli DNA is used 73%, 69% and 85%, 79%, respectively. "nConclusion: The genomic DNA from calf thymus is a potentially useful source of antigen for detection of anti-dsDNA by ELISA. Also the use of methylatted- BSA could have an effective role in reducing of nonspecific binding reactions.

The Diagnostic Value of ELISA Method for Pertussis in Children

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O. P. Popova

2016-01-01

Full Text Available Because of low effectiveness of laboratory methods for diagnosing pertussis it is important to look for new ways of verification of this infection. The article presents the analysis of the diagnostic value of ELISA method, which involves the identification of antibodies of different isotypes (IgM, IgG, IgA to pertussis toxoid (PT and filamentous haemagglutinin (FHA. The study included 279 children: 114 were under 1 year of age, 165 — older than 1 year. The pertussis was confirmed in 74.3 ± 2.6% of patients by using ELISA method. A significant proportion of seronegative patients (46.1 ± 6.2 per cent was revealed in the group of patients under 1 year. The pattern of production of antibodies in unvaccinated children was different. It depended on the age of the children and timing of illness. A low proportion of diagnostically significant indicators of IgM-antibodies at 2—3 weeks of illness was typical for patients under 1 year of age (e.g. 6.7 ± 6.5% as compared to 20.0 ± 7.9% and 50.0 ± 15.3 — 1—3 and 4—6 years of age. The diagnosis of pertussis in children under 1 year of age was confirmed mainly by the detection of IgG, starting from the 4th week of the disease. In the examination of vaccinated children diagnostically significant levels of IgA and IgG were identified (even in the late stages of the disease. Thus, the results of the analysis show special significance of using ELISA method for the diagnosis of pertussis in vaccinated children.

The modification and evaluation of an ELISA test for the surveillance of Mycobacterium avium subsp. paratuberculosis infection in wild ruminants

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Pruvot Mathieu

2013-01-01

Full Text Available Abstract Background Enzyme-linked immunosorbent assay (ELISA is often used to test wildlife samples for Mycobacterium avium subsp. paratuberculosis (MAP infection. However, commercially available kits are only validated for use with domestic ruminant species. A literature review was performed to document the current use of MAP serum ELISA in wild and semi-domestic ruminants. We then modified and evaluated a commercial ELISA kit (IDEXX Mycobacterium paratuberculosis Antibody Test Kit for use with species for which it was not originally developed: elk (Cervus elaphus, bison (Bison bison and caribou (Rangifer tarandus. We tested the affinity of different conjugates for immunoglobulin G (IgG isolated from these species, performed checkerboard tests to determine the optimal dilutions of samples and conjugates, and established cut-off values using two different methods: a Receiver Operational Curve on a panel of known samples for elk, and an alternate method involving a panel of unknown serum samples for the three species. Results We found that the anti-bovine conjugate included in the IDEXX ELISA kit has limited affinity for elk, bison, and caribou IgG. Protein G showed good affinity for IgG of all three species, while anti-deer conjugate also bound elk and caribou IgG. Using Protein G with elk serum, a cut-off sample-to-positive (S/P value of 0.22 was selected, resulting in a sensitivity and specificity of 73% and 90%, respectively, whereas, using an anti-deer conjugate with elk serum, an S/P cut-off value of 0.29 gave a sensitivity of 68%, with 100% specificity. Cut-off values for bison and caribou using the Protein G conjugate were 0.17 and 0.25 respectively. Conclusions Due to incomplete reporting and a lack of test validation, it is difficult to critically appraise results of many sero-surveys that have previously been done for MAP in wildlife. Commercial ELISA kits may have limited or no capacity to detect antibodies from species other than for

Anti-signal recognition particle autoantibody ELISA validation and clinical associations.

Science.gov (United States)

Aggarwal, Rohit; Oddis, Chester V; Goudeau, Danielle; Fertig, Noreen; Metes, Ilinca; Stephens, Chad; Qi, Zengbiao; Koontz, Diane; Levesque, Marc C

2015-07-01

The aim of this study was to develop and validate a quantitative anti-signal recognition particle (SRP) autoantibody serum ELISA in patients with myositis and longitudinal association with myositis disease activity. We developed a serum ELISA using recombinant purified full-length human SRP coated on ELISA plates and a secondary antibody that bound human IgG to detect anti-SRP binding. Protein immunoprecipitation was used as the gold standard for the presence of anti-SRP. Serum samples from three groups were analysed: SRP(+) myositis subjects by immunoprecipitation, SRP(-) myositis subjects by immunoprecipitation and non-myositis controls. The ELISA's sensitivity, specificity, positive predictive value and negative predictive value were evaluated. Percentage agreement and test-retest reliability were assessed. Serial samples from seven SRP immunoprecipitation-positive subjects were also tested, along with serum muscle enzymes and manual muscle testing. Using immunoprecipitation, we identified 26 SRP(+) myositis patients and 77 SRP(-) controls (including 38 patients with necrotizing myopathy). Non-myositis control patients included SLE (n = 4) and SSc (n = 7) patients. Anti-SRP positivity by ELISA showed strong agreement (97.1%) with immunoprecipitation (κ = 0.94). The sensitivity, specificity, positive predictive value, and negative predictive value of the anti-SRP ELISA were 88, 100, 100 and 96, respectively. The area under the curve was 0.94, and test-retest reliability was strong (r = 0.91, P < 0.001). Serial samples showed that anti-SRP levels paralleled changes in muscle enzymes and manual muscle testing. We developed a quantitative ELISA for detecting serum anti-SRP autoantibodies and validated the assay in myositis. Longitudinal assessment of SRP levels by ELISA may be a useful biomarker for disease activity. © The Author 2014. Published by Oxford University Press on behalf of the British Society for Rheumatology. All rights reserved. For Permissions

Improved reliability of serological tools for the diagnosis of West Nile fever in horses within Europe.

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Cécile Beck

2017-09-01

Full Text Available West Nile Fever is a zoonotic disease caused by a mosquito-borne flavivirus, WNV. By its clinical sensitivity to the disease, the horse is a useful sentinel of infection. Because of the virus' low-level, short-term viraemia in horses, the primary tools used to diagnose WNV are serological tests. Inter-laboratory proficiency tests (ILPTs were held in 2010 and 2013 to evaluate WNV serological diagnostic tools suited for the European network of National Reference Laboratories (NRLs for equine diseases. These ILPTs were designed to evaluate the laboratories' and methods' performances in detecting WNV infection in horses through serology. The detection of WNV immunoglobulin G (IgG antibodies by ELISA is widely used in Europe, with 17 NRLs in 2010 and 20 NRLs in 2013 using IgG WNV assays. Thanks to the development of new commercial IgM capture kits, WNV IgM capture ELISAs were rapidly implemented in NRLs between 2010 (4 NRLs and 2013 (13 NRLs. The use of kits allowed the quick standardisation of WNV IgG and IgM detection assays in NRLs with more than 95% (20/21 and 100% (13/13 of satisfactory results respectively in 2013. Conversely, virus neutralisation tests (VNTs were implemented in 33% (7/21 of NRLs in 2013 and their low sensitivity was evidenced in 29% (2/7 of NRLs during this ILPT. A comparison of serological diagnostic methods highlighted the higher sensitivity of IgG ELISAs compared to WNV VNTs. They also revealed that the low specificity of IgG ELISA kits meant that it could detect animals infected with other flaviviruses. In contrast VNT and IgM ELISA assays were highly specific and did not detect antibodies against related flaviviruses. These results argue in favour of the need for and development of new, specific serological diagnostic assays that could be easily transferred to partner laboratories.

Frequency of human toxocariasis in a rural population from Cajamarca, Peru determined by DOT-ELISA test Freqüência de toxocaríase humana numa população rural de Cajamarca, Peru, mediante o uso do teste DOT-ELISA

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William H. Roldán

2009-04-01

Full Text Available The aim of this study was to estimate the frequency of human toxocariasis in Cauday district, Cajamarca, Peru, using a dot-ELISA test. From June to October 2005, a total of 256 adult subjects were studied. Blood samples were collected for serology by a dot-ELISA test and for hematological examination. Parasitological examination was also carried out in stool samples to check cross-reactions in the dot-ELISA. The frequency observed was 44.92%, with a significant higher proportion of positivity in male subjects. From subjects with positive serology, 45.6% had respiratory symptoms, 40.44% abdominal pain, 32.35% hepatic symptoms, 14.7% cutaneous signs, 13.23% ocular manifestations, 43.38% eosinophilia, and all of these were statistically associated to serology. Among the population evaluated, 90.23% (231/256 were parasitized. From subjects with positive serology, 92.17% had at least one intestinal parasite and the most frequent were: Blastocystis hominis (68.38%, Giardia lamblia (28.68%, Hymenolepis nana (20.0%, Ascaris lumbricoides (15.65%, Entamoeba histolytica/E. dispar (13.24%, Cyclospora cayetanensis (4.41%, Cryptosporidium sp. (1.47%, Enterobius vermicularis (0.87%, Strongyloides stercoralis (0.87%, Taenia sp. (0.87%, and Trichuris trichiura (0.87%. The rate of false positives in the dot-ELISA test was improved by serum absorption each with A. suum antigens, with a decrease of cross-reactions. In conclusion, human toxocariasis is highly frequent in this population and some risk factors like dog/cat ownership, presence of pets within house, and previous history of geophagia were observed in the present study.O propósito do presente estudo foi estimar a freqüência da toxocaríase no distrito de Cauday, Cajamarca, Peru, usando o dot-ELISA teste. Entre junho e outubro de 2005, um total de 256 pessoas foram avaliadas. Coletaram-se amostras de sangue para o teste de dot-ELISA e para o exame hematológico e amostras de fezes para exame parasitol

[The lysate and recombinant antigens in ELISA-test-systems for diagnostic of herpes simplex].

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Ganova, L A; Kovtoniuk, G V; Korshun, L N; Kiseleva, E K; Tereshchenko, M I; Vudmaska, M I; Moĭsa, L N; Shevchuk, V A; Spivak, N Ia

2014-08-01

The lysate and recombinant antigens of various production included informula of ELISA-test-systems were analyzed. The ELISA-test-systems are used for detection of IgG to Herpes simplex virus type I and II. For testing the panel of serums PTH 201 (BBI Inc.) were used. The samples of this panel contain antibodies to Herpes simplex virus type I and II in mixed titers. The 69 serums of donors were used too (17 samples had IgG to Herpes simplex virus type I, 23 samples to Herpes simplex virus type II and 29 samples had no antibodies to Herpes simplex virus). The diagnostic capacity of mixture of recombinant antigens gG1 Herpes simplex virus type I and gG2 Herpes simplex virus type II (The research-and-production complex "DiaprofMed") was comparable with mixture of lysate antigen Herpes simplex virus type I and II (Membrane) EIE Antigen ("Virion Ltd."). In the test-systems for differentiation of IgG to Herpes simplex virus type I the recombinant antigen gG1 Herpes simplex virus type I proved to be comparable with commercial analogue Herpes simplex virus-1 gG1M ("Viral Therapeutics Inc."'). At the same time, capacity to detect IgG to Herpes simplex virus type II in recombinant protein gG2 Herpes simplex virus type II is significantly higher than in its analogue Herpes simplex virus-2 gG2c ("Viral Therapeutics Inc.").

Cystatin capture elisa immunodiagnosis of human fasciolosis at Chupaca-Junin Province

International Nuclear Information System (INIS)

Cornejo, W.; Alva, P.; Sevilla, C.; Huiza, A.; Universidad Nacional Mayor de San Marcos, Lima

2003-01-01

To determine the prevalence of human fasciolosis in an endemic area by means of an Enzyme-Linked Immunosorbent Assay (ELISA) using cystatin as a capture agent for the detection of specific antibodies to fasciola hepatica cysteine proteinases. An ELISA plate was sensitized with cystatin, incubated with excretory-secretory products of adult flukes, and followed by standard ELISA procedures. Clinical applicability of the cystatin capture ELISA for the immunodiagnosis of fasciolosis was tested with 200 serum samples of children and adults from an endemic area in Chupaca province, Junin department. Serum samples from the endemic area tested by cystatin capture ELISA showed 27/200 (13,5%) of positive cases. Fasciolosis remains a major health problem at Chupaca province, Junin department

IgM myeloma: A multicenter retrospective study of 134 patients.

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Castillo, Jorge J; Jurczyszyn, Artur; Brozova, Lucie; Crusoe, Edvan; Czepiel, Jacek; Davila, Julio; Dispenzieri, Angela; Eveillard, Marion; Fiala, Mark A; Ghobrial, Irene M; Gozzetti, Alessandro; Gustine, Joshua N; Hajek, Roman; Hungria, Vania; Jarkovsky, Jiri; Jayabalan, David; Laubach, Jacob P; Lewicka, Barbara; Maisnar, Vladimir; Manasanch, Elisabet E; Moreau, Philippe; Morgan, Elizabeth A; Nahi, Hareth; Niesvizky, Ruben; Paba-Prada, Claudia; Pika, Tomas; Pour, Ludek; Reagan, John L; Richardson, Paul G; Shah, Jatin; Spicka, Ivan; Vij, Ravi; Waszczuk-Gajda, Anna; Gertz, Morie A

2017-08-01

IgM myeloma is a rare hematologic malignancy for which the clinicopathological features and patient outcomes have not been extensively studied. We carried out a multicenter retrospective study in patients with diagnosis of IgM myeloma defined by >10% marrow involvement by monoclonal plasma cells, presence of an IgM monoclonal paraproteinemia of any size, and anemia, renal dysfunction, hypercalcemia, lytic lesions and/or t(11;14) identified by FISH. A total of 134 patients from 20 centers were included in this analysis. The median age at diagnosis was 65.5 years with a male predominance (68%). Anemia, renal dysfunction, elevated calcium and skeletal lytic lesions were found in 37, 43, 19, and 70%, respectively. The median serum IgM level was 2,895 mg dL -1 with 19% of patients presenting with levels >6,000 mg dL -1 . International Staging System (ISS) stages 1, 2, and 3 were seen in 40 (33%), 54 (44%), and 29 (24%) of patients, respectively. The malignant cells expressed CD20 (58%) and cyclin D1 (67%), and t(11;14) was the most common cytogenetic finding (39%). The median overall survival (OS) was 61 months. Higher ISS score was associated with worse survival (P = 0.02). Patients with IgM myeloma present with similar characteristics and outcomes as patients with more common myeloma subtypes. © 2017 Wiley Periodicals, Inc.

Diagnóstico de sífilis congênita: comparação entre testes sorológicos na mãe e no recém-nascido Diagnostic of congenital syphilis: a comparison between serological tests in mother and respective newborn

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Claudio Barsanti

1999-12-01

Full Text Available Para determinarmos as freqüências de sífilis materna e congênita, procedemos ao estudo da resposta aos testes treponêmicos e não treponêmicos de 1.000 parturientes e seus respectivos conceptos. As amostras de sangue venoso da mãe e do recém-nascido e do cordão umbilical foram testadas pelo método de VDRL. Os testes TPHA e ELISA (IgG, IgM foram utilizados para confirmar os resultados positivos; entre as mães VDRL positivas foi feita a pesquisa de anticorpos anti-HIV. Encontramos 24 (2,4% mães VDRL reativas (da população estudada, todas HIV negativas e, entre seus recém-nascidos, 18 (1,8% sangue de cordão e 19 (1,9% sangue venoso positivos. Não houve caso de reatividade nos recém-nascidos sem correspondente positividade materna. O teste de VDRL materno pôde, portanto, ser utilizado, isoladamente, na seleção dos casos de sífilis gestacional e congênita, já que não houve maior sensibilidade diagnóstica através da utilização dos testes treponêmicos, que comparados entre si, mostraram-se semelhantes.For the purpose of establishing the incidence of maternal and congenital syphilis among pregnant women at delivery and their respective newborns, a study was carried out to determine treponemic and non-treponemic serology in one thousand (1,000 parturient women and their children at Santa Marcelina Hospital - São Paulo, between June 95 and July 96. All blood samples (maternal venous, umbilical cord and newborn venous were VDRL-tested, treponemic tests (TPHA, ELISA IgG, ELISA IgM being applied whenever one of the samples from mother or newborn proved positive. Further, an anti-HIV search was run through ELISA among VDRL-positive mothers. Among the 1,000 parturients, 24 (2.4% were found to be VDRL-reactive; 18 (1.8% newborn children of these 24 mothers presented positive serology in their umbilical cord blood and 19 (1.9% in venous blood. No positive newborns were found for negative mothers. From the high occurrence of

Platelet antibodies of the IgM class in immune thrombocytopenic purpura

International Nuclear Information System (INIS)

Cines, D.B.; Wilson, S.B.; Tomaski, A.; Schreiber, A.D.

1985-01-01

The clinical course and response to therapy of patients with immune thrombocytopenic purpura (ITP) are not completely determined by the level of IgG present on the platelet surface. It is possible that antibodies of other immunoglobulin classes also play a role in platelet destruction in some of these patients. Therefore, the authors studied 175 patients with ITP for the presence of IgM anti-platelet antibodies using radiolabeled polyclonal or monoclonal anti-IgM. They observed that 57% of patients with clinical ITP had increased levels of IgM on their platelets, compared with normal controls and patients with thrombocytopenia who did not have ITP. They obtained similar results using either radiolabeled polyclonal or monoclonal anti-IgM, reagents whose integrity was first characterized using erythrocytes coated with defined amounts of IgM antibody. Among patients with increased platelet-IgM there was a significant correlation both with the presence of increased platelet-C3 as well as the amount of platelet-C3. The authors demonstrated the presence of warm-reacting IgM anti-platelet antibodies in the plasma of two of these patients who were further studied. These studies demonstrate the presence of warm-reacting IgM anti-platelet antibodies in some patients with ITP. They suggest that the binding of complement to platelets by IgM antibodies may initiate platelet clearance as well as enhance the effect of IgG antibodies in ITP

Variability of IgM response in hepatitis C virus infection

NARCIS (Netherlands)

Zaaijer, H. L.; Mimms, L. T.; Cuypers, H. T.; Reesink, H. W.; van der Poel, C. L.; Taskar, S.; Lelie, P. N.

1993-01-01

The IgM and IgG antibody response to various hepatitis C virus (HCV) antigens was studied in 8 patients who acquired posttransfusion HCV infection. IgM anti-HCV was detectable in only 4 of these patients, coincident with (1 patient) or later than (3 patients) the IgG anti-HCV response. Seven

Modification the ELISA Kit for diagnosis of “Pseudomonas aeruginosa and comparing it with ordinary ELISA kit”

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Taghreed A. Mohammad

2017-07-01

Full Text Available The first aim of the present study was to diagnosis Pseudomonas  aeruginosa by many tests. This study consisted "200 patients " who suffered from burn wound and compare with 100 health individuals (male and female as a control group, Vitek test was used to diagnose  118 (87 "local isolate  ATCC 15692" with 31 other isolate of Pseudomonas  aeruginosa  ((ATCC 15690, ATCC 15688  from 200 samples which were taken from burn patients. This result was similar to Analytical profile index ( API   test (118 isolates of  P. aeruginosa with 82 isolations of  other bacteria. Then the detection P. aeruginosa isolate  ATCC 15692 by new ELISA Technique and comparing its with modify the ordinary ELISA kit.

Microangiopathic antiphospholipid antibody syndrome due to anti-phosphatidylserine/prothrombin complex IgM antibody.

Science.gov (United States)

Senda, Yumi; Ohta, Kazuhide; Yokoyama, Tadafumi; Shimizu, Masaki; Furuichi, Kengo; Wada, Takashi; Yachie, Akihiro

2017-03-01

Herein we describe a case of microangiopathic antiphospholipid syndrome (MAPS) due to anti-phosphatidylserine/prothrombin complex (aPS/PT) IgM antibody successfully treated with rituximab. A significant correlation was observed between the clinical course and the aPS/PT IgM antibody titer, which can rise earlier before the appearance of clinical symptoms. Rituximab can be safely and effectively used for MAPS. Although detection of only aPS/PT IgM antibody is rare, aPS/PT IgM antibody might be associated with the pathogenesis of MAPS and might be a useful marker of disease activity. © 2017 Japan Pediatric Society.

Field trial of a brucellosis competitive enzyme linked immunoabsorbent assay (ELISA)

International Nuclear Information System (INIS)

Samartino, L.E.; Gregoret, R.J.; Sigal, G.

1998-01-01

The purpose of this study was to evaluate the performance of a competitive ELISA system for the diagnosis of bovine brucellosis in comparison to conventional aerological tests routinely used in Argentina. A total of 2.500 serum samples, comprising Brucella-free herds, vaccinated cattle and naturally infected animals, was tested by the following tests: buffered plate agglutination, Rose Bengal, 2-mercaptoethanol, complement fixation, and indirect and competitive ELISAs. Specificity and relative sensitivity at each test were determined. The competitive ELISA was considered suitable for detection of vaccinated animals and had higher specificity than the other tests. The results point to the potential use of the test as a complementary assay in the brucellosis control programme in Argentina. (author)

Toxicological Effects of Nickel Chloride on IgA+ B Cells and sIgA, IgA, IgG, IgM in the Intestinal Mucosal Immunity in Broilers

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Bangyuan Wu

2014-08-01

Full Text Available The objective of this study was to investigate the toxicological effects of dietary NiCl2 on IgA+ B cells and the immunoglobulins including sIgA, IgA, IgG and IgM in the small intestine and cecal tonsil of broilers by the methods of immunohistochemistry and enzyme-linked immunosorbent assay (ELISA. Two hundred and forty one-day-old avian broilers were randomly divided into four groups and fed on a control diet and three experimental diets supplemented with 300, 600, and 900 mg/kg NiCl2 for 42 days. Compared with the control group, the IgA+ B cell number and the sIgA, IgA, IgG, and IgM contents in the NiCl2-treated groups were significantly decreased (p < 0.05 or p < 0.01. It was concluded that dietary NiCl2 in the excess of 300 mg/kg had negative effects on the IgA+ B cell number and the abovementioned immunoglobulin contents in the small intestine and the cecal tonsil. NiCl2-reduced sIgA, IgA, IgG and IgM contents is due to decrease in the population and/or the activation of B cell. The results suggest that NiCl2 at high levels has intestinal mucosal humoral immunotoxicity in animals.

IgM nephropathy; can we still ignore it.

Science.gov (United States)

Vanikar, Aruna

2013-04-01

IgM nephropathy (IgMN) is a relatively less recognized clinico-immunopathological entity in the domain of glomerulonephritis , often thought to be a bridge between minimal change disease and focal segmental glomerulosclerosis. Directory of Open Access Journals (DOAJ), Google Scholar, Pubmed (NLM), LISTA (EBSCO) and Web of Science has been searched. IgM nephropathy can present as nephritic syndrome or less commonly with subnephrotic proteinuria or rarely hematuria. About 30% patients respond to steroids whereas others are steroid dependent / resistant. They should be given a trial of Rituximab or stem cell therapy. IgM nephropathy (IgMN) is an important and rather neglected pathology responsible for renal morbidity in children and adults in developing countries as compared to developed nations with incidence of 2-18.5% of native biopsies. Abnormal T-cell function with hyperfunctioning suppressor T-cells are believed to be responsible for this disease entity. Approximately one third of the patients are steroid responders where as the remaining two thirds are steroid resistant or dependent. Therapeutic trials including cell therapies targeting suppressor T-cells are required.

Comparison of in-house biotin-avidin tetanus IgG enzyme-linked-immunosorbent assay (ELISA) with gold standard in vivo mouse neutralization test for the detection of low level antibodies.

Science.gov (United States)

Sonmez, Cemile; Coplu, Nilay; Gozalan, Aysegul; Akin, Lutfu; Esen, Berrin

2017-06-01

Detection of anti-tetanus antibody levels is necessary for both determination of the immune status of individuals and also for planning preventive measures. ELISA is the preferred test among in vitro tests however it can be affected by the cross reacting antibodies. A previously developed in-house ELISA test was found not reliable for the antibody levels ≤1.0IU/ml. A new method was developed to detect low antibody levels correctly. The aim of the present study was to compare the results of the newly developed in-house biotin-avidin tetanus IgG ELISA test with the in vivo mouse neutralization test, for the antibody levels ≤1.0IU/ml. A total of 54 serum samples with the antibody levels of three different levels, =0.01IU/ml, 0.01-0.1IU/ml, 0.1-1IU/ml, which were detected by in vivo mouse neutralization test were studied by the newly developed in-house biotin-avidin tetanus IgG ELISA test. Test was validated by using five different concentrations (0.01IU/ml, 0.06IU/ml, 0.2IU/ml, 0.5IU/ml, 1.0IU/ml). A statistically significant correlation (r 2 =0.9967 p=0,001) between in vivo mouse neutralization test and in-house biotin-avidin tetanus IgG ELISA test, was observed. For the tested concentrations intra-assay, inter-assay, accuracy, sensitivity, specificity and coefficients of variations were determined as ≤15%. In-house biotin-avidin tetanus IgG ELISA test can be an alternative method to in vivo mouse neutralization method for the detection of levels ≤1.0IU/ml. By using in-house biotin-avidin tetanus IgG ELISA test, individuals with non protective levels, will be reliably detected. Copyright © 2017. Published by Elsevier B.V.

[Effect evaluation of three ELISA kits in detection of fasciolasis].

Science.gov (United States)

Ai, Lin; Chen, Mu-Xin; Chen, Shao-Hong; Chu, Yan-Hong; Cai, Yu-Chun; Zhou, Xiao-Nong; Chen, Jia-Xu

2013-04-01

To evaluate the effect of 3 ELISA kits on detection of human fasciolasis. Twenty-six serum samples from patients with fasciolasis, 180 serum samples from patients with other parasitic diseases as well as 26 serum samples from healthy people were detected by ELISA kits which using soluble antigen of Fasciola gigantica, Fasciola hepatica (Fg-ELISA and Fh-ELISA) as well as IgG antigen ELISA detection kits made by DRG company in Germany. The effects of the 3 kits were evaluated. The sensitivities of Fg-ELISA, Fh-ELISA, and DRG-ELISA were 100.0%, 80.8% (95% CI: 65.7%-95.9%) and 100.0%, respectively; the specificities of the three were 87.9% (95% CI: 83.5%-92.4%), 85.0%(95% CI: 80.1%-89.9%) and 83.5% (95% CI: 78.4%-88.6%), respectively, and Youden indexes of them were 0.88, 0.66 and 0.84, respectively. The detection rate of Fg-ELISA (100%) was significantly higher than that of Fh-ELISA (80.8%) (P DRG-ELISA for clinical sample tests as well as massive screening in fasciolasis endemic areas in southwest China.

[Diagnosis of human brucellosis. Role of pH in the seroagglutination test and influence of pH on the agglutinating activity of IgM, IgG and IgA antibodies].

Science.gov (United States)

Rubio Vallejo, Manuel; del Pozo, José L; Del Pozo León, José Luis; Hernández-Molina, Juan Manuel; Dorronsoro Ibero, Inés; Marrodán Ciordia, Teresa; Díaz García, Ramón

2002-04-01

To evaluate the role of pH in the seroagglutination test (SAT)and Rose Bengal (RB) test, and to determine the influence of pH on the agglutinating activity of IgM, IgG and IgA antibodies. The SAT was performed at pH 7.2 or pH 5.0 in standard microtiter-type polystyrene plates using Ring Test antigen or the Brucella suspension (BRUCAPT) provided in the Brucellacapt kits. Specific antibodies against native hapten were determined by radial immunodiffusion. Additionally, IgG, IgA and IgM fractions were separated from 8 sera by absorption chromatography and their agglutinating capacity was studied at pH 7.2 and 5.0. We studied 72 sera from patients with clinical brucellosis taken at the time of hospitalization, 16 from persons in contact with infected animals, and 16 from healthy donors. SAT results at pH 5.0 correlated with those obtained with the Rose Bengal test. Four Rose Bengal-positive sera were found to be SAT-negative at pH 7.2 and SAT-positive at pH 5.0. SAT performed at pH 5.0 with BRUCAPT antigen yielded higher titers than tests performed at pH 7.2 or 5.0 with Ring Test antigen (p IgA fractions were SAT-negative at pH 7.2 and SAT-positive at pH 5.0; the other 5 agglutinated at both pH conditions and were DTT-sensitive. All IgA fractions but one were positive by Rose Bengal. Agglutinating activity of the IgM fraction was not affected by pH. The SAT performed with the buffer and antigen suspension included in the Brucellacapt kit (pH 5.0) is highly useful for detecting agglutinating and non-agglutinating antibodies at pH 7.2.

Evaluation of a commercial rubella IgM assay for use on oral fluid samples for diagnosis and surveillance of congenital rubella syndrome and postnatal rubella.

Science.gov (United States)

Vijaylakshmi, P; Muthukkaruppan, V R; Rajasundari, A; Korukluoglu, G; Nigatu, W; L A Warrener; Samuel, D; Brown, D W G

2006-12-01

Clinical diagnosis (surveillance) of rubella is unreliable and laboratory confirmation is essential. Detection of virus specific IgM in serum is the most commonly used method. However, the use of serum necessitates the drawing of blood, either through venipuncture or finger/heel prick, which can be difficult in young babies. Oral fluid samples have proved useful as an alternative, less invasive sample for virus specific IgM detection however until recently no commercial rubella IgM tests were available, restricting the usefulness of this approach. To evaluate the performance of the Microimmune Rubella IgM capture EIA using oral fluid samples from outbreaks as well as in cases of suspected congenital rubella syndrome (CRS). Paired serum and oral fluids were collected from cases during a rubella outbreak in three provinces in Turkey. Matched serum and oral fluid samples were collected from children with suspected CRS in an active surveillance programme at the Aravind Eye Hospital in South India. Serum samples were collected as part of the measles surveillance programme in Ethiopia. On serum samples the sensitivity and specificity of the Microimmune Rubella IgM capture EIA compared to Behring Enzygnost rubella IgM test was 96.9% (62/64; 95% CI 94.2-100%) and 100% (53/53; 95% CI 93.2-100%). On oral fluids compared to matched Behring results on serum the sensitivity was 95.5% (42/44; 95% CI 84.5-99.4%). The sensitivity and specificity of Microimmune Rubella IgM capture EIA on oral fluids from suspected CRS cases compared to serum results using Behring Enzygnost IgM assay was 100% (95% CI 84.5-100%) and 100% (95% CI 95.8-100.0%) respectively. Microimmune Rubella IgM capture EIA has adequate performance for diagnosis and surveillance of rubella in outbreak using either serum or oral fluid specimens.

Secretory IgM Exacerbates Tumor Progression by Inducing Accumulations of MDSCs in Mice.

Science.gov (United States)

Tang, Chih-Hang Anthony; Chang, Shiun; Hashimoto, Ayumi; Chen, Yi-Ju; Kang, Chang Won; Mato, Anthony R; Del Valle, Juan R; Gabrilovich, Dmitry I; Hu, Chih-Chi Andrew

2018-06-01

Chronic lymphocytic leukemia (CLL) cells can secrete immunoglobulin M. However, it is not clear whether secretory IgM (sIgM) plays a role in disease progression. We crossed the Eμ-TCL1 mouse model of CLL, in which the expression of human TCL1 oncogene was driven by the V(H) promoter-Ig(H)-Eμ enhancer, with MD4 mice whose B cells produced B-cell receptor (membrane-bound IgM) and sIgM with specificity for hen egg lysozyme (HEL). CLL cells that developed in these MD4/Eμ-TCL1 mice reactivated a parental Ig gene allele and secreted IgM, and did not recognize HEL. The MD4/Eμ-TCL1 mice had reduced survival, increased myeloid-derived suppressor cells (MDSC), and decreased numbers of T cells. We tested whether sIgM could contribute to the accumulation of MDSCs by crossing μS -/- mice, which could not produce sIgM, with Eμ-TCL1 mice. The μS -/- /Eμ-TCL1 mice survived longer than Eμ-TCL1 mice and developed decreased numbers of MDSCs which were less able to suppress proliferation of T cells. We targeted the synthesis of sIgM by deleting the function of XBP-1s and showed that targeting XBP-1s genetically or pharmacologically could lead to decreased sIgM, accompanied by decreased numbers and reduced functions of MDSCs in MD4/Eμ-TCL1 mice. Additionally, MDSCs from μS -/- mice grafted with Lewis lung carcinoma were inefficient suppressors of T cells, resulting in slower tumor growth. These results demonstrate that sIgM produced by B cells can upregulate the functions of MDSCs in tumor-bearing mice to aggravate cancer progression. In a mouse model of CLL, production of secretory IgM led to more MDSCs, fewer T cells, and shorter survival times for the mice. Thus, secretory IgM may aggravate the progression of this cancer. Cancer Immunol Res; 6(6); 696-710. ©2018 AACR . ©2018 American Association for Cancer Research.

A comparative study of an elisa test and an indirect immunofluorescence test for serological diagnosis of Babesia bovis infection

International Nuclear Information System (INIS)

Martins, J.R.; Cheong, F.H.; Correa, B.L.; Radley, D.E.; Cereser, V.H.

1998-01-01

Detection of antibodies to Babesia bovis in cattle is essential for the understanding of the epidemiology of babesiosis and this study was concerned with comparing the indirect fluorescent antibody with the ELISA. Both assays gave rise to 100% sensitivity whilst the ELISA was shown to be marginally more specific at 98%. The ease of use and low cost of the ELISA would make it the more obvious choice in conducting future serological surveys for this parasite. (author)

Seroprevalence of toxoplasmosis in voluntary blood donors of Puducherry and surrounding districts of Tamil Nadu.

Science.gov (United States)

Stephen, Selvaraj; Pradeep, Jothimani; Anitharaj, Velmurugan; Janarthanam, Venkatraman

2017-12-01

Our objective is to study the seroprevalence of toxoplasmosis in the voluntary blood donors of Puducherry and surrounding districts of Tamil Nadu. A total of 275 healthy blood donors were screened for the presence of IgM and IgG antibodies to Toxoplasma gondii by ELISA test. Donor samples positive for IgM and/or IgG antibodies to T. gondii were subjected to IgG avidity ELISA. While, 54 out of 275 donors had IgG antibodies (19.66%), only one donor had IgM (0.36%) along with IgG. Among 54 IgG positive donors, only two had low avidity (3.7%), indicating recent exposure to the protozoa. Feasibility and cost effectiveness studies should be conducted throughout India to decide regarding screening of blood donors for toxoplasmosis.

Environmental Technology Verification Report for Abraxis Ecologenia® 17β-Estradiol (E2) Microplate Enzyme-Linked Immunosorbent Assay (ELISA) Test Kits

Science.gov (United States)

This verification test was conducted according to procedures specifiedin the Test/QA Planfor Verification of Enzyme-Linked Immunosorbent Assay (ELISA) Test Kis for the Quantitative Determination of Endocrine Disrupting Compounds (EDCs) in Aqueous Phase Samples. Deviations to the...

IgM but not IgG monoclonal anti-Nocardia brasiliensis antibodies confer protection against experimental actinomycetoma in BALB/c mice.

Science.gov (United States)

Gonzalez-Suarez, Maria L; Salinas-Carmona, Mario C; Pérez-Rivera, Isabel

2009-10-01

Nocardia brasiliensis is a facultative intracellular microorganism that produces a human chronic infection known as actinomycetoma. Human and mouse anti-N. brasiliensis antibody response identify P24, P26 and P61 immunodominant antigens. In this work, we generated immunoglobulin M (IgM) and IgG monoclonal antibodies (mAbs) specific to immunodominant P61 antigen. The monoclonal IgM (NbM1) and IgG2a (NbG1) antibodies were assessed for their in vitro bactericidal activity, in vivo protective effect and ability to block catalase activity. These mAbs specifically recognized P61, but they did not inhibit its enzyme activity. The in vitro bactericidal effect of NbG1 was higher than the killing ability of the IgM mAb. In vivo experiments with a murine model of experimental infection with N. brasiliensis injected into rear footpads was used to test the effect of NbM1 and NbG1. The negative untreated group developed a chronic actinomycetoma within 4 weeks. IgM mAbs conferred protection to BALB/c mice infected with N. brasiliensis. IgG mAb lacked this protective effect. IgM mAb showed a dose-response correlation between antibody concentration and lesion size. These results demonstrate that humoral immune response mediated by antigen-specific IgM antibody protects against an intracellular bacterial infection.

Genus and species-specific IgG and IgM antibodies pulmonary tuberculosis

International Nuclear Information System (INIS)

Butt, T.; Abbassi, S.A.; Ahmad, R.N.; Mahmood, A.; Karamat, K.A; Malik, H.S.; Anwar, M.

2004-01-01

Objective: To evaluate three different enzyme immunoassays for serological diagnosis of pulmonary tuberculosis and to compare their diagnostic accuracy in different combinations. Subjects and Methods: Sera from patients suffering from pulmonary tuberculosis (n=94) with sputum positive for acid fast bacilli (AFB) and sera from control group of healthy individuals (n=90) with sputum negative for AFB were tested by Pathozyme-Myco G EIA, Pathozyme-TB Complex Plus EIA and Pathozyme Myco M EIA kits for the genus-specific IgG and IgM, and the species-specific IgG antibodies against antigens of Mycobacterium tuberculosis. Results: The detection of IgG against genus-specific antigens by Pathozyme-Myco G had a sensitivity of 46% and a specificity of 93%, of IgG against species-specific antigens by Pathozyme- TB Complex Plus had a sensitivity of 64% and specificity of 97% and of IgM against genus-specific antigens by Pathozyme Myco M had a sensitivity of 67% and specificity of 98%. When the results of these immunoassays were evaluated in combination, their sensitivity improved. Combination of genus-specific IgM and species-specific IgG yielded best results with a sensitivity of 87% and specificity of 93%. Conclusion: The sensitivity of serological diagnosis of tuberculosis is low, but it can be increased by utilizing a combination of several antigens. (author)

Effect of the presence of two commercial adsorbents in animal feed on Aflatoxin B1 determination by ELISA kit test

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Francesco Masoero

2010-01-01

Full Text Available A rapid AFB1 detection method by ELISA kit test was used on feedstuff samples, and compared to an HPLC method, to verify if the presence of clay-adsorbent (SA could cause erroneous quantification of the toxin. Samples were obtained using two AFB1-contaminated feedstuffs (7.92 and 17.58 µg/kg for low and high contaminated feeds; LC and HC respectively, added either one of two commercial SAs (Atox® and Myco AD and three different inclusion doses (0, 10 and 20 g/kg, respectively for CTR, 1% and 2% doses. The HPLC and ELISA data were compared in CTR samples with a paired t-test. The AFB1 recoveries, performed with ELISA, were analysed as a completely randomized design using a 2×2×3 factorial arrangement. The ELISA method tended to underestimate the AFB1 concentrations with respect to the HPLC method, both in HC (P=0.050 and in LC (P<0.001 feedstuffs. A more drastic reduction (P<0.001 was observed when SAs were included in the two feedstuffs. In particular, Atox® determined an AFB1 recovery of 15,5% in HC and 7,6% in LC (1% dose and of 11,1% in HC and 8,4% in LC (2% dose. Less severe penalisation were observed when Myco AD was added to feeds.

Latent class analysis of bulk tank milk PCR and ELISA testing for herd level diagnosis of Mycoplasma bovis

DEFF Research Database (Denmark)

Nielsen, Per Kantsø; Petersen, Mette Bisgaard; Nielsen, Liza Rosenbaum

2015-01-01

of this study was to evaluate the herd-level diagnostic performance of an indirect ELISA test by comparison to a real-time PCR test when diagnosing M. bovis in cattle herds of bulk tank milk. Bulk tank milk samples from Danish dairy herds (N=3437) were analysed with both the antibody detecting BIO K 302 M...

Emerging functions of natural IgM and its Fc receptor FCMR in immune homeostasis

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Hongsheng eWang

2016-03-01

Full Text Available Most natural IgM antibodies are encoded by germline Ig sequences and are produced in large quantities by both mice and humans in the absence of intentional immunization. Natural IgM are reactive with many conserved epitopes, including those shared by microorganisms and autoantigens. As a result, these antibodies play important roles in clearing intruding pathogens, as well as apoptotic/necrotic cells and otherwise damaged tissues. While natural IgM binds to target structures with low affinity due to a lack of significant selection by somatic hypermutation, its pentameric structure with 10 antigen binding sites enables these antibodies to bind multivalent target antigens with high avidity. Opsonization of antigen complexed with IgM is mediated by cell surface Fc receptors. While the existence of Fc alpha/mu receptor has been known for some time, only recently has the Fc receptor specific for IgM (FCMR been identified. In this review, we focus on our current understandings of how natural IgM and FCMR regulate the immune system and maintain homeostasis under physiological and pathological conditions.

Serology of Typhoid Fever in an Area of Endemicity and Its Relevance to Diagnosis

Science.gov (United States)

House, Deborah; Wain, John; Ho, Vo A.; Diep, To S.; Chinh, Nguyen T.; Bay, Phan V.; Vinh, Ha; Duc, Minh; Parry, Christopher M.; Dougan, Gordon; White, Nicholas J.; Hien, Tran Tinh; Farrar, Jeremy J.

2001-01-01

Currently, the laboratory diagnosis of typhoid fever is dependent upon either the isolation of Salmonella enterica subsp. enterica serotype Typhi from a clinical sample or the detection of raised titers of agglutinating serum antibodies against the lipopolysaccharide (LPS) (O) or flagellum (H) antigens of serotype Typhi (the Widal test). In this study, the serum antibody responses to the LPS and flagellum antigens of serotype Typhi were investigated with individuals from a region of Vietnam in which typhoid is endemic, and their usefulness for the diagnosis of typhoid fever was evaluated. The antibody responses to both antigens were highly variable among individuals infected with serotype Typhi, and elevated antibody titers were also detected in a high proportion of serum samples from healthy subjects from the community. In-house enzyme-linked immunosorbent assays (ELISAs) for the detection of specific classes of anti-LPS and antiflagellum antibodies were compared with other serologically based tests for the diagnosis of typhoid fever (Widal TO and TH, anti-serotype Typhi immunoglobulin M [IgM] dipstick, and IDeaL TUBEX). At a specificity of ≥0.93, the sensitivities of the different tests were 0.75, 0.55, and 0.52 for the anti-LPS IgM, IgG, and IgA ELISAs, respectively; 0.28 for the antiflagellum IgG ELISA; 0.47 and 0.32 for the Widal TO and TH tests, respectively; and 0.77 for the anti-serotype Typhi IgM dipstick assay. The specificity of the IDeaL TUBEX was below 0.90 (sensitivity, 0.87; specificity, 0.76). The serological assays based on the detection of IgM antibodies against either serotype Typhi LPS (ELISA) or whole bacteria (dipstick) had a significantly higher sensitivity than the Widal TO test when used with a single acute-phase serum sample (P ≤ 0.007). These tests could be of use for the diagnosis of typhoid fever in patients who have clinical typhoid fever but are culture negative or in regions where bacterial culturing facilities are not available

Immunodiagnosis of Human Fascioliasis by an Enzyme-Linked Immunosorbent Assay (ELISA) and a Micro-ELISA

OpenAIRE

Carnevale, Silvana; Rodríguez, Mónica I.; Santillán, Graciela; Labbé, Jorge H.; Cabrera, Marta G.; Bellegarde, Enrique J.; Velásquez, Jorge N.; Trgovcic, Jorge E.; Guarnera, Eduardo A.

2001-01-01

Enzyme-linked immunosorbent assay (ELISA) and micro-ELISA were evaluated for their ability to detect anti-Fasciola hepatica antibodies in humans by using excretory-secretory antigen. The sensitivity of each method was 100%, but the specificity was 100% for ELISA and 97% for micro-ELISA. The micro-ELISA could be used as a screening assay and ELISA could be used as a confirmatory method for the serodiagnosis of human fascioliasis.

Development of a species-specific coproantigen ELISA for human Taenia solium taeniasis.

Science.gov (United States)

Guezala, Maria-Claudia; Rodriguez, Silvia; Zamora, Humberto; Garcia, Hector H; Gonzalez, Armando E; Tembo, Alice; Allan, James C; Craig, Philip S

2009-09-01

Taenia solium causes human neurocysticercosis and is endemic in underdeveloped countries where backyard pig keeping is common. Microscopic fecal diagnostic methods for human T. solium taeniasis are not very sensitive, and Taenia saginata and Taenia solium eggs are indistinguishable under the light microscope. Coproantigen (CoAg) ELISA methods are very sensitive, but currently only genus (Taenia) specific. This paper describes the development of a highly species-specific coproantigen ELISA test to detect T. solium intestinal taeniasis. Sensitivity was maintained using a capture antibody of rabbit IgG against T. solium adult whole worm somatic extract, whereas species specificity was achieved by utilization of an enzyme-conjugated rabbit IgG against T. solium adult excretory-secretory (ES) antigen. A known panel of positive and negative human fecal samples was tested with this hybrid sandwich ELISA. The ELISA test gave 100% specificity and 96.4% sensitivity for T. solium tapeworm carriers (N = 28), with a J index of 0.96. This simple ELISA incorporating anti-adult somatic and anti-adult ES antibodies provides the first potentially species-specific coproantigen test for human T. solium taeniasis.

EVALUATION OF AN O-ANTIGEN ELISA FOR SCREENING CATTLE HERDS FOR SALMONELLA-TYPHIMURIUM

DEFF Research Database (Denmark)

Hoorfar, Jeffrey; Bitsch, V.

1995-01-01

A total of 2585 serum samples from 62 dairy herds located in four different regions of Denmark were tested in an O-antigen (0:1,4,5,12)-based ELISA for the detection of antibodies against Salmonella typhimurium. Ten closed herds from an island with no reported occurrence of salmonellosis for seve......A total of 2585 serum samples from 62 dairy herds located in four different regions of Denmark were tested in an O-antigen (0:1,4,5,12)-based ELISA for the detection of antibodies against Salmonella typhimurium. Ten closed herds from an island with no reported occurrence of salmonellosis...... for several years, and 12 herds from a salmonella enzootic area which had had clinical outbreaks of S typhimurium were used to define a herd ELISA cut-off value. When herds with at least 5 per cent of the serum samples having an optical density of >0.5 were considered ELISA-positive, all 10 herds from...... the salmonellosis-free island were ELISA-negative, and all but one of the 12 S typhimurium-infected herds were ELISA-positive, which resulted in a herd test sensitivity of 0.92 and herd test specificity of 1.0. Eleven of the 12 S typhimurium-infected herds were negative in a blocking ELISA based on a monoclonal...

Prevalence of Toxoplasma gondii infection in household and feral cats in Korea.

Science.gov (United States)

Kim, Sung-Eon; Choi, Ran; Kang, Seung-Won; Hyun, Changbaig

2017-09-01

This study was designed to investigate the prevalence rate of Toxoplasma gondii ( T. gondii ) infection in household cats in Korea. One hundred household cats and 50 feral cats from nine of the largest cities in Korea were enrolled in this study. The tests performed in this survey was an in-house rapid screen IgG and IgM combo test, faecal PCR test for T. gondii oocysts, and an ELISA immunoassay for IgG antibodies. There were no household cats positive for T. gondii infection detected using the in-house IgG and IgM rapid screen combo test, although 6/50 and 0/50 feral cats were positive in IgG and IgM tests, respectively. This initial finding was confirmed by subsequent ELISA test for IgG antibody and PCR for T. gondii in faeces. Despite the higher prevalence rate of the disease in feral cats in Korea, we did not find any household cats that were either infected or exposed previously to T. gondii in our study population. Our study indicates that there is minimal risk of T. gondii transmission from household cats to human in Korea.

Indirect Competitive Enzyme-Linked Immunosorbent Assay (ELISA).

Science.gov (United States)

Kohl, Thomas O; Ascoli, Carl A

2017-07-05

The indirect competitive ELISA (indirect cELISA) pits plate-immobilized antigen against antigens in solution for binding to antigen-specific antibody. The antigens in solution are in the test sample and are first incubated with antigen-specific antibody. These antibody-antigen complexes are then added to microtiter plates whose wells have been coated with purified antigen. The wells are washed to remove unbound antigen-antibody complexes and free antigen. A reporter-labeled secondary antibody is then added followed by the addition of substrate. Substrate hydrolysis yields a signal that is inversely proportional to antigen concentration within the sample. This is because when antigen concentration is high in the test sample, most of the antibody is bound before adding the solution to the plate. Most of the antibody remains in solution (as complexes) and is thus washed away before the addition of the reporter-labeled secondary antibody and substrate. Thus, the higher the antigen concentration in the test sample, the weaker the resultant signal in the detection step. The indirect cELISA is often used for competitive detection and quantification of antibodies against viral diseases in biological samples. © 2017 Cold Spring Harbor Laboratory Press.

The prevalence of toxoplasma igG and IgM in pregnant women residing in Rawalpindi

International Nuclear Information System (INIS)

Kausar, N.; Akhtar, S.; Ikram, A.

2010-01-01

Objective: To determine the prevalence of Toxoplasma gondii antibodies (IgG/IgM) among pregnant women visiting Military Hospital Rawalpindi and to develop a relationship between various risk factors and disease prevalence. Methods: One thousand pregnant women reporting in out patient Gynaecology department of Military Hospital (MH) Rawalpindi from October 2008 through January 2009 for antenatal check up were included in the study. Their serum samples were tested for the presence of Toxoplasma IgM and IgG immunoglobulins. Enzyme Linked immunosorbent assay test kits for both IgG and IgM were used to detect 1: gondii immunoglobulins in serum samples. Rest of the serum was stored at -20 degree C. Results: Of the 1000 women sampled at hospital, 46 (4.6%) had evidence of past infection and were seropositive for immunoglobulins of T. gondii IgG, while none of them were seropositive for IgM immunoglobulin, suggesting absence of recent infections during pregnancy. Conclusion: In twin cities of Islamabad and Rawalpindi, the sero prevalence of T. gondii IgG in pregnant women is relatively high (4.6%) as compared to other areas nearby. Consequently, the risk of, primary infection during pregnancy and the potential for congenital infection of foetus remains there as a large number of pregnant women were sero-negative for both the antibodies.

Amylolytic activity of IgM and IgG antibodies from patients with multiple sclerosis.

Science.gov (United States)

Saveliev, Andrew N; Ivanen, Dina R; Kulminskaya, Anna A; Ershova, Nadezhda A; Kanyshkova, Tat'yana G; Buneva, Valentina N; Mogelnitskii, Alexander S; Doronin, Boris M; Favorova, Olga O; Nevinsky, Georgy A; Neustroev, Kirill N

2003-05-01

IgG and IgM antibodies from the sera of patients with multiple sclerosis (MS) were found to possess amylolytic activity hydrolyzing alpha-(1-->4)-glucosyl linkages of maltooligosaccharides, glycogen, and several artificial substrates. Individual IgM fractions isolated from 54 analyzed patients with the clinically definite diagnoses of MS had approximately three orders of magnitude higher specific amylolytic activity than that for healthy donors, whereas IgG from only a few patients had high amylolytic activity. Strict criteria were used to prove that the amylolytic activity of IgMs and IgGs is their intrinsic property and is not due to any enzyme contamination. Fab fragments produced from IgM and IgG fractions of the MS patients displayed the same amylolytic activity. IgMs from various patients demonstrated different modes of action in hydrolyzing maltooligosaccharides.

ELISA-BASE: an integrated bioinformatics tool for analyzing and tracking ELISA microarray data

OpenAIRE

White, Amanda M.; Collett, James R.; Seurynck-Servoss, Shannon L.; Daly, Don S.; Zangar, Richard C.

2009-01-01

Summary:ELISA-BASE is an open source database for capturing, organizing and analyzing enzyme-linked immunosorbent assay (ELISA) microarray data. ELISA-BASE is an extension of the BioArray Software Environment (BASE) database system.

Evaluation of CSFV Antibody ELISAs for the differentiation of infected from vacci-nated animals

DEFF Research Database (Denmark)

Schroeder, Sabine; Blome, Sandra; Koenen, Frank

countries and out-breaks occurred recently e.g. in Germany, France, Hungary, Romania, Bulgaria, and the Slovak Republic. Preventive vaccination is prohibited within the EU, but emergency vaccination can be part of the strategy in case of a contingency. Using conventional vaccines, differentiation...... of vaccinated from infected animals (DIVA) is not possible. Newly developed modified live marker vaccines allow a DIVA strategy based on the use of enzyme linked immunosorbent assay (ELISA) tests. The aim of this study was to evaluate CSF virus (CSFV) Antibody ELISAs, com-mercially available in Europe......, for their diagnostic sensitivity as well as for their potential in differentiating between infected and marker vaccinated animals. Two newly available ELISAs were included into the tests, the Priocheck® CSFV Erns ELISA, a special DIVA test, and the LDL Pigtype® CSFV Antibody ELISA. An inter-laboratory comparison test...

Efficacy of an enzyme-linked immunosorbent assay as a diagnostic tool for schistosomiasis mansoni in individuals with low worm burden

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Edward José de Oliveira

2005-07-01

Full Text Available IgM-ELISA is an immunoenzymatic method useful for detection of IgM antibodies against a fraction of Schistosoma mansoni adult worm antigen (AWA that is soluble in trichloroacetic acid (AWA-TCA. This method was applied to three groups of individuals with different clinical and epidemiological characteristics, and the results compared with those obtained by other diagnostic methods: immunofluorescence test for detection of IgM antibodies (IgM-IFT or IgG antibodies (IgG-IFT, ELISA for detection of IgG antibodies (IgG-ELISA, and two parasitological methods, Kato-Katz and miracidium hatching. The IgM-ELISA presented a sensitivity of 98%, when the parasitologic fecal examination was defined as reference diagnostic method, and a specificity of 98 and 97.3%, respectively for the group of clinically healthy individuals and other helminth carriers. A comparative analysis between the results of IgM-ELISA and those obtained by other serologic tests showed a good degree of agreement, with Kappa indices ranging from 0.95 to 0.98. The diagnostic efficacy of 97.8%, as determined with schistosomiasis patients with low parasitic burden, suggests the excellent performance of the IgM-ELISA and its usefulness for the diagnosis of schistosomiasis when applied in low endemic areas.

Syphilis serology: Seroprevalence in a selected population and considerations on the Euroline WB test

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Andrea Amodeo

2010-06-01

Full Text Available Introduction: The clinical diagnosis of syphilis is always supported by appropriate laboratory tests and the test results are interpreted with reference to the patient’s history. In the diagnosis of syphilis, the use of tests based on antibody search that recognize both treponemal and reaginic antigens increases the diagnostic chances. Our study discusses the various serological and alternative tests currently available along with their limitations, and relates their results to the likely corresponding clinical stage of the disease. Methods: in our laboratory were analyzed 264 sera and 4 liquor (123 Females, 145 Males. 187 patients are subject at low risk for luetic infection, including pregnant woman, patient with organ transplant, outpatients or hospitalized undergoing routine serological, and 81 from patients with confirmed syphilis including 4 pregnant women in antibiotic treatment, patients with suspected disease, HIV positive and patients with autoimmune diseases with Cardiolipin positive. All sera were tested with ELISA Anti-Treponema pallidum Screen (IgG / IgM and in parallel with agglutination tests VDRL and TPHA. On all positive sera was tested Euroline-WB EUROIMMUN and reading done with the program EuroLineScan. Results: by ELISA Anti-Treponema pallidum Screen IgG / IgM 162 sera were negative and 106 sera positive (39.5%, distributed as follows: 45 (42% with a value greater than 200 RU / ml, 43 (41% with a value> 22 RU / ml and 18 (17% with a borderline value between> 16 to <22 RU / ml. The execution of the Blot IgG showed: 18 negative sera, 6 with borderline value with one only band of specific antigens (p15, p45, p47 or p17, while 82, including 4 liquor (neurolue, were certainly positive showing more than one band antibody to the treponemal antigens. Only one patient had in place at the time of screening, an initial infection; in fact, there was a single clear positivity in the IgM protein bands, while 7 sera was uncertain values

Comparison of DOT-ELISA and Standard-ELISA for Detection of the Vibrio cholerae Toxin in Culture Supernatants of Bacteria Isolated from Human and Environmental Samples.

Science.gov (United States)

Meza-Lucas, Antonio; Pérez-Villagómez, María-Fernanda; Martínez-López, José-Patricio; García-Rodea, Ricardo; Martínez-Castelán, María-Guadalupe; Escobar-Gutiérrez, Alejandro; de-la-Rosa-Arana, Jorge-Luis; Villanueva-Zamudio, Altagracia

2016-09-01

A comparison of DOT-ELISA and Standard-ELISA was made for detection of Vibrio cholerae toxin in culture supernatants of bacteria isolated from human and environmental samples. A total of 293 supernatants were tested in a double blind assay. A correlation of 100 % was obtained between both techniques. The cholera toxin was found in 20 Inaba and 3 Ogawa strains. Positive samples were from seafood (17 samples), potable water (1 sample) and sewage (5 samples). The DOT-ELISA was useful as the standard-ELISA to confirm the presence of cholera toxin in the environmental samples.

Efficacy demonstration of tetanus vaccines by double antigen ELISA.

Science.gov (United States)

Rosskopf, U; Noeske, K; Werner, E

2005-09-01

This paper describes a double antigen ELISA (DAE) for rapid, specific and reliable assessment of the antitetanus immune status of horses and sheep. Compared with the indirect ELISA, the double antigen ELISA has the advantage of species-independent testing of sera. Thanks to its test design, it is more specific since the detected antibodies are forced to bind tetanus toxoid twice. In addition, it is very sensitive to tetanus antibodies, enabling the detection of low antibody titres, in range which is relevant for the assessment of the protective status (tetanus toxin neutralising antibodies). The detection limit of the DAE for tetanus antibodies is in the order of 10(-4) EU/ml. A comparison of in vitro results of individual sera with in vivo titres showed that horse sera with titres of 0.04 and 0.05 EU/ml in the DAE showed titres of > 0.05 IU and 0.034 IU/ml respectively during in vivo testing thus indicating good agreement. For tested sheep sera which were rated > 0.05 IU/ml in vivo, the corresponding titre in the DAE was 0.24 EU/ml. Clear tetanus antitoxin establishment of protective ELISA limits requires further comparative examination of sera with low titres (tetanus vaccines ad us. vet. As a consequence, the toxin neutralisation test (still being the standard method of choice for quantifying tetanus toxin neutralising antitoxin titres) could be replaced, since it requires too great a number of animals per test and involves considerable suffering for the animals. The test described here reduces the use of mice and guinea pigs within vaccine efficacy testing. In addition, it involves less exposure of the laboratory personnel to toxin.

Evaluation of ELISA screening test for detecting aflatoxin in biogenic dust samples

Energy Technology Data Exchange (ETDEWEB)

Durant, J.T.

1996-05-01

Aflatoxin is a carcinogenic chemical that is sometimes produced when agricultural commodities are infested by the fungi Aspergillus flavus and A. Parasiticus. Aflatoxin has been found to be present in air samples taken around persons handling materials likely to be contaminated. The purpose of this investigation was to demonstrate the feasibility of using an Enzyme Linked Immunosorbent Assay (ELISA) test kit that was developed to screen for aflatoxin in bulk agricultural commodities, to an air sample. Samples were taken from two environments likely to be contaminated with aflatoxin, a dairy farm feed mixing operation and a peanut bagging operation. The dust collected from these environments was considered to be biogenic, in that it originated primarily from biological materials.

Control of Trypanosoma evansi in buffalo in Indonesia: Identification of infected animals by Ag- and Ab-ELISA tests and treatment with diminazene aceturate

International Nuclear Information System (INIS)

Luckins, A.G.

2000-01-01

In order to control effectively infections with Trypanosoma evansi it is necessary to identify all infected individuals, including not only animals with patent infections but also those with non-patent infections. In order to provide a reliable means of diagnosing infected individuals, a combination of Ab-ELISA, Ag-ELISA and parasitological tests were used to identify for treatment groups of buffalo from Central Java, Indonesia in an area in which trypanosomosis caused by T. evansi is endemic. The animals were divided into four groups, Group A comprised animals positive by both Ab- and Ag-ELISA and/or parasitological examination. Group B consisted of animals positive by Ag-ELISA and Group C by Ab-ELISA only. Group D was a control group of animals that were negative by both serological and parasitological tests. All of Group A were treated with diminazene aceturate and the prevalence and incidence of infection in the four groups determined over approximately 12 months. The prevalence of infection declined in Group A declined from 100% to <25% in four months and remained at this low level until the end of the study. In the other groups, the serological prevalence increased up to 50%, although in Group D, the initially uninfected group, the increase was lower. Although treatment was effective in reducing the prevalence of infection, the cumulative incidence in the four groups was found to be similar. (author)

Detection of helicobacter pylori in nasal polyps using rapid urease test and ELISA

Directory of Open Access Journals (Sweden)

Masood Kaviani

2009-01-01

Full Text Available Introduction: Nasal polyposis is an inflammatory condition of unknown etiology. Recently concerns regarding gastroesophageal reflux or helicobacter pylori as a possible pathologic cause of nasal polyps have been increasing. The present study was planned to investigate the presence of helicobacter pylori in nasal polyps. Materials and Methods: This case-control study was undertaken enrolling 37 patients with nasal polyps who had undergone nasal endoscopic sinus surgery and 38 control subjects. Biopsy specimens of nasal polyps and inferior turbinates were assessed by rapid urease test. Blood samples of both study and control subjects were evaluated for anti H.pylori IgG by ELISA. H. pylori status was regarded positive, if both tests were positive. Results: Seropositivity was more common in the patients with nasal polyps (66.2% than control subjects (36.8% (P

Evaluation of an indirect ELISA for detection and typing of foot-and-mouth disease virus

International Nuclear Information System (INIS)

Prado, J.A.

1998-01-01

An indirect enzyme linked immunosorbent assay (ELISA) kit was used for diagnosis of foot-and-mouth disease virus (FMDV) types O1, A23, C3 which occurred in Rio Grande do Sul State, Southern Brazil during 1984-1994. The samples were randomly selected and tested by ELISA, Complement Fixation Test (CFT) and in tissue culture. Out of 106 samples 78 (73,5%) were positive by ELISA and 39 (36,8%) were found positive in CFT, when original suspensions were used. Once these samples were inoculated onto tissue culture both tests gave similar results, although ELISA picked up more positive samples during the 1st passage in tissue culture. The negative samples (16) included in this study were negative in all tests. The ELISA was more sensitive than and as specific as CFT. ELISA and tissue culture together were shown to be a better system for detection of foot-and-mouth disease virus antigen than CFT. (author)

Performance of the multitarget Mikrogen Chlamydia trachomatis IgG ELISA in the prediction of tubal factor infertility (TFI) in subfertile women : Comparison with the Medac MOMP IgG ELISA plus

NARCIS (Netherlands)

van Ess, Eleanne F.; Ouburg, Sander; Spaargaren, Joke; Land, Jolande A.; Morre, Servaas A.

2017-01-01

There is a need for more accurate Chlamydia trachomatis (CT) IgG antibody tests for tubal factor infertility (TFI) diagnostics. We evaluated the predictive value for TFI of Medac ELISA plus (MOMP) and multitarget Mikrogen ELISA (MOMP-CPAF-TARP). Based on Medac ELISA plus results, 183 subfertile

The Induction of IgM and IgG Antibodies against HLA or MICA after Lung Transplantation

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Annelieke W. M. Paantjens

2011-01-01

Full Text Available The production of IgG HLA antibodies after lung transplantation (LTx is considered to be a major risk factor for the development of chronic rejection, represented by the bronchiolitis obliterans syndrome (BOS. It has recently been observed that elevated levels of IgM HLA antibodies also correlates with the development of chronic rejection in heart and kidney transplantation. This study investigates the relationship between IgM and IgG antibodies against HLA and MICA after lung transplantation. Serum was collected from 49 patients once prior to transplantation and monthly for up to 1 year after lung transplantation was analyzed by Luminex to detect IgM and IgG antibodies against HLA and MICA. The presence of either IgM or IgG HLA and/or MICA antibodies prior to or after transplantation was not related to survival, gender, primary disease, or the development of BOS. Additionally, the production of IgG alloantibodies was not preceded by an increase in levels of IgM, and IgM levels were not followed by an increase in IgG. Under current immune suppressive regimen, although the presence of IgM antibodies does not correlate with BOS after LTx, IgM high IgG low HLA class I antibody titers were observed more in patients with BOS compared to patients without BOS.

The diagnosis of bovine basesiosis (babesia bovis) by means of the test of ELISA

International Nuclear Information System (INIS)

Leon Arenas, Edgar; Guillen, Ana Teresa; Silva, Maglene

1997-01-01

Between 1994 and 1996 a kit ELISA, developed by the FAO - IAEA for the diagnose of bovine babesiosis produced by Babesia bovis, was validated. There were processed a total of 547 blood serums from bovine between 9 and 18 months old, coming from high and low risk to illness areas. The point obtained for the test was 0.178 (DO) and the resulting percentages inside the population studied was 48% animal positive and 52% bovine negative. These results confirm that bovine population in Venezuela is in enzootic uncertainty areas for bovine babesiosis [es

MONITORING OF CMV INFECTION IN KIDNEY TRANSPLANT RECIPIENTS

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Zhivka Stoykova

2017-12-01

Full Text Available Human cytomegalovirus is a ubiquitous herpesvirus that establishes lifelong latency after primary infection, but can cause life-threatening disease in immunosuppressed patients. CMV invasive disease leads to significant morbidity and mortality following kidney transplantation. We tested 2 groups of patients - Group A included 20 potential kidney recipients and 29 potential donors investigated by ELISA and Group B included 53 adult kidney transplant recipients all of them tested in ELISA and 24 of them tested in QRT-PCR for CMV-DNA from plasma samples. In group A 16 (80% of 20 potential kidney recipients were anti-CMV IgG positive and 4 (20% were anti-CMV IgG negative. Twenty eight of 29 potential donors were found seropositive, and only one was not infected. In group B overall 119 ELISA tests for specific anti-CMV antibodies were performed. Anti-CMV IgM negative was 68 (57% of the tested samples, twelve (10% showed anti-CMV IgM equivocal results and 39 samples (33% were with anti-CMV IgM positive. Seven of them (13,2% showed repeatedly anti CMV IgM positive results. All 119 (100% displayed аnti-CMV IgG positive results. Overall 41 PCR analyses from plasma samples of 24 kidney transplant recipients (group B were performed. CMV-DNA replication was detected in 5 plasma samples obtained from 3 patients (12.5% at a different time - from 20 days till almost 8 years after the transplantation. Despite the high seroprevalence to CMV 20% of the potential recipients were at high risk of primary infection when receiving a kidney from a seropositive donor. Positive serological results during the regular post-transplantation monitoring complemented with or without clinical data are indicative and require further QRT-PCR analysis.

Food allergen analysis for processed food using a novel extraction method to eliminate harmful reagents for both ELISA and lateral-flow tests.

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Ito, Kaori; Yamamoto, Takayuki; Oyama, Yuriko; Tsuruma, Rieko; Saito, Eriko; Saito, Yoshikazu; Ozu, Takeshi; Honjoh, Tsutomu; Adachi, Reiko; Sakai, Shinobu; Akiyama, Hiroshi; Shoji, Masahiro

2016-09-01

Enzyme-linked immunosorbent assay (ELISA) is commonly used to determine food allergens in food products. However, a significant number of ELISAs give an erroneous result, especially when applied to highly processed food. Accordingly, an improved ELISA, which utilizes an extraction solution comprising the surfactant sodium lauryl sulfate (SDS) and reductant 2-mercaptoethanol (2-ME), has been specially developed to analyze food allergens in highly processed food by enhancing analyte protein extraction. Recently, however, the use of 2-ME has become undesirable. In the present study, a new extraction solution containing a human- and eco-friendly reductant, which is convenient to use at the food manufacturing site, has been established. Among three chemicals with different reducing properties, sodium sulfite, tris(3-hydroxypropyl)phosphine, and mercaptoethylamine sodium sulfite was selected as a 2-ME substitute. The protein extraction ability of SDS/0.1 M sodium sulfite solution was comparable to that of SDS/2-ME solution. Next, the ELISA performance for egg, milk, wheat, peanut, and buckwheat was evaluated by using model-processed foods and commercially available food products. The data showed that the SDS/0.1 M sulfite ELISA significantly correlated with the SDS/2-ME ELISA for all food allergens examined (p analysis of food allergens in processed food, showing consistency with the SDS/0.1 M sulfite ELISA results. Accordingly, a harmonized analysis system for processed food comprising a screening LF test and a quantitative ELISA with identical extraction solution has been established. The ELISA based on the SDS/0.1 M sulfite extraction solution has now been authorized as the revised official method for food allergen analysis in Japan.

Multiple Plasmodium falciparum erythrocyte membrane protein 1 variants per genome can bind IgM via its Fc fragment Fcμ

DEFF Research Database (Denmark)

Jeppesen, Anine; Ditlev, Sisse Bolm; Soroka, Vladyslav

2015-01-01

with severe clinical manifestations, such as cerebral malaria in children and placental malaria in pregnant women. PfEMP1 that can bind the Fc part of IgM (Fcμ) characterizes one such type, although the functional significance of this IgM binding to PfEMP1 remains unclear. In this study, we report...... resemble the rosette-mediating and IgM-binding PfEMP1 HB3VAR06, but none of them mediated formation of rosettes. We could map the capacity for Fc-specific IgM binding to DBLε domains near the C terminus for three of the four PfEMP1 proteins tested. Our study provides new evidence regarding Fc...

Test characteristics of milk amyloid A ELISA, somatic cell count, and bacteriological culture for detection of intramammary pathogens that cause subclinical mastitis.

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Jaeger, S; Virchow, F; Torgerson, P R; Bischoff, M; Biner, B; Hartnack, S; Rüegg, S R

2017-09-01

Bovine mastitis is an important disease in the dairy industry, causing economic losses as a result of withheld milk and treatment costs. Several studies have suggested milk amyloid A (MAA) as a promising biomarker in the diagnosis of mastitis. In the absence of a gold standard for diagnosis of subclinical mastitis, we estimated the diagnostic test accuracy of a commercial MAA-ELISA, somatic cell count (SCC), and bacteriological culture using Bayesian latent class modeling. We divided intramammary infections into 2 classes: those caused by major pathogens (e.g., Escherichia coli, Staphylococcus aureus, streptococci, and lacto-/enterococci) and those caused by all pathogens (major pathogens plus Corynebacterium bovis, coagulase-negative staphylococci, Bacillus spp., Streptomyces spp.). We applied the 3 diagnostic tests to all samples. Of 433 composite milk samples included in this study, 275 (63.5%) contained at least 1 colony of any bacterial species; of those, 56 contained major pathogens and 219 contained minor pathogens. The remaining 158 samples (36.5%) were sterile. We determined 2 different thresholds for the MAA-ELISA using Bayesian latent class modeling: 3.9 µg/mL to detect mastitis caused by major pathogens and 1.6 µg/mL to detect mastitis caused by all pathogens. The optimal SCC threshold for identification of subclinical mastitis was 150,000 cells/mL; this threshold led to higher specificity (Sp) than 100,000 cells/mL. Test accuracy for major-pathogen intramammary infections was as follows: SCC, sensitivity (Se) 92.6% and Sp 72.9%; MAA-ELISA, Se 81.4% and Sp 93.4%; bacteriological culture, Se 23.8% and Sp 95.2%. Test accuracy for all-pathogen intramammary infections was as follows: SCC, sensitivity 90.3% and Sp 71.8%; MAA-ELISA, Se 88.0% and Sp 65.2%; bacteriological culture, Se 83.8% and Sp 54.8%. We suggest the use of SCC and MAA-ELISA as a combined screening procedure for situations such as a Staphylococcus aureus control program. With Bayesian

Dengue Virus NS1 Protein as a Diagnostic Marker: Commercially Available ELISA and Comparison to qRT-PCR and Serological Diagnostic Assays Currently Used by the State of Florida

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Jason H. Ambrose

2017-01-01

Full Text Available Background. The proper management of patients infected with dengue virus requires early detection. Here, real-time molecular assays have proven useful but have limitations, whereas ELISAs that detect antibodies are still favored but results are obtained too late to be of clinical value. The production of DENV NS1 peaks early during infection and its detection can combine the advantages of both diagnostic approaches. Methods. This study compared assays currently used for detecting DENV infection at the Florida Department of Health including anti-DENV IgM and IgG ELISAs as well as qRT-PCR, against a commercially available DENV NS1 ELISA. These comparisons were made among a group of 21 human sera. Results. Nine of 14 (64.3% DENV qRT-PCR+ samples were also DENV NS1+. Interestingly, the 5 NS1− samples that were qRT-PCR+ were additionally IgM− and IgG+ suggesting a nonprimary infection. Compared to qRT-PCR, the NS1 assay had a sensitivity of 64.3%, specificity 100%, PPV of 100%, and NPV of 58.3%. Conclusions. The NS1 ELISA performed as expected in known DENV qRT-PCR+ samples; however negative NS1 results for qRT-PCR+ and IgG+ sera seemingly reduced the usefulness of the NS1 ELISA for nonprimary cases. We therefore conclude that diagnosis obtained via DENV NS1 ELISA deserves further investigation.

Evaluation of two new commercial tests for the diagnosis of acute dengue virus infection using NS1 antigen detection in human serum.

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Dussart, Philippe; Petit, Laure; Labeau, Bhety; Bremand, Laetitia; Leduc, Alexandre; Moua, David; Matheus, Séverine; Baril, Laurence

2008-08-20

We compared the performance of two new commercial tests for the detection of dengue NS1 protein during the clinical phase of dengue virus (DENV) infection-an immunochromatographic test allowing rapid detection of the NS1 antigen, Dengue NS1 Ag STRIP (Bio-Rad Laboratories - Marnes La Coquette, France), and a two-step sandwich-format microplate enzyme-linked immunosorbent assay (ELISA), pan-E Dengue Early ELISA (Panbio - Brisbane, Australia)-with a one-step sandwich-format microplate ELISA, the Platelia Dengue NS1 Ag test (Bio-Rad). We tested 272 serum samples from patients with dengue disease. Of these, 222 were from patients with acute infection of one of the four dengue serotypes, detected by RT-PCR and/or virus isolation. Forty-eight acute-phase serum samples from patients not infected with dengue virus were also included. The sensitivity of the Platelia Dengue NS1 Ag test on acute serum samples (n = 222) was 87.4% (95% confidence interval: 82.3% to 91.5%); that of Dengue NS1 Ag STRIP was 81.5% (95% CI: 75.8% to 86.4%) after 15 minutes and 82.4% (95% CI: 76.8% to 87.2%) after 30 minutes. Both tests had a specificity of 100% (97.5% CI, one-sided test: 92.6% to 100.0%). The pan-E Dengue Early ELISA had a sensitivity of 60.4% (95% CI: 53.4% to 66.8%) and a specificity of 97.9% (95% CI: 88.9% to 99.9%). Our findings support the use of diagnostic tools based on the NS1 antigen detection for the diagnosis of acute DENV infection. The immunochromatographic test, Dengue NS1 Ag STRIP-the first rapid diagnostic test for DENV infection-was highly sensitive and specific, and would therefore be a suitable first-line test in the field. The pan-E Dengue Early ELISA was less sensitive than the Platelia test; this two-step ELISA should be combined with DENV IgM antibody detection for the diagnosis of DENV infection.

Evaluation of two new commercial tests for the diagnosis of acute dengue virus infection using NS1 antigen detection in human serum.

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Philippe Dussart

Full Text Available BACKGROUND: We compared the performance of two new commercial tests for the detection of dengue NS1 protein during the clinical phase of dengue virus (DENV infection-an immunochromatographic test allowing rapid detection of the NS1 antigen, Dengue NS1 Ag STRIP (Bio-Rad Laboratories - Marnes La Coquette, France, and a two-step sandwich-format microplate enzyme-linked immunosorbent assay (ELISA, pan-E Dengue Early ELISA (Panbio - Brisbane, Australia-with a one-step sandwich-format microplate ELISA, the Platelia Dengue NS1 Ag test (Bio-Rad. METHODS: We tested 272 serum samples from patients with dengue disease. Of these, 222 were from patients with acute infection of one of the four dengue serotypes, detected by RT-PCR and/or virus isolation. Forty-eight acute-phase serum samples from patients not infected with dengue virus were also included. RESULTS: The sensitivity of the Platelia Dengue NS1 Ag test on acute serum samples (n = 222 was 87.4% (95% confidence interval: 82.3% to 91.5%; that of Dengue NS1 Ag STRIP was 81.5% (95% CI: 75.8% to 86.4% after 15 minutes and 82.4% (95% CI: 76.8% to 87.2% after 30 minutes. Both tests had a specificity of 100% (97.5% CI, one-sided test: 92.6% to 100.0%. The pan-E Dengue Early ELISA had a sensitivity of 60.4% (95% CI: 53.4% to 66.8% and a specificity of 97.9% (95% CI: 88.9% to 99.9%. CONCLUSION: Our findings support the use of diagnostic tools based on the NS1 antigen detection for the diagnosis of acute DENV infection. The immunochromatographic test, Dengue NS1 Ag STRIP-the first rapid diagnostic test for DENV infection-was highly sensitive and specific, and would therefore be a suitable first-line test in the field. The pan-E Dengue Early ELISA was less sensitive than the Platelia test; this two-step ELISA should be combined with DENV IgM antibody detection for the diagnosis of DENV infection.

Comparing ELISA test-positive prevalence, risk factors and management recommendations for Johne's disease prevention between organic and conventional dairy farms in Ontario, Canada.

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Pieper, Laura; Sorge, Ulrike S; DeVries, Trevor; Godkin, Ann; Lissemore, Kerry; Kelton, David

2015-11-01

Johne's disease (JD) is a chronic, infectious disease in cattle. Between 2010 and 2013, a voluntary JD control program was successfully launched in Ontario, Canada, including a Risk Assessment and Management Plan (RAMP) and JD ELISA testing of the entire milking herd. Over the last decade, the organic dairy sector has been growing. However, organic farming regulations and philosophies may influence the risk for JD transmission on Ontario organic dairy farms. The aim of this cross-sectional study was to investigate differences in JD ELISA test positive prevalence, risk factors for JD and recommendations for JD prevention between organic and conventional dairy herds in Ontario. RAMP results (i.e. RAMP scores and recommendations) and ELISA results were available for 2103 dairy herds, including 42 organic herds. If available, additional data on milk production, milk quality, and herd characteristics were gathered. Organic and conventional herds had a similar herd-level JD ELISA test-positive prevalence (26.2% and 27.2%, respectively). Organic herds (4.2%) had a higher within-herd JD ELISA test-positive prevalence compared to conventional herds (2.3%) if they had at least one JD test-positive animal on the farm. Organic farms had lower risk scores for biosecurity (9 points lower), and higher scores in the calving (7 points higher) and the calf-rearing management areas (4 points higher). After accounting for RAMP score, organic farms received fewer recommendations for the calving management area (Odds Ratio=0.41) and more recommendations in the adult cow management area (Odds Ratio=2.70). A zero-inflated negative binomial model was built with purchase of animals and the herd size included in the logistic portion of the model. Herd type (organic or conventional), colostrum and milk feeding practices, average bulk tank somatic cell count, and presence of non-Holstein breeds were included in the negative binomial portion of the model. Organic farms had a higher number of

Diversity and repertoire of IgW and IgM VH families in the newborn nurse shark.

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Rumfelt, Lynn L; Lohr, Rebecca L; Dooley, Helen; Flajnik, Martin F

2004-05-06

Adult cartilaginous fish express three immunoglobulin (Ig) isotypes, IgM, IgNAR and IgW. Newborn nurse sharks, Ginglymostoma cirratum, produce 19S (multimeric) IgM and monomeric/dimeric IgM1gj, a germline-joined, IgM-related VH, and very low amounts of 7S (monomeric) IgM and IgNAR proteins. Newborn IgNAR VH mRNAs are diverse in the complementarity-determining region 3 (CDR3) with non-templated nucleotide (N-region) addition, which suggests that, unlike in many other vertebrates, terminal deoxynucleotidyl transferase (TdT) expressed at birth is functional. IgW is present in the lungfish, a bony fish sharing a common ancestor with sharks 460 million years ago, implying that the IgW VH family is as old as the IgM VH family. This nurse shark study examined the IgM and IgW VH repertoire from birth through adult life, and analyzed the phylogenetic relationships of these gene families. IgM and IgW VH cDNA clones isolated from newborn nurse shark primary and secondary lymphoid tissues had highly diverse and unique CDR3 with N-region addition and VDJ gene rearrangement, implicating functional TdT and RAG gene activity. Despite the clear presence of N-region additions, newborn CDR3 were significantly shorter than those of adults. The IgM clones are all included in a conventional VH family that can be classified into five discrete groups, none of which is orthologous to IgM VH genes in other elasmobranchs. In addition, a novel divergent VH family was orthologous to a published monotypic VH horn shark family. IgW VH genes have diverged sufficiently to form three families. IgM and IgW VH serine codons using the potential somatic hypermutation hotspot sequence occur mainly in VH framework 1 (FR1) and CDR1. Phylogenetic analysis of cartilaginous fish and lungfish IgM and IgW demonstrated they form two major ancient gene groups; furthermore, these VH genes generally diversify (duplicate and diverge) within a species. As in ratfish, sandbar and horn sharks, most nurse shark IgM VH

Performance of the ELISA test for the diagnosis of cysticercosis using experimentally and naturally cattle infected with metacestode of Taenia saginata

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Rafaella Paola Meneguete dos Guimarães-Peixoto

2015-04-01

Full Text Available The bovine taeniasis-cysticercosis complex can be defined as a set of pathological changes caused by the adult form of Taenia saginata in humans and their larval form in animals (Cysticercus bovis. Data on the occurrence of bovine cysticercosis comes from the records of veterinary inspection of meat in slaughterhouses under fiscalization, where some positive cases may go unnoticed, especially in moderate infections. So, it is relevant the use of serological tests that have greater sensitivity than the post-mortem routine exams. Studies have shown the possible application of the ELISA test as a tool for epidemiological studies of the parasitosis and in the identification of animals with cysts. The aim of this study is to determine the detection threshold of the indirect ELISA test, using experimentally and naturally infected animals in detecting cases of cysticercosis. The sensitivity of the test to naturally infected animals using a cut-off 1 and 2 added with 2 standart-deviation (SD was of 12% and 24.4%, respectively. However, when using the cut-off of 1 and 2 added with 3 SD, the test sensitivity dropped, represented by 14.4% and 1.99% of the test sensitivity. As for the samples from experimentally infected animals, using the cut-off 1 and 2 added with 2 SD the sensitivity was 55.9% and 92.5%; and adding 3 SD the values found were 31.2% and 86%, respectively. The specificity of the test in all situations tested was 100%. It is important to take into account the right choice of control sera used in the ELISA test, whereas, according to its application, it is necessary to increase the sensitivity or specificity.

A liquid phase blocking ELISA for the detection of antibodies against infectious bronchitis virus

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Cardoso T.C.

1999-01-01

Full Text Available A liquid phase blocking ELISA (LPB-ELISA was developed for the detection and measurement of antibodies against infectious bronchitis virus (IBV. The purified and nonpurified virus used as antigen, the capture and detector antibodies, and the chicken hyperimmune sera were prepared and standardized for this purpose. A total of 156 sera from vaccinated and 100 from specific pathogen-free chickens with no recorded contact with the virus were tested. The respective serum titers obtained in the serum neutralization test (SNT were compared with those obtained in the LPB-ELISA. There was a high correlation (r2 = 0.8926 between the two tests. The LPB-ELISA represents a single test suitable for the rapid detection of antibodies against bronchitis virus in chicken sera, with good sensitivity (88%, specificity (100% and agreement (95.31%.

Truly selective primary IgM deficiency is probably very rare.

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Janssen, L M A; Macken, T; Creemers, M C W; Pruijt, J F M; Eijk, J J J; de Vries, E

2018-02-01

Isolated decreased serum-immunoglobulin (Ig)M has been associated with severe and/or recurrent infections, atopy and autoimmunity. However, the reported high prevalence of clinical problems in IgM-deficient patients may reflect the skewed tertiary centre population studied so far. Also, many papers on IgM deficiency have included patients with more abnormalities than simply IgM-deficiency. We studied truly selective primary IgM deficiency according to the diagnostic criteria of the European Society for Immunodeficiencies (ESID) (true sIgMdef) by reviewing the literature (261 patients with primary decreased serum-IgM in 46 papers) and analysing retrospectively all patients with decreased serum-IgM in a large teaching hospital in 's-Hertogenbosch, the Netherlands [1 July 2005-23 March 2016; n = 8049 IgM < 0·4 g/l; n = 2064 solitary (IgG+IgA normal/IgM < age-matched reference)]. A total of 359 of 2064 (17%) cases from our cohort had primary isolated decreased serum-IgM, proven persistent in 45 of 359 (13%) cases; their medical charts were reviewed. Our main finding is that true sIgMdef is probably very rare. Only six of 261 (2%) literature cases and three of 45 (7%) cases from our cohort fulfilled the ESID criteria completely; 63 of 261 (24%) literature cases also had other immunological abnormalities and fulfilled the criteria for unclassified antibody deficiencies (unPAD) instead. The diagnosis was often uncertain (possible sIgMdef): data on IgG subclasses and/or vaccination responses were lacking in 192 of 261 (74%) literature cases and 42 of 45 (93%) cases from our cohort. Our results also illustrate the clinical challenge of determining the relevance of a serum sample with decreased IgM; a larger cohort of true sIgMdef patients is needed to explore fully its clinical consequences. The ESID online Registry would be a useful tool for this. © 2017 British Society for Immunology.

New radioimmunoassay for IgM and IgG rheumatoid factors, based on a double antibody method

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Nordfang, O. (Rigshospitalet, Copenhagen (Denmark)); Hoeier-Madsen, M.; Lieberkind, J. (Statens Seruminstitut, Copenhagen (Denmark)); Halberg, P. (Medical Department, Division of Rheumatology, Hvidovre Hospital, Hvidovre, Denmark)

1981-11-30

A new radioimmunoassay has been developed for measuring IgM and IgG rheumatoid factors. Diluted sera from donors and patients were incubated with immunoprecipitates prepared from sheep serum and rabbit anti-sheep IgG antiserum. The precipitates were washed, and radioiodinated rabbit F(ab')/sub 2/ fragments specific for human IgM or IgG were added. The precipitates were isolated by filtration and measured in a gamma counter. With this assay IgM rheumatoid factors were detected in sera from all patients with seropositive rheumatoid arthritis and in sera from 40% of patients with seronegative rheumatoid arthritis. IgG rheumatoid factors were found in sera from 68% of the seropositive and 40% of the seronegative patients. Gel filtration experiments demonstrated that it is possible to detect monomeric IgG rheumatoid factors and IgM rheumatoid factors of molecular weight smaller than pentameric IgM. Furthermore it has been shown that IgG rheumatoid factor activity is still present after reduction of IgM rheumatoid factors with dithiotreitol.

IgM MGUS associated with anti-MAG neuropathy: a single institution experience.

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Talamo, Giampaolo; Mir, Muhammad A; Pandey, Manoj K; Sivik, Jeffrey K; Raheja, Divisha

2015-06-01

Anti-MAG neuropathy is a very rare form of acquired polyneuropathy associated with IgM monoclonal gammopathy of undetermined significance (MGUS). We conducted a retrospective review of 194 consecutive MGUS patients seen at the Penn State Hershey Cancer Institute. We identified six patients among 37 (16 %) with IgM MGUS with anti-MAG neuropathy. Interestingly, an additional patient had anti-MAG neuropathy without MGUS. Common clinical manifestations were numbness and paresthesias of the extremities and gait imbalance. All four patients treated with rituximab and none of the three untreated ones had a subjective improvement of their symptoms. We conclude that all patients with IgM MGUS and neuropathy should be screened for anti-MAG antibodies and, if positive, they should be offered treatment with rituximab.

Diversity and repertoire of IgW and IgM VH families in the newborn nurse shark

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Dooley Helen

2004-05-01

Full Text Available Abstract Background Adult cartilaginous fish express three immunoglobulin (Ig isotypes, IgM, IgNAR and IgW. Newborn nurse sharks, Ginglymostoma cirratum, produce 19S (multimeric IgM and monomeric/dimeric IgM1gj, a germline-joined, IgM-related VH, and very low amounts of 7S (monomeric IgM and IgNAR proteins. Newborn IgNAR VH mRNAs are diverse in the complementarity-determining region 3 (CDR3 with non-templated nucleotide (N-region addition, which suggests that, unlike in many other vertebrates, terminal deoxynucleotidyl transferase (TdT expressed at birth is functional. IgW is present in the lungfish, a bony fish sharing a common ancestor with sharks 460 million years ago, implying that the IgW VH family is as old as the IgM VH family. This nurse shark study examined the IgM and IgW VH repertoire from birth through adult life, and analyzed the phylogenetic relationships of these gene families. Results IgM and IgW VH cDNA clones isolated from newborn nurse shark primary and secondary lymphoid tissues had highly diverse and unique CDR3 with N-region addition and VDJ gene rearrangement, implicating functional TdT and RAG gene activity. Despite the clear presence of N-region additions, newborn CDR3 were significantly shorter than those of adults. The IgM clones are all included in a conventional VH family that can be classified into five discrete groups, none of which is orthologous to IgM VH genes in other elasmobranchs. In addition, a novel divergent VH family was orthologous to a published monotypic VH horn shark family. IgW VH genes have diverged sufficiently to form three families. IgM and IgW VH serine codons using the potential somatic hypermutation hotspot sequence occur mainly in VH framework 1 (FR1 and CDR1. Phylogenetic analysis of cartilaginous fish and lungfish IgM and IgW demonstrated they form two major ancient gene groups; furthermore, these VH genes generally diversify (duplicate and diverge within a species. Conclusion As in ratfish

Nested-PCR and a new ELISA-based NovaLisa test kit for malaria diagnosis in an endemic area of Thailand.

Science.gov (United States)

Thongdee, Pimwan; Chaijaroenkul, Wanna; Kuesap, Jiraporn; Na-Bangchang, Kesara

2014-08-01

Microscopy is considered as the gold standard for malaria diagnosis although its wide application is limited by the requirement of highly experienced microscopists. PCR and serological tests provide efficient diagnostic performance and have been applied for malaria diagnosis and research. The aim of this study was to investigate the diagnostic performance of nested PCR and a recently developed an ELISA-based new rapid diagnosis test (RDT), NovaLisa test kit, for diagnosis of malaria infection, using microscopic method as the gold standard. The performance of nested-PCR as a malaria diagnostic tool is excellent with respect to its high accuracy, sensitivity, specificity, and ability to discriminate Plasmodium species. The sensitivity and specificity of nested-PCR compared with the microscopic method for detection of Plasmodium falciparum, Plasmodium vivax, and P. falciparum/P. vivax mixed infection were 71.4 vs 100%, 100 vs 98.7%, and 100 vs 95.0%, respectively. The sensitivity and specificity of the ELISA-based NovaLisa test kit compared with the microscopic method for detection of Plasmodium genus were 89.0 vs 91.6%, respectively. NovaLisa test kit provided comparable diagnostic performance. Its relatively low cost, simplicity, and rapidity enables large scale field application.

Immune response to Mycoplasma pneumoniae P1 and P116 in patients with atypical pneumonia analyzed by ELISA

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Birkelund Svend

2004-02-01

Full Text Available Abstract Background Serology is often used for the diagnosis of Mycoplasma pneumoniae. It is important to identify specific antigens that can distinguish between the presence or absence of antibodies against M. pneumoniae. The two proteins, P116 and P1, are found to be immunogenic. By using these in ELISA it is possible to identify an immune response against M. pneumoniae in serum samples. Results A recombinant protein derived from the P116 protein and one from the P1 protein were used in two ELISA tests, rP116-ELISA and rP1-ELISA. Human serum samples from patients with atypical pneumonia were tested and compared to the results of the complement fixation test. There was a good agreement between the two tests but the rP1-ELISA showed the best discrimination between positive and negative samples. Conclusion Two ELISA tests based on recombinant proteins have been analysed and compared to the complement fixation test results. The two ELISA tests were found suitable for use in serodiagnostics of M. pneumoniae infections. The use of specific antigens eliminates the risk of cross reaction to an immune response against other bacteria.

Ocular sarcoidosis masked by positive IgM for toxoplasmosis

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Murilo Bertazzo Peres

Full Text Available ABSTRACT We report a case of ocular sarcoidosis with positive immunoglobulin (Ig M and IgG serology for toxoplasmosis. The patient was a young female with red painful eyes, bilateral eyelid edema, and panuveitis with periphlebitis. In laboratory testing, she was IgM and IgG positive for toxoplasmosis and anergic in the tuberculin test. Topical treatment for anterior uveitis and oral antibiotics for toxoplasmosis were started, without improvement. Orbit tomography showed increased lacrimal glands bilaterally, and chest X-ray radiographic findings were consistent with pulmonary sarcoidosis, which supported the presumed ocular sarcoidosis diagnosis. The patient was treated with oral prednisone and methotrexate without antibiotics. She showed clinical and vision improvement without recurrences during the 1-year follow-up. Ocular sarcoidosis is an important differential diagnosis requiring careful anamnesis and ophthalmological examinations. Ancillary tests, such as X-ray radiography, tomography, and clinical and laboratory evaluations may help rule out other causes. Treatment mainly consists of corticosteroids and immunosuppression.

The Platelia Aspergillus ELISA in diagnosis of invasive pulmonary aspergilosis (IPA).

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Siemann, M; Koch-Dörfler, M

2001-01-01

The sensitivity of a sandwich enzyme-linked immunosorbent assay (ELISA) for detecting Aspergillus galactomannan was evaluated with 66 serum samples and 113 specimens of the respiratory tract obtained from 52 patients with pulmonary diseases. The patients were divided into five groups: proven invasive pulmonary aspergillosis (IPA) (five patients), probable IPA (seven patients), Aspergillus colonization (eight patients) or unlikely Aspergillus infection (27 patients). Another five patients with doubtful diagnostic test results are discussed in detail. The results of the Platelia Aspergillus ELISA (Sanofi Pasteur, Freiburg, Germany) in testing specimens of the respiratory tract were 90% sensitivity in proven (serum 38%), 60% in probable (serum 37%) and 71% in Aspergillus colonization (serum 0%). Furthermore, 85% of the Aspergillus spp. from positive cultures of specimens of the respiratory tract were also detected in the ELISA. A total of 57% of the culture negative specimens of patients with a least one positive culture or proven aspergillosis in a series of specimens were positive in the ELISA.

Generation, characterization and in vivo biological activity of two distinct monoclonal anti-PEG IgMs

International Nuclear Information System (INIS)

Hashimoto, Yosuke; Shimizu, Taro; Mima, Yu; Abu Lila, Amr S.; Ishida, Tatsuhiro; Kiwada, Hiroshi

2014-01-01

PEGylation, the attachment of polyethylene glycol (PEG) to nanocarriers and proteins, is a widely accepted approach to improving the in vivo efficacy of the non-PEGylated products. However, both PEGylated liposomes and PEGylated proteins reportedly trigger the production of specific antibodies, mainly IgM, against the PEG moiety, which possibly leads to a reduction in safety and therapeutic efficacy of the PEGylated products. In the present study, two monoclonal anti-PEG IgMs — HIK-M09 via immunization with an intravenous injection of PEGylated liposomes (SLs) and HIK-M11 via immunization with a subcutaneous administration of PEGylated ovalbumin (PEG-OVA) were successfully generated. The generated IgMs showed efficient reactivity to mPEG 2000 conjugated to 1,2-distearoyl-sn-glycero-3-phospho-ethanolamine (DSPE), PEGylated liposome (SL) and PEG-OVA. It appears that HIK-M09 recognizes ethoxy (OCH 2 CH 2 ) repeat units along with a terminal motif of PEG, while HIK-M11 recognizes only ethoxy repeat units of PEG. Such unique properties allow HIK-M09 to bind with dense PEG. In addition, their impact on the in vivo clearance of the PEGylated products was investigated. It was found that the generated ant-PEG IgMs induced a clearance of SL as they were intravenously administered with SL. Interestingly, the HIK-M11, generated by PEG-OVA, induced the clearance of both SL and PEG-OVA, while the HIK-M09, generated by SL, induced the clearance of SL only. We here revealed that the presence of serum anti-PEG IgM and the subsequent binding of anti-PEG IgM to the PEGylated products are not necessarily related to the enhanced clearance of the products. It appears that subsequent complement activation following anti-PEG IgM binding is the most important step in dictating the in vivo fate of PEGylated products. This study may have implications for the design, development and clinical application of PEGylated products and therapeutics. - Highlights: • Two monoclonal anti-PEG IgMs

Generation, characterization and in vivo biological activity of two distinct monoclonal anti-PEG IgMs

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Hashimoto, Yosuke; Shimizu, Taro; Mima, Yu [Department of Pharmacokinetics and Biopharmaceutics, Subdivision of Biopharmaceutical Sciences, Institute of Health Biosciences, The University of Tokushima, 1-78-1, Sho-machi, Tokushima 770-8505 (Japan); Abu Lila, Amr S. [Department of Pharmacokinetics and Biopharmaceutics, Subdivision of Biopharmaceutical Sciences, Institute of Health Biosciences, The University of Tokushima, 1-78-1, Sho-machi, Tokushima 770-8505 (Japan); Department of Pharmaceutics and Industrial Pharmacy, Faculty of Pharmacy, Zagazig University, Sharqia Governorate, Zagazig 44519 (Egypt); Ishida, Tatsuhiro, E-mail: ishida@tokushima-u.ac.jp [Department of Pharmacokinetics and Biopharmaceutics, Subdivision of Biopharmaceutical Sciences, Institute of Health Biosciences, The University of Tokushima, 1-78-1, Sho-machi, Tokushima 770-8505 (Japan); Kiwada, Hiroshi [Department of Pharmacokinetics and Biopharmaceutics, Subdivision of Biopharmaceutical Sciences, Institute of Health Biosciences, The University of Tokushima, 1-78-1, Sho-machi, Tokushima 770-8505 (Japan)

2014-05-15

PEGylation, the attachment of polyethylene glycol (PEG) to nanocarriers and proteins, is a widely accepted approach to improving the in vivo efficacy of the non-PEGylated products. However, both PEGylated liposomes and PEGylated proteins reportedly trigger the production of specific antibodies, mainly IgM, against the PEG moiety, which possibly leads to a reduction in safety and therapeutic efficacy of the PEGylated products. In the present study, two monoclonal anti-PEG IgMs — HIK-M09 via immunization with an intravenous injection of PEGylated liposomes (SLs) and HIK-M11 via immunization with a subcutaneous administration of PEGylated ovalbumin (PEG-OVA) were successfully generated. The generated IgMs showed efficient reactivity to mPEG{sub 2000} conjugated to 1,2-distearoyl-sn-glycero-3-phospho-ethanolamine (DSPE), PEGylated liposome (SL) and PEG-OVA. It appears that HIK-M09 recognizes ethoxy (OCH{sub 2}CH{sub 2}) repeat units along with a terminal motif of PEG, while HIK-M11 recognizes only ethoxy repeat units of PEG. Such unique properties allow HIK-M09 to bind with dense PEG. In addition, their impact on the in vivo clearance of the PEGylated products was investigated. It was found that the generated ant-PEG IgMs induced a clearance of SL as they were intravenously administered with SL. Interestingly, the HIK-M11, generated by PEG-OVA, induced the clearance of both SL and PEG-OVA, while the HIK-M09, generated by SL, induced the clearance of SL only. We here revealed that the presence of serum anti-PEG IgM and the subsequent binding of anti-PEG IgM to the PEGylated products are not necessarily related to the enhanced clearance of the products. It appears that subsequent complement activation following anti-PEG IgM binding is the most important step in dictating the in vivo fate of PEGylated products. This study may have implications for the design, development and clinical application of PEGylated products and therapeutics. - Highlights: • Two monoclonal

Comparative evaluation of the diagnostic potential of recombinant envelope proteins and native cell culture purified viral antigens of Chikungunya virus.

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Khan, Mohsin; Dhanwani, Rekha; Kumar, Jyoti S; Rao, P V Lakshmana; Parida, Manmohan

2014-07-01

Despite the fact that Chikungunya resurgence is associated with epidemic of unprecedented magnitude, there are challenges in the field of its clinical diagnosis. However, serological tests in an ELISA format provide a rapid tool for the diagnosis of Chikungunya infection. Indeed, ELISAs based on recombinant proteins hold a great promise as these methods are cost effective and are free from the risk of handling biohazardous material. In this study, the performance of recombinant CHIKV antigens was compared in various ELISA formats for the diagnosis of Chikungunya. Two recombinant antigens derived from the envelope proteins of Chikungunya virus were prepared and evaluated by comparing their competence for detecting circulating antibodies in serum samples of patients infected with CHIKV using MAC-ELISA and indirect IgM-ELISA. The efficacy of the recombinant antigens was also compared with the native antigen. The indirect antibody capture IgM microplate ELISA revealed ≥90% concordance with the native antigen in detecting the CHIKV specific IgM antibodies whereas the recombinant antigen based MAC-ELISA showed 100% specificity. The recombinant antigens used in this study were effective and reliable targets for the diagnosis of CHIKV infection and also provide an alternative for native antigen use which is potentially biohazardous. © 2013 Wiley Periodicals, Inc.

Testing and Characterization of a Prototype Telescope for the Evolved Laser Interferometer Space Antenna (eLISA)

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Sankar, S.; Livas, J.

2016-01-01

We describe our efforts to fabricate, test and characterize a prototype telescope for the eLISA mission. Much of our work has centered on the modeling and measurement of scattered light performance. This work also builds on a previous demonstration of a high dimensional stability metering structure using particular choices of materials and interfaces. We will discuss ongoing plans to merge these two separate demonstrations into a single telescope design demonstrating both stray light and dimensional stability requirements simultaneously.

Recognition of Porphyromonas gingivalis gingipain epitopes by natural IgM binding to malondialdehyde modified low-density lipoprotein.

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S Pauliina Turunen

Full Text Available OBJECTIVE: Increased risk for atherosclerosis is associated with infectious diseases including periodontitis. Natural IgM antibodies recognize pathogen-associated molecular patterns on bacteria, and oxidized lipid and protein epitopes on low-density lipoprotein (LDL and apoptotic cells. We aimed to identify epitopes on periodontal pathogen Porphyromonas gingivalis recognized by natural IgM binding to malondialdehyde (MDA modified LDL. METHODS AND RESULTS: Mouse monoclonal IgM (MDmAb specific for MDA-LDL recognized epitopes on P. gingivalis on flow cytometry and chemiluminescence immunoassays. Immunization of C57BL/6 mice with P. gingivalis induced IgM, but not IgG, immune response to MDA-LDL and apoptotic cells. Immunization of LDLR(-/- mice with P. gingivalis induced IgM, but not IgG, immune response to MDA-LDL and diminished aortic lipid deposition. On Western blot MDmAb bound to P. gingivalis fragments identified as arginine-specific gingipain (Rgp by mass spectrometry. Recombinant domains of Rgp produced in E. coli were devoid of phosphocholine epitopes but contained epitopes recognized by MDmAb and human serum IgM. Serum IgM levels to P. gingivalis were associated with anti-MDA-LDL levels in humans. CONCLUSION: Gingipain of P. gingivalis is recognized by natural IgM and shares molecular identity with epitopes on MDA-LDL. These findings suggest a role for natural antibodies in the pathogenesis of two related inflammatory diseases, atherosclerosis and periodontitis.

A new ELISA for determination of potency in snake antivenoms.

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Rial, A; Morais, V; Rossi, S; Massaldi, H

2006-09-15

A competitive ELISA for potency determination of bothropic equine antivenom was developed and compared to the conventional in vivo ED(50) assay, with the aim of partially substituting the in vivo assay in the monitoring of antivenom immunoglobulin levels. On this purpose, blood samples were taken at different times during and after the immunization protocol of the lot of horses used for production of snake antivenom at the Instituto de Higiene, Uruguay. Both the competitive ELISA and the ED(50) assay were performed on those samples. In addition, a group of five commercial pepsin-digested antivenoms were tested by both methods. A significant (P<0.001) correlation (Pearson's r=0.957) was found between the ELISA titres and the corresponding ED(50) values, indicating that the in vitro test can estimate the neutralizing antibody capacity of the sera as well as the in vivo assay. By means of this new ELISA, it was found that the immunized animals maintained good venom antibody titres, in the order of 20-50% of the maximum achieved, even 10 month after the end of the immunization schedule. The main advantage of our ELISA design is its ability to correctly estimate the neutralization capacity of crude hyperimmune plasma and antivenom sera independently of their antibody composition in terms of whole IgG or F(ab')(2) fragment.

Comparative Diagnosis of Serum IgG1 and Coproantigen ELISA for Fasciolosis Detection of Goats in Mexico

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Molina-Mendoza, Pedro; Hernández-Guzmán, Karina; Olivares-Pérez, Jaime; Sarracent-Pérez, Jorge; Zumaquero-Ríos, José

2016-01-01

The objective of present study was to determine the prevalence of natural caprine fasciolosis in the Mixteca region of Mexico using coproantigen and serum IgG1 ELISA tests for comparative purposes. A total of 1070 serum and faecal samples were analyzed for IgG1 antibodies and coproantigens, using ELISA with E/S products as antigen and a monoclonal antibody-based sandwich ELISA. Prevalence of 73.46% was found using the serological ELISA and a percentage of 77.20 was found for coproantigen ELISA. The diagnostic sensitivity and specificity for serum ELISA were 86.7% and 96.4%, and for the coproantigen ELISA they were 93.1% and 97.8%, respectively. The seropositive samples were further categorized as low, medium, or high positivity. Results show a great proportion of low and medium positive goats when the serum ELISA test was used. Correlation coefficients between coproantigens and seropositivity were statistically significant (P < 0.01) for low seropositivity (r = 0.93) and medium seropositivity (r = 0.84). The accuracy of faecal antigen ELISA was higher compared to indirect ELISA serological test. Two ELISAs were shown to be useful for demonstrating the current status of F. hepatica infection in the endemic areas and can be employed in studies on epidemiology as well as anthelmintics treatment for preventing economic loss and the risk of transmission to humans. PMID:27563665

Accuracy of a point-of-care ELISA test kit for predicting the presence of protective canine parvovirus and canine distemper virus antibody concentrations in dogs.

Science.gov (United States)

Litster, A L; Pressler, B; Volpe, A; Dubovi, E

2012-08-01

Canine parvovirus (CPV) and canine distemper virus (CDV) are highly infectious and often fatal diseases with worldwide distributions, and are important population management considerations in animal shelters. A point-of-care ELISA test kit is available to detect serum antibodies to CPV and CDV, and presumptively to predict protective status. The aim of this study was to determine the diagnostic accuracy of the test compared to CPV hemagglutination inhibition titers and CDV serum neutralization titers determined by a reference laboratory, using sera collected from dogs housed at animal shelters. The ELISA test was used under both field and laboratory conditions and duplicate specimens were processed using an extra wash step. The test kit yielded accurate results (CPV: sensitivity 92.3%, specificity 93.5%; CDV: sensitivity 75.7%, specificity 91.8%) under field conditions. CDV sensitivity was improved by performing the test under laboratory conditions and using an optical density (OD) meter (laboratory performed 94.0%; OD 88.1%). Point-of-care ELISA testing for serum CPV and CDV antibody titers was demonstrated to be a useful tool for determining antibody status when making decisions regarding the need for CPV and/or CDV vaccination and also in animal shelters for population management. Copyright © 2012 Elsevier Ltd. All rights reserved.

Glove powder's carrying capacity for latex protein: analysis using the ASTM ELISA test.

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Beezhold, D; Horton, K; Hickey, V; Daddona, J; Kostyal, D

2003-01-01

Glove donning powders carry latex proteins and disperse them into the workplace environment. We have used the ASTM D6499 ELISA to quantify the amount of latex antigen bound to and carried by glove powders. We could differentiate between a small amount of protein actually bound to the powders and a larger amount carried by the powder. Enhanced binding of a major allergen, Hev b 5, to the starch powders was demonstrated by Western blot. The D6499 ELISA is able to measure total latex antigen, soluble and powder bound, simultaneously without the need to centrifuge the samples.

Comparison of ELISA, radioimmunoassay and stool examination for Schistosoma mansoni infection

Energy Technology Data Exchange (ETDEWEB)

Long, E G [Ministry of Health, St. Lucia (West Indies); McLaren, M M; Goddard, M J [London School of Hygiene and Tropical Medicine (UK); Bartholomew, R K; Goodgame, R [Rockefeller Foundation, New York (USA); Peters, P [Case Western Reserve Univ., Cleveland, OH (USA)

1981-01-01

A comparison was made of the sensitivity and specificity of four diagnostic tests for Schistosoma mansoni infection in a community of 516 untreated persons in St. Lucia, West Indies. Prevalence of infection as obtained by: (i) the Bell filtration technique was 44.4% (one filter) and 63.2% (three filters); (ii) the Kato thick smear, 60.2%; (iii) by radioimmunoassay (RIA), using /sup 125/I, 73.3%; and (iv) enzyme-immunoassay (ELISA) 70.9%. The age distribution of persons serologically positive but parasitologically negative showed these to be mostly children and persons 40 years old and over. By means of a statistical test due to Cochrane it was concluded that there was no evidence to indicate a difference between paired serological tests and paired parasitological tests in their diagnostic capability. There was a very significant difference between the Bell technique and the other three tests. The ELISA emerged as a less satisfactory test than the RIA or the Kato thick smear. The levels of sensitivity and specificity of each test were measured by Armitage's ''J'' index. The reliability of the Bell filtration technique was 64%, of the ELISA 68%, of the RIA 78% and of the Kato 85%.

Diagnosis of Caprine Arthritis Encephalitis Virus infection in dairy goats by ELISA, PCR and Viral Culture.

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Panneum, S; Rukkwamsuk, T

2017-03-01

For preventive and control strategies of Caprine Arthritis Encephalitis Virus (CAEV) infection in dairy goats, performance of the available diagnostic tests was described as one of the most important and necessary aspects. The study aimed at evaluating the diagnostic test performance, including PCR, ELISA and viral culture, for CAEV infection in dairy goats in Thailand. Blood samples of 29 dairy goats from five low- to medium-prevalence herds and one very low-prevalence herd were collected for PCR and ELISA methods. The performance of these two diagnostic methods was evaluated by comparing with cytopathic effects (CPE) in the co-cultivation of CAEV and primary synovial cells. Results indicated that sensitivity, specificity were, respectively, 69.6%, 100%, for PCR; and 95.7%, 83.3% for ELISA. The PCR assay tended to have lower sensitivity and higher specificity than ELISA. When multiple tests were applied, parallel testing provided sensitivity and specificity of 98.7% and 83.3%, while series testing showed sensitivity and specificity of 66.6% and 100% respectively. These results indicated that combination of ELISA and PCR provided some advantages and possibly offered optimal methods to detect CAEV-infected goats. Kappa value of the agreement between PCR and ELISA test was 0.34, indicating fair agreement. Regarding the possibility of antigenic variation between CAEV strains used in both PCR and ELISA assays, the actual circulating CAEV strain should be reviewed in order to develop and enhance the diagnostic tests using the CAE viral antigens derived from specific local strains of Thailand.

Genome-wide scan identifies variant in TNFSF13 associated with serum IgM in a healthy Chinese male population.

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Ming Yang

Full Text Available IgM provides a first line of defense during microbial infections. Serum IgM levels are detected routinely in clinical practice. And IgM is a genetically complex trait. We conducted a two-stage genome-wide association study (GWAS to identify genetic variants affecting serum IgM levels in a Chinese population of 3495, including 1999 unrelated subjects in the first stage and 1496 independent individuals in the second stage. Our data show that a common single nucleotide polymorphism (SNP, rs11552708 located in the TNFSF13 gene was significantly associated with IgM levels (p = 5.00×10(-7 in first stage, p = 1.34×10(-3 in second stage, and p = 4.22×10(-9 when combined. Besides, smoking was identified to be associated with IgM levels in both stages (P0.05. It is suggested that TNFSF13 may be a susceptibility gene affecting serum IgM levels in Chinese male population.

Comparative evaluation of antibody positive titer by ELISA and IFA in Theileria annulata vaccinated cattle in Iran

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Hashemi-Fesharki R.

2006-03-01

Full Text Available An enzyme linked immunosorbent assay (ELISA was used to evaluate antibody positive titer in vaccinated and non-vaccinated cattle using schizont infected myeloid cells as an antigen. The result was compared with indirect fluorescent antibody level in the same animals. For this study 116 milking cows, 95 vaccinated and 21 non-vaccinated, were bleeded in order to prepare sera. They were tested with both ELISA and IFA tests. 94 sera had positive antibody titer and 22 sera were negative through ELISA test but, with IFA test, only 89 sera showed positive antibody titer and 27 were negative. Thereby, it was concluded that the sensitivity and specificity of ELISA test in comparison with IFA test was 95.5 % and 66.6 % respectively. This study generally indicated that ELISA could be an effective test for seroepidemiological investigations of bovine tropical theileriosis, and it is considered to be valid as an additional test to distinguish the vaccinated from the non vaccinated cattle in order to schedule vaccination programs.

Evaluation of an indirect elisa for the diagnosis of bovine brucellosis in Patagonia, Argentina

International Nuclear Information System (INIS)

Uzal, F.A.; Carrasco, E.A.; Robles, C.A.; Echaide, S.

1998-01-01

Control and eradication of bovine brucellosis is usually based on the serological detection of antibodies. In Argentina, the Rose Bengal test (RB) and the Buffered Plate antigen test (BPA) are the two screening test officially recognized, while the 2-mercaptoethanol test (2ME) and the Tube Agglutination test (SAT) are the confirmatory assays currently in use. In order to improve the serological diagnosis of bovine brucellosis in Patagonia, Argentina, an indirect ELISA kit produced by the Joint FAO/IAEA Division was evaluated. Sera from negative non-vaccinated, negative but vaccinated and positive animals were tested by all the above techniques. The specificity of the I-ELISA (99.6% and 99.7%) was similar to that of the BPA, RB, 2ME and Complement Fixation test (CF) when used to test sera from non-vaccinated, negative and vaccinated, negative animals, respectively. The sensitivity of the I-ELISA (98%) was higher than the BPA test (96%) and the CF test (95,2%). The I-ELISA kit evaluated in this study was thought to be a valuable tool for the diagnosis of bovine brucellosis in Patagonia region where little epidemiological information is available about this disease and where large numbers of sera should be tested to obtain such information. (author)

The use of the antigen ELISA for monitoring tsetse and trypanosomosis control programmes in Zimbabwe

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Ries, R; Nqindi, J [Central Veterinary Lab., Causeway, Harare (Zimbabwe)

1997-02-01

Blood and serum samples from cattle originating from tsetse free and tsetse infested areas were analyzed using the Buffy Coat technique and an ELISA to detect trypanosomes and trypanosomal antigens, respectively. The results of the two tests were compared and apparent sensitivity and trypanosomal prevalence were calculated. The BCT seemed to be the most suitable test to detect acute infections, while the antigen capture ELISA (Ag-ELISA) was able to detect more chronic infections. The specificity of the Ag-ELISA was found to be very good, but the sensitivity of the test should be improved. One way to detect more T. congolense and T. vivax infections was to lower the cut-off point of percent positivity from 10 to 5%. (author). 1 ref., 1 fig., 7 tabs.

The use of the antigen ELISA for monitoring tsetse and trypanosomosis control programmes in Zimbabwe

International Nuclear Information System (INIS)

Ries, R.; Nqindi, J.

1997-01-01

Blood and serum samples from cattle originating from tsetse free and tsetse infested areas were analyzed using the Buffy Coat technique and an ELISA to detect trypanosomes and trypanosomal antigens, respectively. The results of the two tests were compared and apparent sensitivity and trypanosomal prevalence were calculated. The BCT seemed to be the most suitable test to detect acute infections, while the antigen capture ELISA (Ag-ELISA) was able to detect more chronic infections. The specificity of the Ag-ELISA was found to be very good, but the sensitivity of the test should be improved. One way to detect more T. congolense and T. vivax infections was to lower the cut-off point of percent positivity from 10 to 5%. (author). 1 ref., 1 fig., 7 tabs

Unexpectedly high leprosy seroprevalence detected using a random surveillance strategy in midwestern Brazil: A comparison of ELISA and a rapid diagnostic test.

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Frade, Marco Andrey C; de Paula, Natália A; Gomes, Ciro M; Vernal, Sebastian; Bernardes Filho, Fred; Lugão, Helena B; de Abreu, Marilda M M; Botini, Patrícia; Duthie, Malcolm S; Spencer, John S; Soares, Rosa Castália F R; Foss, Norma T

2017-02-01

Leprosy diagnosis is mainly based on clinical evaluation, although this approach is difficult, especially for untrained physicians. We conducted a temporary campaign to detect previously unknown leprosy cases in midwestern Brazil and to compare the performance of different serological tests. A mobile clinic was stationed at the main bus terminal in Brasília, Brazil. Volunteers were quizzed and given a clinical exam to allow categorization as either patients, known contacts of patients or non-contacts, and blood was collected to determine anti-PGL-I and anti-LID-1 antibody titers by ELISA and by the NDO-LID rapid test. New cases of leprosy and the impact of performing this broad random surveillance strategy were evaluated. Accuracy values and concordance between the test results were evaluated among all groups. Four hundred thirty-four individuals were evaluated, and 44 (10.1%) were diagnosed with leprosy. Borderline forms were the most frequent presentation. Both tests presented higher positivity in those individuals with multibacillary disease. Serological tests demonstrated specificities arround 70% for anti-PGL-1 and anti-LID ELISA; and arround 40% for NDO-LID. Sensitivities ranged from 48 to 62%. A substantial agreement between NDO-LID and ELISA with concomitant positive results was found within leprosy patients (Kappa index = 0.79 CI95% 0.36-1.22). The unexpectedly high leprosy prevalence in this population indicates ongoing community-based exposure to Mycobacterium leprae antigens and high rates of subclinical infection. All tests showed low specificity and sensitivity values and therefore cannot be considered for use as stand-alone diagnostics. Rather, considering their positivity among MB patients and non-patients, these tests can be considered effective tools for screening and identifying individuals at high risk who might benefit from regular monitoring.

Grantee Spotlight: Elisa Rodriguez, Ph.D., M.S.

Science.gov (United States)

Dr. Elisa M. Rodriguez tests the feasibility of community-based participatory research approaches to engaging Hispanics, African Americans, and the medically underserved in the Buffalo, NY area in biospecimen donation for cancer research.

ELISA test for the diagnosis of cysticercosis in pigs using antigens of Taenia solium and Taenia crassiceps cysticerci Teste ELISA para diagnóstico da cisticercose suína usando antígenos de larvas de Taenia solium e Taenia crassiceps

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Paulo Sérgio de Arruda PINTO

2000-04-01

Full Text Available In the present study ELISA was standardized for the diagnosis of swine cysticercosis based on necropsy parameters and confirmed positive and negative control sera. Serum samples from pigs with other infections were also assayed to determine possible cross-reactions. Four antigens were assayed: from Taenia crassiceps vesicular fluid (VF-Tcra and crude larvae extract (T-Tcra, and from Taenia solium extracts of scolex (S-Ts and of larvae (T-Ts. A checkerboard evaluation of antigen, serum and conjugate dilutions, as well as the use of Tween-20 and skim cow milk in wash and blocking solution had a marked effect on improving ELISA performance. All the antigens showed a good performance, but VF-Tcra was the best, with 96.0% and 80.0% sensitivities for cut-offs respectively at 2sd and 3sd, and corresponding specificities of 97.5% and 100.0%. Cross-reactivity was observed only with hydatidosis and ascaridiosis. In view of the high performance observed, the ELISA test should be recommended for the diagnosis of cysticercosis in suspected swine in slaughterhouses and for the screening of cysticercosis in swine production. These results will support integrated measures of cysticercosis control throughout the chain of swine production, effectively contributing to public health.Foi padronizado o teste ELISA para o diagnóstico da cisticercose suína. Após confirmação por exame post-mortem, os soros dos respectivos animais foram empregados como controles positivos e negativos. Soros de suínos portadores de infecções heterólogas foram ensaiados para determinação de reações cruzadas. Os quatro antígenos testados na fase de padronização foram líquido vesicular (VF e extrato total (T de larvas de Taenia crassiceps (Tcra e de extrato de escólex (S e de cisticercos (T de Taenia solium (Tso. A titulação em bloco das ótimas concentrações de antígenos e diluições de soros e de conjugado, bem como o emprego de Tween-20 e de leite desnatado nas

Serological and Molecular Biological Studies of Parvovirus B19, Coxsackie B Viruses, and Adenoviruses as Potential Cardiotropic Viruses in Bulgaria.

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Ivanova, Stefka Kr; Angelova, Svetla G; Stoyanova, Asya P; Georgieva, Irina L; Nikolaeva-Glomb, Lubomira K; Mihneva, Zafira G; Korsun, Neli St

2016-12-01

Inflammatory diseases of the heart (myocarditis, pericarditis) are commonly caused by viruses. Among the human cardiotropic viruses, parvovirus B19, Coxsackie B viruses, and adenoviruses play a leading role. The aim of the present study was to determine the presumptive causative role of parvovirus B19, Coxsackie B viruses, and adenoviruses in the development of myocarditis, pericarditis and dilated cardiomyopathy by demonstrating the presence of specific antiviral antibodies or viral DNA in patients' serum samples. We tested serum samples collected between 2010 and 2014 from 235 patients with myocarditis (n=108), pericarditis (n=79), myopericarditis (n=19), dilated cardiomyopathy (n=7), and fever of unknown origin accompanied by cardiac complaints (n=22). The mean age of patients with the standard deviation was 33 ± 18 years. Serological and molecular methods (ELISA for specific IgM/IgG antibodies to parvovirus B19 and IgM antibodies to Coxsackie B viruses and adenoviruses, and PCR for detection of parvovirus B19 in serum samples, respectively) were used in the study. Of all tested 235 serum samples, in 60 (25.5%) positive results for at least one of the three tested viruses were detected. Forty out of these 235 serum samples (17%) were Coxsackie B virus IgM positive. They were found in 17% (18/108) of the patients with myocarditis, in 15% (12/79) of those with pericarditis, in 16% (3/19) of those with myopericarditis and in 32% (7/22) in those with fever of unknown origin. The 63 Coxsackie B virus IgM negative patient's serum samples were tested by ELISA for presence of adenovirus IgM antibodies. Such were found in 4 patients with pericarditis and in 2 patients with fever of unknown origin. Every IgM negative sample (n=189) for Coxsackie B and adenovirus was further tested by ELISA for parvovirus B19 IgM/IgG antibodies. B19-IgM antibodies were detected in 14 patients (7.4%). The percentages for B19-IgM antibodies was 8% (7/90), 5% (3/63) and 31% (4/13) in the

The evaluation of CLIA, RIA and MSP-ELISA for measurement of thyroid hormones

International Nuclear Information System (INIS)

Jing Hua; Li Dan; Chen Yiguang; Zhou Huiqin; Xu Liyan

2005-01-01

To compare the characteristics of chemiluminescent immunoassay (CLIA), RIA and magnetic solid phase enzyme-linked immnosorbent assay (MSP-ELISA) in measuring thyroid hormones, TT 3 , TT 4 , FT 3 , FT 4 and TSH were tested in 40 samples of human serum and in standard samples of thyroid hormones by CLIA, RIA and MSP-ELISA respectively. The linearity, relativiy, precision, recovery of these three met hods were compared. The result showed that there were no statistical differences between CLIA, RIA and MSP-ELISA in linearity and relativity. CLIA was better than RIA and MSP-ELISA in precision and accuracy. (authors)

Improved detection of canine Angiostrongylus vasorum infection using real-time PCR and indirect ELISA.

Science.gov (United States)

Jefferies, Ryan; Morgan, Eric R; Helm, Jenny; Robinson, Matthew; Shaw, Susan E

2011-12-01

This study reports the development of a real-time PCR assay and an indirect ELISA to improve on current detection of canine Angiostrongylus vasorum infection. A highly specific fluorescent probe-based, real-time PCR assay was developed to target the A. vasorum second internal transcribed spacer region and detected DNA in EDTA blood, lung tissue, broncho-alveolar larvage fluid, endotracheal mucus, pharyngeal swabs and faecal samples. PCR was fast (∼1 h), highly efficient when using EDTA blood samples, consistently detected a single molecule of parasite DNA and did not amplify DNA from other parasitic nematodes or definitive host species. An indirect ELISA was also developed using the soluble protein fraction from adult A. vasorum worms. Some cross-reactive antigen recognition was observed when tested against sera from dogs infected with Crenosoma vulpis (n = 8), Toxocara canis (n = 5) and Dirofilaria immitis (n = 5). This was largely overcome by setting the cut-off for a positive result at an appropriately high level. Field evaluation of the real-time PCR and ELISA was conducted by testing sera and EDTA blood from dogs with suspected A. vasorum infection (n = 148) and compared with the Baermann's larval migration test in faeces. Thirty-one dogs were positive by at least one test. Of these, 20 (65%) were detected by the Baermann method, 18 (58%) by blood PCR, 24 (77%) by ELISA and 28 (90%) by blood PCR and ELISA together. Combined testing using real-time PCR and ELISA therefore improved the detection rate of A. vasorum infection and holds promise for improved clinical diagnosis and epidemiological investigation.

Development and evaluation of porcine cysticercosis QuickELISA in Triturus EIA analyzer.

Science.gov (United States)

Handali, Sukwan; Pattabhi, Sowmya; Lee, Yeuk-Mui; Silva-Ibanez, Maria; Kovalenko, Victor A; Levin, Andrew E; Gonzalez, Armando E; Roberts, Jacquelin M; Garcia, Hector H; Gilman, Robert H; Hancock, Kathy; Tsang, Victor C W

2010-01-01

We evaluated three diagnostic antigens (recombinant GP50, recombinant T24H, and synthetic Ts18var1) for cysticercosis and found that all three performed well in detecting cysticercosis in humans and pigs in several assay formats. These antigens were adapted to a new antibody detection format (QuickELISA). With one single incubation step which involves all reactants except the enzyme substrate, the QuickELISA is particularly suited for automation. We formatted the QuickELISA for the Triturus EIA analyzer for testing large numbers of samples. We found that in QuickELISA formats rGP50 and rT24H have better sensitivity and specificity than sTs18var1 for detecting porcine cysticercosis.

New 21 cm Power Spectrum Upper Limits From PAPER II: Constraints on IGM Properties at z = 7.7

Science.gov (United States)

Pober, Jonathan; Ali, Zaki; Parsons, Aaron; Paper Team

2015-01-01

Using a simulation-based framework, we interpret the power spectrum measurements from PAPER of Ali et al. in the context of IGM physics at z = 7.7. A cold IGM will result in strong 21 cm absorption relative to the CMB and leads to a 21 cm fluctuation power spectrum that can exceed 3000 mK^2. The new PAPER measurements allow us to rule out extreme cold IGM models, placing a lower limit on the physical temperature of the IGM. We also compare this limit with a calculation for the predicted heating from the currently observed galaxy population at z = 8.

Homologous ELISA for detection of oligomeric human TNF: properties of the assay.

Science.gov (United States)

Petyovka, N; Lyach, L; Voitenok, N N

1995-10-26

In order to quantify oligomeric human tumor necrosis factor-alpha (TNF), we have developed a sensitive homologous enzyme-linked immunosorbent assay (Hm-ELISA) using the same monoclonal antibody (MoAb) for both solid and liquid phase. Different anti-TNF MoAb have been compared in terms of their efficacy in the Hm-ELISA, affinity, neutralization capacity and epitope specificity. The data suggest, that effectiveness in the Hm-ELISA may represent a novel characteristic of MoAb. Of the MoAbs tested, 5 N was capable of recognizing oligomeric TNF in the Hm-ELISA with a detection limit of 15 pg/ml. Furthermore, using Hm-ELISA against human TNF, interleukin-8 (IL-8) and lymphotoxin, we have demonstrated that these cytokines are oligomeric in physiological solutions, but are converted into monomeric forms in the presence of the non-ionic detergent Tween 20. High salt buffer was employed to abrogate a nonspecific false positive reaction in the Hm-ELISA found in nearly half of the plasma samples obtained from healthy subjects. Finally, a good correlation between the Hm-ELISA and the L929 bioassay was observed for natural and recombinant TNF measured in human plasma.

Molecular characterization of Orientia tsutsugamushi serotypes causing scrub typhus outbreak in southern region of Andhra Pradesh, India.

Science.gov (United States)

Usha, K; Kumar, E; Kalawat, Usha; Kumar, B Siddhartha; Chaudhury, A; Gopal, D V R Sai

2016-10-01

Scrub typhus is a vector-borne zoonotic infection caused by Orientiatsutsugamushi. Local epidemiology of the circulating serotypes of scrub typhus is not available from most parts of India. We conducted this study for the diagnosis of scrub typhus using IgM ELISA and to detect O. tsutsugamushi serotypes circulating in southern Andhra Pradesh, India. Samples were collected from patients clinically suspected to have scrub typhus and were subjected to IgM ELISA to measure IgM antibodies against O. tsutsugamushi. Nested polymerase chain reaction (PCR) was performed targeting strain-specific regions in ELISA-positive samples. Of a total of 663 samples, 258 (38.91%) were found to be positive by IgM ELISA. Serotypes could be detected in 230 (34.69%) samples only. Only two serotypes, Karp and Kawasaki, were found in the serum samples, with the former being predominant. The dual infection of Karp and Kawasaki serotypes was found in seven patients. Other serotypes such as Gilliam, Kuroki and Kato were not detected in the samples. The nested PCR products proved useful in presumptively identifying the endemic O. tsutsugamushi serotypes. The present study could be significant in understanding scrub typhus epidemiology in this region.

False positive results occurring in a radioimmunoassay for hepatitis A IgM antibody of the IgM class

Energy Technology Data Exchange (ETDEWEB)

Bucens, M R; Pietroboni, G R; Harnett, G B [Virus Lab., Combined Microbiology Service, Queen Elizabeth II Medical Centre, Perth, Western Australia

1983-12-01

The diagnosis of hepatitis A infection is usually based on the presence of hepatitis A specific IgM in a single serum sample. The fortuitous observation in one patient that this reactivity was apparently still present 19 mth after her original illness led to the discovery that the ABBOTT HAVAB-M kit method may produce false positive results. A series of patients who had previously had hepatitis A was retested and false positive results were found in 6% of this group. Control groups consisted of patients with other acute and chronic liver disorders and other acute viral diseases. No reactivity was detected in the control sera. Sucrose gradient fractionation revealed that the factor responsible for the false positive results was associated only with serum fractions containing IgA and IgG and that it could be removed by absorption of sera with staphylococcal protein A but not by absorption with streptococcus AR1 or by 2-mercaptoethanol treatment. It was concluded that following hepatitis A infection some patients produce a rheumatoid factor-like substance (not of IgM class) which is cleared from the serum in 2-3 yr. The presence of this factor may lead to a misdiagnosis in patients presenting with jaundice.

Performance of the commercially available SERION ELISA classic Echinococcus IgG test for the detection of cystic echinococcosis in clinical practice.

Science.gov (United States)

Sarink, M J; Koelewijn, R; Slingerland, B C G C; Tielens, A G M; van Genderen, P J J; van Hellemond, J J

2018-06-28

Diagnosis of cystic echinococcosis (CE) is at present mainly based on imaging techniques. Serology has a complementary role, partly due to the small number of standardized and commercially available assays. Therefore we examined the clinical performance of the SERION ELISA classic Echinococcus IgG test. Using 10 U/ml as a cut-off point, and serum samples from 50 CE patients and 105 healthy controls, the sensitivity and specificity were 98.0% and 96.2%, respectively. If patients with other infectious diseases were used as negative controls, the specificity decreased to 76.9%, which causes poor positive predictive values. However, if results between 10 and 15 U/ml are classified as indecisive, the specificity of positive results (≥15 U/ml) increased to 92.5% without greatly affecting the sensitivity (92.0%). Using this approach in combination with imaging studies, the SERION ELISA classic Echinococcosis IgG test can be a useful aid in the diagnosis of CE.

Validation of pre-coated ELISA tests to detect antibodies against T. congolense and T. vivax

International Nuclear Information System (INIS)

Shumba, W.

2000-01-01

The anti-trypanosomal antibody detecting enzyme linked immunosorbent assay (ELISA) was first described in 1977 and was further developed for use in large scale surveys in Zimbabwe. More recently, the IAEA initiated a programme to improve the robustness and standardisation of the assay. The IAEA supplied plates pre-coated with either a crude T. congolense or T. vivax antigen and the reagents necessary for analysing samples. Parasitologically positive and negative sera were used to validate and determine the cut-off values of the two tests. The samples were tested and results analysed using a variety of cut-off values. The tests provided similar information although the T. congolense pre-coated plates gave significantly higher optical density values than the plates coated with T. vivax. Sensitivity and specificity values were calculated using the different cut-off points. Results indicate that the test using T. congolense antigen had the highest specificity and sensitivity for a given cut-off value. Although the test could distinguish positive from negative sera, it was quite difficult to provide a suitable cut-off value, but the value should be dictated by the use of the test. (author)

An ELISA for the quantitation of von Willebrand Factor

DEFF Research Database (Denmark)

Vinholt, Pernille Just; Overgaard, Martin; Diederichsen, Axel Cosmus Pyndt

2013-01-01

for measurement of von Willebrand factor-osteoprotegerin complex (VWF:OPG) in human plasma. Furthermore, the significance of VWF:OPG complex as a marker of cardiovascular disease (CVD) was evaluated. PATIENTS/METHODS: A sandwich ELISA for quantification of VWF:OPG was developed using a polyclonal rabbit anti...... with and without documented coronary calcification (total n=118). RESULTS AND CONCLUSIONS: The assay detected VWF:OPG complexes in human plasma, while no significant signal was observed when testing solutions containing VWF or recombinant OPG alone. Importantly, the ELISA assay was able to detect in vitro formed...

Biotin IgM Antibodies in Human Blood: A Previously Unknown Factor Eliciting False Results in Biotinylation-Based Immunoassays

Science.gov (United States)

Chen, Tingting; Hedman, Lea; Mattila, Petri S.; Jartti, Laura; Jartti, Tuomas; Ruuskanen, Olli; Söderlund-Venermo, Maria; Hedman, Klaus

2012-01-01

Biotin is an essential vitamin that binds streptavidin or avidin with high affinity and specificity. As biotin is a small molecule that can be linked to proteins without affecting their biological activity, biotinylation is applied widely in biochemical assays. In our laboratory, IgM enzyme immuno assays (EIAs) of µ-capture format have been set up against many viruses, using as antigen biotinylated virus like particles (VLPs) detected by horseradish peroxidase-conjugated streptavidin. We recently encountered one serum sample reacting with the biotinylated VLP but not with the unbiotinylated one, suggesting in human sera the occurrence of biotin-reactive antibodies. In the present study, we search the general population (612 serum samples from adults and 678 from children) for IgM antibodies reactive with biotin and develop an indirect EIA for quantification of their levels and assessment of their seroprevalence. These IgM antibodies were present in 3% adults regardless of age, but were rarely found in children. The adverse effects of the biotin IgM on biotinylation-based immunoassays were assessed, including four inhouse and one commercial virus IgM EIAs, showing that biotin IgM do cause false positivities. The biotin can not bind IgM and streptavidin or avidin simultaneously, suggesting that these biotin-interactive compounds compete for the common binding site. In competitive inhibition assays, the affinities of biotin IgM antibodies ranged from 2.1×10−3 to 1.7×10−4 mol/L. This is the first report on biotin antibodies found in humans, providing new information on biotinylation-based immunoassays as well as new insights into the biomedical effects of vitamins. PMID:22879954

Detection of ciguatoxin in fish tissue using sandwich ELISA and neuroblastoma cell bioassay.

Science.gov (United States)

Empey Campora, Cara; Dierking, Jan; Tamaru, Clyde S; Hokama, Yoshitsugi; Vincent, Douglas

2008-01-01

The applicability of a new enzyme-linked immunoassay (ELISA) for detecting ciguatoxin (CTX) in fish tissue was evaluated by testing three fish species commonly implicated in ciguatera fish poisoning in Hawaii. A total of 164 individual almaco jack (Seriola rivoliana) and greater amberjack (S. dumerili) and a total of 175 individuals of the blue-spotted grouper (Cephalopholis argus) were caught at various locations in the Hawaiian Islands. Muscle tissue from each individual was assessed for the presence of CTX using two methods: a semi-quantitative ELISA that was recently developed for detecting picogram levels of CTX in fish extract and a neuroblastoma (NB) cell assay commonly used to screen for marine toxins in fish. Results of the tests were highly correlated, with the ELISA indicating the presence of CTX in 9.4% of all fish samples, and the NB assay indicating toxicity in 6.8% of the fish samples. We conclude that the ELISA produces reliable and accurate results that are consistent with those provided by the accepted NB assay and that the ELISA has potential for future applications in screening fish populations for CTX.

Investigation of enrofloxacin residues in broiler tissues using ELISA and LC-MS/MS.

Science.gov (United States)

Panzenhagen, Pedro Henrique N; Aguiar, Waldemir S; Gouvêa, Raquel; de Oliveira, Andréa M G; Barreto, Fabiano; Pereira, Virgínia L A; Aquino, Maria Helena C

2016-01-01

This study investigated the efficiency of an enrofloxacin ELISA test kit to detect the presence of enrofloxacin residues in broiler tissues compared with LC-MS/MS. Broiler tissues from 72 samples consisting of 60 breast muscle, six pools of livers (500 g each) and six pools of kidneys (500 g each) were obtained from six different slaughterhouses. Breast muscle from 10 carcasses and pools of livers and kidneys from approximately 200 carcasses of the same flock were collected from each slaughterhouse. ELISA and HPLC were used to identify and quantify the contamination of the samples with enrofloxacin. A total of 72% of the analysed samples contained enrofloxacin residues detected by the ELISA and 22.2% were detected by LC-MS/MS. The mean values of enrofloxacin contamination found in chicken breast by ELISA and HPLC were 8.63 and 12.25 μg kg(-1), respectively. None of the samples exceeded the maximum limit of 100 μg kg(-1) by both methods set by the European Union as well as the Brazilian Agriculture Ministry. All positive samples for enrofloxacin residues detected by LC-MS/MS were also positive by ELISA. These data confirm the efficiency of the ELISA test, and suggest its use as a screening method for enrofloxacin residues in poultry tissues due to its quick results, low price and ease of applicability.

Serological profile of HSV-2 in patients attending STI clinic: Evaluation of diagnostic utility of HSV-2 IgM detection

Directory of Open Access Journals (Sweden)

Choudhry Shilpee

2009-07-01

Full Text Available Objective: The present study was done to evaluate the serological profile of herpes simplex virus-2 (HSV-2 among patients attending sexually transmitted infections (STI clinic and to determine the utility of detecting HSV-2 IgM antibodies in such patients. A correlation of HSV-2 infection with other STI including HIV has also been attempted. Materials and Methods: Hundred consecutive patients who attended STI clinic, with one or more of the complaints as enunciated by WHO in syndromic approach for the diagnosis of STI, were included as subjects. All subjects were screened for common STI by standard laboratory procedures/ commercially available kits. HSV-1 and HSV-2 IgM antibody was detected by commercially available enzyme immuno assay kit in all patient′s sera. Sera were also tested for other STI, namely HIV, Hepatitis B virus, Hepatitis C virus and Treponema pallidum. Antigen detection for Chlamydia trachomatis was done in genital swabs of all patients by Bio-Rad Chlamydia Microplate EIA 31189 (United States kit. Results: Thirty patients were found to have genital herpes. In 17/30 (56.6% patients, HSV-2 serology was found to correlate with the clinical diagnosis. The coexistence of other infection in HSV-2 seropositive patients was detected in 8/30 patients. None of the patients having concomitant infections were clinically diagnosed accurately. Sensitivity, specificity, positive predictive value and negative predictive value of IgM antibodies for the diagnosis of genital herpes was 73.91%, 90.91%, 70.83% and 92.91% respectively. Conclusion: HSV-2 IgM detection could only be used as a supportive test for the diagnosis of genital herpes . It needs to be emphasized that the sensitivity and positive predictive value scores are pointers for further improvement in the commercial assay systems and a large sample size may determine the broader utility of such systems.

Assessing the validity of an ELISA test for the serological diagnosis of human fascioliasis in different epidemiological situations.

Science.gov (United States)

Valero, M Adela; Periago, M Victoria; Pérez-Crespo, Ignacio; Rodríguez, Esperanza; Perteguer, M Jesús; Gárate, Teresa; González-Barberá, Eva M; Mas-Coma, Santiago

2012-05-01

To improve the diagnosis of human fascioliasis caused by Fasciola hepatica and Fasciola gigantica, we evaluated the diagnostic accuracy of an enzyme-linked immunosorbent assay (ELISA), with Fasciola antigen from the adult liver fluke, for the detection of IgG against fascioliasis in human sera. The sera of 54 fascioliasis cases, originating from three endemic areas, were used in this evaluation: (i) a hyperendemic F. hepatica area where humans usually shed a great number of parasite eggs in faeces (11 sera); (ii) an epidemic F. hepatica area where humans usually shed small amounts of parasite eggs (24 sera) and (iii) an overlap area of both Fasciola species and where human shedding of parasite eggs in faeces is usually scarce or non-existent (19 sera). One hundred and sixty-eight patients with other parasitic infections and 89 healthy controls were also analysed. The respective sensitivity and specificity of this assay were 95.3% (95% confidence intervals, 82.9-99.2%) and 95.7% (95% confidence intervals, 92.3-97.5%). No correlation between egg output and the OD450 values of the F. hepatica IgG ELISA test was observed. This test could be used both as an individual serodiagnostic test for human fascioliasis when backed up by a compatible clinical history together with a second diagnostic technique for other cross-reactive helminth infections, and in large-scale epidemiological studies of human fascioliasis worldwide. © 2012 Blackwell Publishing Ltd.

Evaluation of commercial ELISA kits for detection of antibodies against bovine atypical pestivirus

DEFF Research Database (Denmark)

Larska, Magdalena; Polak, Mirosław P.; Uttenthal, Åse

A group of emerging bovine pestiviruses becomes a possible threat to Bovine Viral diarrhea virus (BVDV) control and eradication programs in the countries of their origin and in the new continents due to the lack of validated detection methods. The use of ELISA kits may be acheaper, time saving...... and less laborious option allowing screening for antibodies in large populations. Since test specific for emerging and new BVDV strains are still under preparation, the purpose of this work was to evaluate available BVDV antibody ELISA assays for their ability to detect antibodies against Hobi-like viruses....... Analysis of a panel of sera obtained from calves experimentally inoculated with Hobi-like virus (isolated from a calf from Thailand) and BVDV type 1 strain using five different ELISA kits in comparison to neutralization test was performed. The specificity and sensitivity of the tests depended greatly...

Seroprevalence of human parvovirus B19 in healthy blood donors.

Science.gov (United States)

Kumar, Satish; Gupta, R M; Sen, Sourav; Sarkar, R S; Philip, J; Kotwal, Atul; Sumathi, S H

2013-07-01

Human parvovirus B19 is an emerging transfusion transmitted infection. Although parvovirus B19 infection is connected with severe complications in some recipients, donor screening is not yet mandatory. To reduce the risk of contamination, plasma-pool screening and exclusion of highly viraemic donations are recommended. In this study the prevalence of parvovirus B19 in healthy blood donors was detected by ELISA. A total of 1633 samples were screened for IgM and IgG antibodies against parvovirus B19 by ELISA. The initial 540 samples were screened for both IgM and IgG class antibodies and remaining 1093 samples were screened for only IgM class antibodies by ELISA. Net prevalence of IgM antibodies to human parvovirus B19 in our study was 7.53% and prevalence of IgG antibodies was 27.96%. Dual positivity (IgG and IgM) was 2.40%. The seroprevalence of human parvovirus B19 among blood donor population in our study is high, and poses an adverse transfusion risk especially in high-risk group of patients who have no detectable antibodies to B19. Studies with large sample size are needed to validate these results.

ELISA technique standardization for strongyloidiasis diagnosis

International Nuclear Information System (INIS)

Huapaya, P.; Espinoza, I.; Huiza, A.; Universidad Nacional Mayor de San Marcos, Lima; Sevilla, C.

2002-01-01

To standardize ELISA technique for human Strongyloides stercoralis infection diagnosis a crude antigen was prepared using filariform larvae obtained from positive stool samples cultured with charcoal. Harvested larvae were crushed by sonication and washed by centrifugation in order to obtain protein extracts to be used as antigen. Final protein concentration was 600 μg/mL. Several kinds of ELISA plates were tested and antigen concentration, sera dilution, conjugate dilution and cut off were determined to identify infection. Sera from patients with both hyper-infection syndrome and intestinal infection demonstrated by parasitological examination were positive controls and sera from people living in non-endemic areas with no infection demonstrated by parasitological examination were negative controls. Best values were 5 μg/mL for antigen, 1/64 for sera, 1/1000 for conjugate; optical density values for positive samples were 1,2746 (1,1065 - 1,4206, DS = 0,3284) and for negative samples 0,4457 (0,3324 - 0,5538, DS = 0,2230). Twenty sera samples from positive subjects and one hundred from negative subjects were examined, obtaining 90% sensitivity and 88% specificity. The results show this technique could be useful as strongyloidiasis screening test in population studies

Duration of secretory IgM and IgA antibodies to respiratory syncytial virus in a community study in Guinea-Bissau

DEFF Research Database (Denmark)

Stensballe, L G; Kofoed, P E; Nante, E J

2000-01-01

phase of infection. A secondary response may be more likely in children with low IgM responses in the acute phase (RR = 2.08 (95% confidence interval (CI) 0.92-4.70)). The IgA response was highest on days 28 and 42 after antigen detection, 72% having a detectable IgA response within the first 1.5 mo...... of these children had a simultaneous IgM-positive response. When 29 of the children were tested after an epidemic when they were 1-3-y-old, >80% again had high IgM (24/29, 82%) and IgA (28/29, 94%) levels. Among samples collected over a 1-y period from infants with LRI in a community morbidity surveillance...

Early diagnosis of dengue virus infection in clinically suspected cases

International Nuclear Information System (INIS)

Afridi, N.K.; Ahmed, S.; Ali, N.; Khan, S.A.

2016-01-01

Objective: Comparison of real time reverse transcriptase polymerase chain reaction (RTPCR) and immunoglobulin M (IgM) capture enzyme linked immunosorbent assay (ELISA) for diagnosis of dengue virus infection in first week of illness in clinically suspected patients of dengue fever. Study Design: Cross sectional study. Place and Duration of Study: Department of haematology, Armed Forces Institute of Pathology (AFIP) Rawalpindi from Jan 2013 to Nov 2013. Material and Methods: A cross sectional study including 68 clinically suspected patients of dengue fever according to the World Health Organization (WHO) criteria. IgM capture ELISA and RT PCR for dengue virus ribonucleic acid (RNA) was performed on samples collected from patients having fever for 1 to 7 days. These were divided into two groups. Patients in group 1 presented with fever of 4 days or less, patients in group 2 had fever of 5 to 7 days duration. Results: In group 1, 72 percent of the patients were positive by RT PCR while 31 percent were positive by IgM capture ELISA. In group 2, 43 percent of the patients were positive by RT PCR while 97 percent were positive by ELISA. Conclusion: RT PCR can be used for early detection of dengue virus infection in the first few days of fever while IgM ELISA is diagnostic afterwards. (author)

A noise simulator for eLISA: Migrating LISA Pathfinder knowledge to the eLISA mission

OpenAIRE

Armano, M.; Audley, H.; Auger, G.; Baird, J.; Binetruy, P.; Born, Michael; Bortoluzzi, D.; Brandt, N.; Bursi, A.; Caleno, M.; Cavalleri, A.; Cesarini, A.; Cruise, M.; Danzmann, Karsten; Diepholz, I.

2015-01-01

We present a new technical simulator for the eLISA mission, based on state space modeling techniques and developed in MATLAB. This simulator computes the coordinate and velocity over time of each body involved in the constellation, i.e. the spacecraft and its test masses, taking into account the different disturbances and actuations. This allows studying the contribution of instrumental noises and system imperfections on the residual acceleration applied on the TMs, the latter reflecting the ...

Evaluation of monoclonal antibody-based sandwich direct ELISA (MSD-ELISA) for antigen detection of foot-and-mouth disease virus using clinical samples.

Science.gov (United States)

Morioka, Kazuki; Fukai, Katsuhiko; Sakamoto, Kenichi; Yoshida, Kazuo; Kanno, Toru

2014-01-01

A monoclonal antibody-based sandwich direct ELISA (MSD-ELISA) method was previously developed for foot-and-mouth disease (FMD) viral antigen detection. Here we evaluated the sensitivity and specificity of two FMD viral antigen detection MSD-ELISAs and compared them with conventional indirect sandwich (IS)-ELISA. The MSD-ELISAs were able to detect the antigen in saliva samples of experimentally-infected pigs for a longer term compared to the IS-ELISA. We also used 178 RT-PCR-positive field samples from cattle and pigs affected by the 2010 type-O FMD outbreak in Japan, and we found that the sensitivities of both MSD-ELISAs were about 7 times higher than that of the IS-ELISA against each sample (P<0.01). In terms of the FMD-positive farm detection rate, the sensitivities of the MSD-ELISAs were about 6 times higher than that of the IS-ELISA against each farm (P<0.01). Although it is necessary to conduct further validation study using the other virus strains, MSD-ELISAs could be appropriate as a method to replace IS-ELISA for FMD antigen detection.

Comparison of an enzyme linked immunosorbent assay (ELISA) and a radioallergosorbent test (RAST) for detection of IgE antibodies to Brugia malayi

NARCIS (Netherlands)

Wahyuni, Sitti; van Ree, Ronald; Mangali, Andarias; Supali, Taniawati; Yazdanbakhsh, Maria; Sartono, Erliyani

2003-01-01

The enzyme linked immunosorbent assay (ELISA) for specific IgE antibodies to Brugia malayi was compared with the radioallergosorbent test (RAST) for use in immunoepidemiological studies of lymphatic filariasis. Sera used were from individuals (aged 5-82 years) living in an area endemic for lymphatic

[In vitro immunization for the production of antibodies to tetanus toxin and toxoid. 1. Systems for the detection of in vitro synthetized specific immunoglobulins. Strategies of test development].

Science.gov (United States)

Kiessig, S T; Jahn, S; Porstmann, T; von Baehr, R

1987-01-01

By means of semipurified tetanus toxin for solid phase coating in an enzyme immunoassay (ELISA) for detection of specific IgG and IgM antibodies a detection limit of 0.02 IU per litre was achieved. The addition of serum from animals like horses or goats as inert protein to the dilution medium was omitted to prevent a displacement of human antibodies by antitetanus antibodies present in the animals sera. The specificity of the ELISA was demonstrated by inhibition experiments with soluble antigen and in an ELISA for detection of anti-tetanus toxin antibodies from mice immunized with the toxoid from the different purification steps.

Low-Frequency Gravitational-Wave Science with eLISA/ NGO

Science.gov (United States)

Amaro-Seoane, Pau; Aoudia, Sofiane; Babak, Stanislav; Binetruy, Pierre; Berti, Emanuele; Bohe, Alejandro; Caprini, Chiara; Colpi, Monica; Cornish, Neil J.; Danzmann, Karsten;

Clinical Evaluation of Rapid Diagnostic Test Kit for Scrub Typhus with Improved Performance.

Science.gov (United States)

Kim, Young-Jin; Park, Sungman; Premaratna, Ranjan; Selvaraj, Stephen; Park, Sang-Jin; Kim, Sora; Kim, Donghwan; Kim, Min Soo; Shin, Dong Hoon; Choi, Kyung-Chan; Kwon, Soon-Hwan; Seo, Wonjun; Lee, Nam Taek; Kim, Seung-Han; Kang, Heui Keun; Kim, Yoon-Won

2016-08-01

Diagnosis of scrub typhus is challenging due to its more than twenty serotypes and the similar clinical symptoms with other acute febrile illnesses including leptospirosis, murine typhus and hemorrhagic fever with renal syndrome. Accuracy and rapidity of a diagnostic test to Orientia tsutsugamushi is an important step to diagnose this disease. To discriminate scrub typhus from other diseases, the improved ImmuneMed Scrub Typhus Rapid Diagnostic Test (RDT) was evaluated in Korea and Sri Lanka. The sensitivity at the base of each IgM and IgG indirect immunofluorescent assay (IFA) in Korean patients was 98.6% and 97.1%, and the specificity was 98.2% and 97.7% respectively. The sensitivity and specificity for retrospective diagnosis at the base of IFA in Sri Lanka was 92.1% and 96.1%. ImmuneMed RDT was not reactive to any serum from seventeen diseases including hemorrhagic fever with renal syndrome (n = 48), leptospirosis (n = 23), and murine typhus (n = 48). ImmuneMed RDT shows superior sensitivity (98.6% and 97.1%) compared with SD Bioline RDT (84.4% at IgM and 83.3% at IgG) in Korea. The retrospective diagnosis of ImmuneMed RDT exhibits 94.0% identity with enzyme-linked Immunosorbent assay (ELISA) using South India patient serum samples. These results suggest that this RDT can replace other diagnostic tests and is applicable for global diagnosis of scrub typhus. This rapid and accurate diagnosis will be beneficial for diagnosing and managing scrub typhus.

RT-PCR-ELISA as a tool for diagnosis of low-pathogenicity avian influenza

DEFF Research Database (Denmark)

Dybkaer, Karen; Munch, Mette; Handberg, Kurt Jensen

2003-01-01

A one-tube reverse transcriptase/polymerase chain reaction coupled with an enzyme-linked immunosorbent assay (RT-PCR-ELISA) was developed for the rapid detection of avian influenza virus (AIV) in clinical specimens. A total of 419 swab pools were analyzed from chickens experimentally infected wit...... of the twenty-three VI-positive specimens were negative when tested by RT-PCR-ELISA. The diagnostic sensitivity and specificity of the RT-PCR-ELISA was 91% and 97%, respectively, using VI in SPF eggs as the gold reference standard....

DIAGNOSIS OF CONGENITAL CYTOMEGALOVIRUS INFECTION IN HIGH RISK NEONATES

Directory of Open Access Journals (Sweden)

Ehab abdelmoniem Albanna

2013-07-01

Full Text Available Objectives: This study aimed to compare polymerase chain reaction (PCR and IgM detection using enzyme linked immune-sorbent assay (ELISA in diagnosis of congenital cytomegalovirus (CMV infection.   Methods: This study was conducted from May 2009 to December 2010. Urine and blood samples were collected from 94 neonates with suspected congenital CMV infection. Serum and part of urine samples were stored at -20°C freezer, until the serologic and PCR tests were achieved. A 94 fresh urine samples were processed for cell culture. Nineteen (20.2% out of 94 urine samples were proven positive for CMV infection by viral culture. For comparing PCR and IgM ELISA we used tissue culture technique as a reference, the 19 positive samples on culture (CMV group and 20 negative samples (control group were included in the comparison. Some characteristics of CMV and control groups were compared including sex, age, birth weight, gestational age < 37 and small for gestational age. Clinical and laboratory abnormalities were also compared in both groups.   Results: This study showed that the sensitivity and specificity of PCR in relation to viral culture were 100% and 100% respectively, there was excellent agreement between both tests (Kappa coefficient was 1 and P=0.000. On the other hand, the sensitivity of IgM CMV ELISA in relation to viral culture was 63.2% and the specificity was 85%. There was good agreement between both tests (Kappa coefficient was 0.48 and P=0.002. By comparing CMV and control groups, there were high statistically significant differences between both groups as regard the birth weight, gestational age < 37 and small for gestational age items (P= 0.00, 0.03 and 0.01 respectively. There were statistically insignificant differences as regarding the clinical and laboratory abnormalities detected for neonates of both groups. In this study jaundice (63% and hepato-splenomegaly (42% were the most common clinical signs in both groups.   Conclusion

P35 and P22 Toxoplasma gondii antigens abbreviate regions to diagnose acquired toxoplasmosis during pregnancy: toward single-sample assays.

Science.gov (United States)

Costa, Juan G; Peretti, Leandro E; García, Valeria S; Peverengo, Luz; González, Verónica D G; Gugliotta, Luis M; Dalla Fontana, Maria L; Lagier, Claudia M; Marcipar, Iván S

2017-03-01

P35 and P22 Toxoplasma gondii proteins are recognized by specific IgG at the early infection stage, making them ideal for acute toxoplasmosis pregnancy control. Both proteins have been studied to discriminate between acute and chronic toxoplasmosis. However, results were hardly comparable because different protein obtainment procedures led to different antigens, the reference panels used were not optimally typified, and avidity tests were either not performed or narrowly examined. We bioinformatically predicted P35 and P22 regions with the highest density of epitopes, and expressed them in pET32/BL21DE3 alternative expression system, obtaining the soluble proteins rP35a and rP22a. We assessed their diagnostic performance using pregnant woman serum samples typified as: not infected, NI (IgG-, IgM-), typical-chronic, TC (IgM-, IgG+), presumably acute, A (IgG+, IgM+, low-avidity IgG), and recently chronic, RC (IgG+, IgM+, high-avidity IgG). rP35a performed better than rP22a to differentiate A from RC, the areas under the curve (AUC) being 0.911 and 0.818, respectively. They, however, performed similarly to differentiate A from TC+RC (AUC: 0.915 and 0.907, respectively). rP35a and rP22a evaluation by avidity ELISA to discriminate A from RC rendered AUC values of 0.974 and 0.921, respectively. The indirect ELISA and avidity ELISA results analyzed in tandem were consistent with those obtained using commercial kits. rP35a and rP22a features suggest that, with complementary use, they could replace parasite lysate for toxoplasmosis infection screening and for acute toxoplasmosis diagnosis. Our proposal should be validated by a longitudinal study and may lead to a reliable toxoplasmosis pregnancy control, performing tests in only one serum sample.

Development and optimization of an ESAT6-ELISA-based detection system of Mycobacterium tuberculosis complex, suitable for bovine TB eradication

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Rouhollah Keshavarz

2015-01-01

Conclusion: Performing the ELISA test based on ESAT-6 antigen shows that this test can be a suitable way for screening beside the tuberculin test for accurate detection. It is noticed that the specificity of the ELISA test was determined more than the tuberculin test, especially since the culture and PCR are gold standards. Therefore, incorrect sampling can change the specificity of the tuberculin test. The results of this kit can encourage designing of an ELISA kit for the detection of human TB.

Seroprevalence of Mycoplasma gallisepticum antibody by ELISA and serum plate agglutination test of laying chicken

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Md. Zulfekar Ali

2015-01-01

Full Text Available Aim: Mycoplasma gallisepticum (MG is important avian pathogen responsible for chronic respiratory disease of chicken and turkeys, which result in large economic loss for the poultry industry. The objectives of this study were determination of seroprevalence of MG antibody of commercial layer chicken at laying period in selected areas of Bangladesh. Materials and Methods: A total of 563 blood samples were collected randomly from selected commercial layer chickens at laying period during the period from July to December, 2013. Indirect enzyme linked immunosorbent assay (iELISA and serum plate agglutination (SPA test were performed to detect the presence of antibodies against MG. Results: Of 563 samples, 64.47% and 56.13% showed an overall prevalence of MG antibodies in iELISA and SPA test respectively. Prevalence of MG was recorded the highest (69.63% at 50-55 weeks of age compared with lowest (53.26% at 56-61 weeks of age (p<0.05. Significant (p<0.05 effect of breed were observed in the seroprevalence of MG infection in layer birds in the present study. The overall, 68.77%, 63.74% and 59.37% prevalence were found respectively in sonali, ISA Brown and White leg horn. The prevalence of MG antibodies was the highest (70.13% in December followed by November (68%, October (65.67%, August (63.46%, September (58.54% and July (51.78% month. The seroprevalence of MG antibodies was higher (69.63% in most of the large flocks and lower (56.82% in small flocks. Conclusion: Therefore, might be suggested that the commercial layer farms should be routinely checked to monitor MG infection and the reactor birds should be culled since MG organism has the potential to transmit vertically. The correlation between MG antibody in month and flock size was not significant (p=0.359 and p=0.868, respectively.

First Colombian multicentric newborn screening for congenital toxoplasmosis.

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Jorge Enrique Gómez-Marin

Full Text Available AIMS: To determine the incidence of congenital toxoplasmosis in Colombian newborns from 19 hospital or maternal child health services from seven different cities of five natural geographic regions (Caribbean, Central, Andean, Amazonia and Eastern. MATERIALS AND METHODS: We collected 15,333 samples from umbilical cord blood between the period of March 2009 to May 2010 in 19 different hospitals and maternal-child health services from seven different cities. We applied an IgM ELISA assay (Vircell, Spain to determine the frequency of IgM anti Toxoplasma. The results in blood cord samples were confirmed either by western blot and repeated ELISA IgM assay. In a sub-sample of 1,613 children that were negative by the anti-Toxoplasma IgM assay, the frequency of specific anti-Toxoplasma IgA by the ISAGA assay was determined. All children with positive samples by IgM, IgA, clinical diagnosis or treatment during pregnancy were recalled for confirmatory tests after day 10 of life. RESULTS: 61 positive samples for specific IgM (0.39% and 9 positives for IgA (0.5% were found. 143 questionnaires were positive for a clinical diagnosis or treatment for toxoplasmosis during pregnancy. 109 out of the 218 children that had some of the criteria for postnatal confirmatory tests were followed. Congenital toxoplasmosis infection was confirmed in 15 children: 7 were symptomatic, and three of them died before the first month of life (20% of lethality. A significant correlation was found between a high incidence of markers for congenital toxoplasmosis and higher mean annual rainfall for the city. CONCLUSIONS: Incidence for congenital toxoplasmosis is significantly different between hospitals or maternal child health services from different cities in Colombia. Mean annual rainfall was correlated with incidence of congenital toxoplasmosis.

Performance of microscopy and ELISA for diagnosing Giardia duodenalis infection in different pediatric groups.

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Silva, Renata K N R; Pacheco, Flávia T F; Martins, Adson S; Menezes, Joelma F; Costa-Ribeiro, Hugo; Ribeiro, Tereza C M; Mattos, Ângela P; Oliveira, Ricardo R; Soares, Neci M; Teixeira, Márcia C A

2016-12-01

Techniques for Giardia diagnosis based on microscopy are usually applied as routine laboratory testing; however, they typically exhibit low sensitivity. This study aimed to evaluate Giardia duodenalis and other intestinal parasitic infections in different pediatric groups, with an emphasis on the comparison of Giardia diagnostic techniques. Feces from 824 children from different groups (diarrheic, malnourished, with cancer and from day care) were examined by microscopy and ELISA for Giardia, Cryptosporidium sp. and Entamoeba histolytica coproantigen detection. Giardia-positive samples from day-care children, identified by either microscopy or ELISA, were further tested by PCR targeting of the β-giardin and Gdh genes. Statistically significant differences (Psp. in diarrheic and malnourished groups; infections by Entamoeba histolytica were found only in children with diarrhea. Considering positivity for Giardia by at least one method, ELISA was found to be more sensitive than microscopy (97% versus 55%). To examine discrepancies among the diagnostic methods, 71 Giardia-positive stool samples from day-care children were tested by PCR; of these, DNA was amplified from 51 samples (77.4%). Concordance of positivity between microscopy and ELISA was found for 48 samples, with 43 confirmed by PCR. Parasite DNA was amplified from eleven of the 20 Giardia samples (55%) identified only by ELISA. This study shows the higher sensitivity of ELISA over microscopy for Giardia diagnosis when a single sample is analyzed and emphasizes the need for methods based on coproantigen detection to identify this parasite in diarrheic fecal samples. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

Diagnostic accuracy and comparison of two assays for Borrelia-specific IgG and IgM antibodies

DEFF Research Database (Denmark)

Dessau, Ram

2013-01-01

characteristic (ROC) curves to optimize and standardize test interpretation, it was shown that testing with both IDEIA IgG and IgM was comparable to testing with Liaison IgG alone by comparing the area under the curve of the diagnostically relevant 25 % partial ROC curve (P = 0.1). When using the Liaison Osp......M combined) were 85 and 95 % and for the Liaison (VlsE IgG) method were 67 and 96 %, respectively. Methods for test evaluation, test interpretation and statistical testing are presented and discussed. In conclusion, Liaison VlsE IgG alone and IDEIA IgG/IgM combined showed a high and comparable discriminatory...

Evaluation of monoclonal antibody-based sandwich direct ELISA (MSD-ELISA for antigen detection of foot-and-mouth disease virus using clinical samples.

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Kazuki Morioka

Full Text Available A monoclonal antibody-based sandwich direct ELISA (MSD-ELISA method was previously developed for foot-and-mouth disease (FMD viral antigen detection. Here we evaluated the sensitivity and specificity of two FMD viral antigen detection MSD-ELISAs and compared them with conventional indirect sandwich (IS-ELISA. The MSD-ELISAs were able to detect the antigen in saliva samples of experimentally-infected pigs for a longer term compared to the IS-ELISA. We also used 178 RT-PCR-positive field samples from cattle and pigs affected by the 2010 type-O FMD outbreak in Japan, and we found that the sensitivities of both MSD-ELISAs were about 7 times higher than that of the IS-ELISA against each sample (P<0.01. In terms of the FMD-positive farm detection rate, the sensitivities of the MSD-ELISAs were about 6 times higher than that of the IS-ELISA against each farm (P<0.01. Although it is necessary to conduct further validation study using the other virus strains, MSD-ELISAs could be appropriate as a method to replace IS-ELISA for FMD antigen detection.

Decreased IgA+ B Cells Population and IgA, IgG, IgM Contents of the Cecal Tonsil Induced by Dietary High Fluorine in Broilers

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Kangping Wang

2013-05-01

Full Text Available Fluoride is an environmental and industrial pollutant that affects various organs in humans and animals. The cecal tonsil is an important component of the mucosal immune system and performs important and unique immune functions. In the present study, we investigated the effects of dietary high fluorine on the quantities of IgA+ B cells in the cecal tonsil by immunohistochemistry, and the immunoglobulin A (IgA, immunoglobulin G (IgG and immunoglobulin M (IgM contents in the cecal tonsil by ELISA. A total of 280 one-day-old avian broilers were divided into four groups and fed on a corn-soybean basal diet as control diet (fluorine 22.6 mg/kg or the same diet supplemented with 400, 800 and 1,200 mg/kg fluorine (high fluorine groups I, II and III in the form of sodium fluoride, respectively, throughout a 42-day experimental period. The results showed that the quantities of IgA+ B cells were lower (p < 0.05 or p < 0.01 and the IgA, IgG, and IgM contents were decreased (p < 0.05 or p < 0.01 in high fluorine groups II and III in comparison with those of control group. It was concluded that dietary fluorine, in the 800–1,200 mg/kg range, could reduce the numbers of the IgA+ B cells and immunoglobulin contents in the cecal tonsil, implying the local mucosal immune function was ultimately impacted in broilers.

Evaluation of laboratory tests for dengue diagnosis in clinical specimens from consecutive patients with suspected dengue in Belo Horizonte, Brazil.

Science.gov (United States)

Ferraz, Fernanda Oliveira; Bomfim, Maria Rosa Quaresma; Totola, Antônio Helvécio; Ávila, Thiago Vinícius; Cisalpino, Daniel; Pessanha, José Eduardo Marques; da Glória de Souza, Danielle; Teixeira Júnior, Antônio Lúcio; Nogueira, Maurício Lacerda; Bruna-Romero, Oscar; Teixeira, Mauro Martins

2013-09-01

Dengue is a widely spread arboviral disease in tropical and subtropical regions of the world. Dengue fever presents clinical characteristics similar to other febrile illness. Thus laboratory diagnosis is important for adequate management of the disease. The present study was designed to evaluate the diagnostic performance of real-time PCR and serological methods for dengue in a real epidemic context. Clinical data and blood samples were collected from consecutive patients with suspected dengue who attended a primary health care unit in Belo Horizonte, Brazil. Serologic methods and real-time PCR were performed in serum samples to confirm dengue diagnosis. Among the 181 consecutive patients enrolled in this study with suspected dengue, 146 were considered positive by serological criteria (positive NS1 ELISA and/or anti-dengue IgM ELISA) and 138 were positive by real-time PCR. Clinical criteria were not sufficient for distinguishing between dengue and non-dengue febrile illness. The PCR reaction was pre-optimized using samples from patients with known viral infection. It had similar sensitivity compared to NS1 ELISA (88% and 89%, respectively). We also evaluated three commercial lateral flow immunochromatographic tests for NS1 detection (BIOEASY, BIORAD and PANBIO). All three tests showed high sensitivity (94%, 91% and 81%, respectively) for dengue diagnosis. According to our results it can be suggested that lateral flow tests for NS1 detection are the most feasible methods for early diagnosis of dengue. Copyright © 2013 Elsevier B.V. All rights reserved.

IgM repertoire biodiversity is reduced in HIV-1 infection and systemic lupus erythematosus

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Li eYin

2013-11-01

Full Text Available Background: HIV-1 infection or systemic lupus erythematosus [SLE] disrupt B cell homeostasis, reduce memory B cells, and impair function of IgG and IgM antibodies. Objective: To determine how disturbances in B cell populations producing polyclonal antibodies relate to the IgM repertoire, the IgM transcriptome in health and disease was explored at the complementarity determining region 3 [CDRH3] sequence population level. Methods: 454-deep pyrosequencing in combination with a novel analysis pipeline was applied to define populations of IGHM CDRH3 sequences based on absence or presence of somatic hypermutations [SHM] in peripheral blood B cells. Results: HIV or SLE subjects have reduced biodiversity within their IGHM transcriptome compared to healthy subjects, mainly due to a significant decrease in the number of unique combinations of alleles, although recombination machinery was intact. While major differences between sequences without or with SHM occurred among all groups, IGHD and IGHJ allele use, CDRH3 length distribution, or generation of SHM were similar among study cohorts. Antiretroviral therapy failed to normalize IGHM biodiversity in HIV-infected individuals. All subjects had a low frequency of allelic combinations within the IGHM repertoire similar to known broadly-neutralizing HIV-1 antibodies. Conclusions: Polyclonal expansion would decrease overall IgM biodiversity independent of other mechanisms for development of the B cell repertoire. Applying deep sequencing as a strategy to follow development of the IgM repertoire in health and disease provides a novel molecular assessment of multiple points along the B cell differentiation pathway that is highly sensitive for detecting perturbations within the repertoire at the population level.

Evaluation of a colloidal gold immunochromatography assay in the detection of Treponema pallidum specific IgM antibody in syphilis serofast reaction patients: a serologic marker for the relapse and infection of syphilis.

Science.gov (United States)

Lin, Li-Rong; Tong, Man-Li; Fu, Zuo-Gen; Dan, Bing; Zheng, Wei-Hong; Zhang, Chang-Gong; Yang, Tian-Ci; Zhang, Zhong-Ying

2011-05-01

Syphilis remains as a worldwide public health problem; hence, it is necessary to develop a new diagnostic approach that is easier and faster than conventional tests. A new testing method to detect Treponema pallidum IgM (TP-IgM), named colloidal gold immunochromatography assay (GICA), is presented in place of fluorescent treponemal antibody absorption (FTA-Abs). TP-IgM was detected using GICA developed on syphilis-specific recombinant proteins TPN17 and TPN47. The FTA-Abs IgM test was set as the gold standard. A GICA TP-IgM test was performed to detect syphilis in 1208 patients who received recommended therapy for syphilis for more than 1 year at the Xiamen Center of Clinical Laboratory in China from June 2005 to May 2009. One hundred blood donors were set up as control. The sensitivity, specificity, positive predictive value, negative predictive value, positive likelihood ratio, and negative likelihood ratio were 98.21%, 99.04%, 93.75%, 99.73%, 102.3, and 0.018, respectively. Detection on 500 interference specimens indicated that the biological false-positive rate of the GICA test was extremely low and was free from other biological and chemical factors. The patients were divided into the following experimental groups based on the results of toluidine red unheated serum test (TRUST) and treponemal pallidum particle agglutination (TPPA): (1) the syphilis serofast reaction (SSR) group consisted of 411 cases with (+) TRUST and (+) TPPA, which exhibited no clinical manifestations of syphilis after 1 year of recommended syphilis treatment; (2) the serum cure group, which was further subdivided into group A, a group that consisted of 251 cases with (-) TRUST and (+) TPPA, and (3) group B, a group that consisted of 546 cases with (-) TRUST and (-) TPPA; and (4) the blood donor control group, which consisted of 100 healthy persons with (-) ELISA-TP and (-) TPPA. We used the FTA-Abs method and the GICA method to detect TP-IgM; the positive rate of TP-IgM in 411 SSR

A Simple and Specific Noncompetitive ELISA Method for HT-2 Toxin Detection

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Henri O. Arola

2017-04-01

Full Text Available We developed an HT-2 toxin-specific simple ELISA format with a positive read-out. The assay is based on an anti-immune complex (IC scFv antibody fragment, which is genetically fused with alkaline phosphatase (AP. The anti-IC antibody specifically recognizes the IC between a primary anti-HT-2 toxin Fab fragment and an HT-2 toxin molecule. In the IC ELISA format, the sample is added together with the scFv-AP antibody to the ELISA plate coated with the primary antibody. After 15 min of incubation and a washing step, the ELISA response is read. A competitive ELISA including only the primary antibody recognizes both HT-2 and T-2 toxins. The anti-IC antibody makes the assay specific for HT-2 toxin, and the IC ELISA is over 10 times more sensitive compared to the competitive assay. Three different naturally contaminated matrices: wheat, barley and oats, were used to evaluate the assay performance with real samples. The corresponding limits of detection were 0.3 ng/mL (13 µg/kg, 0.1 ng/mL (4 µg/kg and 0.3 ng/mL (16 µg/kg, respectively. The IC ELISA can be used for screening HT-2 toxin specifically and in relevant concentration ranges from all three tested grain matrices.

Canine specific ELISA for coagulation factor VII

DEFF Research Database (Denmark)

Knudsen, Tom; Kjelgaard-Hansen, Mads; Tranholm, Mikael

2011-01-01

available to date. In this study, a canine specific ELISA for measurement of FVII:Ag in plasma was developed and validated. The FVII:Ag ELISA correctly diagnosed homozygous and heterozygous hereditary FVII deficiency. Together with activity based assays, such as FVII:C, the FVII:Ag ELISA should be valuable...

Parvovirus B19 infections in state of Rio de Janeiro, Brasil: 526 sera analyzed by IgM-enzyme-linked immunosorbent assay and polymerase chain reaction

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MCL Mendonça

2005-12-01

Full Text Available In this study were analyzed 526 sera; the patients aged from two days to 65 years old presenting exanthema, which was the most frequent symptom observed, besides fever, adenomegaly, and arthralgia. These sera were negative by enzyme-linked immunosorbent assay (IgM-ELISA for either rubella (495, toxoplasma (41, cytomegalovirus (12, measles (40, dengue (56, and they were submitted to nested polymerase chain reaction (PCR for B19 DNA and commercial IgM-ELISA for B19. In 39 abortion cases, IgM or DNA were not detected, therefore they were not took into account for analysis. Specific DNA and IgM were detected respectively in 71 (14.5% and IgM in 62 (12.7% sera from 487 sera analyzed. IgM and DNA were simultaneously detected in 43 (8.8%, while agreement among the results by PCR and IgM-ELISA was observed in 440 (90.4%. The sera were collected from January 1999 to December 2000, most of them in 1999 (325, during winter and spring. The major number of clinical cases was observed in the age group from one to ten years old. IgM or DNA were detected in 23 from 51 municipal districts of the state of Rio de Janeiro, where the samples were collected.

Antibody dynamics in BRSV-infected Danish dairy herds as determined by isotype-specific immunoglobulins

DEFF Research Database (Denmark)

Uttenthal, Åse; Larsen, Lars Erik; Philipsen, J.S.

2000-01-01

Using specific ELISAs, antibody levels of four different isotypes to bovine respiratory syncytial virus (BRSV) were determined in calves, following experimental BRSV infection. Most calves experienced an increase in the specific IgM and IgG1 titres about 6-10 days after infection with BRSV. The Ig......M titre was transient showing positive titres for only 5-10 days, while specific IgG1 was present for a longer time. IgA was detected concomitantly with IgM but at a lower level. Production of IgG2 anti-BRSV antibodies was detected from 3 weeks after infection. In two closed herds, repeated blood......, another herd with acute BRSV was followed by weekly blood samples in six calves; in both herds IgM and IgG1 was detected shortly after the appearance of clinical signs. Serum samples from 50 Danish dairy herds (453 samples) were tested for immunoglobulins of the isotypes IgG1, IgG2 and IgM. The presence...

Evaluation of a blocking ELISA for screening of antibodies against porcine reproductive and respiratory syndrome (PRRS) virus

DEFF Research Database (Denmark)

Sørensen, K.J.; Bøtner, Anette; Madsen, E.S.

1997-01-01

A blocking Elisa was developed for the detection of antibodies against PRRS virus with a view to satisfying the need for examination of blood samples on a large scale. The test was evaluated in comparison with an indirect Elisa and the immunoperoxidase monolayer assay. The blocking Elisa...... was sensitive and specific. It had a higher capacity and was cheaper to perform than the immunoperoxidase monolayer assay and the indirect Elisa. It was comparable to the immunoperoxidase monolayer assay and better than the indirect Elisa in detecting antibodies formed early after infection, and it was superior...... to both the immunoperoxidase monolayer assay and the indirect Elisa in detecting antibodies at a late stage of infection....

Update: Ongoing Zika Virus Transmission - Puerto Rico, November 1, 2015-July 7, 2016.

Science.gov (United States)

Adams, Laura; Bello-Pagan, Melissa; Lozier, Matthew; Ryff, Kyle R; Espinet, Carla; Torres, Jomil; Perez-Padilla, Janice; Febo, Mitchelle Flores; Dirlikov, Emilio; Martinez, Alma; Munoz-Jordan, Jorge; Garcia, Myriam; Segarra, Marangely Olivero; Malave, Graciela; Rivera, Aidsa; Shapiro-Mendoza, Carrie; Rosinger, Asher; Kuehnert, Matthew J; Chung, Koo-Whang; Pate, Lisa L; Harris, Angela; Hemme, Ryan R; Lenhart, Audrey; Aquino, Gustavo; Zaki, Sherif; Read, Jennifer S; Waterman, Stephen H; Alvarado, Luisa I; Alvarado-Ramy, Francisco; Valencia-Prado, Miguel; Thomas, Dana; Sharp, Tyler M; Rivera-Garcia, Brenda

2016-08-05

Zika virus is a flavivirus transmitted primarily by Aedes aegypti and Aedes albopictus mosquitoes, and infection can be asymptomatic or result in an acute febrile illness with rash (1). Zika virus infection during pregnancy is a cause of microcephaly and other severe birth defects (2). Infection has also been associated with Guillain-Barré syndrome (GBS) (3) and severe thrombocytopenia (4,5). In December 2015, the Puerto Rico Department of Health (PRDH) reported the first locally acquired case of Zika virus infection. This report provides an update to the epidemiology of and public health response to ongoing Zika virus transmission in Puerto Rico (6,7). A confirmed case of Zika virus infection is defined as a positive result for Zika virus testing by reverse transcription-polymerase chain reaction (RT-PCR) for Zika virus in a blood or urine specimen. A presumptive case is defined as a positive result by Zika virus immunoglobulin M (IgM) enzyme-linked immunosorbent assay (MAC-ELISA)* and a negative result by dengue virus IgM ELISA, or a positive test result by Zika IgM MAC-ELISA in a pregnant woman. An unspecified flavivirus case is defined as positive or equivocal results for both Zika and dengue virus by IgM ELISA. During November 1, 2015-July 7, 2016, a total of 23,487 persons were evaluated by PRDH and CDC Dengue Branch for Zika virus infection, including asymptomatic pregnant women and persons with signs or symptoms consistent with Zika virus disease or suspected GBS; 5,582 (24%) confirmed and presumptive Zika virus cases were identified. Persons with Zika virus infection were residents of 77 (99%) of Puerto Rico's 78 municipalities. During 2016, the percentage of positive Zika virus infection cases among symptomatic males and nonpregnant females who were tested increased from 14% in February to 64% in June. Among 9,343 pregnant women tested, 672 had confirmed or presumptive Zika virus infection, including 441 (66%) symptomatic women and 231 (34%) asymptomatic

Co-infection of herpes simplex virus (HSV) with human immunodeficiency virus (HIV) in women with reproductive tract infections (RTI).

Science.gov (United States)

Devi, Ksh Mamta; Devi, Kh Sulochana; Singh, Ng Brajachand; Singh, N Nabakishore; Singh, I Dorendra

2008-09-01

In India, HSV seroprevalence and its coinfection with HIV among female patients with reproductive tract infections (RTI) are sparse. We aim to ascertain the seroprevalence of HSV and its coinfection with HIV and common sexually transmitted infections attending Obstetrics and Gynaecology outpatient department, RIMS. The study included 92 female patients with RTI. Diagnostic serology was done for HSV-1 and HSV-2 using group specific IgM indirect immunoassay using ELISA, HIV by 3 ELISA/Rapid/Simple (E/R/S) test of different biological antigen. Diagnosis of RTI was made on clinical grounds with appropriate laboratory investigations--microscopy, Gram stain smear etc. Bacterial vaginosis was diagnosed using Nugent's criteria, Syphilis by rapid plasma reagin (RPR) card test and Chlamydia trachomatis by IgG ELISA. Out of 92 sera tested for HSV, 18 (19.6%) were IgM HSV positive and 9 (9.8%) were HIV positive. Co-infection rate of HSV in HIV positive was 16.7%. None of the patients had clinical herpes genitalis, all were subclinical cases. 55.5% of HSV positives belongs to age group 21 to 30 years. Of the HSV-1 and HSV-2 IgM positives 3 (15%) had HIV, 4 (22.2%) bacterial vaginosis, 2 (11.1%) were RPR positive, 4 (22.2%) Chlamydia trachomatis, 3 (15%) were pregnant. 16 (88.8%) were unemployed, 14 (77.7%) had education level below 10 standard. Our study suggest that every case of RTI, be it an ulcerative or nonulcerative must be thoroughly evaluated by laboratory testing for primary subclinical genital HSV coinfection as this has profound implications on their judicious management and aversion of complications. Early diagnosis and treatment of HSV infection together with prophylaxis for recurrent HSV disease will prevent progression and spread of HIV disease.

Use of the Brucella IgM and IgG flow assays in the serodiagnosis of human brucellosis in an area endemic for brucellosis

NARCIS (Netherlands)

Irmak, Hasan; Buzgan, Turan; Evirgen, Omer; Akdeniz, Hayrettin; Demiroz, A. Pekcan; Abdoel, Theresia H.; Smits, Henk L.

2004-01-01

The clinical utility of two complementary tests for brucellosis, the Brucella IgM and IgG flow assays, was evaluated in a hospital in eastern Turkey. The results show that the flow assays are convenient diagnostic tests for use in endemic areas. A positive result in the flow assays was obtained in

Exclusion and diagnosis of pulmonary embolism by a rapid ELISA D-dimer test and noninvasive imaging techniques within the context of a clinical model.

Science.gov (United States)

Michiels, J J; Pattynama, P M

2000-01-01

A negative rapid ELISA D-dimer test alone in out-patients with a low to moderate clinical probability (CP) on pulmonary embolism (PE) is predicted to safely exclude pulmonary embolism. The combination of a negative rapid ELISA D-dimer test and a low to moderate CP on PE followed by compression ultrasonography (CUS) for the detection of deep vein thrombosis (DVT) is safe and cost-effective as it reduces the need for noninvasive imaging techniques to about 50% to 60% of outpatients with suspected PE. A high probability ventilation-perfusion (VP) scan or a positive spiral CT consistent with PE and the detection of DVT by CUS are currently considered to be clear indications for anticoagulant treatment. Subsequent pulmonary angiography (PA) is the gold standard diagnostic strategy to exclude or diagnose PE in suspected outpatients with a negative CUS, a positive rapid ELISA D-dimer test, and a nondiagnostic VP scan or negative spiral CT to prevent overtreatment with anticoagulants. However, the willingness of clinicians and the availability of resources to perform PA is restricted, a fact that has provided an impetus for clinical investigators to search for alternative noninvasive strategies to exclude or detect venous thromboembolism (VTE). Serial CUS testing for the detection of DVT in patients with a low to moderate CP on PE and a nondiagnostic VP scan or negative spiral CT is predicted to be safe and will reduce the need for PA to less than 10% or even less than 5%. This noninvasive serial CUS strategy restricts the need for invasive PA to a minor group of patients (spiral CT and a high CP on PE. Prospective evaluations are warranted to implement and to validate the advantages and the disadvantages of the various combinations of noninvasive strategies and to compare serial CUS testing versus PA in randomized clinical management studies of outpatients with suspected pulmonary embolism.

Use of enzyme linked immunosorbent assay (ELISA) for the diagnosis of brucellosis in cattle in Yucatan, Mexico

International Nuclear Information System (INIS)

Dajer, A.; Gutierrez, E.; Zapata, D.

1998-01-01

Sera (247) from non-vaccinated brucellosis negative herds, 328 negative sera from Brucella abortus strain 19 vaccinated herds (brucellosis free), and 95 sera positive to the Rose Bengal test (RBT) and Complement Fixation test (CFT) from Brucella abortus-infected herds, were used to determine the relative sensitivity and specificity of a FAO/IAEA I-ELISA kit and the Rivanol Agglutination Test (RAT), using the CFT as a 'gold standard'. A threshold value for the I-ELISA was determined to be 37 PP using the mean plus 3 standard deviations of the negative sera from vaccinated animals. The I-ELISA showed a high relative sensitivity (100%) and a good relative specificity (92.5%), using the threshold determined for local conditions. The RAT gave a lower sensitivity value than the CFT (97.8%) and good specificity (99.3%). The I-ELISA could be used as a screening test under Yucatan conditions or as a confirmatory test in places where vaccination is not carried out. The RAT lacks sensitivity and is therefore not recommended for use in final stages of eradication programs but could be used in control programmes or early stages of eradication campaigns as a confirmatory test. (author)

Hyperglucagonaemia analysed by glucagon sandwich ELISA

DEFF Research Database (Denmark)

Albrechtsen, Nicolai Jacob Wewer; Hartmann, Bolette; Veedfald, Simon

2014-01-01

the extent to which the hyperglucagonaemia measured in clinical samples was caused by authentic glucagon. METHODS: We examined the performance of three commercial glucagon 'sandwich' ELISAs. The ELISA with the best overall performance was selected to compare glucagon measurements in clinical samples...... sensitivity for glucagon in plasma (>10-20 pmol/l). Thus, only the third assay was suitable for measuring glucagon concentrations in clinical samples. The ELISA and RIA measured similar glucagon levels in healthy individuals. Measurements of samples from individuals with abnormally high (type 2 diabetes...... or obese) or very elevated (post vagotomy with pyloroplasty, post-RYGB) glucagon levels were also similar in both assays. However, glucagon levels in participants with ESRD were much lower when measured by ELISA than by RIA, indicating that the apparent hyperglucagonaemia is not caused by fully processed...

Development of indirect sandwich ELISA for determination of excretory-secretory antigens of Fasciola hepatica

Directory of Open Access Journals (Sweden)

Libertad Alzamora-Gonzales

2016-05-01

Full Text Available Fasciolosis is a cosmopolitan parasitosis medical-veterinary importance caused by Fasciola hepatica, which affects sheep, goats and cattle; and it affects man accidentally causing an epidemic-endemic infection difficult to diagnose. The aim was to develop an indirect sandwich ELISA with 3 antibodies for detecting excretory-secretory antigens of Fasciola hepatica (ESFh. For the development of indirect sandwich ELISA were used, as capture antibody, mouse polyclonal antibodies anti ESFh and polyclonal antibodies rabbit anti-ESFh as detection antibody, at the concentrations of 10 and 5 µg/mL respectively. The conjugate used was mouse monoclonal anti- total immunoglobulins rabbit linked to peroxidase (1/1000. Were analized 31 sheep fecal samples, and the results were compared with those obtained by direct coproparasitological examination (DC and counterimmunoelectrophoresis (CIEP. The detection limit obtained for indirect sandwich ELISA was 100 ng/mL. The test had a 100% sensitivity, 96.6% specificity, positive and negative predictive values of 50% and 96.6% respectively, in relation to DC test. Comparing with CIEP the specificity obtained for indirect sandwich ELISA was 93.5% and a negative predictive value of 100%. We concluded that indirect sandwich ELISA designed is able to detect metabolic antigens in ovine feces samples and can be used for Fasciola hepatica diagnosis.

Development of an Aquaporin-4 Orthogonal Array of Particle-Based ELISA for Neuromyelitis Optica Autoantibodies Detection.

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Francesco Pisani

Full Text Available Serological markers of Nuromyelitis Optica (NMO, an autoimmune disorder of the central nervous system, are autoantibodies targeting the astrocytic water channel aquaporin-4 (AQP4. We have previously demonstrated that the main epitopes for these autoantibodies (AQP4-IgG are generated by the supramolecular arrangement of AQP4 tetramers into an Orthogonal Array of Particles (OAPs. Many tests have been developed to detect AQP4-IgG in patient sera but several procedural issues affect OAP assembly and consequently test sensitivity. To date, the protein based ELISA test shows the lowest sensitivity while representing a valid alternative to the more sensitive cell based assay (CBA, which, however, shows economic, technical and interpretation problems. Here we have developed a high perfomance ELISA in which native OAPs are used as the molecular target. To this aim a native size exclusion chromatography method has been developed to isolate integral, highly pure and AQP4-IgG-recognized OAPs from rat brain. These OAPs were immobilized and oriented on a plastic plate by a sandwich approach and 139 human sera were tested, including 67 sera from NMO patients. The OAP-ELISA showed a 99% specificity and a higher sensitivity (91% compared to the CBA test. A comparative analysis revealed an end-point titer three orders of magnitude higher than the commercial ELISA and six times higher than our in-house CBA test. We show that CNS-extracted OAPs are crucial elements in order to perform an efficient AQP4-IgG test and the OAP-ELISA developed represents a valid alternative to the CBA currently used.

Characterization of additional rabbit IgM allotypes and the effect of suppression of a VH locus allotypes on the expression of n Cμ locus allotype

International Nuclear Information System (INIS)

Gilman-Sachs, A.; Roux, K.H.; Horing, W.J.; Dray, S.

1982-01-01

Anti-allotype antisera were produced that identified eight rabbit IgM allotypic specificities, n80, n81, n82, n83, n84, n85, n86, and n87. The n locus Cμ genes controlling these IgM allotypic specificities are closely linked to the a (VH subgroup) locus. The genes controlling these allotypic specificities were found to be in the heavy chain chromosomal region and were assigned to 11 haplotypes present in our rabbit colony. The n locus and a locus genes appeared in the haplotypes in six combinations: a 1 n 81 , a 2 n/sup 81,n87/, a 1 n/sup 80,83/, a 2 n/sup 80,82,87/, a 3 n/sup 81,84,85/ and a 3 n/sup 80,84,86,87/. By radioprecipitation analysis, 70 to 80% of serum IgM reacts with the antiserum directed to each n locus allotypic specificity found encoded in one haplotype; thus, each allotypic specificity of the haplotype is present on the same IgM molecule. When sera from a locus allotype-suppressed homozygous rabbits were tested for expression of each n locus allotypic specificity, n80, n81, and n87 were still expressed, whereas n82, n83, n84, n85, and n86 were not. These data provide direct evidence that some IgM specificities are expressed independently of the a locus (i.e., ''true''), and other s are dependent on the expression of an a locus specificity (i.e., conformational). The expression of the ''true'' allotypic specificities probably reflects genetic control of the germline Cμ gene, and the expression of ''conformationally dependent'' allotypic specificities probably reflects the interaction of VH and Cμ gene segments. This distinction is important and must be recognized when evaluating the genetics and structure of the IgM molecule

Emerging trends in Lassa fever: redefining the role of immunoglobulin M and inflammation in diagnosing acute infection

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Branco Luis M

2011-10-01

Full Text Available Abstract Background Lassa fever (LF is a devastating hemorrhagic viral disease that is endemic to West Africa and responsible for thousands of human deaths each year. Analysis of humoral immune responses (IgM and IgG by antibody-capture ELISA (Ab-capture ELISA and Lassa virus (LASV viremia by antigen-capture ELISA (Ag-capture ELISA in suspected patients admitted to the Kenema Government Hospital (KGH Lassa Fever Ward (LFW in Sierra Leone over the past five years is reshaping our understanding of acute LF. Results Analyses in LF survivors indicated that LASV-specific IgM persists for months to years after initial infection. Furthermore, exposure to LASV appeared to be more prevalent in historically non-endemic areas of West Africa with significant percentages of reportedly healthy donors IgM and IgG positive in LASV-specific Ab-capture ELISA. We found that LF patients who were Ag positive were more likely to die than suspected cases who were only IgM positive. Analysis of metabolic and immunological parameters in Ag positive LF patients revealed a strong correlation between survival and low levels of IL-6, -8, -10, CD40L, BUN, ALP, ALT, and AST. Despite presenting to the hospital with fever and in some instances other symptoms consistent with LF, the profiles of Ag negative IgM positive individuals were similar to those of normal donors and nonfatal (NF LF cases, suggesting that IgM status cannot necessarily be considered a diagnostic marker of acute LF in suspected cases living in endemic areas of West Africa. Conclusion Only LASV viremia assessed by Ag-capture immunoassay, nucleic acid detection or virus isolation should be used to diagnose acute LASV infection in West Africans. LASV-specific IgM serostatus cannot be considered a diagnostic marker of acute LF in suspected cases living in endemic areas of West Africa. By applying these criteria, we identified a dysregulated metabolic and pro-inflammatory response profile conferring a poor

Emerging trends in Lassa fever: redefining the role of immunoglobulin M and inflammation in diagnosing acute infection.

Science.gov (United States)

Branco, Luis M; Grove, Jessica N; Boisen, Matt L; Shaffer, Jeffrey G; Goba, Augustine; Fullah, Mohammed; Momoh, Mambu; Grant, Donald S; Garry, Robert F

2011-10-24

Lassa fever (LF) is a devastating hemorrhagic viral disease that is endemic to West Africa and responsible for thousands of human deaths each year. Analysis of humoral immune responses (IgM and IgG) by antibody-capture ELISA (Ab-capture ELISA) and Lassa virus (LASV) viremia by antigen-capture ELISA (Ag-capture ELISA) in suspected patients admitted to the Kenema Government Hospital (KGH) Lassa Fever Ward (LFW) in Sierra Leone over the past five years is reshaping our understanding of acute LF. Analyses in LF survivors indicated that LASV-specific IgM persists for months to years after initial infection. Furthermore, exposure to LASV appeared to be more prevalent in historically non-endemic areas of West Africa with significant percentages of reportedly healthy donors IgM and IgG positive in LASV-specific Ab-capture ELISA. We found that LF patients who were Ag positive were more likely to die than suspected cases who were only IgM positive. Analysis of metabolic and immunological parameters in Ag positive LF patients revealed a strong correlation between survival and low levels of IL-6, -8, -10, CD40L, BUN, ALP, ALT, and AST. Despite presenting to the hospital with fever and in some instances other symptoms consistent with LF, the profiles of Ag negative IgM positive individuals were similar to those of normal donors and nonfatal (NF) LF cases, suggesting that IgM status cannot necessarily be considered a diagnostic marker of acute LF in suspected cases living in endemic areas of West Africa. Only LASV viremia assessed by Ag-capture immunoassay, nucleic acid detection or virus isolation should be used to diagnose acute LASV infection in West Africans. LASV-specific IgM serostatus cannot be considered a diagnostic marker of acute LF in suspected cases living in endemic areas of West Africa. By applying these criteria, we identified a dysregulated metabolic and pro-inflammatory response profile conferring a poor prognosis in acute LF. In addition to suggesting that the

AN EVALUATION STUDY OF ENZYME-LINKED IMMUNOSORBENT ASSAY (ELISA USING RECOMBINANT PROTEIN GRA1 FOR DETECTION OF IGG ANTIBODIES AGAINTS TOXOPLASMA GONDII INFECTIONS

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Nina Difla Muflikhah

2017-08-01

Full Text Available Toxoplasmosis is an infectious disease caused by Toxoplasma gondii, an intracellular protozoan parasite that live inside the cells of the reticulo endothelial and parenchymal cells of human and animals (mammals and birds. Some cases of toxoplasmosis usually have no symptoms, but in any cases caused severe symptoms, such as hydrocephalus, microcephalus, intracranial calcification, retinal damage, brain abscess, mental retardation, lymphadenopathy, and others. Its severe symptoms usually showed a long time after first exposure, except symptoms showed by congenital transmission caused by infected mother. Early diagnosis is important to prevent the illness but methods for toxoplasmosis screening are still too expensive for developing country. Enzyme-linked immunosorbent assay (ELISA allow the testing of a large number samples within short time frame and based on antibody or antigen detection. This study aimed to know the sensitivity and specificity of recombinat protein GRA1 as antigen using ELISA methods. We tested the sensitivity and spesificity of GRA1 protein as antigen in ELISA methods to diagnose toxoplasmosis and compared with ELISA Kit Commercial. Reliable laboratory testing is important to detect Toxoplasma gondii infection, and focused to improving the low cost and easy-to-use diagnostic instrument. Seventy sera collected and tested using both indirect ELISA, commercial ELISA kit and GRA1 protein coated as antigen. Fourty eight and fifty one samples showed positive IgG antibody result of ELISA-GRA1 and ELISA kit. Negative sample tested by ELISA-GRA1 was 22 samples and 19 sample tested by ELISA Kit. The sensitivity and specificity of GRA1-based on ELISA were 100% and 86.36%, positive prediction value (ppv was 94.11%. These data indicate that the recombinant protein GRA1 is a highly immunogenic protein in human toxoplasmosis and become a promising marker for the screening of toxoplasmosis.

The time course of the specific antibody response by various ELISAs in pigs experimentally infected with Toxoplasma gondii

DEFF Research Database (Denmark)

Lind, Peter; Haugegaard, J.; Wingstrand, Anne

1997-01-01

With the aim of developing routine serological tests for monitoring the Toxoplasma infection status of Danish swine herds, four ELISAs based on tachyzoite antigen were set up: (1) an indirect ELISA for IgG-antibody; (2) a blocking ELISA for antibody to the membrane antigen, P-30; (3) an indirect ...

Rapid Detection of Food Allergens by Microfluidics ELISA-Based Optical Sensor

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Xuan Weng

2016-06-01

Full Text Available The risks associated with the presence of hidden allergens in food have increased the need for rapid, sensitive, and reliable methods for tracing food allergens in commodities. Conventional enzyme immunosorbent assay (ELISA has usually been performed in a centralized lab, requiring considerable time and sample/reagent consumption and expensive detection instruments. In this study, a microfluidic ELISA platform combined with a custom-designed optical sensor was developed for the quantitative analysis of the proteins wheat gluten and Ara h 1. The developed microfluidic ELISA biosensor reduced the total assay time from hours (up to 3.5 h to 15–20 min and decreased sample/reagent consumption to 5–10 μL, compared to a few hundred microliters in commercial ELISA kits, with superior sensitivity. The quantitative capability of the presented biosensor is a distinctive advantage over the commercially available rapid methods such as lateral flow devices (LFD and dipstick tests. The developed microfluidic biosensor demonstrates the potential for sensitive and less-expensive on-site determination for rapidly detecting food allergens in a complex sample system.

Comparison of viral RNA electrophoresis and indirect ELISA methods in the diagnosis of human rotavirus infection

International Nuclear Information System (INIS)

Avendano, L.F.; Dubinovsky, S.

1984-01-01

A total of 177 stool samples from Chilean diarrhea patients under two years of age were tested for rotavirus by two methods - the indirect enzyme-linked immunosorbent assay (indirect ELISA) and viral RNA electrophoresis in agarose gels (v RNA EPH). Fifty of the specimens came from patients with acute diarrhea and 127 came from patients with protracted diarrhea. The indirect ELISA testing was performed at the National Institutes of Health in the United States: the electrophoretic testing was carried out in Santiago, Chile by the authors. The electrophoretic method detected rotavirus in 36% of the acute samples and 25% of the samples from protracted cases, while the indirect ELISA method detected rotavirus in higher percentages of samples - 46% and 38%, respectively. These results support the conclusion that v RNA EPH is a less sensitive method for detecting rotavirus than the indirect ELISA. Nevertheless, the former method's high specificity, ease of application, and low cost make it a worthwhile alternative to indirect ELISA. Thus, considering the important role played by rotavirus in infant diarrhea and the need for a diagnostic technique that can be incorporated into the routines of medical center laboratories in developing countries, there is good reason to conclude that v RNA EPH is a useful tool for studying rotavirus diarrhea. (author)

Determination du niveau d'anticorps antitetaniques en donneurs de sang au moyen du test ELISA-TÉTANOS (São Paulo, SP, Bresil

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Luzia Cristina Contim Ferrato

1990-12-01

Full Text Available Le test ELISA-TÉTANOS (Biosys, France a été utilisé pour le titrage des anti-corps tétaniques (sensibilité = 0,0025 UI/ml en sérums humains de donneurs de sang, 566 hommes et 108 femmes, âges de 18 à 58 ans, moyenne de 29 ans, provenant de São Paulo, SP, Brésil. L'OMS, acceptant seulement la séroneutralisation sur souris (NT, la méthode de référence, pour les études sur la protection contre le tétanos, préconise le titre de 0,01 UI/ml comme minimum protecteur. BOURLEAUD & HUET ont proposé la limite de 0,06 UI/ml quand s'emploie le test ELISA, en attendant à une certaine discordance inévitable entre les méthodes. Parmi les 674 sérums étudiés, 178 (26,41% n'ont pas présenté d'anticorps ( 0,06 UI/ml.

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

International Nuclear Information System (INIS)

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

1978-01-01

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

Opportunities and challenges when pooling milk samples using ELISA

DEFF Research Database (Denmark)

Græsbøll, Kaare; Andresen, Lars Ole; Hisham Beshara Halasa, Tariq

2017-01-01

-positive samples by pooling. To illustrate this, the sensitivity of antibody ELISA on pooled samples of bovine milk for Salmonella Dublin, Mycobacterium avium spp. paratuberculosis, and bovine virus diarrhea was tested. For these milk assays, the analytical sensitivity decreased rapidly with increasing pool sizes...

Validation of an indirect ELISA for the diagnosis of Babesia bovis in cattle in Yucatan, Mexico

International Nuclear Information System (INIS)

Dominguez, A.J.L.; Rodriguez, V.R.I.; Oura, C.; Cob, G.L.A.

1998-01-01

The ELISA kit provided by the FAO/IAEA for the diagnosis of Babesia bovis was validated. In order to determine the appropriate ELISA cut-off point that would serve as the threshold between positive and negative samples, 119 serum samples from a Mexican Babesia-free zone were analyzed. The optimal cut-off point chosen was at 12% of the reactivity of the high positive control serum sample (PP) which resulted in a specificity of 97%. One hundred and ninety-six cattle from Wisconsin, USA, were introduced into Yucatan, Mexico, of which 181 were vaccinated with an attenuated live Babesia bovis vaccine; 15 animals remained as unvaccinated controls. Before and after vaccination all animals were bled and tested by enzyme linked immunosorbent assay (ELISA) and indirect fluorescence antibody test (IFAT). Both tests showed a high degree of correlation in their results. To evaluate an immune response to vaccination the optimal cut-off point chosen was 12% PP resulting in a sensitivity 99% and a specificity 95%. We concluded that the ELISA test has proved to be useful in Yucatan, Mexico for serological surveys and monitoring the efficiency o vaccination programmes. (author)

Characterization of novel monoclonal antibodies against the MERS-coronavirus spike protein and their application in species-independent antibody detection by competitive ELISA.

Science.gov (United States)

Fukushi, Shuetsu; Fukuma, Aiko; Kurosu, Takeshi; Watanabe, Shumpei; Shimojima, Masayuki; Shirato, Kazuya; Iwata-Yoshikawa, Naoko; Nagata, Noriyo; Ohnishi, Kazuo; Ato, Manabu; Melaku, Simenew Keskes; Sentsui, Hiroshi; Saijo, Masayuki

2018-01-01

Since discovering the Middle East respiratory syndrome coronavirus (MERS-CoV) as a causative agent of severe respiratory illness in the Middle East in 2012, serological testing has been conducted to assess antibody responses in patients and to investigate the zoonotic reservoir of the virus. Although the virus neutralization test is the gold standard assay for MERS diagnosis and for investigating the zoonotic reservoir, it uses live virus and so must be performed in high containment laboratories. Competitive ELISA (cELISA), in which a labeled monoclonal antibody (MAb) competes with test serum antibodies for target epitopes, may be a suitable alternative because it detects antibodies in a species-independent manner. In this study, novel MAbs against the spike protein of MERS-CoV were produced and characterized. One of these MAbs was used to develop a cELISA. The cELISA detected MERS-CoV-specific antibodies in sera from MERS-CoV-infected rats and rabbits immunized with the spike protein of MERS-CoV. The MAb-based cELISA was validated using sera from Ethiopian dromedary camels. Relative to the neutralization test, the cELISA detected MERS-CoV-specific antibodies in 66 Ethiopian dromedary camels with a sensitivity and specificity of 98% and 100%, respectively. The cELISA and neutralization test results correlated well (Pearson's correlation coefficients=0.71-0.76, depending on the cELISA serum dilution). This cELISA may be useful for MERS epidemiological investigations on MERS-CoV infection. Copyright © 2017 Elsevier B.V. All rights reserved.

Comparing Levels of Serum IgA, IgG, IgM and Cortisol in the Professional Bodybuilding Athletes and Non-Athletes

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S. Hadi Naghib

2013-10-01

Full Text Available Background: Bodybuilding athlete's bodies are placed under much pressure in during the exercise, which is causing changes in the immune and hormone system in the long term. The purpose of this study was to compare levels of serum immunoglobulin A (IgA, immunoglobulin G (IgG, immunoglobulin M (IgM and cortisol in the professional bodybuilding athletes (BA and the non-athletes (NA male. Materials and Methods: This study was a descriptive-analytic and 29 volunteer subjects in the professional BA and NA men participated. Levels of serum IgA, IgG, IgM using Single Radial Immunodiffusion (SRID and levels of serum cortisol using Radioimmunoassay (RIA were measured with blood sampling from brachial vein at rest and fasting. Data were analyzed using the Mann-Whitney U-test (p0.05, while, the levels of serum cortisol (22.10±2.60 vs. 15.41±3.44 μg/dl, U=0.001, p=0.001 significantly greater in the BA than the NA.Conclusion: The results of this study showed that participation in training and competitions bodybuilding has no effect on serum levels of IgG, IgA, IgM, but increased levels of serum cortisol.

Immunoglobulins G, M, and A against Sporothrix schenckii Exoantigens in Patients with Sporotrichosis before and during Treatment with Itraconazole▿

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Almeida-Paes, Rodrigo; Pimenta, Monique Amorim; Monteiro, Paulo Cezar F.; Nosanchuk, Joshua D.; Zancopé-Oliveira, Rosely Maria

2007-01-01

Sporotrichosis is an important subcutaneous mycosis, with an increasing worldwide incidence. However, few data are available regarding the immunological aspects of Sporothrix schenckii infection, particularly the humoral responses to the fungus. In this study we measured immunoglobulin G (IgG), IgM, and IgA in sera from 41 patients with sporotrichosis before antifungal treatment and from another 35 patients with sporotrichosis during itraconazole treatment by using a recently described S. schenckii exoantigen enzyme-linked immunosorbent assay (ELISA). More than 95% of patients had detectable IgA antibodies, and more than 85% had IgM and IgG antibodies before treatment. The number of patients with IgG antibodies increased to 91% during treatment. Conversely, significantly fewer samples from treated patients were positive for IgM (71%) and IgA (89%). Overall, 78% of patients had detectable levels of all isotypes tested at diagnosis, and this percentage dropped to 62.9% in patients receiving itraconazole. Testing of all three isotypes improved the sensitivity; at least two isotypes were detected in 93% of patients before and 89% after treatment. The reactivity of 94 sera from patients with other diseases and healthy individuals was also tested. Cross-reactivity occurred in 33% of the heterologous sera. Most of them were positive only in one isotype, 8.5% were positive for at least two isotypes, and only one serum (1.1%) was positive for the three isotypes. Antibodies produced during S. schenckii infection are diverse, and we demonstrate that an exoantigen ELISA for the detection of combinations of IgA, IgG, and IgM antibodies is a highly sensitive and specific diagnostic assay for sporotrichosis. PMID:17634504

The evolution of multiple isotypic IgM heavy chain genes in the shark.

Science.gov (United States)

Lee, Victor; Huang, Jing Li; Lui, Ming Fai; Malecek, Karolina; Ohta, Yuko; Mooers, Arne; Hsu, Ellen

2008-06-01

The IgM H chain gene organization of cartilaginous fishes consists of 15-200 miniloci, each with a few gene segments (V(H)-D1-D2-J(H)) and one C gene. This is a gene arrangement ancestral to the complex IgH locus that exists in all other vertebrate classes. To understand the molecular evolution of this system, we studied the nurse shark, which has relatively fewer loci, and characterized the IgH isotypes for organization, functionality, and the somatic diversification mechanisms that act upon them. Gene numbers differ slightly between individuals ( approximately 15), but five active IgM subclasses are always present. Each gene undergoes rearrangement that is strictly confined within the minilocus; in B cells there is no interaction between adjacent loci located > or =120 kb apart. Without combinatorial events, the shark IgM H chain repertoire is based on junctional diversity and, subsequently, somatic hypermutation. We suggest that the significant contribution by junctional diversification reflects the selected novelty introduced by RAG in the early vertebrate ancestor, whereas combinatorial diversity coevolved with the complex translocon organization. Moreover, unlike other cartilaginous fishes, there are no germline-joined VDJ at any nurse shark mu locus, and we suggest that such genes, when functional, are species-specific and may have specialized roles. With an entire complement of IgM genes available for the first time, phylogenetic analyses were performed to examine how the multiple Ig loci evolved. We found that all domains changed at comparable rates, but V(H) appears to be under strong positive selection for increased amino acid sequence diversity, and surprisingly, so does Cmicro2.

ELISA reader does not interfere by mobile phone radiofrequency radiation

Science.gov (United States)

Mortazavi, Seyyed Mohammad Javad; Baradaran-Ghahfarokhi, Hamid Reza; Abdi, Mohammad Reza; Baradaran-Ghahfarokhi, Milad; Mostafavi, Nayyer Sadat; Mahmoudi, Golshan; Berenjkoub, Nafiseh; Akmali, Zahra; Hossein-Beigi, Fahimeh; Arsang, Vajiheh

2016-01-01

Background: The increasing number of mobile phones can physically cause electromagnetic interference (EMI) in medical environments; can also cause errors in immunoassays in laboratories. The ELISA readers are widely used as a useful diagnostic tool for Enzymun colorimetric assay in medicine. The aim of this study was to investigate whether the ELISA reader could be interfered by the exposure to the 900 MHz cell phones in the laboratory. Materials and Methods: Human serum samples were collected from 14 healthy donors (9 women and 5 men) and each sample was divided into four aliquots and was placed into four batches for the in-vitro quantitative determination of human chorionic gonadotropin (hCG). During colorimetric reading of the first, second, and third batches, the ELISA reader (Stat Fax 2100, Awareness Technology, Inc., USA) was exposed to 0.5, 1.0, and 2.0 W exposure of 900 MHz radiation, respectively. For the forth batch (control group), no radiation was applied. All experiments were performed comparing ELISA read out results of the I, II, and III batches with the control batch, using the Wilcoxon test with criterion level of P = 0.050. Results: The final scores in the exposed batches I, II, and III were not statistically significant relative to the control batch (P > 0.05). The results showed that 900 MHz radiation exposure did not alter the ELISA measured levels of hCG hormone in I (P = 0.219), II (P = 0.909), and III (P = 0.056) batches compared to the control batch. Conclusion: This study showed that ELISA reader does not interfere by mobile phone RF radiation at a closed contact (less than 5 cm distance). However, we recommend that medical institutions discuss these issues in the context of their specific use of technologies and frame a policy that is clear and straightforward to guide staff, patients, and visitors. PMID:27376040

Solid phase radioimmunoassay for quantitation of IgM rheumatoid factor (RF). Comparison with agglutination techniques and radioimmunoprecipitation polyethylene glycol assay (RIPEGA)

Energy Technology Data Exchange (ETDEWEB)

Herrmann, D.; Jaeger, L.; Hein, G.; Henzgen, M.; Fiebig, H.; Schlenvoigt, G.; Vogelsang, H. (Friedrich-Schiller-Universitaet, Jena (German Democratic Republic). Bereich Medizin; Karl-Marx-Universitaet, Leipzig (German Democratic Republic). Sektion Biowissenschaften)

1985-01-01

A solid-phase radioimmunoassay capable of detecting nanogram quantities of human IgM rheumatoid factor using a monoclonal anti-..mu..-chain antibody is described. Human IgG did not interfere with the detection of IgM RF by this method. The small nonspecific binding of nonRF IgM to the human IgG coated tubes utilized in the assay must be corrected for by assaying samples in parallel bovine serum albumin coated control tubes only in cases of deviation of IgM from normal range. 69 coded and randomly arranged sera from patients with rheumatoid arthritis (RA), nonrheumatic joint diseases and healthy adult control subjects were investigated by this method, agglutination techniques as well as RIPEGA. A good correlation between solid-phase radioimmunoassay and agglutination techniques was found. Patients with seropositive RA had significantly higher concentrations of IgM RF than seronegative RA patients or control subjects.

Anti-GM2 gangliosides IgM paraprotein induces neuromuscular block without neuromuscular damage.

Science.gov (United States)

Santafé, Manel M; Sabaté, M Mar; Garcia, Neus; Ortiz, Nico; Lanuza, M Angel; Tomàs, Josep

2008-11-15

We analyzed the effect on the mouse neuromuscular synapses of a human monoclonal IgM, which binds specifically to gangliosides with the common epitope [GalNAc beta 1-4Gal(3-2 alpha NeuAc)beta 1-]. We focused on the role of the complement. Evoked neurotransmission was partially blocked by IgM both acutely (1 h) and chronically (10 days). Transmission electron microscopy shows important nerve terminal growth and retraction remodelling though axonal injury can be ruled out. Synapses did not show mouse C5b-9 immunofluorescence and were only immunolabelled when human complement was added. Therefore, the IgM-induced synaptic changes occur without complement-mediated membrane attack.

Evaluation of a rabies ELISA as an alternative method to seroneutralisation tests in the context of international trade of domestic carnivores.

Science.gov (United States)

Wasniewski, M; Labbe, A; Tribout, L; Rieder, J; Labadie, A; Schereffer, J L; Cliquet, F

2014-01-01

For several years, international movements with pets have greatly increased. Most countries have relaxed their quarantine measures and adopted a scheme combining vaccination of pets against rabies followed by a serological test to check the efficacy of vaccination. This new scheme has been strongly supported by the OIE, WHO and the European Commission to facilitate the free movement of people and pets around the world. Currently, only two reference methods are recognised and prescribed (the FAVN test and the RFFIT) to measure rabies antibody levels in serum samples for international trade. They are reliable and valuable methods of assessing the efficacy of rabies vaccination but they are time-consuming and require well-trained people and specialised laboratory facilities. A few years ago, an ELISA (Platelia™ Rabies II kit ad usum Veterinarium) was developed for domestic carnivores and wildlife. To our knowledge, this ELISA is the only one certified and prescribed by the OIE. Following its marketing, one task of the EURL for rabies serology was to evaluate the performance of laboratories using this new kit. The results revealed that 26% of the participants, which were already approved laboratories for rabies serology, failed the inter-laboratory trial. Such unsatisfactory results have never been observed during any of the previous proficiency tests organised annually since 2000 by the EURL for rabies serology using reference methods. More investigations were undertaken through internal and collaborative studies to assess the performance of this newly marketed ELISA kit. The results of the internal study revealed that even with a specificity of 100%, the sensitivity evaluated on 593 samples of domestic carnivores came to 78.2%. An issue regarding the underestimation of serum titres was also revealed during the study. The results of a collaborative study involving 23 international laboratories reinforced the preliminary conclusions regarding lack of sensitivity

Validation of the ELISA technique for diagnosis of trypanosomiasis in cattle in Uganda

International Nuclear Information System (INIS)

Okuna, N.M.

1992-01-01

ELISA, developed in ILRAD for diagnosis of T. congolense, T. brucei and T. vivax in cattle, has not been validated in Uganda. This study was undertaken to validate the technique. Negative reference sera were collected from 44 cattle in Kapchorwa, a tsetse-free area. The cattle were free of the three trypanosome species T. congolense, T. brucei and T. vivax by the haematocrit buffy coat technique (BCT). But by ELISA, three were positive for T. vivax, one for both T. congolense and T. vivax and one for T. congolense. Sera were collected from the same 44 cattle 10 weeks later. The cattle were again free of T. congolense, T. brucei and T. vivax, both by BCT and by mouse inoculations. Two cattle out of 450 screened at a centre 5 km away had T. vivax by BCT. The ELISA results for the second set of sera were quite similar to the results obtained from the first set of sera. The calculated optical density (D) cut off point was 50 for both T. brucei and T. vivax, but it was 60 for T. congolense. Sera from 5 cattle which had T. theileri and two which had microfilaria were all negative for antigenaemia by ELISA. Positive reference sera were collected form 40 cattle in a high tsetse challenge area. Using the haematocrit buffy coat technique, 5 had T. vivax, two had T. brucei and one had T. congolense. Checked by ELISA for antigenaemia, only 4 cattle were free of all the three trypanosome species, T. congolense, T. vivax and T. brucei. All the 40 cattle were treated with Diminazene aceturate at the rate of 7 mg/kg body weight. Two weeks later, the ELISA test showed that 10 cattle were free of any antigenaemia. Those still positive for antigenaemia had lower OD readings. The ELISA technique is valid. It is much more sensitive compared to parasitological tests. It is specific since none of the 7 cattle with either T. theileri or microfilaria gave positive results by ELISA. The technique would be very useful for epizootiological studies. (author)

Enzyme-Linked Immunosorbent Assay (ELISA).

Science.gov (United States)

Konstantinou, George N

2017-01-01

Food allergy is a public health concern especially after recognizing its constantly increased prevalence and severity. Despite careful reading of food ingredient statements, food allergic individuals may experience reactions caused by "hidden", "masked", or "contaminated" proteins that are known major allergens. Many techniques have been developed to detect even small traces of food allergens, for clinical or laboratory purposes. Enzyme-linked immunosorbent assay (ELISA) is one of the best validated and most routinely used immunoassay in allergy research, in allergy diagnosis in allergy-related quality control in various industries. Although as a technique it has been implemented for the last 45 years, the evolution in biochemistry allowed the development of ultrasensitive ELISA variations that are capable of measuring quantities in the scale of picograms, rendering ELISA attractive, robust, and very famous.

Evaluation of the performance of two tuberculosis interferon gamma release assays (IGRA-ELISA and T-SPOT.TB) for diagnosing Mycobacterium tuberculosis infection.

Science.gov (United States)

Wang, Linchuan; Tian, Xu-Dong; Yu, Yan; Chen, Wei

2018-04-01

The IGRA-ELISA and T-SPOT.TB are widely used in China. The aim of the study was to evaluate the performance of the two assays in diagnosis Mycobacterium tuberculosis infection. Of the 3727 patients in the study, 204 underwent testing using both the T-SPOT.TB and IGRA-ELISA, 1794 were tested using the T-SPOT.TB only, and 1729 were tested using the IGRA-ELISA only. The positive rate and consistency of the two assays were analyzed, and their sensitivity and specificity for diagnosing active tuberculosis were compared. There were no significant differences in the positive rate between the T-SPOT.TB test (25.8%) and IGRA-ELISA (28.6%), p = .065. The two assays were highly consistent, with a kappa value of 0.852 (p SPOT.TB test were 82.9% (107/129) and 78.6% (1309/1665), respectively, and those of IGRA-ELISA were 81.7% (94/115) and 75.2% (1214/1614), respectively. There were no significant differences in sensitivity (p > .05), but the specificity of the T-SPOT.TB test was slightly higher than that of IGRA-ELISA (p = .023). Both in terms of diagnosing M. tuberculosis infection and ruling out active tuberculosis, the performance of the IGRA-ELISA-a simple, almost labor-free assay that allows simultaneous processing of a very large number of samples-was well-matched with that of T-SPOT.TB test. However, IGRAs cannot be used as the only test to diagnose active tuberculosis. Copyright © 2018 Elsevier B.V. All rights reserved.

Development and primary application of ELISA method for detecting residual calf serum protein

International Nuclear Information System (INIS)

Li Hua; Yu Jiankun; Hong Chao; Long Ruixiang; Zhai Yougang; Xu Qiongfang; Cui Pingfang; Ding Xuefeng; Xie Zhongping

2005-01-01

To develop a new DAS-ELISA (double antibody sandwich ELISA) kit for detecting residual calf serum protein (CSP) in vaccines, calf sera from different district were pooled and used to immunize rabbits and hens respectively. Then, the IgY from yolk and the anti-CSP IgG from rabbit were separated and purified. The purified IgY was used as the coating antibody, and purified rabbit anti-CSP IgG was labeled by HRP. The optimal concentration of IgY was 25-30 μg/mL. The coating buffer was 0.01mol/L PBS(pH7.4) containing 0.4% glutin. The optimal dilutions of HRP-IgG were from 1:2000 to 1:3000. The sensitivity of this ELISA method was higher (up to 2.5μg/mL) than that of current RPHA, the variation coefficient was about 6.3%-9.4%, and the recovery rate was 90.4%-112.8%. Furthermore, there was no cross-reaction with sera of pig, monkey and guinea pig. Twenty lots of vaccines with Al(OH) 3 or without Al(OH) 3 were tested by ELISA and RPHA respectively. The results proved that the adjuvant of Al(OH) 3 had fewer influence on ELISA than on RPHA, the variation of PRHA among different lots of vaccines was more significant than ELISA. The ELISA method is a highly sensitive and useful method to detect CSP in vaccines. (authors)

HLA-DQBl*0402 alleles polymorphisms detected in Javanese HIV patients with positive anti-Toxoplasma gondii IgM

Science.gov (United States)

Sari, Yulia; Haryati, Sri; Prasetyo, Afiono Agung; Hartono, Adnan, Zainal Arifin

2017-02-01

The human leukocyte antigen (HLA)-DQB1 gene polymorphisms may associated with the infection risk of Toxoplasma gondii in HIV patients. The HLA-DQB1*0402 in HIV-1-positive patients could be considered risk factors for developing neurological opportunistic infections, mainly Toxoplasma encephalitis. However, the HLA-DQB1*0402 gene polymorphisms status in the Javanese HIV patients is unknown. This study evaluated the prevalence of HLA-DQB*0402 alleles polymorphisms in Javanese HIV patients with positive anti-Toxoplasma gondii IgM status. Since 2009 our research group performing a molecular epidemiology of blood borne viruses in Central Java Indonesia, by collecting the epidemiological and clinical data from the high risk communities. All blood samples were screened for blood borne pathogens by serological and molecular assays including for HIV and Toxoplasma gondii. The genomic DNA was isolated from the whole blood samples. Genetic polymorphisms of HLA-DQB1*0402 alleles were detected with polymerase chain reaction-sequence-specific primers (PCR-SSPs) technique. The genotypes were defined according to generated fragment patterns in the agarose gel electrophoresis analysis of PCR products. All of the samples were tested at least in duplicate. HLA-DQB1*0402 alleles were detected in 20.8% (16/77) patients and not detected in all HIV positive samples with negative anti-Toxoplasma gondii IgM status (n= 200). The HLA-DQB1*0402 alleles polymorphisms were detected in Javanese HIV patients with positive anti-Toxoplasma gondii IgM. The polymorphisms found may have association with the infection risk of Toxoplasma gondii in HIV patients.

The prevalence of toxoplasmosis in Imam Reza Hospital blood bank samples, Tehran, Iran.

Science.gov (United States)

Shaddel, M; Mirzaii Dizgah, I; Sharif, F

2014-10-01

The prevalence of toxoplasma gondii (T.g) infection in blood donors has been poorly studied. The aim of this study was to assess the prevalence of acute and chronic toxoplasmosis in blood products. A total of 223 blood products (101 fresh frozen plasma (FFP) and 122 packed cells (PC)) in Imam Reza hospital blood bank, Tehran, Iran were tested for specific T.g antibodies (IgG and IgM) by ELISA method. Positive IgG anti-T.g samples were further tested for IgM anti-T.g. A positive IgG test with the negative and positive IgM test was interpreted as a chronic and acute toxoplasmosis respectively. Of 223 samples 38.6% and 0.45% were positive for IgG anti-T.g and IgM anti-T.g levels respectively. Therefore, one and 85 samples were involved acute and chronic toxoplasmosis respectively. Twenty-six of fresh frozen plasma samples were positive for IgG anti-T.g and one of them was positive for IgM anti-T.g. Sixty packed cell samples were positive for IgG anti-T.g. Our study showed that there were chronic and acute toxoplasmosis in blood products and the prevalence of toxoplasmosis especially chronic form was high. Therefore screening of blood for T.g antibodies may be considered. Copyright © 2014 Elsevier Ltd. All rights reserved.

Evaluation of an indirect ELISA for the diagnosis of Babesia bovis in Uruguay

International Nuclear Information System (INIS)

Cardozo, H.; Solari, M.A.; Etchebarne, J.

1992-01-01

In initially establishing the FAO/IAEA indirect ELISA for the detection of antibodies to Babesia bovis, the optical density (OD) values of sera from known positive or negative local cattle were compared to the OD values obtained from the negative and positive reference sera provided with the ELISA kit. The percentage of false positive and negative sera were 2.53% and 2.97% respectively. The cut-off values for the negative reference serum in the kit were compared with those of a local negative population. These values were found to be similar. The specificity of the test was evaluated by testing 30 sera from animals experimentally infected with Anaplasma marginale and 30 sera from animals infected with Babesia bigemina. These were no cross-reaction either between A. marginale and B. bovis or between B. bigemina and B. bovis. A serological survey using this ELISA kit was carried out on animals from an enzootic area and an area free from the vecot Boophilus microplus. 53 out of 282 animals (18.8%) in the enzootic area were positive whilst all the animals (113) from the free area were negative. This study would indicate that the FAO/IAEA ELISA kit has a sensitivity of around 98% and specificity of 97%. (author). 8 refs, 2 figs, 2 tabs

O uso de Elisa como ferramenta complementar para o controle da tuberculose bovina no Brasil

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Walter Lilenbaum

2006-04-01

Full Text Available A detecção de animais infectados é um dos mais importantes fatores envolvidos no controle da tuberculose e, com algumas variações, é realizado através de testes intradérmicos de tuberculinização. No entanto, animais negativos aos testes intradérmicos podem estar infectados e representam uma importante ameaça aos programas de erradicação da tuberculose. Apesar deste conhecido fenômeno, o uso de ELISA não é rotina nestes programas. Nosso objetivo foi o de descrever experiências do uso a campo de ELISA na detecção de animais anérgicos no Rio de Janeiro, Brasil. Dentre 18 rebanhos envolvidos em um programa de controle da tuberculose, dois apresentaram animais infectados negativos aos testes intradérmicos, o que atrasou e comprometeu o sucesso do programa, com severas perdas econômicas. A infecção nestes animais foi identificada através de ELISA e confirmada pelo isolamento de M.bovis nas lesões pulmonares. Desta forma foram considerados como a mais provável fonte de infecção e responsáveis pela manutenção da enfermidade nos rebanhos. Sem o uso de testes sorológicos como ELISA estes animais provavelmente permaneceriam nos rebanhos perpetuando a infecção e a erradicação da enfermidade seria impossível. Em conclusão, sugere-se o uso de ELISA como uma valiosa ferramenta complementar para identificar animais anérgicos que possam atuar como reservatórios do agente nos rebanhos.

The use of monoclonal antibodies in competitive ELISA for the detection of antibodies to rinderpest and peste des petits ruminants viruses

International Nuclear Information System (INIS)

Anderson, J.; McKay, J.A.; Butcher, R.N.

1991-01-01

A monoclonal antibody against the haemagglutinin of rinderpest virus has been used in a competitive ELISA (C-ELISA) for the detection of antibodies to rinderpest virus in cattle, sheep, goat and game sera. Unlike the indirect ELISA and the virus neutralisation test (VNT), the C-ELISA detects only antibodies to rinderpest virus and gives no cross-reactivity with antibodies to peste des petits ruminants (PPR) virus. Antibodies to a wide range of strains of rinderpest virus have been detected using this assay, suggesting its suitability for both sero-monitoring and sero-surveillance. Analysis of C-ELISA results from the examination of field sera shows a much greater separation of negative and positive populations as compared to the indirect ELISA. A further monoclonal antibody against the H protein of PPR has also been found suitable for use in a C-ELISA for the detection of antibodies to PPR virus. The use of these two C-ELISA's has made possible rapid differential sero-diagnosis without recourse to cross-VNT testing. The use of monoclonal antibody-based assays will allow much greater standardisation of rinderpest and PPR diagnosis, and following field-trials the C-ELISA will replace the indirect ELISA for sero-monitoring throughout the Pan African Rinderpest Campaign. (author). 3 refs, 6 figs, 1 tab

[Contribution of the detection of IgA antibodies to the laboratory diagnosis of mumps in the population with a high vaccination coverage].

Science.gov (United States)

Limberková, R; Smíšková, D; Havlíčková, M; Herrmannová, K; Lexová, P; Malý, M

2015-03-01

Serological diagnosis of epidemic mumps can be difficult in vaccinated persons, particularly due to the absence of specific IgM antibodies. The aim was to find whether adding the detection of IgA antibodies to the currently used routine serological diagnosis of mumps (detection of IgM and IgG antibodies in an acute serum sample) would make the serological diagnosis of mumps more effective in a population with a high vaccination coverage. At the same time, ELISA kits for the detection of early IgA and IgM antibodies against the mumps virus were compared and statistical analysis of the results was performed. Sixty-four acute sera from patients with laboratory confirmed diagnosis of mumps were included in the study. Clinical specimens were collected at the onset of clinical symptoms. To test the sera, the MASTAZYME ELISA Mumps IgA kit (MAST DIAGNOSTICA, Germany) with the MASTSORB sorbent (RF and IgG) and Enzygnost Anti-Parotitis-Virus/IgM kit (Siemens, Germany) were used. A panel of 121 acute sera with no epidemiological link to mumps virus served as specificity controls for the IgA assay. The epidemiological data were derived from the EPIDAT system. The level of agreement was assessed using the McNemara test and Cohen's coefficient kappa. The Stata 9.2 software (Stata Corp LP, College Station, USA) was used for statistical analysis. The detection of IgA and IgM antibodies against the mumps virus yielded concordant results in 50/64 acute sera, 32 positive and 18 negative, i.e. an agreement of 78.12 %. Of the remaining 14 samples, 13 were only IgA positive and one was only IgM positive. The controls showed non-specific IgA positivity in 5/121 samples which indicates a 96% specificity. The absence of specific IgM antibodies against mumps virus is relatively often seen in vaccinated indivi-duals; nevertheless, the test is routinely used in patients with suspected active infection. The test for IgA antibodies, which is not routinely performed, significantly increased the

Prevalence of Peste Des Petits Ruminants Virus (PPRV in Mardan, Hangu and Kohat District of Pakistan; Comparative Analysis of PPRV Suspected serum samples using Competitive ELISA (cELISA and Agar Gel Immunodiffusion (AGID

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Misbah Aslam

2009-06-01

Full Text Available Peste des petits Ruminants (PPR is an acute, febrile, highly contagious and economically important viral disease of small ruminants. However PPR is more prevalent in sheep and goat. Competitive ELISA, Virus neutrilization test, and RT-PCR are the available techniques for diagnosis of PPR which give rapid detection where as Agar gel immunodiffusion and Counter immunoelectrophoresis were previously used for PPR detection. In this study two serological techniques were compared for PPR diagnosis. The main aim of this study was to evaluate the comparative sensitivity of both techniques for PPR detection. For this purpose one hundred and sixty PPR suspected serum samples collected from goats and sheep flocks (unvaccinated from three Districts of NWFP including Mardan, Hangu and Kohat were analyzed in National Veterinary Laboratories, Islamabad. Out of these 160 samples, fifty (50 were found positive for PPR antibodies with cELISA (Prevalence = 31.25%. The cELISA positive serum samples however gave negative results when tested with AGID although the control well was always positive. Thus it was concluded that cELISA technique is more sensitive and specific than AGID for PPR antibody detection. [Vet. World 2009; 2(3.000: 89-92

ELISA indireto para detecção de IgG antivírus da doença de Newcastle em soro de codorna Indirect ELISA for the detection of IgG specific to Newcastle disease virus in quail serum

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D.D. Oliveira

2007-10-01

Full Text Available An indirect ELISA for the detection of japanese quail IgG specific to Newcastle disease virus (NDV was developed. The secondary anti-quail IgG was produced in Balb/c mice, by inoculating Freund's complete adjuvant emulsified japanese quail-IgG extract. The purification of IgG was achieved using the caprilic acid method. The ELISA was compared to the haemagglutination-inhibition (HI test for antibodies to NDV. ELISA cut-off point was established through TG-ROC analysis. Total correlation was observed between the ELISA and the HI, being the ELISA efficient in the identification of positive and negative sera, with high sensitivity and specificity (100%. These results validate the use of the indirect ELISA as an alternative for the detection of NDV-specific IgG in japanese quail sera, with the advantage of high sensitivity and automation.

Anti-Streptococcus IgM Antibodies Induce Repetitive Stereotyped Movements: Cell Activation and Co-Localization with Fcα/μ Receptors in the Striatum and Motor Cortex

Science.gov (United States)

Zhang, Danhui; Patel, Ankur; Zhu, Youhua; Siegel, Allan; Zalcman, Steven S.

2012-01-01

Group A beta-hemolytic streptococcus (GABHS) infections are implicated in neuropsychiatric disorders associated with an increased expression of repetitive stereotyped movements. Anti-streptococcus IgG presumably cross-reacts with elements on basal ganglia cells, modifies their function, and triggers symptoms. IgM may play a unique role in precipitating behavioral disturbances since variations in cortico-striatal activity occur in temporal congruity with peak IgM titers during an orchestrated immune response. We discovered in Balb/c mice that single subcutaneous injections of mouse monoclonal IgM antibodies to Streptococcus Group A bacteria induce marked dose-dependent increases in repetitive stereotyped movements, including head bobbing, sniffing, and intense grooming. Effects were antibody- and antigen-specific: anti-streptococcus IgG stimulated ambulatory activity and vertical activity but not these stereotypies, while anti-KLH IgM reduced activity. We suggest that anti-streptococcus IgM and IgG play unique roles in provoking GABHS-related behavioral disturbances. Paralleling its stereotypy-inducing effects, anti-streptococcus IgM stimulated Fos-like immunoreactivity in regions linked to cortico-striatal projections involved in motor control, including subregions of the caudate, nucleus accumbens, and motor cortex. This is the first evidence that anti-streptococcus IgM antibodies induce in vivo functional changes in these structures. Moreover, there was a striking similarity in the distributions of anti-streptococcus IgM deposits and Fos-like immunoreactivity in these regions. Of further importance, Fcα/μ receptors, which bind IgM, were present- and co-localized with anti-streptococcus IgM in these structures. We suggest that anti-streptococcus IgM-induced alterations of cell activity reflect local actions of IgM that involve Fcα/μ receptors. These findings support the use of anti-streptococcus monoclonal antibody administration in Balb/c mice to model GABHS

Utilidad de sangre almacenada en papel de filtro para estudios serologicos por ELISA de inhibicion Use of filter paper strips on an ELISA inhibition test for serologic studies on dengue

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S. Vázquez

1991-08-01

Full Text Available Para evaluar la utilidad del método de recolección de muestras de sangre en papel de filtro para la detección de anticuerpos anti-dengue mediante un ELISA de Inhibición recientemente desarrollado en nuestro laboratorio, se realizó una toma simultánea de muestras de sangre en papel de filtro y de suero, de donantes de Banco de Sangre. Ambas muestras fueron conservadas a -20ºC y probadas a los 15 dias, 3 y 6 meses respectivamente. A las muestras que resultaron positivos se les amplió el rango de dilución para determinar título. Al realizar la comparación entre ambas muestras, sangre en papel de filtro y suero, encontramos que no existían diferencias de detección significativas, tanto para los casos positivos como los negativos. No obstante se observó en ambas muestras y de forma general una disminución del titulo de anticuerpos (una dilución al transcurrir el tiempo máximo establecido en nuestro estudio (6 meses.To evaluate the usefullness of the collecting method of blood samples in filter paper strips for anti-dengue antibody detection using an ELISA Inhibition test which has been recently developed in our laboratory, blood samples collected on filter paper strips and serum samples were obtained from the same blood donors. Both samples were kept at -20ºC and tested at 15 days, 3 and 6 months. Titers were determined in positive samples. Comparing the results, no significant differences were found between serum samples and blood samples collected in filter paper strips in relation to the number of negative and positive cases. Nevertheless, it was observed in both types of samples a decrease of the antibody titers (one dilution in the longest period of our study (6 months.

Immunoprecipitation techniques and Elisa in the detection of anti-Fonsecaea pedrosoi antibodies in chromoblastomycosis

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Vidal Mônica Scarpelli Martinelli

2003-01-01

Full Text Available Chromoblastomycosis (CBM is a chronic subcutaneous infection caused by several dematiaceous fungi. The most commonly etiological agent found in Brazil is Fonsecaea pedrosoi, which appears as thick walled, brownish colored cells with transverse and longitudinal division in the lesions, called "muriform cells". This disease is found worldwide but countries like Madagascar and Brazil have highest incidence. Diagnosis is made by clinical, direct and histopathologic examination and culture of specimens. Serological tests have been used to identify specific antibodies against Fonsecaea pedrosoi antigens, as well as immunotechniques have been used for CBM serological identification and diagnosis. In the present study double immunodiffusion (DID, counterimmunoelectrophoresis (CIE and immunoenzymatic test (ELISA have been used to evaluate humoral immune response in patients with CBM caused by F. pedrosoi. Metabolic antigen was used for immunoprecipitation tests (DID and CIE while somatic antigen for ELISA. Our results demonstrated 53% sensitivity and 96% specificity for DID, while CIE presented 68% sensitivity and 90.5% specificity. ELISA demonstrated 78% sensibility and 83% specificity. Serological tests can be a useful tool to study different aspects of CBM, such as helping differential diagnosis, when culture of the pathogenic agent is impossible.

Seroprevalence of equine granulocytic anaplasmosis and lyme borreliosis in Canada as determined by a point-of-care enzyme-linked immunosorbent assay (ELISA).

Science.gov (United States)

Schvartz, Gili; Epp, Tasha; Burgess, Hilary J; Chilton, Neil B; Pearl, David L; Lohmann, Katharina L

2015-06-01

Equine granulocytic anaplasmosis (EGA) and Lyme borreliosis (LB) are an emerging concern in Canada. We estimated the seroprevalence of EGA and equine LB by testing 376 convenience serum samples from 3 provinces using a point-of-care SNAP(®) 4Dx(®) ELISA (IDEXX Laboratories, Westbrook, Maine, USA), and investigated the agreement between the point-of-care ELISA and laboratory-based serologic tests. The estimated seroprevalence for EGA was 0.53% overall (0.49% in Saskatchewan, 0.71% in Manitoba), while the estimated seroprevalence for LB was 1.6% overall (0.49% in Saskatchewan, 2.86% in Manitoba). There was limited agreement between the point-of-care ELISA and an indirect fluorescent antibody test for EGA (kappa 0.1, PABAK 0.47) and an ELISA/Western blot combination for LB (kappa 0.23, PABAK 0.71). While the SNAP(®) 4Dx(®) ELISA yielded expected seroprevalence estimates, further evaluation of serologic tests for the purposes of disease exposure recognition may be needed.

A Colorimetric Enzyme-Linked Immunosorbent Assay (ELISA) Detection Platform for a Point-of-Care Dengue Detection System on a Lab-on-Compact-Disc

Science.gov (United States)

Thiha, Aung; Ibrahim, Fatimah

2015-01-01

The enzyme-linked Immunosorbent Assay (ELISA) is the gold standard clinical diagnostic tool for the detection and quantification of protein biomarkers. However, conventional ELISA tests have drawbacks in their requirement of time, expensive equipment and expertise for operation. Hence, for the purpose of rapid, high throughput screening and point-of-care diagnosis, researchers are miniaturizing sandwich ELISA procedures on Lab-on-a-Chip and Lab-on-Compact Disc (LOCD) platforms. This paper presents a novel integrated device to detect and interpret the ELISA test results on a LOCD platform. The system applies absorption spectrophotometry to measure the absorbance (optical density) of the sample using a monochromatic light source and optical sensor. The device performs automated analysis of the results and presents absorbance values and diagnostic test results via a graphical display or via Bluetooth to a smartphone platform which also acts as controller of the device. The efficacy of the device was evaluated by performing dengue antibody IgG ELISA on 64 hospitalized patients suspected of dengue. The results demonstrate high accuracy of the device, with 95% sensitivity and 100% specificity in detection when compared with gold standard commercial ELISA microplate readers. This sensor platform represents a significant step towards establishing ELISA as a rapid, inexpensive and automatic testing method for the purpose of point-of-care-testing (POCT) in resource-limited settings. PMID:25993517

A Colorimetric Enzyme-Linked Immunosorbent Assay (ELISA) Detection Platform for a Point-of-Care Dengue Detection System on a Lab-on-Compact-Disc.

Science.gov (United States)

Thiha, Aung; Ibrahim, Fatimah

2015-05-18

The enzyme-linked Immunosorbent Assay (ELISA) is the gold standard clinical diagnostic tool for the detection and quantification of protein biomarkers. However, conventional ELISA tests have drawbacks in their requirement of time, expensive equipment and expertise for operation. Hence, for the purpose of rapid, high throughput screening and point-of-care diagnosis, researchers are miniaturizing sandwich ELISA procedures on Lab-on-a-Chip and Lab-on-Compact Disc (LOCD) platforms. This paper presents a novel integrated device to detect and interpret the ELISA test results on a LOCD platform. The system applies absorption spectrophotometry to measure the absorbance (optical density) of the sample using a monochromatic light source and optical sensor. The device performs automated analysis of the results and presents absorbance values and diagnostic test results via a graphical display or via Bluetooth to a smartphone platform which also acts as controller of the device. The efficacy of the device was evaluated by performing dengue antibody IgG ELISA on 64 hospitalized patients suspected of dengue. The results demonstrate high accuracy of the device, with 95% sensitivity and 100% specificity in detection when compared with gold standard commercial ELISA microplate readers. This sensor platform represents a significant step towards establishing ELISA as a rapid, inexpensive and automatic testing method for the purpose of point-of-care-testing (POCT) in resource-limited settings.

The Induction of IgM and IgG Antibodies against HLA or MICA after Lung Transplantation

OpenAIRE

Paantjens, Annelieke W. M.; van de Graaf, Ed A.; Kwakkel-van Erp, Johanna M.; Hoefnagel, Tineke; van Ginkel, Walter G. J.; Fakhry, Farzia; van Kessel, Diana A.; van den Bosch, Jules M. M.; Otten, Henny G.

2011-01-01

The production of IgG HLA antibodies after lung transplantation (LTx) is considered to be a major risk factor for the development of chronic rejection, represented by the bronchiolitis obliterans syndrome (BOS). It has recently been observed that elevated levels of IgM HLA antibodies also correlates with the development of chronic rejection in heart and kidney transplantation. This study investigates the relationship between IgM and IgG antibodies against HLA and MICA after lung transplantati...

Comparison of viral RNA electrophoresis and indirect ELISA methods in the diagnosis of human rotavirus infection

Energy Technology Data Exchange (ETDEWEB)

Avendano, L F; Dubinovsky, S; James, Jr, H D

1984-01-01

A total of 177 stool samples from Chilean diarrhea patients under two years of age were tested for rotavirus by two methods - the indirect enzyme-linked immunosorbent assay (indirect ELISA) and viral RNA electrophoresis in agarose gels (v RNA EPH). Fifty of the specimens came from patients with acute diarrhea and 127 came from patients with protracted diarrhea. The indirect ELISA testing was performed at the National Institutes of Health in the United States: the electrophoretic testing was carried out in Santiago, Chile by the authors. The electrophoretic method detected rotavirus in 36% of the acute samples and 25% of the samples from protracted cases, while the indirect ELISA method detected rotavirus in higher percentages of samples - 46% and 38%, respectively. These results support the conclusion that v RNA EPH is a less sensitive method for detecting rotavirus than the indirect ELISA. Nevertheless, the former method's high specificity, ease of application, and low cost make it a worthwhile alternative to indirect ELISA. Thus, considering the important role played by rotavirus in infant diarrhea and the need for a diagnostic technique that can be incorporated into the routines of medical center laboratories in developing countries, there is good reason to conclude that v RNA EPH is a useful tool for studying rotavirus diarrhea. 18 refs, 3 tabs. Also published in the Bol. Oficina Sanit. Panam. (1984) v. 97(1), p. 1-7 (In Spanish).

Elisa Studio showroom = Elisa Studio showroom / Jan Joonas Graps ; kommenteerinud Tiina Kuusisto

Index Scriptorium Estoniae

Graps, Jan Joonas, 1972-

2015-01-01

Elisa Studio showroom Helsingis Lasiplatsi, Mannerheimintie 22-24. Sisekujunduse autorid Jan Joonas Graps, Ken-Kristjan Ruut, Anne Määrmann (JanKen Wisespace). Lühidalt loovstuudiost JanKen Wisespace

Seroprevalence of Toxoplasma gondii in southern districts of Tamil Nadu using IgG-ELISA.

Science.gov (United States)

Sucilathangam, G; Palaniappan, N; Sreekumar, C; Anna, T

2012-10-01

The present study was conducted to assess the seroprevalence of Toxoplasma gondii in and around Tirunelveli by in-house IgG assay using ELISA. Serum samples from 175 immunodeficient and 175 immunocompetent patients were collected at Tirunelveli district, Tamil Nadu from May 2006 to October 2007. They were subjected into in-house IgG assay using enzyme-linked immune sorbent assay (ELISA) in which tachyzoite soluble antigen derived from solubilised whole organisms was used. Out of 350 patients tested by IgG ELISA, 46 patients (13.14%) had antibodies for toxoplasmosis with mean OD value of 0.2 ± 0.073 and the OD value ranged from 0.144 to 0.444. Among the immunocompetent group of 175 patients, 19 patients (10.86%) had antibodies to toxoplasmosis whereas, in immunodeficient group of 175 patients, 27 patients (15.43%) had antibodies for toxoplasmosis. There was no statistical difference (P > 0.05) between the immunocompetent and immunodeficient group. The sensitivity and specificity of IgG ELISA in detecting toxoplasmosis was 90 and 100%, respectively. The overall seroprevalence of toxoplasmosis in and around Tirunelveli district of Tamil Nadu was 13.14% based on IgG ELISA. The study has proved ELISA to be a sensitive and specific procedure for the serodiagnosis of toxoplasmosis.

Use of a trypanosomal antigen ELISA to monitor tsetse and trypanosomosis control programmes in Kenya

Energy Technology Data Exchange (ETDEWEB)

Olaho-Mukani, W; Munga, L K; Nyanga` O, J N.M.; Ouma, J O; Masika, P; Okech, G; Ndungu, J M [Kenya Trypanosomiasis Research Inst., Kikuyu (Kenya)

1997-02-01

The capture Antigen-ELISA was used to monitor serum samples originating from three study areas in Kenya. At the Galana ranch the test was used to assess re-invasion of an area previously cleared of Glossina pallidipes. In Busia district the Ag-ELISA is being used to monitor the progress of a tsetse and trypanosomosis control programme. At Taita and Tara ranches the capture Antigen ELISA and the buffy coat technique (BCT) were used to evaluate the efficacy of a commercial Cypermethrin dip for the control of Glossina pallidipes. (author). 3 refs, 4 figs, 2 tabs.

An Evidence-Based Approach to Detection by DASI-ELISA and RT-PCR in Dormant Period

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Antonio Olmos

2008-01-01

Full Text Available An evidence-based approach, such as those developed in clinical and veterinary medicine, was applied to the detection of Plum pox virus (PPV during the dormant period. A standardized methodology was used for the calculation of parameters of the operational capacity of DASI-ELISA and RT-PCR in wintertime. These methods are routinely handled to test the sanitary status of plants in national or international trading and in those cases concerning export-import of plant materials. Diagnosis often has to be performed during the dormant period, when plant material is commercialized. Some guidelines to interpret diagnostic results of wintertime are provided in an attempt to minimize risks associated with the methods and over-reliance on the binary outcome of a single assay. In order to evaluate if a complementary test increased the confidence of PPV diagnosis when discordant results between DASI-ELISA and RT-PCR are obtained, NASBA-FH also was included. Likelihood ratios of each method were estimated based on the sensitivity and specificity obtained in wintertime. Subsequently, a Bayesian approach was performed to calculate post-test probability of PPV infection in spring. Results of evidence-based approach show that different PPV prevalences require different screening tests. Thus, at very low PPV prevalence levels DASI-ELISA should be used as the election method, whilst at the highest PPV prevalence levels RT-PCR should be performed. NASBA-FH could be used at medium prevalences to clarify discordances between DASI-ELISA and RT-PCR.

Galactic binaries with eLISA

OpenAIRE

Nelemans, G.

2013-01-01

I review what eLISA will see from Galactic binaries -- double stars with orbital periods less than a few hours and white dwarf (or neutron star/black hole) components. I discuss the currently known binaries that are guaranteed (or verification) sources and explain why the expected total number of eLISA Galactic binaries is several thousand, even though there are large uncertainties in our knowledge of this population, in particular that of the interacting AM CVn systems. I very briefly sketch...

¿Es necesario investigar anticuerpos IgM contra el virus de la hepatitis A cuando el enzimograma hepático es normal?

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C. Coitinho

Full Text Available La hepatitis por virus A (VHA es la más frecuente de las hepatitis virales en el mundo, especialmente en los países subdesarrollados. Donde esta enfermedad es endémica, se suelen realizar un gran número de estudios de laboratorio para confirmarla. El objetivo del presente trabajo fue evaluar la utilidad de investigar anticuerpos IgM anti hepatitis A (IgM anti-VHA para el diagnóstico de la VHA en pacientes con niveles séricos normales de aspartato y alanina aminotransferasas (AST/ALT. Todos los pacientes que concurrieron al laboratorio con solicitud de enzimograma hepático y anticuerpos IgM anti-VHA durante el período octubre 2005-marzo 2006 fueron evaluados en este estudio. Los datos clínicos más frecuentes fueron presunción de hepatitis e ictericia (27,5 y 12,7%. La determinación de IgM anti-VHA se realizó por ensayo inmunoenzimático de micropartículas (MEIA; la de enzimas hepáticas en un multianalizador. De los 158 pacientes estudiados, 84 tenían valores elevados de AST/ALT; dentro de este grupo, el 82% fue reactivo para IgM anti-VHA. Los 74 pacientes restantes mostraron niveles normales de AST/ALT y solo 7 de ellos, bajo control de evolución por VHA ya confirmada, fueron reactivos para IgM anti-VHA. El 49% de los pacientes IgM anti-VHA reactivos correspondió a menores de 10 años. De acuerdo con estas observaciones, sugerimos que los estudios de laboratorio para confirmar infección aguda por VHA deberían realizarse en forma secuencial, ya que es innecesaria la determinación de anticuerpos IgM anti-VHA cuando las aminotransferasas séricas son normales.

Utility of dengue NS1 antigen rapid diagnostic test for use in difficult to reach areas and its comparison with dengue NS1 ELISA and qRT-PCR.

Science.gov (United States)

Shukla, Mohan K; Singh, Neeru; Sharma, Ravendra K; Barde, Pradip V

2017-07-01

The objective of this study was to demonstrate the utility of dengue virus (DENV) non structural protein 1 (NS1) based rapid diagnostic test (RDT) for use in tribal and difficult to reach areas for early dengue (DEN) diagnosis in acute phase patients and evaluate its sensitivity and specificity against DENV NS1 enzyme linked immune sorbent assay (ELISA) and real time reverse transcriptase polymerase chain reaction (qRT-PCR). The DENV NS1 RDT was used for preliminary diagnosis during outbreaks in difficult to reach rural and tribal areas. The diagnosis was confirmed by DENV NS1 ELISA in the laboratory. The samples were also tested and serotyped by qRT-PCR. The results were evaluated using statistical tests. The DENV NS1 RDT showed 99.2% sensitivity and 96.0% specificity when analyzed using DENV NS1 ELISA as standard. The specificity and sensitivity of the RDT when compared with qRT-PCR was 93.6% and 91.1%, respectively. The serotype specific evaluation showed more than 90% sensitivity and specificity for DENV-1, 2, and 3. The RDT proved a good diagnostic tool in difficult to reach rural and tribal areas. Further evaluation studies with different commercially available RDTs in different field conditions are essential, that will help clinicians and patients for treatment and programme managers for timely intervention. © 2017 Wiley Periodicals, Inc.

Antibody to human T-lymphotropic virus in a patient with Guillain-Barré syndrome (case report Anticorpo para o vírus linfotrópico humano T em um paciente com a síndrome de Guillain-Barré

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C.M. Nakauchi

1991-08-01

Full Text Available Serum sample obtained from a male, 12 year old patient suffering from Guillain-Barré syndrome (GBS was positive for human T-lymphotropic virus (HTLV-I antibody by the enzyme-linked immunosorbent assay (ELISA and the Western Blot analysis (WB. Attempts to isolate enteroviruses (including poliovirus from faecal material in both tissue culture and suckling mice were unsuccessful; in addition, acute and convalescent paired serum samples did not show any evidence of recent poliovirus infection when tested against the three serotypes. Specific tests for detection of Epstein-Barr virus infection were not performed; however, the Paul-Bunnel test yielded negative results. ELISA for detection of anti-cytomegalovirus IgM was also negative. The concomitant occurrence of either adult T cell leukemia (ATL or lymphoma was not recorded in this case.Amostra de soro obtida de paciente com a síndrome de Guillain-Barré revelou-se positiva quanto à presença de anticorpos para o vírus linfotrópico humano T (HTLV-I pelo método imuno-enzimático (ELISA e a análise por "Western-Blot". Resultaram negativos os testes visando à detecção de enterovírus (incluindo poliovírus a partir de material fecal, tanto em cultura de tecidos como em camundongos recém-nascidos; exames com amostras de soro aguda e convalescente não exibiram qualquer evidência de infecção recente pelos três tipos de poliovírus. O teste de Paul-Bunnel, assim como o "ELISA" para a detecção de IgM anti-citomegalovírus resultaram negativos. Não foi registrada, no presente caso, quer a leucemia adulta de células T, quer linfomas.

Detection of Bovine IgG Isotypes in a PPA-ELISA for Johne's Disease Diagnosis in Infected Herds.

Science.gov (United States)

Fernández, Bárbara; Gilardoni, Liliana Rosa; Jolly, Ana; Colavecchia, Silvia Beatriz; Paolicchi, Fernando Alberto; Mundo, Silvia Leonor

2012-01-01

Johne's Disease or Paratuberculosis is a chronic granulomatous enteritis disease affecting ruminants. Detection of subclinically infected animals is difficult, hampering the control of this disease. The aim of this work was to evaluate the performance of detection of IgG isotypes in a PPA-ELISA to improve the recognition of cattle naturally infected with Map in different stages. A total of 108 animals from Tuberculosis-free herds were grouped as follows: exposed (n = 30), subclinically infected (n = 26), clinically infected (n = 14), and healthy controls (n = 38). Receiver-operating characteristic (ROC) curves of isotypes/PPA-ELISAs were constructed and areas under the curves were compared to evaluate the performance of each test. Our study demonstrated that the conventional PPA-ELISA (detecting IgG) is the best to identify clinically infected animals with high sensitivity (92.9%) and specificity (100%). Meanwhile, IgG2/PPA-ELISA improved the number of subclinically infected cattle detected as compared with conventional IgG/PPA-ELISA (53.8 versus 23.1%). In addition, it had the maximum sensitivity (65.0%, taking into account all Map-infected cattle). In conclusion, the combination of IgG and IgG2/PPA-ELISAs may improve the identification of Map-infected cattle in different stages of disease. The usefulness of IgG2 detection in serological tests for Johne's Disease diagnosis should be further evaluated.

Consistency of direct microscopic examination and ELISA in detection of Giardia in stool specimen among children

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Zohreh Torabi

2014-09-01

Full Text Available Objective: To investigate the consistency of direct microscopic examination and ELISA for determination of Giadia in stool specimen. Method: Study population consisted of children with any clinical symptoms of Giardia infestation since last two weeks. Fresh stool specimen was collected from each child. The stools specimens were assessed by two methods of direct microscopic examination and ELISA.The degree of agreement between direct stool exam and ELISA was calculated by Cohen's kappa coefficient. Results: In this study, 124 children with age range 2-12 years were investigated. A total of 64 (61.7% and 79 (65.7% of children had Giardia by direct stool exam and ELISA test respectively. There was association between frequency of constipation and Giardia infection (P=0.036. The Cohen's kappa coefficient calculated for degree of agreement between direct stool exam and ELISA showed κ=0.756 (P<0.001. Conclusions: The frequency of Giardia infection in symptomatic children was high and there was high agreement rate between ELISA and direct stool smear.

Evaluation of an enzyme-linked immunosorbent assay (ELISA) for the serological diagnosis of sarcoptic mange in dogs.

Science.gov (United States)

Lower, K S; Medleau, L M; Hnilica, K; Bigler, B

2001-12-01

Canine scabies is a challenging disease to diagnose because sarcoptic mites are hard to find on skin scrapings. The purpose of this study was to evaluate a serologic enzyme-linked immunosorbent assay (ELISA) as an aid in the diagnosis of canine scabies. In addition, serum samples were obtained post treatment to determine the duration and persistence of circulating scabies antibodies after resolution of natural infection. Nineteen dogs diagnosed with sarcoptic mange and 38 control dogs were tested. Sixteen scabies-infested dogs showed positive pretreatment ELISA results (84.2% sensitivity). Thirty-four control dogs showed negative ELISA results (89.5% specificity). In the 11 scabies dogs from which multiple post treatment serum samples were obtained, detectable antibodies were not present 1 month after treatment in four cases, but were present for 1-4.5 months post treatment in seven dogs. Our results suggest that this scabies ELISA test is useful in the diagnosis of canine scabies.

Using the AD12-ICT rapid-format test to detect Wuchereria bancrofti circulating antigens in comparison to Og4C3-ELISA and nucleopore membrane filtration and microscopy techniques.

Science.gov (United States)

El-Moamly, Amal Abdul-Rasheed; El-Sweify, Mohamed Aly; Hafez, Mohamad Abdul

2012-09-01

Lymphatic filariasis (LF) continues to be a major source of permanent disability and an impediment to socio-economic development in 73 countries where more than 1 billion people are at risk and over 120 millions are infected. The global drive to eliminate LF necessitates an increasing demand for valid, reliable and rapid diagnostic tests. This study aimed to assess the performance of the AD12 rapid format immunochromatographic test (ICT) to detect Wuchereria bancrofti circulating antigens, against the combined gold standard: TropBio Og4C3-ELISA (enzyme-linked immunosorbent assay) which detects circulating filarial antigen (CFA) and the nucleopore membrane filtration and microscopic examination. This prospective case-control study involved 647 asymptomatic migrant workers from filariasis-endemic countries. Of these specimens, 32 were positive for microfilaremia using the membrane filtration and microscopy, 142 positive by ELISA (of which 32 had microfilaremia), and 128 positive by the ICT (of which 31 had microfilaremia). The performance of the ICT was calculated against 32 true-positive and 90 true-negative cases. For the detection of CFA, the ICT had a sensitivity of 97% (95% confidence interval [CI] 91-103), specificity 100% (95% CI 100-100), Positive Predictive Value (PPV) 100% (95% CI 100-100), Negative Predictive Value (NPV) 99% (95% CI 97-101); and the total accuracy of the test was 99% (95% CI 98-101). The agreement between ICT and ELISA in detecting W. bancrofti antigens was excellent (kappa = 0.934; p = 0.000). In conclusion, the AD12-ICT test for the detection of W. bancrofti-CFA was sensitive and specific and comparable to the performance of ELISA. The ICT would be a useful additional test to facilitate the proposed strategies for control and elimination of LF. Because it is rapid, simple to perform, and does not require the use of special equipment, the ICT may be most appropriate in screening programs and in monitoring the possible risk of introducing

Comparison of a flow assay for brucellosis antibodies with the reference cELISA test in West African Bos indicus.

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Barend M deC Bronsvoort

Full Text Available Brucellosis is considered by the Food and Agricultural Organisation and the World Health Organisation as one of the most widespread zoonoses in the world. It is a major veterinary public health challenge as animals are almost exclusively the source of infection for people. It is often undiagnosed in both human patients and the animal sources and it is widely acknowledged that the epidemiology of brucellosis in humans and animals is poorly understood, particularly in sub-Saharan Africa. It is therefore important to develop better diagnostic tools in order to improve our understanding of the epidemiology and also for use in the field for disease control and eradication. As with any new diagnostic test, it is essential that it is validated in as many populations as possible in order to characterise its performance and improve the interpretation of its results. This paper describes a comparison between a new lateral flow assasy (LFA for bovine brucellosis and the widely used cELISA in a no gold standard analysis to estimate test performance in this West African cattle population. A Bayesian formulation of the Hui-Walter latent class model incorporated previous studies' data on sensitivity and specificity of the cELISA. The results indicate that the new LFA is very sensitive (approximately 87% and highly specific (approximately 97%. The analysis also suggests that the current cut-off of the cELSIA may not be optimal for this cattle population but alternative cut-offs did not significantly change the estimates of the LFA. This study demonstrates the potential usefulness of this simple to use test in field based surveillance and control which could be easily adopted for use in developing countries with only basic laboratory facilities.

Comparison of a Flow Assay for Brucellosis Antibodies with the Reference cELISA Test in West African Bos indicus

Science.gov (United States)

Bronsvoort, Barend M. deC.; Koterwas, Bronwyn; Land, Fiona; Handel, Ian G.; Tucker, James; Morgan, Kenton L.; Tanya, Vincent N.; Abdoel, Theresia H.; Smits, Henk L.

2009-01-01

Brucellosis is considered by the Food and Agricultural Organisation and the World Health Organisation as one of the most widespread zoonoses in the world. It is a major veterinary public health challenge as animals are almost exclusively the source of infection for people. It is often undiagnosed in both human patients and the animal sources and it is widely acknowledged that the epidemiology of brucellosis in humans and animals is poorly understood, particularly in sub-Saharan Africa. It is therefore important to develop better diagnostic tools in order to improve our understanding of the epidemiology and also for use in the field for disease control and eradication. As with any new diagnostic test, it is essential that it is validated in as many populations as possible in order to characterise its performance and improve the interpretation of its results. This paper describes a comparison between a new lateral flow assasy (LFA) for bovine brucellosis and the widely used cELISA in a no gold standard analysis to estimate test performance in this West African cattle population. A Bayesian formulation of the Hui-Walter latent class model incorporated previous studies' data on sensitivity and specificity of the cELISA. The results indicate that the new LFA is very sensitive (∼87%) and highly specific (∼97%). The analysis also suggests that the current cut-off of the cELSIA may not be optimal for this cattle population but alternative cut-offs did not significantly change the estimates of the LFA. This study demonstrates the potential usefulness of this simple to use test in field based surveillance and control which could be easily adopted for use in developing countries with only basic laboratory facilities. PMID:19381332

Expresión y sororreactividad de la lipoproteína recombinante de 43-kda de Bartonella bacilliformis

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Carlos Padilla R

2006-07-01

Full Text Available Objetivo: La lipoproteína de 43-kDa de Bartonella bacilliformis fue obtenida en su forma recombinante (rBbLppB y purificada para evaluar su serorreactividad mediante ELISA. Materiales y métodos: Los niveles de anticuerpos IgG e IgM humanos en los sueros de pacientes con Bartonelosis confirmada y sueros de otras enfermedades (salmonelosis, Brucelosis y leptospirosis frente a rBbLppB fueron evaluados por ELISA, se utilizó sueros de personas sanas como controles. Resultados: La sensibilidad y la especificidad del ELISA IgG fueron 70,4% y 90% respectivamente. Asimismo, la sensibilidad y especificidad de ELISA IgM fueron 85,2% y 90% respectivamente. Conclusiones: Estos resultados demuestran que el ELISA usando rBbLppB tiene una buena sensibilidad y especificidad y puede ser considerada como un buen antígeno para el diagnóstico de Bartonelosis causada por B. bacilliformis.

Deterioration of lung function is associated with presence of IgM rheumatoid factor and smoking in patients with systemic sclerosis

DEFF Research Database (Denmark)

Broholm, B.; Ullman, S.; Halberg, P.

2008-01-01

of patients with systemic sclerosis (SSc) the influence of smoking and IgM RF on the lung function was calculated. One hundred fifty-five persons with SSc had vital capacity (VC) and diffusing capacity (DLco) measured at least twice with at least 1-year interval as percents of predicted values according......Smoking is a known risk factor for the development of several lung diseases, autoimmune diseases, and IgM rheumatoid factor (RF) in nonrheumatic persons. In patients with rheumatoid arthritis and IgM RF the diffusion capacity is decreased in smokers but not in nonsmokers. In the present study......M RF was found only in smokers or previous smokers, P = 0.007 and P = 0.01, respectively. These findings were confirmed by means of multiple regression analyses. The presence of IgM RF in smoking SSc patients is associated with deteriorating lung function. Whether this is a causal association...

Comparison of indirect ELISA based on recombinant protein NcSRS2 and IFAT for detection of Neospora caninum antibodies in sheep Comparação entre ELISA baseado no antígeno recombinante NcSRS2 e RIFI para detecção de anticorpos de Neospora caninum em ovinos

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Renato Andreotti

2009-06-01

Full Text Available Neospora caninum, an Apicomplexan parasite that can causes abortion, is responsible for considerable economic and reproductive losses in livestock. The purpose of the present study was to determine whether recombinant NcSRS2 is a suitable indirect ELISA antigen for determining specific immune response to N. caninum in sheep. A total of 441 serum samples were subjected to IFAT and rNcSRS2 based-ELISA, with both tests performing similarly. The sensitivity and specificity of indirect ELISA were 98.6 and 98.3%, respectively. The kappa index shows 0.98 concordance between the two tests, which is considered excellent. Seroprevalences of 30.8 and 32.0% were detected by IFAT and indirect ELISA, respectively, showing these tests did not differ significantly on this measure (p > 0.05. Serological analysis showed that HisG tag was detected by Western Blotting recognizing rNcSRS2 protein. The potential value of rNcSRS2-based ELISA as a highly specific and sensitive tool for serological diagnosis is also supported by the strong agreement found between IFAT and ELISA. The results support the potential use of recombinant protein NcSRS2 as an antigen in indirect ELISA in sheep.Neospora caninum é um parasito Apicomplexa que pode causar abortos e é reconhecido como agente importante responsável por perdas econômicas e reprodutivas. Este estudo avaliou a proteína recombinante NcSRS2 como antígeno para ELISA indireto na determinação de resposta imune para N. caninum em ovinos. 441 amostras de soro foram analisadas por IFAT e ELISA indireto com rNcSRS2 e ambos os testes revelaram comportamento similar. A sensibilidade e especificidade de ELISA indireto foram 98,6 e 98,3%, respectivamente. O índice kappa mostrou uma concordância entre os dois testes com valor de 0,98, que é considerado excelente. Prevalências de 30,8 e 32,0% detectadas por IFAT e ELISA indireto, respectivamente, mostraram que os testes não diferiram significativamente nesse aspecto (P

Detection of IgE in the sera of rodents: comparison of the applicability of ELISA and RIA

Energy Technology Data Exchange (ETDEWEB)

Reiner, G; Zahner, H [Institut fuer Parasitologie der Justus-Liebig-Universitaet Giessen, Germany, F.R.; Haque, A [Institut Pasteur, 59 - Lille (France). Centre d' Immunologie et de Biologie Parasitaire

1984-04-13

RIA and ELISA were compared for their ability to detect IgE in different rodent species. With a sheep anti-rat IgE antibody good correlation (P < 0.001) between the 2 assay methods for IgE was found in rats. RIA failed to detect the IgE of Mastomys natalensis while ELISA proved to be a suitable test. However, both tests failed to measure IgE in sera of Nile rats.

Development of duplex RT-PCR-ELISA for the simultaneous detection of hepatitis A virus and hepatitis E virus.

Science.gov (United States)

Tahk, Hongmin; Lee, Min Hwa; Lee, Kang Bum; Cheon, Doo-Sung; Choi, Changsun

2011-07-01

This study aimed to develop a specific and sensitive duplex reverse transcription polymerase chain reaction enzyme-linked immunosorbent assay (duplex RT-PCR-ELISA) for hepatitis A virus (HAV) and hepatitis E virus (HEV). Duplex RT-PCR-ELISA could detect and differentiate HAV and HEV with specific probes. When ELISA technique was used to detect probe-bound RT-PCR products, duplex RT-PCR-ELISA could detect as little as 0.1 ng/μL HAV and HEV from clinical samples. Human norovirus, enterovirus, poliovirus, murine norovirus and feline calicivirus were used for the specificity test; all were negative. Therefore duplex RT-PCR-ELISA can be used for the simultaneous detection of HAV and HEV in contaminated fecal samples. Copyright © 2011 Elsevier B.V. All rights reserved.

ELISA techniques for the determination of methanogenic bacteria

Energy Technology Data Exchange (ETDEWEB)

Bryniok, D; Troesch, W [Fraunhofer-Institut fuer Grenzflaechen- und Bioverfahrenstechnik (IGB), Stuttgart (Germany, F.R.)

1989-12-01

Easy-to-handle enzyme-linked immunosorbent assay (ELISA) techniques have been developed suitable for quantitative species-specific determination of very low numbers of methanogens in complex bacterial populations. The amount and the distribution of different species of methanogens in anaerobic digestors is a reflection of the functional status of the degradation process; this can be recognized with these tests and hence may be used for process control. (orig.).

Comparsion of an immunochromatographic strip with ELISA for simultaneous detection of thiamphenicol, florfenicol and chloramphenicol in food samples.

Science.gov (United States)

Guo, Lingling; Song, Shanshan; Liu, Liqiang; Peng, Juan; Kuang, Hua; Xu, Chuanlai

2015-09-01

Rapid and sensitive indirect competitive enzyme-linked immunosorbent assays (ic-ELISA) and gold nanoparticle immunochromatographic strip tests were developed to detect thiamphenicol (TAP), florfenicol (FF) and chloramphenicol (CAP) in milk and honey samples. The generic monoclonal antibody for TAP, FF and CAP was prepared based on a hapten [D-threo-1-(4-aminophenyl)-2- dichloroacetylamino-1,3-propanediol], and the haptenwas linked to a carrier protein using the diazotization method. After the optimization of several parameters (coating, pH, sodium chloride content and methanol content), the ic-ELISA was established. The quantitative working range for TAP was 0.11-1.36 ng/mL, with an IC50 of 0.39 ng/mL. The optimized ELISA showed cross-reactivity to CAP (300%) and FF (15.6%), with IC50 values of 0.13 and 2.5 ng/mL, respectively. The analytical recovery of TAP, FF and CAP in milk and honey samples in the ic-ELISA ranged from 81.2 to 112.9%. Based on this monoclonal antibody, a rapid and sensitive immunochromatographic test strip was also developed. This strip had a detection limit of 1 ng/mL for TAP, FF and CAP in milk and honey samples. Moreover, the test was completed within 10 min. Our results showed that the proposed ic-ELISA and immunochromatographic test strip method are highly useful screening tools for TAP, FF and CAP detection in milk and honey samples. Copyright © 2015 John Wiley & Sons, Ltd.

Trends in the patterns of IgM and IgG antibodies in febrile persons with suspected dengue in Barbados, an English-speaking Caribbean country, 2006–2013

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Alok Kumar

2015-11-01

Full Text Available Summary: Long-term seroprevalence studies of dengue have provided a measure of the degree of endemicity and future trends in disease prevalence and severity. In this study, we describe the seroprevalence of dengue antibodies in febrile persons with suspected acute dengue in Barbados. It is a retrospective population-based study of all febrile persons with suspected dengue from 2006 to 2013. All of the cases had IgM and IgG antibodies in the blood sample drawn between days 3 and 5 of their illness. Among the 8296 cases that were tested for IgM antibodies, 3037 (36.6% had recent dengue infection. In the age groups 20 years, 23.3%, 39.6% and 35.5% had acute infection, respectively. Of the 7227 cases with documented IgG results, 5473 (75.7% were positive and had a past infection. In the age groups 20 years, 31.2%, 65.2% and 86.6%, respectively, had a past infection (IgG positive. During the first 5 years of life, 10–20% of febrile persons investigated for dengue had a positive IgM and a negative IgG titer, between 5 and 10% had a positive IgM and IgG titer, 5% had a positive IgG and a negative IgM titer, and between 45% and 65% had a negative IgM and a negative IgG titer. Throughout the study period, between 12% and 20% of febrile persons failed to show any evidence of current or previous dengue. In the age groups 20 years, 45.0%, 18.8% and 7.2%, respectively, had no evidence of recent or past dengue (both IgM and IgG negative. Between 37% and 59% of the febrile persons had serological evidence of past dengue in the absence of any current dengue. In conclusion, the pattern of IgG antibodies in this study was comparable to those in countries known to be hyperendemic for dengue. The age of infection is likely to shift to younger adults and children who are more likely to have severe dengue in the future. Keywords: Dengue, Seroprevalence, Febrile, Caribbean

ELISA with double antigen sandwich for screening specific serum anti-TP antibody in blood donors

International Nuclear Information System (INIS)

Wang Yiqing; Shi Zhixu

2002-01-01

Objective: To select a sensitive and specific laboratory examination suitable for screening serum anti-TP antibody in blood donors. Methods: The serum anti-TP antibody in 11271 blood donors were detected using ELISA with double antigen sandwich and the outcomes were compared with those using RPR assay. The conflicting specimen were confirmed by repeating the test with TPHA assay. Results: The positive rates of serum anti-TP antibody by ELISA with double antigen sandwich and RPR was 0.36% (41/11271) and 0.26% (29/11271), respectively. The coincidence of the detecting outcomes by ELISA with double antigen sandwich and RPR with TPHA was 97.5% (40/41) and 63.41%(26/41) respectively. Conclusion: Compared with RPR assay, ELISA with double antigen sandwich has higher sensibility and specificity for screening serum anti-TP antibody in blood donors

DEVELOPMENT AND STANDARDIZATION OF AN INDIRECT ELISA FOR THE DIAGNOSIS MAEDI-VISNA IN SHEEP DESENVOLVIMENTO E PADRONIZAÇÃO DE UM ELISA INDIRETO PARA DIAGNÓSTICO DE MAEDI VISNA EM OVINOS

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Tânia Valeska Medeiros Dantas

2008-04-01

Full Text Available The objective of this work was to develop and standardize an indirect ELISA for diagnosis of Maedi Visna (MV infection. The antigen was produced from the supernatants of caprine synovial membrane (CSM cell monolayers inoculated with Maedi Visna virus (MVV, strain K1514, by cycles of freezing and thawed, and clarified by centrifugation at 3000 g for 40 min. The clarified suspension was precipitated with PEG 8000 and centrifugated at 12000 g for 60 min; the pellet was resuspended in buffer TNE and layered onto a sucrose cushion by centrifugation at 42000 g for 105 min. The pellet was resuspended in PBS containing phenylmethylsulphonyl fluoride (PMSF. The ELISA was performed in 96 wells plates, incubated for 1 h at 37 ºC. The reaction was detected by incubation with the enzyme substrate and o-phenylenediamine (OPD during 15 min.  The tests were compared using 175 sera samples. The concentration of the antigen was 2 µg/mL and the best dilution of the sera was 1:100. ELISA detected more positive samples (22.9% than AGID (6.3% and presented a better sensitivity than AGID and, although the specificity was below the expected, it could already be recomended in the diagnosis of MVV infection.KEY WORDS: ELISA, MaediVisna, serologic diagnosis, sheep lentivirus. O objetivo deste trabalho foi desenvolver e padronizar um ELISA indireto para diagnóstico de Maedi Visna (MV. Produziu-se o antígeno em sobrenadantes de cultivo celular de membrana sinovial caprina (MSC inoculado com o Maedi Visna Vírus (MVV cepa K1514, que passou por ciclos de congelamento e descongelamento, sendo logo após clarificado

Comparison of immunofluorescence and enzyme-linked immunosorbent assay and immunoglobulin G avidity techniques for screening of anti: Toxoplasma antibodies among single serum sample pregnant women in Tabriz, Iran

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Mehrangiz Rajaii

2015-01-01

Full Text Available Background: Congenital toxoplasmosis is that pregnant women acquire the infection during gestation; diagnosis of the acute infection during pregnancy is a complex subject of maternal toxoplasmosis. Thus, the presence of immunoglobulin G (IgG and/or IgM Toxoplasma antibodies in a single serum sample drawn during gestation cannot be used to define whether the infection was recently acquired or chronic. Materials and Methods: At this cross-sectional descriptive study, sera of 391 pregnant women examined and compared. They were in an age range of 21-35 years, referred by gynecologists and infectious disease specialists, during March 2012-April 2013. They have referred, 215 (54.98%, 102 (26%, 74 (18.92% in the first, second and third trimesters of gestation, respectively. For each of them, a questionnaire was completed and serum samples were prepared in an equal condition, examined according to the procedures of indirect immunofluorescence (IIF, enzyme-linked immunosorbent assay (ELISA and IgG Avidity techniques. Results: We have found 111 (28.38% seronegative and 280 (71.61% seropositive cases by IIF and 124 (31.70% seronegative, 267 (68.28% seropositive cases by ELISA. The IgG avidity test confirmed 45 (69.23% and 7 (10.76% doubtful cases of IgM test in IIF and ELISA techniques. Conclusions: This study highlights how to manage pregnant women with toxoplasmosis, especially in a single serum sample condition.

Replacement of Antibodies in Pseudo-ELISAs: Molecularly Imprinted Nanoparticles for Vancomycin Detection.

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Canfarotta, Francesco; Smolinska-Kempisty, Katarzyna; Piletsky, Sergey

2017-01-01

The enzyme-linked immunosorbent assay (ELISA) is a widely employed analytical test used to quantify a given molecule. It relies on the use of specific antibodies, linked to an enzyme, to target the desired molecule. The reaction between the enzyme and its substrate gives rise to the analytical signal that can be quantified. Thanks to their robustness and low cost, molecularly imprinted polymer nanoparticles (nanoMIPs) are a viable alternative to antibodies. Herein, we describe the synthesis of nanoMIPs imprinted for vancomycin and their subsequent application in an ELISA-like format for direct replacement of antibodies.

Diagnostic accuracy study of a factor VIII ELISA for detection of factor VIII antibodies in congenital and acquired haemophilia A.

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Batty, Paul; Moore, Gary W; Platton, Sean; Maloney, James C; Palmer, Ben; Bowles, Louise; Pasi, K John; Rangarajan, Savita; Hart, Daniel P

2015-10-01

Antibody formation to factor VIII (FVIII) remains the greatest clinical and diagnostic challenge to the haemophilia-treating physician. Current guidance for testing for inhibitory FVIII antibodies (inhibitors) recommends the functional Nijmegen-Bethesda assay (NBA). A FVIII ELISA offers a complementary, immunological approach for FVIII antibody testing. It was the aim of this study to retrospectively evaluate the performance of a FVIII ELISA (index) for detection of FVIII antibodies, compared with the NBA (reference). All samples sent for routine FVIII antibody testing at two haemophilia Comprehensive Care Centres, were tested in parallel using the NBA and a solid-phase, indirect FVIII ELISA kit (Immucor). A total of 497 samples from 239 patients (severe haemophilia A=140, non-severe haemophilia A=85, acquired haemophilia A=14) were available for analysis. Sixty-three samples tested positive by the NBA (prevalence 12.7%, 95% confidence interval [CI], 9.9-15.9 %), with a median inhibitor titre of 1.2 BU/ml (range 0.7-978.0). The FVIII ELISA demonstrated a specificity of 94.0% (95%CI, 91.3-96.0), sensitivity of 77.8% (95%CI, 65.5-87.3), negative predictive value of 96.7% (95%CI, 94.5-98.2), positive predictive value 65.3% (95%CI, 53.5-76.0), negative likelihood ratio 0.2 (95%CI, 0.1-0.4), positive likelihood ratio 13.0 (95%CI, 8.7-19.3) and a diagnostic odds ratio of 54.9 (95%CI, 27.0-112.0). Strong positive correlation (r=0.77, pNBA (log adjusted) and FVIII ELISA optical density. In conclusion, FVIII ELISA offers a simple, specific, surveillance method enabling batch testing of non-urgent samples for the presence of FVIII antibodies.

Influence of affinity on antibody determination in microtiter ELISA systems

International Nuclear Information System (INIS)

Peterman, J.H.; Voss, E.W. Jr.; Butler, J.E.

1986-01-01

Theoretically, all immunoassays are affinity (Ka) dependent when the product of the antibody (Ab) Ka and the free epitope concentration is less than 10. Thus, the degree of dependence on Ka depends on the concentration of available antigen in the system. The authors examined the binding of 125 I-anti-fluorescein (a-FLU) monoclonal antibodies of different affinities to FLU-gelatin adsorbed on Immunlon 2 microtiter plates. Data obtained were in general agreement with our theoretical predictions; the percent of 125 I-a-FLU which bound correlated with Ka, as did the shape of the titration curves. Measurement of 5 a-FLU monoclonals by the ELISA showed that the determination of Ab concentrations depends on the FLU-gelatin concentration, epitope density, and on the relationship between the Kas of test samples and the reference standard Ab preparation. Thus the ELISA is Ka dependent and should not be used routinely to estimate the absolute amount to Ab in unknown samples. However, the Ka dependency of the ELISA might provide a convenient assay for the estimation of the relative functional Ka (rfKa) of antibody preparations

DETECTION OF HUMAN BLOODSTAINS BY ENZYME-LINKED IMMUNOSORBENT ASSAY (ELISA

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GHOLAM-HOSSEIN EDRISSIAN

1982-07-01

Full Text Available The microplate method of e nzyme-l i nke d i rnmuno s o r be n t a s s ay (ELISA , usi ng alkaline phosphatase anti-human I gG conj ugate , was modified and appl ied in t he dete c t i on of the human b lood specimens among the blood samples prep a r ed fr om human and laborat or y anima l s i n t he form of small dr ied b loodst a i ns on f ilt e r paper . The modi f i e d ELISA t e chnique wa s compa red wit h t he agar double d i f f us ion me t hod of prec ipitin test ."nThe results of this primary study showed t ha t the ELISA i n compare to gel diffusi o n t e st is sensitive and specific. It is also enough repr oducible and practical t o be consider as a competent technique for i de nt i f i c ation o f human bloodstains in medicolegal laboratories .

Application of the antigen ELISA for monitoring the effectiveness of the tsetse and trypanosomosis control campaign in Zambia

Energy Technology Data Exchange (ETDEWEB)

Sinyangwe, L N; Munyama, G M; Mubanga, J [Central Veterinary Research Inst. (CVRI), Lusaka (Zambia)

1997-02-01

Antibody and antigen-detection ELISA were used to screen sera originating from a tsetse free area. In addition, bovine samples from tsetse infested areas were analysed using the Buffy Coat Technique (BCT) and the antigen ELISA. Few samples from a negative control population were detected positive resulting in a very good specificity for both tests. When screening a trypanosome infected population the BCT detected more acute and the Ag-ELISA more chronic infections. In conclusion, the antigen ELISA should be used in combination with the BCT, especially in geographical areas where the BCT does not detect any patent infections. (author). 2 refs, 4 figs, 4 tabs.

Application of the antigen ELISA for monitoring the effectiveness of the tsetse and trypanosomosis control campaign in Zambia

International Nuclear Information System (INIS)

Sinyangwe, L.N.; Munyama, G.M.; Mubanga, J.

1997-01-01

Antibody and antigen-detection ELISA were used to screen sera originating from a tsetse free area. In addition, bovine samples from tsetse infested areas were analysed using the Buffy Coat Technique (BCT) and the antigen ELISA. Few samples from a negative control population were detected positive resulting in a very good specificity for both tests. When screening a trypanosome infected population the BCT detected more acute and the Ag-ELISA more chronic infections. In conclusion, the antigen ELISA should be used in combination with the BCT, especially in geographical areas where the BCT does not detect any patent infections. (author). 2 refs, 4 figs, 4 tabs

[Evaluation of an ELISA test with Fasciola hepatica metabolic antigen for diagnosis of human fascioliasis in Cajamarca, Peru].

Science.gov (United States)

Cornejo, Hernán; Oblitas, Fátima; Cruzado, Sandro; Quispe, William

2010-01-01

Metabolic (excretion/secretion) antigen was obtained from sheep infected with Fasciola hepatica, with a 1005 μg/μL of protein concentration, composed principally by proteins of molecular weight between 1.2 and 170 KDa. Bands of 170, 150, 31, 24, 18-14 and 10 kDa were detected. With this antigen an ELISA test was developed and the cut off was determined in 0.140. We evaluated 33 serums of patient with fascioliasis confirmed by visualization of eggs in feces, 177 serums of persons without fascioliasis from endemic rural areas of Cajamarca and 88 serums of patients with others parasitic and bacterial infections. We found a 97.0% of sensitivity, 96.6 specificity, 78.1% predictive positive value, 99.6 % predictive negative value. In 9/88 serums was found cross reactions. We recommended the implementation and use of this test for the fascioliasis diagnosis.

Comparative study of the enzyme linked immunosorbent assay (ELISA) and two radioimmunoassays (RIA'S) for in-sulin

Energy Technology Data Exchange (ETDEWEB)

Klimes, I; Jurcovicova, J; Palkovic, M [Slovenska Akademia Vied, Bratislava (Czechoslovakia). Ustav Experimentalnej Endokrinologie

1978-06-30

The results of the quality control tests for enzyme linked immunosorbent assay (ELISA) were compared with the results of two different radioimmunoassays (RIA'S) for insulin. Using the manufacturer's procedure for the ELISA kit we found that the analytical variables such as assay sensitivity, recovery study and the 50% binding intercept were in good agreement with those obtained with the RIA method.

A Simple ELISA Exercise for Undergraduate Biology.

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Baker, William P.; Moore, Cathy R.

Understanding of immunological techniques such as the Enzyme Linked Immuno Sorbent Assay (ELISA) is an important part of instructional units in human health, developmental biology, microbiology, and biotechnology. This paper describes a simple ELISA exercise for undergraduate biology that effectively simulates the technique using a paper model.…

Natural IgM antibodies that bind neoepitopes exposed as a result of spinal cord injury , drive secondary injury by activating complement.

Science.gov (United States)

Narang, Aarti; Qiao, Fei; Atkinson, Carl; Zhu, Hong; Yang, Xiaofeng; Kulik, Liudmila; Holers, V Michael; Tomlinson, Stephen

2017-06-19

Natural IgM antibodies (Abs) function as innate immune sensors of injury via recognition of neoepitopes expressed on damaged cells, although how this recognition systems function following spinal cord injury (SCI) exposes various neoepitopes and their precise nature remains largely unknown. Here, we investigated the role of two natural IgM monoclonal Abs (mAbs), B4 and C2, that recognize post-ischemic neoepitopes following ischemia and reperfusion in other tissues. Identification of post-SCI expressed neoepitopes was examined using previously characterized monoclonal Abs (B4 and C2 mAbs). The role of post-SCI neoepitopes and their recognition by natural IgM Abs in propagating secondary injury was examined in Ab-deficient Rag1-/- or wild type C57BL/6 mice using Ab reconstitution experiments and neoepitope-targeted therapeutic studies, respectively. Administration of B4 or C2 mAb following murine SCI increased lesion size and worsened functional outcome in otherwise protected Ab-deficient Rag1-/- mice. Injury correlated with colocalized deposition of IgM and C3d in injured spinal cords from both mAb reconstituted Rag1-/- mice and untreated wild-type mice. Depletion of peritoneal B1 B cells, a source of natural Abs, reduced circulating levels of IgM with B4 (annexin-IV) and C2 (subset of phospholipids) reactivity, reduced IgM and complement deposition in the spinal cord, and protected against SCI. We therefore investigated whether the B4 neoepitope represents a therapeutic target for complement inhibition. B4-Crry, a fusion protein consisting of a single-chain Ab derived from B4 mAb, linked to the complement inhibitor Crry, significantly protected against SCI. B4-Crry exhibited a dual function in that it inhibited both the binding of pathogenic IgM and blocked complement activation in the spinal cord. This study identifies important neoepitopes expressed within the spinal cord after injury. These neoepitopes are recognized by clonally specific natural IgM Abs that

Evaluation of three 3ABC ELISAs for foot-and-mouth disease non-structural antibodies using latent class analysis

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Malirat Viviane

2006-10-01

Full Text Available Abstract Background Foot-and-mouth disease (FMD is a highly contagious viral disease of even-toed ungulates. Serological diagnosis/surveillance of FMD presents several problems as there are seven serotypes worldwide and in the event of vaccination it may be necessary to be able to identify FMD infected/exposed animals irrespective of their vaccination status. The recent development of non-structural 3ABC protein (NSP ELISA tests has greatly advanced sero-diagnosis/surveillance as these tests detect exposure to live virus for any of the seven serotypes of FMD, even in vaccinated populations. This paper analyses the performance of three NSP tests using a Bayesian formulation of the Hui-Walter latent class model to estimate test sensitivity and specificity in the absence of a "gold-standard" test, using sera from a well described cattle population in Cameroon with endemic FMD. Results The analysis found a high sensitivity and specificity for both the Danish C-ELISA and the World Organisation for Animal Health (O.I.E. recommended South American I-ELISA. However, the commercial CHEKIT kit, though having high specificity, has very low sensitivity. The results of the study suggests that for NSP ELISAs, latent class models are a useful alternative to the traditional approach of evaluating diagnostic tests against a known "gold-standard" test as imperfections in the "gold-standard" may give biased test characteristics. Conclusion This study demonstrates that when applied to naturally infected zebu cattle managed under extensive rangeland conditions, the FMD ELISAs may not give the same parameter estimates as those generated from experimental studies. The Bayesian approach allows for full posterior probabilities and capture of the uncertainty in the estimates. The implications of an imperfect specificity are important for the design and interpretation of sero-surveillance data and may result in excessive numbers of false positives in low prevalence

Antibody reactivities to glutamate-rich peptides of Plasmodium falciparum parasites in humans from areas of different malaria endemicity

DEFF Research Database (Denmark)

Jakobsen, P H; Theander, T G; Hviid, L

1996-01-01

Synthetic P. falciparum peptides were evaluated as tools in epidemiological investigations of malaria. Plasma IgM and IgG antibody reactivities against synthetic peptides covering sequences of glutamate-rich protein (GLURP) and acidic-basic repeat antigen (ABRA) were measured by ELISA...... in individuals from malaria-endemic areas of Sudan, Indonesia and The Gambia to study antibody responses to these peptides in donors living in areas of different malaria endemicity. IgG and IgM reactivities to the peptides increased with malaria endemicity, although there were no differences in reactivities...... tested were shortlived in most patients. In Gambian children with malaria, IgM reactivities but not IgG antibody reactivities against the ABRA peptide were higher in those with mild malaria than in those with severe malaria. The peptides may be useful in future epidemiological studies, especially...

Scalp Lesions in a Pediatric Patient with Hyper IgM Syndrome: Clinical and Histologic Mimicry of Cryptococcus neoformans Infection.

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Acker, Karen P; Fetch, Audrey; Schnell, Stephanie A; Hammond, Jennifer; Herrera, Christina; Niedt, George; Ratner, Adam J; Lauren, Christine T

2018-01-01

We report a case of cutaneous cryptococcosis due to Cryptococcus neoformans in a pediatric patient with hyper IgM syndrome with scalp lesions that resembled tinea capitis on gross examination and mimicked juvenile xanthogranuloma on histologic examination. This case highlights the importance of considering cutaneous cryptococcosis in patients with hyper IgM syndrome. Copyright © 2017 Elsevier Inc. All rights reserved.

Multiplex polymerase chain reaction test for the diagnosis of acute viral hepatitis A.

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Heo, Nae-Yun; Lim, Young-Suk; An, Jihyun; Ko, Sun-Young; Oh, Heung-Bum

2012-12-01

The early diagnosis of acute hepatitis A (AHA) is hindered because serum IgM against hepatitis A virus (HAV) can yield false-negative results during the window period. This study evaluated the diagnostic accuracy of a polymerase chain reaction (PCR) kit for HAV RNA for the diagnosis of AHA. Samples were collected from 136 patients with acute severe hepatitis at their admission to Asan Medical Center between June 2010 and July 2010. Samples were analyzed for serum IgM anti-HAV using an immunoassay test and for qualitative HAV RNA using the Magicplex HepaTrio PCR test kit. The diagnostic accuracies of these methods were tested on the basis of clinical and laboratory diagnoses of AHA. The concordance rate and kappa value between IgM anti-HAV and HAV RNA PCR were 88.2% and 0.707, respectively. For the diagnosis of AHA, the sensitivity and specificity of IgM anti-HAV were 90.7% and 100%, respectively, when an "equivocal" result was regarded as positive; and 79.1% and 100%, respectively, when an "equivocal" result was regarded as negative. The sensitivity and specificity of HAV RNA PCR were 81.4% and 100%, respectively. All four patients with negative IgM anti-HAV and positive HAV RNA PCR results and all four patients with equivocal IgM anti-HAV RNA and positive HAV RNA PCR results were eventually diagnosed with AHA. The qualitative HAV RNA PCR test has an equivalent diagnostic accuracy for AHA compared to IgM anti-HAV and may be more sensitive during the window period.

Diagnostic accuracy of an in-house ELISA using the intermediate species Leptospira fainei as antigen for diagnosis of acute leptospirosis in dogs.

Science.gov (United States)

Penna, Bruno; Marassi, Carla D; Libonati, Hugo; Narduche, Lorena; Lilenbaum, Walter; Bourhy, Pascale

2017-02-01

Diagnosis of animal leptospirosis is still challenging. The microscopic agglutination test, is the current method for diagnosing leptospirosis. However, this technique requires specific equipment, highly trained staff and the maintenance of live cultures of several reference strains of Leptospira for use as antigens. Recently, an ELISA (enzyme-linked immunosorbent assay) employing a Leptospira fainei serovar Hurstbridge based antigen for the early diagnostic of human leptospirosis was developed. In this study we estimate the diagnostic sensitivity and specificity of this test in identifying acute canine leptospirosis. A total of 271 serum samples divided into five panels and tested by MAT as a reference test, were used to evaluate the ELISA. Comparing acutely and non-acutely infected dogs, ELISA-Hb showed 95.6% sensitivity and 93% specificity. L. fainei-based ELISA is adequate for diagnosing acute canine leptospirosis, with high sensitivity and specificity and presenting practical advantages when compared to current techniques. Copyright © 2016 Elsevier Ltd. All rights reserved.

Assessment of specific IgM antibodies to core antigen of hepatitis B virus in acute and chronic hepatitis B using immunoradiometric assay

International Nuclear Information System (INIS)

Zichova, M.; Vodak, M.; Kostrhun, L.; Nadvornik, V.; Stransky, J.

1986-01-01

A group of 24 patients with acute viral hepatitis B was assessed for specific antibodies against the ''core'' antigen class IgM (HB c AB IgM) during 1st-4th week of the illness. These specific antibodies were positive in all patients, the mean titre being 10 -5 . The high content of these antibodies persisted for 1-2 months after the onset of the disease. The assessment of specific antibodies against ''core'' antigen class IgM was also made in a group of 39 patients with chronic hepatitis. In these patients positive HB c Ab IgM with a lower content were found (titre 10 -3 ) than in the group with acute viral hepatitis B. Based on the results the conclusion is made that specific antibodies HB c Ab class IgM are, in addition to the estimation of the surface antigen of the hepatitis B virus (HB s Ag), one more indicator of acute viral hepatitis B. The assessment is diagnostically valuable, in particular in acute hepatitis of obscure etiology, in acute jaundice of obscure etiology for the period of low and short-term antigenemia. (author). 6 figs., 1 tab., 14 refs

Image-based ELISA on an activated polypropylene microtest plate--a spectrophotometer-free low cost assay technique.

Science.gov (United States)

Parween, Shahila; Nahar, Pradip

2013-10-15

In this communication, we report ELISA technique on an activated polypropylene microtest plate (APPµTP) as an illustrative example of a low cost diagnostic assay. Activated test zone in APPµTP binds a capture biomolecule through covalent linkage thereby, eliminating non-specific binding often prevalent in absorption based techniques. Efficacy of APPµTP is demonstrated by detecting human immunoglobulin G (IgG), human immunoglobulin E (IgE) and Aspergillus fumigatus antibody in patient's sera. Detection is done by taking the image of the assay solution by a desktop scanner and analyzing the color of the image. Human IgE quantification by color saturation in the image-based assay shows excellent correlation with absorbance-based assay (Pearson correlation coefficient, r=0.992). Significance of the relationship is seen from its p value which is 4.087e-11. Performance of APPµTP is also checked with respect to microtiter plate and paper-based ELISA. APPµTP can quantify an analyte as precisely as in microtiter plate with insignificant non-specific binding, a necessary prerequisite for ELISA assay. In contrast, paper-ELISA shows high non-specific binding in control sera (false positive). Finally, we have carried out ELISA steps on APPµTP by ultrasound waves on a sonicator bath and the results show that even in 8 min, it can convincingly differentiate a test sample from a control sample. In short, spectrophotometer-free image-based miniaturized ELISA on APPµTP is precise, reliable, rapid, and sensitive and could be a good substitute for conventional immunoassay procedures widely used in clinical and research laboratories. Copyright © 2013 Elsevier B.V. All rights reserved.

Analysis of fenbendazole residues in bovine milk by ELISA.

Science.gov (United States)

Brandon, David L; Bates, Anne H; Binder, Ronald G; Montague, William C; Whitehand, Linda C; Barker, Steven A

2002-10-09

Fenbendazole residues in bovine milk were analyzed by ELISAs using two monoclonal antibodies. One monoclonal antibody (MAb 587) bound the major benzimidazole anthelmintic drugs, including fenbendazole, oxfendazole, and fenbendazole sulfone. The other (MAb 591) was more specific for fenbendazole, with 13% cross-reactivity with the sulfone and no significant binding to the sulfoxide metabolite. The limit of detection of the ELISA method in the milk matrix was 7 ppb for MAb 587 and 3 ppb for MAb 591. Fenbendazole was administered in feed, drench, and paste form to three groups of dairy cattle. Milk was collected immediately before dosing and then every 12 h for 5 days. The ELISA indicated that residue levels varied widely among individual cows in each group. Fenbendazole levels peaked at approximately 12-24 h and declined rapidly thereafter. Metabolites were detected at much higher levels than the parent compound, peaked at approximately 24-36 h, and declined gradually. Residue levels were undetectable by 72 h. The ELISA data correlated well with the total residues determined by chromatographic analysis, but the use of the two separate ELISAs did not afford an advantage over ELISA with the single, broadly reactive MAb 587. The ELISA method could be used to flag high-residue samples in on-site monitoring of fenbendazole in milk and is a potential tool for studying drug pharmacokinetics.

Predictive diagnostic value of the tourniquet test for the diagnosis of dengue infection in adults

Science.gov (United States)

Mayxay, Mayfong; Phetsouvanh, Rattanaphone; Moore, Catrin E; Chansamouth, Vilada; Vongsouvath, Manivanh; Sisouphone, Syho; Vongphachanh, Pankham; Thaojaikong, Thaksinaporn; Thongpaseuth, Soulignasack; Phongmany, Simmaly; Keolouangkhot, Valy; Strobel, Michel; Newton, Paul N

2011-01-01

Objective To examine the accuracy of the admission tourniquet test in the diagnosis of dengue infection among Lao adults. Methods Prospective assessment of the predictive diagnostic value of the tourniquet test for the diagnosis of dengue infection, as defined by IgM, IgG and NS1 ELISAs (Panbio Ltd, Australia), among Lao adult inpatients with clinically suspected dengue infection. Results Of 234 patients with clinically suspected dengue infection on admission, 73% were serologically confirmed to have dengue, while 64 patients with negative dengue serology were diagnosed as having scrub typhus (39%), murine typhus (11%), undetermined typhus (12%), Japanese encephalitis virus (5%), undetermined flavivirus (5%) and typhoid fever (3%); 25% had no identifiable aetiology. The tourniquet test was positive in 29.1% (95% CI = 23.2–34.9%) of all patients and in 34.1% (95% CI = 27.0–41.2%) of dengue-seropositive patients, in 32.7% (95% CI = 23.5–41.8) of those with dengue fever and in 36.4% (95% CI = 24.7–48.0) of those with dengue haemorrhagic fever. Interobserver agreement for the tourniquet test was 90.2% (95% CI = 86.4–94.0) (Kappa = 0.76). Using ELISAs as the diagnostic gold standard, the sensitivity of the tourniquet test was 33.5–34%; its specificity was 84–91%. The positive and negative predictive values were 85–90% and 32.5–34%, respectively. Conclusions The admission tourniquet test has low sensitivity and adds relatively little value to the diagnosis of dengue among Lao adult inpatients with suspected dengue. Although a positive tourniquet test suggests dengue and that treatment of alternative diagnoses may not be needed, a negative test result does not exclude dengue. PMID:20958892