Detection of cytomegalovirus infections by PCR in renal transplant patients

Cytomegalovirus (CMV) is the single most important infectious agent affecti ng recipients of organ transplants. To evaluate the incidence and the clini cal importance of CMV infection in renal transplants in Brazil, 37 patients submitted to renal allograft transplants were tested periodically for the presence of cytomegalovirus DNA in urine using the polymerase chain reactio n (PCR), and for the presence of IgM and IgG antibodies against CMV by enzy me-linked immunosorbent assay (ELISA) and indirect immunofluorescence (IFI) . The PCR-amplified products were detected by gel electrophoresis and confi rmed by dot-blot hybridization with oligonucleotide probes. Thirty-two of t he 37 patients (86.4%) were positive by at least one of the three methods. In six patients, PCR was the only test which detected the probable CMV infe ction. Ten patients had a positive result by PCR before transplantation. In general, the diagnosis was achieved earlier by PCR than by serologic tests . Active infection occurred more frequently during the first four months af ter transplantation. Sixteen of the 32 patients (50%) with active CMV infec tion presented clinical symptoms consistent with CMV infection. Five patien ts without evidence of active CMV infection by the three tests had only min or clinical manifestations during follow-up. Our results indicate that PCR is a highly sensitive procedure for the early detection of CMV infection an d that CMV infection in renal transplant patients is a frequent problem in Brazil.