Enzyme-linked immunoadsorbent assay for the detection of cytomegalovirus-IgM: comparison between eight commercial kits, immunofluorescence, and immunoblotting.

Eight commercially available enzyme-linked immunoadsorbent assays (ELISA) for the detection of cytomegalovirus (CMV)-specific IgM were used in parallel to determine the presence of CMV-IgM in 123 serum samples from pregnant women. The results obtained with the eight kits were compared. Based on concordance of six or more of the eight kits, we assessed sensitivity, specificity, and overall agreement, as well as incidence of false-positive and -negative results for each kit. The results obtained by ELISA were then compared with those obtained by immunofluorescence (IF) and immunoblotting (IB). Our study did not single out one outstanding ELISA kit among the eight evaluated, nor did it suggest that IF or IB are better than ELISA. Furthermore our results indicate that IB might be useful in several cases as, beside its good sensitivity, most IB-false-positive sera are easily recognized as reacting exclusively with pp150, the unique reactivity to pp150 not being among the IB profiles of IB-true-positive sera. Nevertheless 14.6% of sera remained CMV-IgM-indeterminate.