Objectives: To test diagnostic efficiency of a novel method for detection of IgM antibodies to VCA EBV. To compare sensitivity and specificity of detection of IgM antibodies to VCA EBV from patients at various stages of EBV infection by various serological methods.
Material and methods: IgM antibodies to VCA EBV were detected using IgM ELISA Viditest anti-VCA EBV IgM assay (Vidia, Ltd., Czech Republic) and comparative serological methods (indirect immunofluorescence assay, indirect ELISA (Human, SRN) and reverse ELISA (DiaSorin, Italy) in four independent diagnostic laboratories on panels of sera from 1) infectious mononucleosis patients, 2) patients with serological markers of EBV reactivation, 3) seropositive individuals lacking serological markers of active EBV infection, 4) seronegative individuals, 5) patients with IgM antibodies against another herpesvirus and 6) patients positive for rheumatoid factor. The sera yielding discrepant results were retested in the reference laboratory using the reference methods (indirect immunofluorescence and reverse ELISA). Overall, 854 IgM anti-VCA-positive or -negative sera were evaluated.
Results: The sensitivity and specificity of the IgM Viditest anti-VCA EBV assay were 94.7 and 96.1 %, respectively. All of the three tests compared were similarly reliable in detecting IgM anti -VCA EBV antibodies in the samples from infectious mononucleosis patients. On the other hand, indirect fluorescence assay proved clearly superior to ELISAs for detection of IgM anti-VCA antibodies in the samples with serological pattern of EBV reactivation, typically showing significantly lower IgM anti-VCA titers compared with those from primary infection.
Conclusions: The multilaboratory comparative study proved that the novel IgM ELISA-Viditest anti-VCA EBV assay (Vidia, Ltd., Czech Republic) which shows comparable diagnostic efficiency for detection of IgM EBV antibodies to viral capsid antigen (VCA) as compared to the other assays tested, i.e. ELISA (Human, Germany) and reverse ELISA (DiaSorin, Italy), is suitable for use in serological diagnosis of EBV.