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Chen H, Feng S, Zhou W, Li Z, Richard-Greenblatt M, Wang P. Pretreatment Methods for Human Nasopharyngeal Swabs to Increase the Signal to Noise Ratio of High Sensitivity Immunoassays. ACS MEASUREMENT SCIENCE AU 2022; 2:414-421. [PMID: 36785662 PMCID: PMC9885992 DOI: 10.1021/acsmeasuresciau.2c00024] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 06/18/2023]
Abstract
Mucous samples collected through nasopharyngeal (NP) swabs are considered gold standard specimens for the detection of respiratory pathogens. Matrices of these highly viscous samples often cause significant background noises in immunoassays, especially immunoassays with high sensitivity. We demonstrated such nonspecific background signals in both a chemiluminescence enzyme-linked immunosorbent assay (ELISA) and a novel highly sensitive immunoassay called Microbubbling SARS-CoV-2 Antigen Assay (MSAA). We developed and demonstrated the effectiveness of two quick sample pretreatment methods, filtration and preadsorption, to decrease nonspecific signals and increase the signal-to-noise ratio (SNR). Using these pretreatment methods, the SNR (at 3.6 × 104 copies/mL of inactivated SARS-CoV-2) was increased by 42.4-fold (95% CI 41.0-43.8) and 67.1-fold (95% CI 57.9-76.3) in the MSAA, and 1.3-fold (95% CI 0.9-1.7) and 1.8-fold (95% CI 1.6-2.0) in the chemiluminescence ELISA assay. Sample pretreatment methods developed in this study are broadly adaptable for the development of immunoassays for highly viscous samples.
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High level of HIV false positives using EIA-based algorithm in survey: Importance of confirmatory testing. PLoS One 2020; 15:e0239782. [PMID: 33091019 PMCID: PMC7580971 DOI: 10.1371/journal.pone.0239782] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2020] [Accepted: 09/12/2020] [Indexed: 12/20/2022] Open
Abstract
The Mozambique Indicators of Immunization, Malaria and HIV/AIDS (IMASIDA) survey was conducted in 2015 and used a two Enzyme Immunoassay (EIA) (Vironostika HIV-1/2 and Murex HIV-1/2) based algorithm to determine the HIV status of the consented participants. The Mozambique Ministry of Health, with support from the US Centers for Disease Control and Prevention (US CDC), added Bio-Rad Geenius™ HIV-1/2 Supplemental Assay to the IMASIDA HIV testing algorithm to confirm all specimens that were found to be reactive on one or both EIAs. In total 11690 specimens were collected to estimate the proportion of HIV positive samples. Results indicate that the proportion of HIV positive samples based on the concordant positive results of two EIA assays was 21.5% (2518/11690). The addition of the Geenius assay to the IMASIDA HIV testing algorithm demonstrated that 792 (31.5%) of 2518 specimens were false-positive and reduced the proportion of HIV positive samples to 14.7% (1722/11690), demonstrating the importance of including a highly specific HIV test to confirm HIV diagnosis. HIV surveys exclusively based on EIA testing algorithm may result in misleading high prevalence results. Our results demonstrate that more specific confirmatory testing should be added to the EIA-based algorithms to ensure accurate HIV diagnosis and correct HIV prevalence estimate in cross-sectional surveys.
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Kiely P, Hoad VC, Wood EM. False positive viral marker results in blood donors and their unintended consequences. Vox Sang 2018; 113:530-539. [PMID: 29974475 DOI: 10.1111/vox.12675] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2018] [Revised: 05/29/2018] [Accepted: 06/06/2018] [Indexed: 12/15/2022]
Abstract
False positive (FP) viral marker results in blood donors continue to pose many challenges. Informing donors of FP results and subsequent deferral can result in stress and anxiety for donors and additional complexity and workload for blood services. Donor management strategies need to balance the requirement to minimise donor anxiety and inconvenience while maintaining sufficiency of supply. Decisions about how and when to inform donors of FP results and determine deferral periods can be difficult as FP results, while often transitory, can take up to several years to resolve. Additional complexities include the interpretation of indeterminate serological confirmatory testing without detectable viral RNA or non-discriminated NAT results with concomitant anti-HBc reactivity - both may be due to FP results, but the former may also represent past infection and the later may represent occult hepatitis B infection. In this review we discuss strategies to minimise indeterminate serological confirmatory results, possible donor deferral policies and the impact on donors when notified of FP results. We also provide some new data from Australia that address the challenge of interpreting non-discriminated NAT results with concomitant anti-HBc reactivity. Ultimately, the challenge is for each blood service to develop appropriate strategies for donor management, taking into account local information and requirements.
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Affiliation(s)
- Philip Kiely
- Australian Red Cross Blood Service, Melbourne, Victoria, Australia
- Transfusion Research Unit, Department of Epidemiology and Preventive Medicine, School of Public Health and Preventive Medicine, Monash University, Melbourne, Victoria, Australia
| | - Veronica C Hoad
- Australian Red Cross Blood Service, Perth, Western Australia, Australia
| | - Erica M Wood
- Transfusion Research Unit, Department of Epidemiology and Preventive Medicine, School of Public Health and Preventive Medicine, Monash University, Melbourne, Victoria, Australia
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Lang R, Charlton C, Beckthold B, Kadivar K, Lavoie S, Caswell D, Levett PN, Horsman GB, Kim J, Gill MJ. HIV misdiagnosis: A root cause analysis leading to improvements in HIV diagnosis and patient care. J Clin Virol 2017; 96:84-88. [PMID: 29031156 DOI: 10.1016/j.jcv.2017.10.005] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2017] [Revised: 08/27/2017] [Accepted: 10/07/2017] [Indexed: 11/26/2022]
Abstract
BACKGROUND Standard diagnostic testing for HIV infection has traditionally relied on a high sensitivity HIV antibody screening test using an enzyme-linked immunosorbent assay (ELISA) followed by a high specificity antibody confirmatory test such as a Western Blot. Recently several of the screening assays have been enhanced with an ability to identify p24 antigen thereby narrowing the diagnostic window. OBJECTIVES To explore the implications of enhanced HIV screening methods that may be leading to HIV misdiagnoses. STUDY DESIGN A patient deemed to be an HIV infected 'elite controller' was found to be misdiagnosed when undergoing detailed investigations prior to initiating antiretroviral therapy. A root cause analysis was performed to identify the causative factors of this misdiagnosis. A retrospective review of all "elite controllers" in Alberta, Canada revealed challenges of current HIV testing algorithms. RESULTS Technical and human factors were identified as being causative in this HIV misdiagnosis including (i) high rates of false reactive results on the Abbott ARCHITECT HIV-1&2 COMBO EIA, (ii) human error in reading the initial Western blot, (iii) HIV algorithmic directives in which confirmatory (Western blot) testing was not performed on a repeatedly reactive screen test. The outcome of this analysis identified opportunities for improvement, including implementation of a newly approved (automated) confirmatory assay and improved communication between the clinician and laboratory. CONCLUSIONS HIV testing remains problematic despite significant advances in HIV test performance and algorithm development, presenting new and unexpected issues. Ensuring a high-quality management system including implementation of the latest HIV technologies and algorithms along with human resources and policies are required to minimize the impact of false positive diagnoses, especially in the era of universal screening and 'test and treat' recommendations.
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Affiliation(s)
- Raynell Lang
- Department of Medicine, University of Calgary, Calgary, Canada
| | - Carmen Charlton
- Department of Laboratory Medicine and Pathology University of Alberta, Edmonton, Canada; Provincial Laboratory of Public Health, Edmonton, Canada
| | | | - Kiana Kadivar
- National HIV Reference Laboratory, National Microbiology Laboratory, Winnipeg, Canada
| | - Stephanie Lavoie
- National HIV Reference Laboratory, National Microbiology Laboratory, Winnipeg, Canada
| | - Debbie Caswell
- Saskatchewan Disease Control Laboratory, Ministry of Health, Regina, Saskatchewan, Canada
| | - Paul N Levett
- Saskatchewan Disease Control Laboratory, Ministry of Health, Regina, Saskatchewan, Canada
| | - Greg B Horsman
- Saskatchewan Disease Control Laboratory, Ministry of Health, Regina, Saskatchewan, Canada
| | - John Kim
- National HIV Reference Laboratory, National Microbiology Laboratory, Winnipeg, Canada
| | - M John Gill
- Department of Medicine, University of Calgary, Calgary, Canada; Southern Alberta HIV Clinic, Calgary, Canada.
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Nygaard U, Vestergaard C, Johansen C, Deleuran M, Hvid M. Measuring serum concentrations of interleukin-33 in atopic dermatitis is associated with potential false positive results. SPRINGERPLUS 2016; 5:33. [PMID: 26788445 PMCID: PMC4712182 DOI: 10.1186/s40064-016-1673-z] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/30/2015] [Accepted: 01/06/2016] [Indexed: 11/10/2022]
Abstract
Background In the search for valid biomarkers in inflammatory diseases, cytokine serum concentrations are often measured by enzyme-linked immunosorbent assay and correlated to disease activity. Interleukin-33 is a relatively newly described cytokine, which holds a promising potential as a biomarker for different diseases including atopic dermatitis. However, interfering human anti-animal IgG antibodies and heterophilic antibodies might give rise to false positive or negative results that often go unnoticed. Findings We performed a three-step validation of commercially available and widely used human interleukin-33 enzyme-linked immunosorbent assay kit with serum samples from eight atopic dermatitis patients and five healthy controls. Through addition of unspecific animal IgG (rabbit, mouse, goat and bovine) and unspecific human IgG to the assay diluent, we disclosed false positive values in 12 out of 13 samples. Conclusion This study show that the present human interleukin-33 enzyme-linked immunosorbent assay kit might give rise to a high prevalence of false positive values if not validated. This inaccuracy is easily eliminated with a simple set of validation steps.
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Affiliation(s)
- Uffe Nygaard
- Department of Dermatology and Venereology, Aarhus University Hospital, P.P. Ørumsgade 11, 8000 Århus C, Denmark ; Department of Clinical Medicine, Aarhus University, 8000 Århus C, Denmark
| | - Christian Vestergaard
- Department of Dermatology and Venereology, Aarhus University Hospital, P.P. Ørumsgade 11, 8000 Århus C, Denmark
| | - Claus Johansen
- Department of Dermatology and Venereology, Aarhus University Hospital, P.P. Ørumsgade 11, 8000 Århus C, Denmark
| | - Mette Deleuran
- Department of Dermatology and Venereology, Aarhus University Hospital, P.P. Ørumsgade 11, 8000 Århus C, Denmark
| | - Malene Hvid
- Department of Clinical Medicine, Aarhus University, 8000 Århus C, Denmark ; Department of Biomedicine, Aarhus University, 8000 Århus C, Denmark
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Vo MT, Bruhn R, Kaidarova Z, Custer BS, Murphy EL, Bloch EM. A retrospective analysis of false-positive infectious screening results in blood donors. Transfusion 2015; 56:457-65. [PMID: 26509432 DOI: 10.1111/trf.13381] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2015] [Revised: 09/09/2015] [Accepted: 09/09/2015] [Indexed: 12/30/2022]
Abstract
BACKGROUND False-positive infectious transfusion screening results remain a challenge with continued loss of both donors and blood products. We sought to identify associations between donor demographic characteristics (age, race, sex, education, first-time donor status) and testing false positive for viruses during routine blood donation screening. In addition the study assessed the prevalence of high-risk behaviors in false-positive donors. STUDY DESIGN AND METHODS Blood Systems, Inc. donors with allogeneic donations between January 1, 2011, and December 31, 2012, were compared in a case-control study. Those with a false-positive donation for one of four viruses (human immunodeficiency virus [HIV], human T-lymphotropic virus [HTLV], hepatitis B virus [HBV], and hepatitis C virus [HCV]) were included as cases. Those with negative test results were controls. For a subset of cases, infectious risk factors were evaluated. RESULTS Black race and Hispanic ethnicity were associated with HCV and HTLV false-positive results. Male sex and lower education were associated with HCV false positivity, and age 25 to 44 was associated with HTLV false positivity. First-time donors were more likely to be HCV false positive although less likely to be HBV and HTLV false positive. No significant associations between donor demographics and HIV false positivity were observed. A questionnaire for false-positive donors showed low levels of high-risk behaviors. CONCLUSION Demographic associations with HCV and HTLV false-positive results overlap with those of true infection. While true infection is unlikely given current testing algorithms and risk factor evaluation, the findings suggest nonrandom association. Further investigation into biologic mechanisms is warranted.
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Affiliation(s)
- Michelle T Vo
- School of Public Health, University of California at Berkeley, Berkeley, California
| | | | | | - Brian S Custer
- Blood Systems Research Institute.,University of California at San Francisco, San Francisco, California
| | - Edward L Murphy
- Blood Systems Research Institute.,University of California at San Francisco, San Francisco, California
| | - Evan M Bloch
- Blood Systems Research Institute.,University of California at San Francisco, San Francisco, California
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Evaluation of two HIV antibody confirmatory assays: Geenius™ HIV1/2 Confirmatory Assay and the recomLine HIV-1 & HIV-2 IgG Line Immunoassay. J Virol Methods 2015; 224:91-4. [PMID: 26315319 DOI: 10.1016/j.jviromet.2015.08.015] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2014] [Revised: 08/19/2015] [Accepted: 08/21/2015] [Indexed: 11/24/2022]
Abstract
The laboratory diagnosis of an HIV infection mainly depends on the detection of HIV-specific antibodies/HIV p24 antigen whereby different algorithms for the confirmation of reactive screening assays exist. The objective of the present study was to compare the performance of two supplemental HIV antibody confirmatory assays: the Geenius™ HIV1/2 Confirmatory Assay and the recomLine HIV-1 & HIV-2 IgG Line Immunoassay. Therefore 279 serum samples previously analyzed for HIV during routine diagnostics at the Institute for Medical Virology, National Reference Center for Retroviruses, University Hospital Frankfurt, were analyzed retrospectively. 96.8% samples had concordant results in both HIV confirmatory assays, whereby the Geenius Assay showed a discrimination rate of 100% while two HIV-1 samples were not typeable with the recomLine Assay. Overall assay sensitivity was 100% in both assays and specificity was 99.0% (recomLine Assay) and 93.4% (Geenius Assay), respectively. The κ-values for both assays indicated high agreement. Overall nine samples had discordant results from which four were from acutely EBV/CMV-infected patients and one from a patient with primary HIV-1 infection during seroconversion. In conclusion, both assays are well suited for the detection, confirmation and discrimination of HIV-1- and -2-specific antibodies.
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Karanikola SN, Krücken J, Ramünke S, de Waal T, Höglund J, Charlier J, Weber C, Müller E, Kowalczyk SJ, Kaba J, von Samson-Himmelstjerna G, Demeler J. Development of a multiplex fluorescence immunological assay for the simultaneous detection of antibodies against Cooperia oncophora, Dictyocaulus viviparus and Fasciola hepatica in cattle. Parasit Vectors 2015; 8:335. [PMID: 26084663 PMCID: PMC4492007 DOI: 10.1186/s13071-015-0924-0] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2015] [Accepted: 06/01/2015] [Indexed: 12/04/2022] Open
Abstract
Background A major constraint for the effective control and management of helminth parasites is the lack of rapid, high-throughput, routine diagnostic tests to assess the health status of individual animals and herds and to identify the parasite species responsible for these helminthoses. The capability of a multiplex platform for the simultaneous detection of three pasture associated parasite species was evaluated and compared to existing ELISAs. Methods The recombinant antigens 14.2 kDa ES protein for Cooperia oncophora, major sperm protein for Dictyocaulus viviparus and Cathepsin L1 for Fasciola hepatica were recombinantly expressed either in Escherichia coli or Pichia pastoris. Antigens were covalently coupled onto magnetic beads. Optimal concentrations for coupling were determined following the examination of serum samples collected from experimentally mono-infected animals, before and after their infection with the target species. Absence of cross-reactivity was further determined with sera from calves mono-infected with Haemonchus contortus, Ostertagia ostertagi and Trichostrongylus colubriformis. Examination of negative serum samples was characterised by low median fluorescence intensity (MFI). Results Establishment of the optimal serum dilution of 1:200 was achieved for all three bead sets. Receiver Operating Characteristic analyses were performed to obtain cut-off MFI values for each parasite separately. Sensitivity and specificity at the chosen cut-off values were close to, or 100 % for all bead sets. Examination of serum samples collected on different days post infection from different animals showed a high reproducibility of the assays. Serum samples were additionally examined with two already established ELISAs, an in-house ELISA using the recombinant MSP as an antigen and a DRG ELISA using Cathepsin L1 for liver fluke. The results between the assays were compared and kappa tests revealed an overall good agreement. Conclusions A versatile bead-based assay using fluorescence detection (xMAP® technology) was developed to simultaneously detect antibodies against C. oncophora, D. viviparus and F. hepatica in cattle serum samples. This platform provides rapid, high-throughput results and is highly sensitive and specific in comparison to existing serological as well as coproscopical diagnostic techniques.
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Affiliation(s)
- Sofia N Karanikola
- Institute for Parasitology and Tropical Veterinary Medicine, Freie Universität Berlin, Berlin, Germany.
| | - Jürgen Krücken
- Institute for Parasitology and Tropical Veterinary Medicine, Freie Universität Berlin, Berlin, Germany.
| | - Sabrina Ramünke
- Institute for Parasitology and Tropical Veterinary Medicine, Freie Universität Berlin, Berlin, Germany.
| | - Theo de Waal
- UCD School of Agriculture, Food Science and Veterinary Medicine, University College Dublin, Dublin, Ireland.
| | - Johan Höglund
- Department of Biomedical Sciences and Veterinary Public Health, Section for Parasitology (SWEPAR), Swedish University of Agricultural Sciences, Uppsala, Sweden.
| | - Johannes Charlier
- Department of Virology, Parasitology and Immunology, Faculty of Veterinary Medicine, Ghent University, Ghent, Belgium.
| | | | | | - Slawomir J Kowalczyk
- Laboratory of Veterinary Epidemiology and Economics, Faculty of Veterinary Medicine, Warsaw University of Life Science, Warsaw, Poland.
| | - Jaroslaw Kaba
- Laboratory of Veterinary Epidemiology and Economics, Faculty of Veterinary Medicine, Warsaw University of Life Science, Warsaw, Poland.
| | | | - Janina Demeler
- Institute for Parasitology and Tropical Veterinary Medicine, Freie Universität Berlin, Berlin, Germany.
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Chen TH, Lee F, Lin YL, Pan CH, Shih CN, Tseng CH, Tsai HJ. Development of a multiplex Luminex assay for detecting swine antibodies to structural and nonstructural proteins of foot-and-mouth disease virus in Taiwan. JOURNAL OF MICROBIOLOGY, IMMUNOLOGY, AND INFECTION = WEI MIAN YU GAN RAN ZA ZHI 2014; 49:196-207. [PMID: 25074628 DOI: 10.1016/j.jmii.2014.05.009] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/16/2014] [Revised: 04/28/2014] [Accepted: 05/01/2014] [Indexed: 11/16/2022]
Abstract
BACKGROUND/PURPOSE(S) Foot-and-mouth disease (FMD) and swine vesicular disease (SVD) are serious vesicular diseases that have devastated swine populations throughout the world. The aim of this study was to develop a multianalyte profiling (xMAP) Luminex assay for the differential detection of antibodies to the FMD virus of structural proteins (SP) and nonstructural proteins (NSP). METHODS After the xMAP was optimized, it detected antibodies to SP-VP1 and NSP-3ABC of the FMD virus in a single serum sample. These tests were also compared with 3ABC polypeptide blocking enzyme-linked immunosorbent assay (ELISA) and virus neutralization test (VNT) methods for the differential diagnosis and assessment of immune status, respectively. RESULTS To detect SP antibodies in 661 sera from infected naïve pigs and vaccinated pigs, the diagnostic sensitivity (DSn) and diagnostic specificity (DSp) of the xMAP were 90.0-98.7% and 93.0-96.5%, respectively. To detect NSP antibodies, the DSn was 90% and the DSp ranged from 93.3% to 99.1%. The xMAP can detect the immune response to SP and NSP as early as 4 days postinfection and 8 days postinfection, respectively. Furthermore, the SP and NSP antibodies in all 15 vaccinated but unprotected pigs were detected by xMAP. A comparison of SP and NSP antibodies detected in the sera of the infected samples indicated that the results from the xMAP had a high positive correlation with results from the VNT and a 3ABC polypeptide blocking ELISA assay. However, simultaneous quantitation detected that xMAP had no relationship with the VNT. Furthermore, the specificity was 93.3-94.9% with 3ABC polypeptide blocking ELISA for the FMDV-NSP antibody. CONCLUSION The results indicated that xMAP has the potential to detect antibodies to FMDV-SP-VP1 and NSP-3ABC and to distinguish FMDV-infected pigs from pigs infected with the swine vesicular disease virus.
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Affiliation(s)
- Tsu-Han Chen
- Animal Health Research Institute, New Taipei City, Taiwan; Graduate Institute of Veterinary Medicine, School of Veterinary Medicine, National Taiwan University, Taipei, Taiwan
| | - Fan Lee
- Animal Health Research Institute, New Taipei City, Taiwan
| | - Yeou-Liang Lin
- Animal Health Research Institute, New Taipei City, Taiwan
| | - Chu-Hsiang Pan
- Animal Health Research Institute, New Taipei City, Taiwan
| | - Chia-Ni Shih
- Animal Health Research Institute, New Taipei City, Taiwan
| | | | - Hsiang-Jung Tsai
- Animal Health Research Institute, New Taipei City, Taiwan; Graduate Institute of Veterinary Medicine, School of Veterinary Medicine, National Taiwan University, Taipei, Taiwan.
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Liu Y, Li D, Wang T, Yan K, Zhu S, Yang T, Luo L, Tao C. Clinical application evaluation of two fourth-generation human immunodeficiency virus (HIV) screening assays in West China Hospital. J Clin Lab Anal 2014; 29:146-52. [PMID: 24797498 DOI: 10.1002/jcla.21743] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2013] [Accepted: 01/08/2014] [Indexed: 02/05/2023] Open
Abstract
BACKGROUND Fourth-generation human immunodeficiency virus (HIV) screening assays have been used in many laboratories. The Elecsys® HIV combi PT assay is a new kind of fourth-generation HIV screening assay developed to allow earlier detection of seroconversion. METHODS A total of 271,845 routine specimens were detected using the Elecsys® HIV combi assay and Elecsys® HIV combi PT assay from September 2010 to December 2012 in a large university hospital. Repeatedly, reactive screening samples were confirmed according to recommended confirmatory algorithms. RESULTS The false-positive rate and positive predictive value (PPV) of two assays are 0.08 and 78.35%, respectively, for the Elecsys® HIV combi assay and 0.07 and 82.21% for the Elecsys® HIV combi PT assay. Ninety-four percent cases with cutoff index ratio <15.0 were false-positive. When we set the specificity as 95.0 and 99.0%, PPV could increase to 98.7, 99.6, 98.8, and 99.7%, and sensitivity reduced to 99.2, 98.4, 98.5, and 96.8% for the Elecsys® HIV combi assay and the Elecsys® HIV combi PT assay, respectively. CONCLUSIONS The Elecsys® HIV combi PT assay shows a better performance in specificity than the Elecsys® HIV combi assay. Most weakly reactive results were false-positive, this means it still need to be improved and it will need laboratory personnel to communicate with the clinical doctor and patients more properly about the result of the assay.
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Affiliation(s)
- Yongming Liu
- Division of Clinical Microbiology, Department of Laboratory Medicine, West China Hospital, Sichuan University, Chengdu, China
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Chen TH, Lee F, Lin YL, Pan CH, Shih CN, Lee MC, Tsai HJ. Development of a Luminex assay for the detection of swine antibodies to non-structural proteins of foot-and-mouth disease virus. J Immunol Methods 2013; 396:87-95. [PMID: 23962586 PMCID: PMC7127766 DOI: 10.1016/j.jim.2013.08.002] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2013] [Revised: 05/16/2013] [Accepted: 08/01/2013] [Indexed: 11/29/2022]
Abstract
Foot-and mouth disease (FMD), swine vesicular disease (SVD), and vesicular stomatitis (VS) are highly contagious vesicular diseases of swine but are not easy to differentiate clinically. For the purpose of instant detecting of FMD and differentiating it from the other vesicular diseases, a Luminex assay was developed. Sera from 64 infected, 307 vaccinated, and 280 naïve pigs were tested by the Luminex assay. Diagnostic sensitivity of the assay was 100%. Diagnostic specificity of the assay was 98.7% in vaccinated pigs and 97.5% to 100% in naïve pigs. Agreement between the results from the Luminex assay and those from a 3ABC polypeptide blocking ELISA was 96.3% with kappa statistics of 0.92. The Luminex assay can detect the immune response to NSP-3ABC in swine as early as eight days post-infection. Moreover, all of the 15 vaccinated but unprotected pigs were all detected by the Luminex assay. The results indicated that the Luminex assay has potential with specificity in detecting antibodies to FMDV 3ABC NSP and in distinguishing FMDV-infected pigs from with either SVDV or VSV.
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Affiliation(s)
- Tsu-Han Chen
- Animal Health Research Institute, 376, Chung-Cheng Road, Tamsui District, New Taipei City 25158, Taiwan; Graduate Institute of Veterinary Medicine, School of Veterinary Medicine, National Taiwan University, 1, Section 4 Roosevelt Road, Taipei 10617, Taiwan
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Performance of six commercial enzyme immunoassays and two alternative HIV-testing algorithms for the diagnosis of HIV-1 infection in Kisumu, Western Kenya. J Virol Methods 2011; 176:24-31. [PMID: 21635920 DOI: 10.1016/j.jviromet.2011.05.021] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2010] [Revised: 05/11/2011] [Accepted: 05/12/2011] [Indexed: 11/21/2022]
Abstract
Performances of serological parallel and serial testing algorithms were analyzed using a combination of three ELISA and three rapid tests for the confirmation of HIV infection. Each was assessed individually for their sensitivity and specificity on a blinded panel of 769 retrospective sera of known HIV status. Western blot was used as a confirmatory assay for discordant results. Subsequently, one parallel and one serial testing algorithm were assessed on a new panel of 912 HIV-positive and negative samples. Individual evaluation of the ELISAs and rapid tests indicated a sensitivity of 100% for all assays except Uni-Gold with 99.7%. The specificities ranged from 99.1% to 99.4% for rapid assays and from 97.5% to 99.1% for ELISAs. A parallel and serial testing algorithms using Enzygnost and Vironostika, and Determine followed by Uni-Gold respectively, showed 100% sensitivity and specificity. The cost for testing 912 samples was US$4.74 and US$ 1.9 per sample in parallel and serial testing respectively. Parallel or serial testing algorithm yielded a sensitivity and specificity of 100%. This alternative algorithm is reliable and reduces the occurrence of both false negatives and positives. The serial testing algorithm was more cost effective for diagnosing HIV infections in this population.
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Gallagher DJ, Riches J, Bajorin DF. False elevation of human chorionic gonadotropin in a patient with testicular cancer. Nat Rev Urol 2010; 7:230-3. [DOI: 10.1038/nrurol.2010.10] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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Chappel RJ, Wilson KM, Dax EM. Immunoassays for the diagnosis of HIV: meeting future needs by enhancing the quality of testing. Future Microbiol 2010; 4:963-82. [PMID: 19824789 DOI: 10.2217/fmb.09.77] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Immunoassays for detecting HIV infection perform better than other serological assays. HIV immunoassays are presented in a number of different formats: instrument-based, plate, rapid assays and as immunoblots. HIV immunoassays for screening and diagnosis are now in their fourth generation; an assay generation meaning that significant modifications to the assay format have led to a significant enhancement in quality. Although still not perfect, they are now of exceptionally high quality if conducted properly. Most problems relate to how the assays are performed. Many laboratories, especially in high human development index (HDI) countries, manage testing within functioning quality-management systems, but this is not true of laboratories in low HDI countries or in many medium HDI countries. Simple rapid tests for HIV are being used increasingly, and create special challenges for assuring quality. Users of HIV immunoassays are learning that a poorer assay used well has better outcomes than a splendid assay performed poorly. Experience highlights the importance of conducting HIV testing within quality-managed systems and according to international standards, but testing quality and laboratory quality management must be funded adequately.
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Affiliation(s)
- Roderick J Chappel
- National Serology Reference Laboratory, Fitzroy, Victoria 3065, Australia.
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Chou CC, Sun CY, Wu MS. Human Immunodeficiency Virus (HIV) Infection Screening in a Dialysis Unit. Ren Fail 2009; 29:459-61. [PMID: 17497469 DOI: 10.1080/08860220701260644] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022] Open
Abstract
BACKGROUND Human immunodeficiency virus (HIV) screening is a routine for long-term hemodialysis patients because of a high risk for infection. Enzyme-immunoassay (EIA) is a simple tool for screening HIV, but clinically false-positive EIA is a frequent result. Other tests such as Western blot analysis (WB) and HIV DNA and RNA by polymerase chain reaction have better specificity and sensitivity, but they cannot be accessible in many dialysis units. METHODS Four hundred and four patients with end stage renal disease on long-term hemodialysis were screened with EIA for HIV antibodies. Repeated EIA was performed if the first test was positive result. WB was used as the confirmatory test. RESULTS Two persons initially showed a positive EIA pattern among the 404 patients, but nobody had positive WB test result later. CONCLUSION The ratio of false-positive EIA results for screening HIV is relatively high in long-term hemodialysis patients. Further tests should be employed to confirm the diagnosis.
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Affiliation(s)
- Chia-Chi Chou
- Division of Nephrology, Chang Gung Memorial Hospital, Keelung, Taiwan
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16
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Spencer DV, Nolte FS, Zhu Y. Heterophilic antibody interference causing false-positive rapid human immunodeficiency virus antibody testing. Clin Chim Acta 2008; 399:121-2. [PMID: 18950610 DOI: 10.1016/j.cca.2008.09.030] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2008] [Revised: 09/22/2008] [Accepted: 09/23/2008] [Indexed: 10/21/2022]
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17
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Kiely P, Thomas B, Kebede M. Long-term serologic follow-up of blood donors with biologic false reactivity on an anti-human T-cell lymphotropic virus Types I and II chemiluminescent immunoassay and implications for donor management. Transfusion 2008; 48:1833-41. [DOI: 10.1111/j.1537-2995.2008.01760.x] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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18
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Owen SM, Yang C, Spira T, Ou CY, Pau CP, Parekh BS, Candal D, Kuehl D, Kennedy MS, Rudolph D, Luo W, Delatorre N, Masciotra S, Kalish ML, Cowart F, Barnett T, Lal R, McDougal JS. Alternative algorithms for human immunodeficiency virus infection diagnosis using tests that are licensed in the United States. J Clin Microbiol 2008; 46:1588-95. [PMID: 18322061 PMCID: PMC2395119 DOI: 10.1128/jcm.02196-07] [Citation(s) in RCA: 134] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2007] [Revised: 01/14/2008] [Accepted: 02/25/2008] [Indexed: 02/05/2023] Open
Abstract
Serodiagnosis of human immunodeficiency virus (HIV) infection in the United States has traditionally relied on a sequential two-test algorithm: an initial screen with an enzyme immunoassay (EIA) and reflex testing of EIA-reactive specimens with a more specific supplemental test such as Western blotting or immunofluorescence. The supplemental tests are tedious, subjective, and expensive. In addition, there have been major improvements in the performance and accuracy of the EIA tests as well as the introduction of rapid serologic tests (RT) and HIV nucleic acid amplification tests (NAAT). Related to these improvements is the possibility that alternative algorithms using combinations of currently approved HIV tests may function as well as if not better than the current algorithm, with more flexibility, improved accuracy, and lower cost. To this end, we evaluated the performance of 12 currently licensed tests and 1 in-house HIV test (6 EIA, 4 RT, and 3 NAAT) on panels of plasma samples from HIV-infected (n = 621 HIV type 1 [HIV-1] and 34 HIV-2) and uninfected (n = 513) people and of sequential specimens from people early in seroconversion (183 specimens from 15 patients). Test combinations were analyzed in two dual-test (sensitivity-optimized and specificity-optimized) algorithms and in a three-test (tie-breaking) algorithm, and performance was compared to the conventional algorithm. The results indicate that alternative algorithm strategies with currently licensed tests compare favorably with the conventional algorithm in detecting and confirming established HIV infection. Furthermore, there was a lower frequency of discordant or indeterminate results that require follow-up testing, and there was improved detection of early infection.
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Affiliation(s)
- S M Owen
- HIV Laboratory Branch, Division of HIV/AIDS Prevention, National Center for HIV/AIDS, Hepatitis, STD and TB Prevention, Centers for Disease Control and Prevention, Atlanta, Georgia 30333, USA.
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19
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Guan M. Frequency, causes, and new challenges of indeterminate results in Western blot confirmatory testing for antibodies to human immunodeficiency virus. CLINICAL AND VACCINE IMMUNOLOGY : CVI 2007; 14:649-59. [PMID: 17409223 PMCID: PMC1951092 DOI: 10.1128/cvi.00393-06] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Affiliation(s)
- Ming Guan
- MP Biomedicals Asia Pacific Pte Ltd., 85 Science Park Drive No. 04-01, Singapore Science Park, Singapore 118259, Republic of Singapore.
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20
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Phillips DJ, League SC, Weinstein P, Hooper WC. Interference in microsphere flow cytometric multiplexed immunoassays for human cytokine estimation. Cytokine 2007; 36:180-8. [PMID: 17306558 DOI: 10.1016/j.cyto.2006.12.002] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2005] [Revised: 11/07/2006] [Accepted: 12/06/2006] [Indexed: 10/23/2022]
Abstract
The present study describes positive and negative interference of human cytokine measurement in multiplexed bead-based immunoassays. Significant differences in measured IL-6 and TNF-alpha values in 30 normal human plasma samples were apparent depending on whether measurements were with a 2-plex assay or embedded in a multiplex of 8-or more cytokine antibody pairs, as well as among the kits of 3-different vendors. Sample diluents containing proprietary blocking ingredients were shown to greatly affect the outcome of measured cytokine values. Additionally, recovery of IL-6 and TNF-alpha from spiked samples suggests significant negative interference from either endogenous antibodies, soluble receptors or anti-cytokine antibodies in 10% and 26% of samples, respectively. While it is evident that multiplexed immunoassays hold great promise for cytokine profiling, there are still important issues needing further study. Especially needed are universally optimized sample diluents, uniformly calibrated standards with mass values, and internal assay controls, which should greatly facilitate intralaboratory accuracy and precision and interlaboratory comparisons of cytokine measurements. Possible causes of interference and remedies are discussed.
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Affiliation(s)
- Donald J Phillips
- Centers for Disease Control and Prevention, National Center on Birth Defects and Development Disabilities, Mail Stop D02, 1600 Clifton Rd., NE, Atlanta, GA 30333, USA
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21
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Earle CD, King EM, Tsay A, Pittman K, Saric B, Vailes L, Godbout R, Oliver KG, Chapman MD. High-throughput fluorescent multiplex array for indoor allergen exposure assessment. J Allergy Clin Immunol 2007; 119:428-33. [DOI: 10.1016/j.jaci.2006.11.004] [Citation(s) in RCA: 77] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2006] [Revised: 11/01/2006] [Accepted: 11/07/2006] [Indexed: 11/16/2022]
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22
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Fouda GG, Leke RFG, Long C, Druilhe P, Zhou A, Taylor DW, Johnson AH. Multiplex assay for simultaneous measurement of antibodies to multiple Plasmodium falciparum antigens. CLINICAL AND VACCINE IMMUNOLOGY : CVI 2006; 13:1307-13. [PMID: 17035513 PMCID: PMC1694450 DOI: 10.1128/cvi.00183-06] [Citation(s) in RCA: 67] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Antibodies to Plasmodium falciparum are classically measured using the enzyme-linked immunosorbent assay (ELISA). Although highly sensitive, this technique is labor-intensive when large numbers of samples must be screened against multiple antigens. The suspension array technology (SAT) might be an alterative to ELISA, as it allows measurement of antibodies against multiple antigens simultaneously with a small volume of sample. This study sought to adapt the new SAT multiplex system for measuring antibodies against nine malarial vaccine candidate antigens, including recombinant proteins from two variants of merozoite surface protein 1, two variants of apical merozoite antigen 1, erythrocyte binding antigen 175, merozoite surface protein 3, and peptides from the circumsporozoite protein, ring erythrocyte surface antigen, and liver-stage antigen 1. Various concentrations of the antigens were coupled to microspheres with different spectral addresses, and plasma samples from Cameroonian adults were screened by SAT in mono- and multiplex formats and by ELISA. Optimal amounts of protein required to perform the SAT assay were 10- to 100-fold less than that needed for ELISA. Excellent agreement was found between the single and multiplex formats (R > or = 0.96), even when two variants of the same antigen were used. The multiplex assay was rapid, reproducible, required less than 1 mul of plasma, and had a good correlation with ELISA. Thus, SAT provides an important new tool for studying the immune response to malaria rapidly and efficiently in large populations, even when the amount of plasma available is limited, e.g., in studies of neonates or finger-prick blood.
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Affiliation(s)
- Genevieve G Fouda
- Department of Biology, Georgetown University, Washington, DC 20057, USA
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23
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Haroun M. Effect of anti-immunoglobulin antibodies provides new insights into immune response to HCV. THE JOURNAL OF MEDICAL INVESTIGATION 2005; 52:172-7. [PMID: 16167535 DOI: 10.2152/jmi.52.172] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022]
Abstract
To determine the effect of anti-immunoglobulin antibodies on the measurement of the humoral immune response in hepatitis C virus (HCV) infected patients. Anti-immunoglobulin antibodies were defined using sheep immunoglobulins as a target to characterize distinct changes in patterns of immunoglobulin levels. Serum immunoglobulin A, G and M concentrations were measured by ELISA in 45 patients with recent-onset HCV infection and 45 matched normal individuals. It was found that normal individuals had mean IgA, IgG and IgM levels of 2.67 mg/ml, 9.39 mg/ml and 1.77 mg/ml, respectively while HCV infected patients had mean levels of 3.19 mg/ml, 10.76 mg/ml and 1.94 mg/ml. These represented significant increases in immunoglobulin levels in the sera of HCV patients compared to normal individuals (p < 0.0001, p < 0.00004 and p < 0.0004). Anti-immunoglobulin antibodies lead to an overestimation of serum immunoglobulin levels in HCV patients. Interestingly, the mean levels of immunoglobulins A, G and M in HCV infected sera, determined after purification from anti-sheep immunoglobulins, was 2.73 mg/ml, 9.55 mg/ml and 1.79 mg/ml. Therefore, there was no significant difference in HCV patients compared to normal individuals (p < 0.42, p < 0.36 and p < 0.44). The presence of circulating immune complex in serum during the early phase of infection may contribute to immunopathological effects in the infected host and provide some new insights into antibody response to HCV.
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Affiliation(s)
- Medhat Haroun
- Department of Bioscience and Technology, Institute of Graduate Studies and Research, Alexandria University, Alexandria, Egypt
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24
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Kiely P, Wood E. Can we improve the management of blood donors with nonspecific reactivity in viral screening and confirmatory assays? Transfus Med Rev 2005; 19:58-65. [PMID: 15830328 DOI: 10.1016/j.tmrv.2004.09.004] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Donors with nonspecific reactivity in viral screening or confirmatory assays are problematic for blood services because of donor management issues and product loss. Considerable experience has now accumulated in the use of screening and confirmatory assays; therefore, it is timely to examine the ways in which donors with nonspecific reactivity are managed. In this review, we summarize the causes and characteristics of nonspecific reactivity in blood donors and approaches for reducing the number of nonspecific reactive results and we offer some suggestions for improving the management of these donors.
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Affiliation(s)
- Philip Kiely
- Virus Serology Laboratory, Australian Red Cross Blood Service, South Melbourne, Victoria 3205, Australia.
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25
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Song EY, VanDunk C, Kuddo T, Nelson PG. Measurement of Vasoactive Intestinal Peptide using a Competitive Fluorescent Microsphere Immunoassay or ELISA in human blood samples. J Immunol Methods 2005; 300:63-73. [PMID: 15894328 DOI: 10.1016/j.jim.2005.02.009] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2004] [Revised: 02/21/2005] [Accepted: 02/28/2005] [Indexed: 10/25/2022]
Abstract
The concentration of Vasoactive Intestinal Peptide (VIP) as measured by recycling immunoaffinity chromatography (RIC) has been reported to be elevated in the blood of patients with autism as compared with normal subjects. In this study, we have developed a "Competitive Fluorescent Microsphere Immunoassay" (cFMI) in which VIP competes with biotinylated VIP in binding to polyclonal antibodies on microspheres. The results were obtained using the Luminex100 system. We measured VIP in serum, plasma, and material eluted from dried blood spots on filter paper with both the cFMI and an ELISA procedure. We found that a purification procedure was necessary for obtaining useful results from plasma and serum, however, a preincubation step was required with the blood eluates. This newly developed cFMI was more sensitive (2.5 vs. 20.0 pg/ml), and more reproducible than the ELISA. To get accurate measurements of VIP in eluted material high sensitivity is especially important. Thus, the cFMI using the Luminex system has definite advantages over a conventional ELISA including the possibility that samples can be assayed at higher dilutions. We have determined that the VIP concentrations of serum, plasma, and dried blood spot eluate specimens as measured with the cFMI assay system were similar to those measured with ELISA. Thus, the new cFMI using Luminex system may be useful for detection of VIP in human blood samples.
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Affiliation(s)
- Eun Young Song
- LDN, National Institute of Child Health and Human Development, National Institutes of Health, Building 31 Room 2 A 25, Bethesda, MD 20892-4480, USA
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26
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Hogrefe WR, Moore R, Lape-Nixon M, Wagner M, Prince HE. Performance of immunoglobulin G (IgG) and IgM enzyme-linked immunosorbent assays using a West Nile virus recombinant antigen (preM/E) for detection of West Nile virus- and other flavivirus-specific antibodies. J Clin Microbiol 2004; 42:4641-8. [PMID: 15472323 PMCID: PMC522294 DOI: 10.1128/jcm.42.10.4641-4648.2004] [Citation(s) in RCA: 67] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2004] [Revised: 03/26/2004] [Accepted: 06/23/2004] [Indexed: 11/20/2022] Open
Abstract
Focus Technologies developed an indirect immunoglobulin G (IgG) enzyme-linked immunosorbent assay (ELISA) and a mu-capture IgM ELISA for the detection of West Nile virus (WNV)-specific antibodies based on a WNV preM/E protein recombinant antigen. Normal and disease state serum panels were used to assess the performance characteristics of the two WNV ELISA kits. Totals of 807 and 1,423 sera were used to assess the IgG ELISA and IgM ELISA kits, respectively. The Focus Technologies IgG ELISA had a sensitivity of 97.6% and a specificity of 92.1% (excluding non-WNV flavivirus sera). The comparative method for WNV IgG may lack sensitivity in detecting IgG in early WNV infection, so the specificity of the Focus IgG ELISA may be higher than 92.1%. When sera from patients either infected with or vaccinated against other flaviviruses were tested on the WNV IgG assay, 35% of the sera reacted as positive for WNV IgG. Yellow fever and Japanese encephalitis vaccinees were less reactive in the IgG ELISA than St. Louis and dengue fever patients. The Focus Technologies IgM ELISA had a sensitivity and a specificity of 99.3% (excluding the non-WNV flavivirus sera). The overall cross-reactivity for the IgM ELISA to flavivirus sera was 12%, with 31% of St. Louis encephalitis patients found to be WNV IgM positive and no yellow fever vaccinees found to be WNV IgM positive. In a selected population of 706 sera, 15 false-positive WNV IgM sera were identified. The use of a background subtraction method for the IgM ELISA eliminated all 15 false-positive results, giving a specificity of 100% for the Focus IgM ELISA.
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27
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Enarson P, Rattner JB, Ou Y, Miyachi K, Horigome T, Fritzler MJ. Autoantigens of the nuclear pore complex. J Mol Med (Berl) 2004; 82:423-33. [PMID: 15175862 DOI: 10.1007/s00109-004-0554-z] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2004] [Accepted: 03/12/2004] [Indexed: 01/27/2023]
Abstract
The nuclear envelope (NE) is one of many intracellular targets of the autoimmune response in patients with autoimmune liver disease, systemic lupus erythematosus, and related conditions. In eukaryotic organisms the NE consists of five interconnected regions: an outer nuclear membrane (ONM) that is continuous with the endoplasmic reticulum, an intermembrane or perinuclear space, an inner nuclear membrane (INM) with a unique set of integral membrane proteins, the underlying nuclear lamina, and the pore domains that are regions where the ONM and INM come together. The pore domains are sites of regulated continuity between the cytoplasm and nucleus that are occupied by supramolecular structures, termed nuclear pore complexes (NPCs). Human autoantibodies identified to date bind to specific components in three of the five NE compartments. Autoantigen targets include the lamins A, B, and C of the nuclear lamina, gp210, p62 complex proteins, Nup153, and Tpr within the NPC, and LBR, MAN1, LAP1, and LAP2 that are integral proteins of the INM. Autoantibodies to these NE targets have been shown to be correlated with various autoimmune diseases such as primary biliary cirrhosis, other autoimmune liver diseases and systemic rheumatic diseases. Now that the proteome of the NE is more clearly defined, other autoantibodies to components in this cell compartment are likely to be defined.
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Affiliation(s)
- P Enarson
- Department of Anatomy and Cell Biology, Faculty of Medicine, University of Calgary, 3330 Hospital Dr. N.W., Calgary, AB, T2N 4N1, Canada
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28
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Silverstein DM, Aviles DH, Vehaskari VM. False-positive human immunodeficiency virus antibody test in a dialysis patient. Pediatr Nephrol 2004; 19:547-9. [PMID: 14991392 DOI: 10.1007/s00467-003-1405-9] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/30/2003] [Revised: 12/10/2003] [Accepted: 12/11/2003] [Indexed: 11/25/2022]
Abstract
A patient developed end-stage renal disease secondary to p-anti-neutrophil cytoplasmic antibody (p-ANCA) positive rapidly progressive glomerulonephritis. He subsequently had human immunodeficiency virus (HIV)-1 antibody screening performed as part of a pre-transplant evaluation. The HIV-1 enzyme immunoassay (EIA) antibody test was repeatedly reactive. The HIV-1 western blot was indeterminate. The western blot pattern revealed "non-specific staining obscuring bands in that region." Another sample of serum was sent and the results were identical to the first result. An HIV-1 proviral qualitative polymerase chain reaction test was then performed several months later and no HIV-1 DNA was detected. One year later, an HIV-1 RNA test was negative. Thus, the positive antibody EIA test and the indeterminate western blot represent a false-positive result, most likely due to cross-reacting antigens in the patient's serum with various HIV antibodies. Throughout this period and thereafter, the patient has exhibited no symptoms of HIV infection.
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29
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Kellar KL, Oliver KG. Multiplexed Microsphere Assays for Protein and DNA Binding Reactions. Methods Cell Biol 2004; 75:409-29. [PMID: 15603435 DOI: 10.1016/s0091-679x(04)75016-5] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/13/2023]
Affiliation(s)
- Kathryn L Kellar
- Biotechnology Core Facility Branch, Scientific Resources Program, National Center for Infectious Diseases, Centers for Disease Control and Prevention, Atlanta, Georgia 30333, USA
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30
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Clavijo A, Wright P, Kitching P. Developments in diagnostic techniques for differentiating infection from vaccination in foot-and-mouth disease. Vet J 2004; 167:9-22. [PMID: 14623146 DOI: 10.1016/s1090-0233(03)00087-x] [Citation(s) in RCA: 88] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Abstract
Foot-and-mouth disease (FMD) is a highly contagious and economically significant disease of cattle, pigs, sheep, goats and wild ruminant species. The FMD virus genome encodes a unique polyprotein from which the different viral polypeptides are cleaved by viral proteases, including eight different non-structural proteins (NSPs). Both structural and non-structural antigens induce the production of antibodies in infected animals. In contrast, vaccinated animals which have not been exposed to replicating virus will develop antibodies only to the viral antigens in the inactivated material. Vaccination against FMD is a key element in the control of the disease in addition to slaughter and movement restrictions. However, countries that vaccinate in the event of an outbreak will have to re-establish their FMD free status to the satisfaction of their trading partners. Because currently available vaccines stimulate the production of antibodies indistinguishable from those produced by infected animals in response to live virus and because vaccinated animals can be infected and become carriers of FMD virus, efforts have been made to develop diagnostic test that can differentiate vaccinated animals from those that are convalescent and from those that have been vaccinated and become carriers following subsequent contact with live virus. Currently the detection of antibodies to non-structural protein's (NSPs) is the preferred diagnostic method to distinguish virus infected, carrier, animals from vaccinated animals. However this is currently only possible at the herd level because of the great variability in the initiation, specificity and duration of the immune response in individual animals to the NSPs shown in many studies. Considerable effort and attention is now being directed toward the development of new methods and techniques for the rapid and accurate detection of anti-NSP antibodies, harmonization and standardization of current diagnostic techniques, as well as the production of defined reagents.
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Affiliation(s)
- Alfonso Clavijo
- National Centre for Foreign Animal Disease, Canadian Food Inspection Agency, Suite T2300, 1015 Arlington Street, Winnipeg, Manitoba, Canada R3E 3M4.
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31
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Eystathioy T, Chan EKL, Mahler M, Luft LM, Fritzler ML, Fritzler MJ. A panel of monoclonal antibodies to cytoplasmic GW bodies and the mRNA binding protein GW182. HYBRIDOMA AND HYBRIDOMICS 2003; 22:79-86. [PMID: 12831532 DOI: 10.1089/153685903321947996] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
GW182 is a mRNA binding protein characterized by 60 repeats of glycine (G):tryptophan (W) motifs and is localized in cytoplasmic structures referred to as GW bodies (GWBs). Current evidence suggests that this unique protein plays a role in mRNA processing. To enable a more detailed study of GW182 and GWBs in cells and tissues, including their role in mRNA processing, we developed four monoclonal antibodies (MAbs) that bind the human recombinant GW182 protein. These MAbs can be used for Western blot analysis and indirect immunofluorescence (IIF) on cultured cells and tissues. Of special interest, one of the MAbs, 2D6, can be used to identify GW182 and GWBs in formalin-fixed and paraffin-embedded tissues after using an antigen retrieval method (ARM). All the MAbs described in this study immunoprecipitate the GW182 protein. Epitope mapping using overlapping 15-mer peptides representing the full-length GW182 showed that the major antibody-binding domains of these MAbs are distinct. These MAbs are valuable tools for cell biologists and pathologists to study the location and function of the novel GW182 protein in tissue culture cells, as well as cryopreserved or archived tissues.
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Affiliation(s)
- Theophany Eystathioy
- Department of Biochemistry and Molecular Biology, University of Calgary, Calgary, Alberta, Canada
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32
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Levinson SS, Miller JJ. Towards a better understanding of heterophile (and the like) antibody interference with modern immunoassays. Clin Chim Acta 2002; 325:1-15. [PMID: 12367762 DOI: 10.1016/s0009-8981(02)00275-9] [Citation(s) in RCA: 162] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
BACKGROUND Heterophile antibodies interfere with immunoassays. Understanding the nature and characteristics of these antibodies provides a format for better identifying and removing them. Growing evidence suggests many of these antibodies are natural antibodies. Very large number of tests are being performed with automated analyzers and there has been a problem with misdiagnosis due to interference. New commercial agents for blocking heterophile antibodies have been developed. METHODS Review of the immunology and methodological literature with critical interpretation of the findings. CONCLUSIONS Heterophile antibodies consist of natural antibodies and autoantibodies. Both types are usually weak antibodies that interfere by noncompetitive mechanisms. Based on very strong circumstantial evidence, we propose that natural antibodies account for most interference with automated immunoassays. In terms of false positive results, the interference rate is very low, about 99.95% accuracy. Specific blocking agents have some theoretical advantage over nonspecific blocking agents, but in actual practice, the very low false positive frequency makes it difficult if not impossible to statistically compare blocking agents or other assay modifications with adequate statistical power. In the absence of a technique that lends itself to automation for removing all immunoglobulins, it appears that infrequent heterophile interference cannot be avoided.
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Affiliation(s)
- Stanley S Levinson
- Department of Pathology and Laboratory Medicine, University of Louisville, Louisville, KY, USA.
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33
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Dasso J, Lee J, Bach H, Mage RG. A comparison of ELISA and flow microsphere-based assays for quantification of immunoglobulins. J Immunol Methods 2002; 263:23-33. [PMID: 12009201 DOI: 10.1016/s0022-1759(02)00028-5] [Citation(s) in RCA: 57] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
An automated microsphere-based flow cytometric assay (FlowMetrix system) was compared with a conventional enzyme-linked immunosorbent assay (ELISA) for quantifying Ig classes in serum and stool samples. The reproducibility of the process of coupling capture antibodies to microspheres was tested. The use of independently coupled microspheres did not increase the variation of assay results relative to using the same bead set in repeated assays. However, it is necessary to ensure quality control of the coupling process since slight variations in the coupling procedures can profoundly affect the density of capture reagents coupled to the microspheres and consequently adversely affect assay precision. Although the ELISA was more sensitive and did not have the problems with instrument performance encountered with the FlowMetrix assay, the latter was more reproducible, had a greater dynamic range of measurement, and took considerably less preparation time than the ELISA. Greater reproducibility is especially important for measurement of fecal Ig, which is typically highly variable. Thus, in addition to its multi-analyte capability, the FlowMetrix assay system has definite advantages over a conventional ELISA. Mechanical problems such as microspheres settling to the bottom of wells during analysis by an automated plate reader will likely be overcome, and sensitivity improved as this technology develops.
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Affiliation(s)
- Joseph Dasso
- Laboratory of Immunology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD 20892-1892, USA.
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34
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Martins TB. Development of internal controls for the Luminex instrument as part of a multiplex seven-analyte viral respiratory antibody profile. CLINICAL AND DIAGNOSTIC LABORATORY IMMUNOLOGY 2002; 9:41-5. [PMID: 11777827 PMCID: PMC119915 DOI: 10.1128/cdli.9.1.41-45.2002] [Citation(s) in RCA: 37] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
The ability of the Luminex system to simultaneously quantitate multiple analytes from a single sample source has proven to be a feasible and cost-effective technology for assay development. In previous studies, my colleagues and I introduced two multiplex profiles consisting of 20 individual assays into the clinical laboratory. With the Luminex instrument's ability to classify up to 100 distinct microspheres, however, we have only begun to realize the enormous potential of this technology. By utilizing additional microspheres, it is now possible to add true internal controls to each individual sample. During the development of a seven-analyte serologic viral respiratory antibody profile, internal controls for detecting sample addition and interfering rheumatoid factor (RF) were investigated. To determine if the correct sample was added, distinct microspheres were developed for measuring the presence of sufficient quantities of immunoglobulin G (IgG) or IgM in the diluted patient sample. In a multiplex assay of 82 samples, the IgM verification control correctly identified 23 out of 23 samples with low levels (<20 mg/dl) of this antibody isotype. An internal control microsphere for RF detected 30 out of 30 samples with significant levels (>10 IU/ml) of IgM RF. Additionally, RF-positive samples causing false-positive adenovirus and influenza A virus IgM results were correctly identified. By exploiting the Luminex instrument's multiplexing capabilities, I have developed true internal controls to ensure correct sample addition and identify interfering RF as part of a respiratory viral serologic profile that includes influenza A and B viruses, adenovirus, parainfluenza viruses 1, 2, and 3, and respiratory syncytial virus. Since these controls are not assay specific, they can be incorporated into any serologic multiplex assay.
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Affiliation(s)
- Thomas B Martins
- Associated Regional and University Pathologists Institute for Clinical and Experimental Pathology, 500 Chipeta Way, Salt Lake City, Utah 84108, USA.
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