Performance of new enzyme-linked fluorescent assays for detection of Epstein-Barr virus specific antibodies in routine diagnostics.

Background And Aims: Indirect fluorescent antibody assays are still the gold standard for the detection of Epstein-Barr-virus-specific antibodies; however, this technique requires several manual steps and an experienced technician. This retrospective study investigated the performance of the new VIDAS(®) enzyme-linked fluorescent assays for automated qualitative detection of EBV VCA IgM, VCA/EA IgG, and EBNA IgG antibodies in routine diagnostics.

Methods: 174 serum samples were tested first with the gold standard. In context with the clinical status, 60 samples IFA IgG/IgM positive and with clinical symptoms compatible with infectious mononucleosis, 26 samples IFA IgG/IgM negative and missing any clinical symptoms and 88 samples with varying IFA status and without any clinical information were defined. In a second step all samples were retested with the new assays.

Results: In the overall agreement between VIDAS(®) and IFA for evaluable results, almost perfect agreement was observed (kappa = 0.91; 95% confidence interval (CI), 0.86-0.97). Estimating all indeterminate VIDAS(®) results as discordant or concordant the observed kappa values were 0.71 (CI 0.63-0.79) and 0.93 (CI 0.88-0.98), respectively. With the new assays 45, 22, and 70 identical results were obtained, respectively. Western blot analysis of the discrepant samples showed a quasi similar performance of both assays.

Conclusions: The new VIDAS(®) assays can be an alternative to IFA testing especially in high-throughput laboratories. Full automation of EBV serological diagnostis by the new VIDAS assays is of major importance for routine diagnostic laboratories.