Latex agglutination and enzyme-linked immunosorbent assays for cytomegalovirus serologic screening of transplant donors and recipients.

The effectiveness of three serologic assays (two enzyme-linked immunosorbent assays [ELISAs] and latex agglutination) for cytomegalovirus (CMV) serologic matching of donors and recipients was assessed over a 2-year period in a major organ transplant program. Sera with equivocal test results were investigated by repeat testing of serum samples and additional specimens from the individuals involved and monitoring of CMV infection in recipients. An in-house ELISA identified all CMV-infective donors as seropositive. Of 63 ELISA-positive donors, 5 were negative by latex agglutination; recipients from 3 of these donors developed primary CMV infection posttransplant. The in-house ELISA and a commercial ELISA (Abbott enzyme immunoassay; Abbott Laboratories, North Chicago, Ill.) had a 93% concordance of results; follow-up testing indicated that the Abbott assay was sensitive but had a false-positive rate of about 11%. One recipient with a false-positive result developed symptomatic primary CMV infection after receiving a seropositive organ. Thus, performance characteristics of currently used screening assays affect recipient outcome.