High incidence of false-positive results of IgG antibody against SARS-CoV-2 with rapid immunochromatographic antibody test due to human common cold coronavirus infection

ABSTRACTA concern during the early AIDS epidemic was the lack of a test to identify individuals who carried the virus. The first HIV antibody test, developed in 1985, was designed to screen blood products, not to diagnose AIDS. The first-generation assays detected IgG antibody and became positive 6 to 12 weeks postinfection. False-positive results occurred; thus, a two-test algorithm was developed using a Western blot or immunofluorescence test as a confirmatory procedure. The second-generation HIV test added recombinant antigens, and the third-generation HIV tests included IgM detection, reducing the test-negative window to approximately 3 weeks postinfection. Fourth- and fifth-generation HIV assays added p24 antigen detection to the screening assay, reducing the test-negative window to 11 to 14 days. A new algorithm addressed the fourth-generation assay's ability to detect both antibody and antigen and yet not differentiate between them. The fifth-generation HIV assay provides separate antigen and antibody results and will require yet another algorithm. HIV infection may now be detected approximately 2 weeks postexposure, with a reduced number of false-positive results.

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Validation of a new automated chemiluminescent anti-SARS-CoV-2 IgM and IgG antibody assay system detecting both N and S proteins in Japan

10.1101/2020.07.16.20155796 ◽

2020 ◽

Author(s):

RIn Yokoyama ◽

Makoto Kurano ◽

Yoshifumi Morita ◽

Takuya Shimura ◽

Yuki Nakano ◽

...

Keyword(s):

Measurement System ◽

False Positive ◽

Laboratory Testing ◽

Antibody Test ◽

Measurement Range ◽

Antibody Assay ◽

Serum Samples ◽

Igg Antibody ◽

Antibody Titers ◽

Pcr Test

PCR methods are presently the standard for the diagnosis of Coronavirus disease 2019 (COVID-19), but additional methodologies are needed to complement PCR methods, which have some limitations. Here, we validated and investigated the usefulness of measuring serum antibodies against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) using the iFlash3000 CLIA analyzer. We measured IgM and IgG titers against SARS-CoV-2 in sera collected from 26 PCR-positive COVID-19 patients, 53 COVID-19-suspected but PCR-negative patients, and 20 and 100 randomly selected non-COVID-19 patients who visited our hospital in 2020 and 2017, respectively. The within-day and between-day precisions were regarded as good, since the coefficient variations were below 5%. Linearity was also considered good between 0.6 AU/mL and 112.7 AU/mL for SARS-CoV-2 IgM and between 3.2 AU/mL and 55.3 AU/mL for SARS-CoV-2 IgG, while the linearity curves plateaued above the upper measurement range. We also confirmed that the seroconversion and no-antibody titers were over the cutoff values in all 100 serum samples collected in 2017. These results indicate that this measurement system successfully detects SARS-CoV-2 IgM/IgG. We observed four false-positive cases in the IgM assay and no false-positive cases in the IgG assay when 111 serum samples known to contain autoantibodies were evaluated. The concordance rates of the antibody test with the PCR test were 98.1% for SARS-CoV-2 IgM and 100% for IgG among PCR-negative cases and 30.8% for SARS-CoV-2 IgM and 73.1% for SARS-CoV-2 IgG among PCR-positive cases. In conclusion, the performance of this measurement system is sufficient for use in laboratory testing.

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Performance verification of anti-SARS-CoV-2-specific antibody detection by using four chemiluminescence immunoassay systems

Annals of Clinical Biochemistry International Journal of Laboratory Medicine ◽

10.1177/0004563220963847 ◽

2020 ◽

Vol 57 (6) ◽

pp. 429-434

Author(s):

Yafang Wan ◽

Zhijie Li ◽

Kun Wang ◽

Tian Li ◽

Pu Liao

Keyword(s):

False Positive ◽

Detection System ◽

False Positive Rate ◽

Antibody Test ◽

The Other ◽

Antibody Detection ◽

Igg Antibody ◽

Chi Square ◽

Chemiluminescence Immunoassay ◽

Chi Square Test

Objectives The purpose of the current study was to evaluate the analytical performance of seven kits for detecting IgM/IgG antibodies against coronavirus (SARS-CoV-2) by using four chemiluminescence immunoassay systems. Methods Fifty patients diagnosed with SARS-CoV-2 infection and 130 controls without coronavirus infection from the General Hospital of Chongqing were enrolled in the current retrospective study. Four chemiluminescence immunoassay systems, including seven IgM/IgG antibody detection kits for SARS-CoV-2 (A_IgM, A_IgG, B_IgM, B_IgG, C_IgM, C_IgG and D_Ab), were employed to detect antibody concentrations. The chi-square test, the receiver operating characteristic (ROC) curve and Youden’s index were determined to verify the cut-off value of each detection system. Results The repeatability verification results of the A, B, C and D systems are all qualified. D_Ab performed best (92% sensitivity and 99.23% specificity), and B_IgM performed worse than the other systems. Except for the A_IgM and C_IgG systems, the optimal diagnostic thresholds and cut-off values of the other kits and their recommendations are inconsistent with each other. B_IgM had the worst AUC, and C_IgG had the best diagnostic accuracy. More importantly, the B_IgG system had the highest false-positive rate for testing patients with AIDS, tumours and pregnancies. The A_IgM system test showed the highest false-positive rates among elderly individuals over 90 years old. COVID-2019 IgM/IgG antibody test systems exhibit performance differences. Conclusions The Innodx Biotech Total Antibody serum diagnosis kit is the most reliable detection system for anti-SARS-CoV-2 antibodies, which can be used together with nucleic acid tests as an alternative method for SARS-CoV-2 detecting.

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Factors Associated with False-Positive Results from Fingerstick OraQuick ADVANCE Rapid HIV 1/2 Antibody Test

Journal of the International Association of Physicians in AIDS Care ◽

10.1177/1545109712454194 ◽

2012 ◽

Vol 11 (6) ◽

pp. 356-360 ◽

Cited By ~ 1

Author(s):

Samara B. Rifkin ◽

Lauren E. Owens ◽

Jeffrey L. Greenwald

Keyword(s):

Risk Factors ◽

False Positive ◽

Medical Center ◽

Antibody Test ◽

Blood Type ◽

Factors Associated ◽

Rapid Tests ◽

Antibody Tests ◽

Positive Results ◽

Hiv 1

Objective: Identify factors associated with false-positive rapid HIV antibody tests. Design: This retrospective cohort study with nested case–controls involved patients tested for HIV by Boston Medical Center (BMC) affiliates. Methods: Cases had a reactive fingerstick OraQuick ADVANCE rapid HIV 1/2 antibody test and a negative Western blot. Controls had nonreactive rapid tests. We compared the prevalence of HIV risk factors between cases and the total nonreactive population and the prevalence of other clinical factors between cases and controls. Results: Of the 15 094 tests, 14 937 (98.9%) were negative and 11 (0.07%) were false positives (specificity of 99.9%). Cases were more likely to have had an HIV-infected sex partner and to be tested at certain sites compared to true negatives. More cases than controls had O-negative blood type. Conclusion: O-negative blood type and sex with an HIV-infected person may increase false-positive HIV fingerstick results. More targeted studies should examine these risk factors.

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Validation of a new automated chemiluminescent anti-SARS-CoV-2 IgM and IgG antibody assay system detecting both N and S proteins in Japan

PLoS ONE ◽

10.1371/journal.pone.0247711 ◽

2021 ◽

Vol 16 (3) ◽

pp. e0247711

Author(s):

Rin Yokoyama ◽

Makoto Kurano ◽

Yoshifumi Morita ◽

Takuya Shimura ◽

Yuki Nakano ◽

...

Keyword(s):

False Positive ◽

Antibody Test ◽

Measurement Range ◽

Antibody Assay ◽

Serum Samples ◽

Igg Antibody ◽

Automated Method ◽

Antibody Titers ◽

Pcr Test ◽

S Proteins

PCR methods are presently the standard for the diagnosis of Coronavirus disease 2019 (COVID-19), but additional methodologies are needed to complement PCR methods, which have some limitations. Here, we validated and investigated the usefulness of measuring serum antibodies against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) using the iFlash3000 CLIA analyzer. We measured IgM and IgG titers against SARS-CoV-2 in sera collected from 26 PCR-positive COVID-19 patients, 53 COVID-19-suspected but PCR-negative patients, and 20 and 100 randomly selected non-COVID-19 patients who visited our hospital in 2020 and 2017, respectively. The repeatability and within-laboratory precision were obviously good in validations, following to the CLSI document EP15-A3. Linearity was also considered good between 0.6 AU/mL and 112.7 AU/mL for SARS-CoV-2 IgM and between 3.2 AU/mL and 55.3 AU/mL for SARS-CoV-2 IgG, while the linearity curves plateaued above the upper measurement range. We also confirmed that the seroconversion and no-antibody titers were over the cutoff values in all 100 serum samples collected in 2017. These results indicate that this measurement system successfully detects SARS-CoV-2 IgM/IgG. We observed four false-positive cases in the IgM assay and no false-positive cases in the IgG assay when 111 serum samples known to contain autoantibodies were evaluated. The concordance rates of the antibody test with the PCR test were 98.1% for SARS-CoV-2 IgM and 100% for IgG among PCR-negative cases and 30.8% for SARS-CoV-2 IgM and 73.1% for SARS-CoV-2 IgG among PCR-positive cases. In conclusion, the performance of this new automated method for detecting antibody against both N and S proteins of SARS-CoV-2 is sufficient for use in laboratory testing.

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Identification of False-Positive Syphilis Antibody Results Using a Semiquantitative Algorithm

Clinical and Vaccine Immunology ◽

10.1128/cvi.05066-11 ◽

2011 ◽

Vol 18 (6) ◽

pp. 1038-1040 ◽

Cited By ~ 8

Author(s):

Belinda Yen-Lieberman ◽

Juliet Daniel ◽

Cathy Means ◽

Joan Waletzky ◽

Thomas M. Daly

Keyword(s):

False Positive ◽

Antibody Test ◽

Test Results ◽

Repeat Testing ◽

Screening Algorithm ◽

Low Prevalence ◽

Syphilis Serology ◽

Positive Results ◽

Potential False Positive

ABSTRACTScreening patients for syphilis serology using a “treponemal assay-first” approach presents unique challenges, particularly when applied to low-prevalence populations. The use of a screening algorithm that incorporates semiquantitative values from treponemal antibody test results can help to identify potential false-positive results while requiring a minimum of repeat testing.

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Investigation of False Positive Results with an Oral Fluid Rapid HIV-1/2 Antibody Test

PLoS ONE ◽

10.1371/journal.pone.0000185 ◽

2007 ◽

Vol 2 (1) ◽

pp. e185 ◽

Cited By ~ 31

Author(s):

Krishna Jafa ◽

Pragna Patel ◽

Duncan A. MacKellar ◽

Patrick S. Sullivan ◽

Kevin P. Delaney ◽

...

Keyword(s):

False Positive ◽

Oral Fluid ◽

Antibody Test ◽

Positive Results ◽

Hiv 1

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A Case of Malaria Patient with SARS-CoV-2 Antibody False-Positive

10.21203/rs.3.rs-773536/v1 ◽

2021 ◽

Author(s):

hong zhou

Keyword(s):

Nucleic Acid ◽

False Positive ◽

Malaria Patient ◽

Antibody Detection ◽

Nucleic Acid Detection ◽

Malaria Rapid Diagnostic Test ◽

Igg Antibody ◽

Case Presentation ◽

Igm Antibody ◽

Positive Results

Abstract Background: The SARS-CoV-2 antibody detection are used to diagnose or exclude suspected COVID-19 patients as a supplement to nucleic acid detection. False-positive results of SARS-CoV-2 antibody have been reported but rarely associated with malaria. A case of malaria patient with SARS-CoV-2 antibody false-positive is described.Case presentation: A 24 year-old male returned from Côte d’Ivoire was diagnosed Plasmodium falciparum by Malaria rapid diagnostic test. The patient had suspicious exposure to COVID-19. His SARS-CoV-2 IgM antibody was positive one day before admission and turned negative on the 18th day of admission, while the IgG antibody and nasopharyngeal swabs SARS-Cov-2 nucleic acid had been negative. Conclusion: Malaria might cause false positive for SARS-CoV-2 IgM antibody. A careful interpretation of the SARS-CoV-2 antibody result is useful to avoid wasting medical resources especially malaria-endemic areas.

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Comparative diagnostics of Cattle leukemia by ELISA method in test kits of various constructions

Veterinary Medicine: inter-departmental subject scientific collection ◽

10.36016/vm-2019-105-6 ◽

2019 ◽

pp. 32-36

Author(s):

B. T. Stegniy ◽

A. I. Zavgorodniy ◽

S. K. Gorbatenko ◽

O. M. Kornieikov ◽

M. Yu. Stegniy ◽

...

Keyword(s):

False Positive ◽

Bovine Leukemia Virus ◽

Leukemia Virus ◽

Antibody Test ◽

Virus Antibody ◽

Specific Antibodies ◽

Test Kit ◽

Diagnostic Capacity ◽

Cattle Blood ◽

Positive Results

The purpose of the work was to carry out comparative analysis of the positive and negative on leukemia cattle blood sera in ELISA kits of different constructions. Research was carried out using “DIA®-BLV-Ab” kit, in which the reaction had been performed in the indirect ELISA, and “ID Screen® BLV Competition” kit in a competitive format. There were used 15 cattle blood sera for testing, in which antibodies to BLV were confirmed in the ID and the ELISA “Bovine leukemia virus antibody test kit” (IDEXX), as well as 10 positive cattle blood sera confirmed in ID, 10 weak positive sera tested in ID and 10 sera with a weak line of precipitate in ID, 34 negative for leukemia blood sera tested in ID, from which 24 were also tested in the ELISA “Bovine leukemia virus antibody test kit”. The “DIA®-BLV-Ab” kit and “ID Screen® BLV Competition” kit determined positive 25 blood sera with antibodies to BLV, which were positive in ID, and 15 samples were also confirmed in IDEXX test kit. When analyzing 10 sera, that were weak positive in ID, the “DIA®-BLV-Ab” kit determined 8 sera as positive and 2 samples as negative. The “ID Screen® BLV Competition” kit detected specific antibodies to all sera. When analyzing 14 sera with a weak precipitate line in ID, the “DIA®-BLV-Ab” kit determined 9 samples as positive and 5 as negative. The “ID Screen® BLV Competition” determined specific antibodies in 11 samples When analyzing 3 sera, the test result was negative in both ELISA kits. The “DIA®-BLV-Ab” kit determined as negative all 34 sera, which were negative in ID, 24 samples from them were negative in IDEXX test kit. In the “ID Screen® BLV Competition” kit 5 false positive results were received. Studies have shown that both test kits have a high diagnostic capacity and detect antibodies to BLV at different concentrations in all positive sera. The “DIA®-BLV-Ab” kit determined 34 sera as negative, in which specific antibodies were absent, and the “ID Screen® BLV Competition” kit identified 5 samples with a false positive result

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Updated Clinical Evaluation of the CLUNGENE® Rapid COVID-19 Antibody Test

Healthcare ◽

10.3390/healthcare9091124 ◽

2021 ◽

Vol 9 (9) ◽

pp. 1124

Author(s):

Christopher C. Lamb ◽

Fadi Haddad ◽

Christopher Owens ◽

Alfredo Lopez-Yunez ◽

Marion Carroll ◽

...

Keyword(s):

False Positive ◽

Point Of Care ◽

Rapid Test ◽

Antibody Test ◽

Cross Reactivity ◽

Blood Collection ◽

Rt Pcr ◽

Antibody Testing ◽

Reactivity Study ◽

Positive Results

Background: COVID-19 antibody testing has been shown to be predictive of prior COVID-19 infection and an effective testing tool. The CLUNGENE® SARS-COV-2 VIRUS (COVID-19) IgG/IgM Rapid Test Cassette was evaluated for its utility to aide healthcare professionals. Method: Two studies were performed by using the CLUNGENE® Rapid Test. (1) An expanded Point-of-Care (POC) study at two clinical sites was conducted to evaluate 99 clinical subjects: 62 positive subjects and 37 negative subjects were compared to RT-PCR, PPA, and NPA (95% CI). Sensitivity was calculated from blood-collection time following symptom onset. (2) A cross-reactivity study was performed to determine the potential for false-positive results from other common infections. Results: The specificity of subjects with confirmed negative COVID-19 by RT-PCR was 100% (95% CI, 88.4–100.0%). The sensitivity of subjects with confirmed positive COVID-19 by RT-PCR was 96.77% (95% CI, 88.98–99.11%). In the cross-reactivity study, there were no false-positive results due to past infections or vaccinations unrelated to the SARS-CoV-2 virus. Conclusion: There is a need for a rapid, user-friendly, and inexpensive on-site monitoring system for diagnosis. The CLUNGENE® Rapid Test is a useful diagnostic test that provides results within 15 min, without high-complexity laboratory instrumentation.

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