title: An ELISA method to compute endpoint titers to Epstein-Barr virus and cytomegalovirus: application to population-based studies.
abstract: Indirect fluorescence analysis (IFA), the gold standard for determining herpesvirus antibody titers, is labor-intensive and poorly suited for large population-based studies. The enzyme-linked immunosorbent assay (ELISA) is used widely for measuring antiviral antibodies but also suffers drawbacks such as reduced specificity and the qualitative nature of the results due to limited interpretation of the optical density (OD) units. This paper describes a method to titer herpesvirus antibodies using microplates coated with virally-infected cells in which a standard curve, derived from IFA-scored samples, allowed OD units to be converted into titers. A LOOKUP function was created in order to report the data as traditional IFA-based (i.e., 2-fold) titers. The modified ELISA correlated significantly with IFA and was subsequently used to compute endpoint antibody titers to Epstein-Barr virus (EBV)-virus capsid antigen (VCA) and cytomegalovirus (CMV) in blood samples taken from 398 pregnant Hispanic women. Four women were EBV negative (1%), while 58 women were CMV negative (14.6%). EBV VCA antibody titers were significantly higher than CMV antibody titers (p<0.001). This method allows titering of herpesvirus antibodies by ELISA suitable for large population-based studies. In addition, the LOOKUP table enables conversion from OD-derived titers into 2-fold titers for comparison of results with other studies.
authors.affiliation: Microgen Laboratories, La Marque, TX, United States. Electronic address: rpstowe@microgenlabs.com.
authors.forename: Raymond P
authors.initials: RP
authors.lastname: Stowe
authors.affiliation: Gayle Greve Hunt College of Nursing, Texas Tech University Health Sciences Center, El Paso, TX, United States.
authors.forename: R Jeanne
authors.initials: RJ
authors.lastname: Ruiz
authors.affiliation: Department of Health Disparities Research, The University of Texas MD Anderson Cancer Center, United States.
authors.forename: Christopher P
authors.initials: CP
authors.lastname: Fagundes
authors.affiliation: Microgen Laboratories, La Marque, TX, United States.
authors.forename: Robin H
authors.initials: RH
authors.lastname: Stowe
authors.affiliation: Department of Molecular Virology, Immunology, and Medical Genetics, The Ohio State University, Columbus, OH, United States; Institute for Behavioral Medicine Research, The Ohio State University, Columbus, OH, United States.
authors.forename: Min
authors.initials: M
authors.lastname: Chen
authors.affiliation: Department of Molecular Virology, Immunology, and Medical Genetics, The Ohio State University, Columbus, OH, United States; Institute for Behavioral Medicine Research, The Ohio State University, Columbus, OH, United States.
authors.forename: Ronald
authors.initials: R
authors.lastname: Glaser
mesh_terms: D000328:Adult; D000914:Antibodies, Viral / Q000097:blood*; D000956:Antigens, Viral / Q000276:immunology*; D015415:Biomarkers / Q000097:blood; D036022:Capsid Proteins / Q000276:immunology*; D016022:Case-Control Studies; D003587:Cytomegalovirus / Q000276:immunology*; D003586:Cytomegalovirus Infections / Q000097:blood / Q000175:diagnosis* / Q000453:epidemiology / Q000276:immunology; D004797:Enzyme-Linked Immunosorbent Assay / Q000592:standards; D020031:Epstein-Barr Virus Infections / Q000097:blood / Q000175:diagnosis* / Q000453:epidemiology / Q000276:immunology; D005260:Female; D004854:Herpesvirus 4, Human / Q000276:immunology*; D006630:Hispanic or Latino; D006801:Humans; D008297:Male; D011159:Population Surveillance; D011237:Predictive Value of Tests; D011247:Pregnancy; D015203:Reproducibility of Results; D019562:Viral Load; D055815:Young Adult
chemical_list: D000914:Antibodies, Viral; D000956:Antigens, Viral; D015415:Biomarkers; D036022:Capsid Proteins; C041788:Epstein-Barr viral capsid antigen
keywords: Antibody titer; CMV; EBV; ELISA; Herpesvirus; IFA