Detection of human cytomegalovirus IgG antibody using automated immunoassay with recombinant antigens gives uniform results to established assays using whole virus antigens

Aim: Serological testing for human cytomegalovirus (CMV) immunoglobulin G (IgG) continues to play a major role in the evaluation of tissue and organ transplant donors and recipients, screening blood donors and in estimating the risk of infection in pregnant women. In this study we evaluated the performance and technical characteristics of two semi-automated commercial CMV IgG immunoassays. Methods: One hundred consecutive sera submitted to a referral serology laboratory for CMV IgG antibody testing were assayed using two automated CMV IgG immunoassays: the Architect (Abbott Diagnostics) and Elecsys (Roche Diagnostics) immunoassays. Because this patient population has a high rate (∼87) of seropostivity, we took a further 50 sera that were CMV IgG negative on Architect and tested on the Elecsys assay, in order to assess the specificity of the assays. Results: The assays showed an excellent qualitative agreement with two (2) discrepant results in the 100 patients tested initially, with all of the 50 additional sera negative on Architect also negative on the Elecsys. However, there was no correlation between the optical density of results generated by the instruments for the set of samples. Conclusion: Both Elecsys and Architect immunoassays are convenient for detection of CMV IgG antibody, with near identical qualitative results.