Antibody reactivity to human and vervet cytomegalovirus early antigen(s) in sera from patients with active cytomegalovirus infections and from asymptomatic donors.

Human fibroblasts were infected with vervet cytomegalovirus (VCMV) and cultured in medium containing 50 micrograms of cytosine arabinoside per ml for 72 h. Early antigens (EAg) were detected in the nuclei of infected cells by an indirect fluorescent antibody test with human sera having antibody to EAg of human cytomegalovirus (HCMV). Sera from patients with serological and/or virological evidence of active HCMV infection and from asymptomatic blood donors were examined for antibody activity with the HCMV and VCMV EAg's. The HCMV and VCMV EAg's were comparable in detecting levels of antibody activity and fluctuations in antibody titer of paired sera from patients. A total of 81% of patient sera reactive with HCMV EAg were also reactive with VCMV EAg. In contrast, only 14% of the asymptomatic donor sera reactive with HCMV EAg were also reactive with VCMV EAg. The VCMV EAg, therefore, appeared to differentiate latent from active infections in humans more effectively than did HCMV EAg.