title: Calibration and Evaluation of Quantitative Antibody Titers for Measles Virus by Using the BioPlex 2200.
abstract: The BioPlex 2200 (Bio-Rad Laboratories, Hercules, CA) is a rapid, automated platform, which can screen large numbers of specimens for antibodies to measles, mumps, rubella, and varicella. Although approved for producing qualitative results, in this study we validated the test (off-label) to allow reporting of quantitative results. To do this, we used the third anti-measles World Health Organization standard to generate a calibration curve that allowed relative fluorescence intensity to be translated into quantitative antibody titer (antibody units [AU]/ml). The results from the BioPlex 2200 and the reference plaque reduction neutralization test (PRNT) exhibited a reasonable correlation following an exponential function, but correlation was poor in low-titer samples. Using a receiver operating characteristics analysis, an equivocal zone for the BioPlex 2200 was established between ≥0.13 and <1.10 AU/ml to achieve 100% specificity (95% confidence interval [CI] = 83.2 to 100%) and 100% sensitivity (95% CI = 93.5 to 100%) versus PRNT. By determining an equivocal range requiring confirmation by PRNT, we can avoid underestimating the levels of immunity through false-negative results and optimize methods for seroepidemiological studies.
authors.affiliation: Department of Pathology and Laboratory Medicine, Nova Scotia Health Authority, Halifax, Nova Scotia, Canada todd.hatchette@cdha.nshealth.ca.|Canadian Center for Vaccinology, IWK Health Centre and Dalhousie University, Halifax, Nova Scotia, Canada.
authors.forename: Todd F
authors.initials: TF
authors.lastname: Hatchette
authors.affiliation: Bio-Rad Laboratories, Benicia, California, USA.
authors.forename: Heidi
authors.initials: H
authors.lastname: Scholz
authors.affiliation: Public Health Ontario, Toronto, Ontario, Canada.|Dalla Lana School of Public Health, University of Toronto, Toronto, Ontario, Canada.
authors.forename: Shelly
authors.initials: S
authors.lastname: Bolotin
authors.affiliation: Public Health Ontario, Toronto, Ontario, Canada.|Dalla Lana School of Public Health, University of Toronto, Toronto, Ontario, Canada.|Department of Laboratory Medicine, University of Toronto, Toronto, Ontario, Canada.
authors.forename: Natasha S
authors.initials: NS
authors.lastname: Crowcroft
authors.affiliation: Department of Pathology and Laboratory Medicine, Nova Scotia Health Authority, Halifax, Nova Scotia, Canada.
authors.forename: Colleen
authors.initials: C
authors.lastname: Jackson
authors.affiliation: National Microbiology Laboratory, Public Health Agency of Canada, Winnipeg, Manitoba, Canada.
authors.forename: Elizabeth
authors.initials: E
authors.lastname: McLachlan
authors.affiliation: National Microbiology Laboratory, Public Health Agency of Canada, Winnipeg, Manitoba, Canada.|Department of Medical Microbiology, University of Manitoba, Winnipeg, Manitoba, Canada.
authors.forename: Alberto
authors.initials: A
authors.lastname: Severini
mesh_terms: D000914:Antibodies, Viral / Q000097:blood*; D057205:Automation, Laboratory; D002138:Calibration; D006801:Humans; D007118:Immunoassay / Q000379:methods* / Q000592:standards*; D008459:Measles virus / Q000276:immunology*; D012680:Sensitivity and Specificity
chemical_list: D000914:Antibodies, Viral
keywords: BioPlex; antibody titers; immunity; immunobead; measles; neutralizing antibody; quantitative; seroepidemiology