Human cytomegalovirus infection: diagnostic potential of recombinant antigens for cytomegalovirus antibody detection.

Recombinant antigen-based enzyme immunoassays (EIAs) for the detection of human cytomegalovirus (HCMV) specific antibody are believed to yield a higher sensitivity and specificity than virus lysate EIAs. The aim of the present study was to evaluate the accuracy of newly established HCMV assays (Copalis CMV Multiplex, Sorin; Cobas Core CMV IgG and IgM EIAs, Roche Diagnostics; Anti-HCMV recombinant IgG, gB-IgG, IgM and IgA, Biotest; and ETI-CYTOK-G PLUS and M reverse PLUS, Sorin) based on recombinant antigens and/or virus lysate for laboratory diagnosis of HCMV infection. For the assessment of sensitivity, follow-up samples from patients suffering from active HCMV infection were tested. Testing a large number of potentially interfering samples challenged the specificity of the assays. There was no statistically significant difference in the performance of HCMV IgG assays. The results were more heterogeneous for the detection of serological markers of active infection (HCMV IgM, HCMV IgA and anti-CM2). The sensitivities of the different assays ranged between 40.5 and 71.4%. A variable number (17.8-1.7%) of false-positive results were obtained among potentially interfering serum samples. Two of the recombinant antigen based assays showed a high degree of interference with EBV VCA-IgM-positive sera. The best performance was achieved with ETI-CYTOK-M reverse PLUS since it combined the highest sensitivity with specificity. Commercially available assays based on recombinant antigens showed, overall, a poorer performance than the virus lysate EIA.