LONGITUDINAL MONITORING OF LATENT AND ACTIVE HUMAN CYTOMEGALOVIRUS INFECTIONS IN PERIPHERAL-BLOOD OF HEART-TRANSPLANT RECIPIENTS BY SINGLE-TUBE NESTED RT-PCR

PCR is a sensitive diagnostic tool for the detection of human cytomega lovirus (HCMV) DNA in the peripheral blood of immunosuppressed transpl ant recipients. However, its specificity as a prognostic marker for cl inical disease is unclassified, because infections considered to be la tent may be detected by this method. In order to diagnose active viral infections, we used reverse transcription-PCR (RT-PCR) to identify HC MV mRNA in blood. We developed a single-tube nested RT-PCR with prefor med PCR mixes embedded in a trehalose matrix. Blood samples of 48 hear t transplant recipients were investigated for HCMV DNA. 8 patients det ected to be HCMV DNA positive after transplantation were investigated in longitudinal monitoring for at least 6 months. HCMV mRNA was found in 5 patients who developed HCMV related symptoms during the period of RNA detection. There was no clear relation between the onset of DNA d etection and the first demonstration of mRNA. In 2 patients HCMV DNA c ould be detected 74 and 81 days before the appearance of mRNA, suggest ing long persistence until active infection is started. In 3 patients HCMV mRNA disappeared during or immediately after the end of ganciclov ir therapy. In contrast, HCMV DNA was detectable continuously for prol onged periods after therapy, indicating that the persistance of HCMV D NA is not influenced by ganciclovir treatment. In summary, HCMV mRNA d etection seems to be a reliable early marker for the differentiation o f persistent and active HCMV infections in immunosuppressed patients. Our data show that viral mRNA detection is probably a better predictor of the effectiveness of antiviral therapy than viral DNA detection.