A prospective study of the natural course of cytomegalovirus infection anddisease in renal allograft recipients

Background Cytomegalovirus (CMV) infection is the single most frequent infe ctious complication in renal transplant recipients. Because no CMV-prophyla xis is given and ganciclovir is used only as deferred therapy for CMV disea se at our center, we have been able to study the natural course of CMV infe ctions. The aim was to assess risk factors for CMV infection and disease an d thus identify subgroups of patients likely to benefit from CMV prophylaxi s or preemptive therapy. Methods. Between October 1994 and July 1997, 477 consecutive renal transpla nt recipients (397 first transplants and 80 retransplants) were included in the study. The patients were followed prospectively for 3 months with seri al measurements of CMV pp65 antigen for monitoring activity of CMV infectio ns. Results. The incidence of CMV infections in first transplants was 68% in DR- and D+/-R+/- serostatus groups, whereas the incidence of CMV disease was higher in D+R- (56%) than in D+/-R+ (20%, P<0.001). No difference in sever ity of CMV disease in D+R- and D+/-R+ was seen except for an increased inci dence of hepatitis in primary infections. One of 14 deaths could be associa ted with CMV disease in a seropositive recipient. Cox regression analysis s howed that rejection (RR 2.5, P<0.01) and serostatus group D+R- (RR 3.9, P< 0.001) were significant risk factors for development of CMV disease. The ma ximum CMV pp65 antigen count had significant correlation to disease only in CMV seropositive recipients, P<0.001. Conclusion. Renal transplant recipients can safely be given deferred gancic lovir therapy for CMV disease if they are intensively monitored for CMV inf ection. Patients with primary CMV infection (D+R-), CMV infected patients u ndergoing anti-rejection therapy and R+ patients with high CMV pp65 counts seem to have a particular potential for benefit from preemptive anti-CMV-th erapy.