MONITORING LEVELS OF HUMAN CYTOMEGALOVIRUS DNA IN BLOOD AFTER LIVER-TRANSPLANTATION

We evaluated a semiquantitative PCR assay prospectively in 40 liver tr ansplant recipients as an aid in making a prompt diagnosis of cytomega lovirus (CMV) infection, For 2 months after transplantation, clinical specimens from patients were tested weekly by PCR, virus isolation fro m peripheral blood and urine, and CMV serology, The incidence of activ e CMV infection was 70%, The levels of CMV DNA determined by hybridiza tion of PCR samples and densitometric scanning of blots were assigned a score of 1 to 4 by comparison with four external standards amplified in parallel and corresponding to a range of 80 to 80,000 genomes. The first detection of CMV in blood by PCR occurred at a mean of 15 days, and high-level PCR scores of 3 or 4 were obtained 21 days after trans plantation, whereas viremia occurred 33 days after transplantation. Si gnificantly higher levels of CMV DNA were seen in patients with CMV di sease (P < 0.05) than in asymptomatic patients, The prevalence of symp tomatic CMV infection was 30%, The positive predictive value of PCR wa s 48%, while the negative predictive value was 100%, After treatment, the clearance of CMV DNA was always observed and the disappearance of symptoms occurred concomitantly with undetectable PCR signals.