Comparison of polymerase chain reaction and pp65 antigen test for early detection of human cytomegalovirus in blood leukocytes of cardiac transplant recipients

ObjectiveTo establish whether polymerase chain reaction (PCR) for cytomegalovirus deoxyribonucleic acid (DNA) can provide clinical information for the management of the infection.MethodsLeukocytes in 30 heart transplant recipients were monitored by pp65 antigen testing and PCR for 82 to 365 days after transplantation.ResultsOf the 30 patients, 26 developed cytomegalovirus infection, nine of whom were symptomatic. Altogether, 300 leukocyte samples were examined. The concordance between PCR and pp65 antigen test was 82.6%. In symptomatic patients after surgery, PCR detected cytomegalovirus infection after 38 ± 16 days and the pp65 antigen test, after 48 ± 15 days. Symptomatic infection correlated with a higher number of pp65-positive leukocytes than did asymptomatic infection: 310 ± 356 vs 24 ± 35 (p < 0.005)/200,000 examined, respectively. Clearance of virus was observed by PCR after 125 ± 73 days (range 29 to 225) in symptomatic, and after 82 ± 70 days (range 16 to 301) in asymptomatic, cases of infection.ConclusionsThe positive predictive value of PCR for symptomatic infection was 34.6%. Our findings correlate with previous reports and show that the qualitative detection of cytomegalovirus DNA is not associated with overt disease whereas quantitation of pp65-positive leukocytes closely correlate with symptom onset. Insofar as the results are not quantitative, PCR is not a marker of clinically apparent infection. Careful monitoring of cytomegalovirus infection based on quantitative pp65 antigen assay can fulfill all clinical needs for early diagnosis and proper management of the infectio