QUANTITATIVE POLYMERASE-CHAIN-REACTION TO PREDICT OCCURRENCE OF SYMPTOMATIC CYTOMEGALOVIRUS-INFECTION AND ASSESS RESPONSE TO GANCICLOVIR THERAPY IN RENAL-TRANSPLANT RECIPIENTS

Cytomegalovirus (CMV) DNA levels were measured by quantitative-competi tive polymerase chain reaction (PCR) in weekly leukocyte samples from 50 renal transplant recipients, including 23 with symptomatic;ind 27 w ith asymptomatic CMV infection. Peak and week 4 CMV DNA levels were hi gher in symptomatic subjects (P =.07 and,02, respectively). In a logis tic regression model, the logarithm of the week 4 level independently predicted symptomatic infection (odds ratio, 1.78 for a 1 log(10) incr ease; 95% confidence interval, 1.14-2.78; P =.01). All subjects whose week 4 level exceeded 1000 copies/100,000 leukocytes developed symptom s. In subjects with adequate samples for analysis, CMV levels declined exponentially with ganciclovir treatment, with an average half-life o f 3.3 days. Levels exceeding 10,000 copies were associated with prolon ged time to clearing of CMV DNA. Potential clinical applications of qu antitative CMV PCR include predicting occurrence of symptomatic first episodes after transplantation and individualizing duration of antivir al therapy.