Antigen test for early diagnosis of active cytomegalo-virus infection in heart-transplant recipients

An assay was developed for the detection of cytomegalovirus (CMV) antigens in blood leukocytes and evaluated for its diagnostic significance in six heart transplant recipients. Slides of cytocentrifuged blood leukocytes were prepared at regular intervals during the posttransplantation period and stained with CMV-specific monoclonal antibodies, a procedure that took 3 hours. CMV-antigen-positive leukocytes were detected in all five patients with active CMV infection but not in the patient without CMV infection. These CMV-antigen-positive cells were transiently present and first detected 10 to 28 days before there was a significant increase in serum antibody levels. It is concluded that detection of CMV antigens in blood cells is a useful assay for the early diagnosis of active CMV infection in heart transplant recipients.