title: Development of a time-resolved fluorescence immunoassay for Epstein-Barr virus nuclear antigen 1-immunoglobulin A in human serum.
abstract: Enzyme-linked immunosorbent assay (ELISAs) specific for Epstein-Barr virus nuclear antigen 1 (EBNA1)-immunoglobulin A (IgA) are most commonly used in the clinical diagnosis of EBV infection. But they have a low sensitivity and the enzyme-labeled antibodies are unstable. In this study, a novel immunoassay based on an indirect time-resolved fluoroimmunoassay (TRFIA) was developed. Microtiter plates were coated with recombinant EBNA1. We used Eu(3) (+)-labeled anti-human IgA as probe. The precision, sensitivity, specificity, and stability were evaluated, and comparison with traditional and commercially available ELISAs was also made. The cut-off value for our TRFIA was 2.7. Intra- and inter-assay coefficients of variation for the TRFIA were 1.56-4.99% and 3.92-6.95%, respectively; whereas those for the ELISA were 4.54-8.16% and 7.07-10.52%, respectively. Sensitivity was obviously better than traditional ELISA when diluted positive samples serially. Additionally, stability, specificity test and comparison of sensitivity and specificity between the TRFIA and commercial ELISAs all proved satisfactory. In conclusion, the results demonstrated that EBNA1 IgA TRFIA was a sensitive immunoassay and had potential value in large-scale screening of human serum samples in developing countries.
authors.affiliation: State Key Laboratory of Organ Failure Research, School of Biotechnology, Institute of Antibody Engineering, Southern Medical University, Guangzhou, Guangdong, People's Republic of China.
authors.forename: Juan-Juan
authors.initials: JJ
authors.lastname: Chen
authors.affiliation: State Key Laboratory of Organ Failure Research, School of Biotechnology, Institute of Antibody Engineering, Southern Medical University, Guangzhou, Guangdong, People's Republic of China.
authors.forename: Tian-Cai
authors.initials: TC
authors.lastname: Liu
authors.affiliation: State Key Laboratory of Organ Failure Research, School of Biotechnology, Institute of Antibody Engineering, Southern Medical University, Guangzhou, Guangdong, People's Republic of China.
authors.forename: Qian-Ni
authors.initials: QN
authors.lastname: Liang
authors.affiliation: State Key Laboratory of Organ Failure Research, School of Biotechnology, Institute of Antibody Engineering, Southern Medical University, Guangzhou, Guangdong, People's Republic of China.
authors.forename: Zhi-Ning
authors.initials: ZN
authors.lastname: Dong
authors.affiliation: State Key Laboratory of Organ Failure Research, School of Biotechnology, Institute of Antibody Engineering, Southern Medical University, Guangzhou, Guangdong, People's Republic of China.
authors.forename: Ying-Song
authors.initials: YS
authors.lastname: Wu
authors.affiliation: State Key Laboratory of Organ Failure Research, School of Biotechnology, Institute of Antibody Engineering, Southern Medical University, Guangzhou, Guangdong, People's Republic of China.
authors.forename: Ming
authors.initials: M
authors.lastname: Li
mesh_terms: D000914:Antibodies, Viral / Q000097:blood*; D020031:Epstein-Barr Virus Infections / Q000175:diagnosis* / Q000276:immunology; D019309:Epstein-Barr Virus Nuclear Antigens / Q000276:immunology*; D005455:Fluorescent Antibody Technique / Q000379:methods*; D004854:Herpesvirus 4, Human / Q000276:immunology*; D006801:Humans; D007070:Immunoglobulin A / Q000097:blood*; D012680:Sensitivity and Specificity; D044967:Serum / Q000737:chemistry
chemical_list: D000914:Antibodies, Viral; D019309:Epstein-Barr Virus Nuclear Antigens; D007070:Immunoglobulin A; C417029:EBV-encoded nuclear antigen 1
keywords: EBNA1 IgA; EBV; ELISA; TRFIA; nasopharyngeal carcinoma