Background: The impact of cytomegalovirus (CMV) infection and disease on long-term outcome after kidney transplantation is still unsettled.
Methods: Between 1994 and 1997, 397 consecutive first kidney graft recipients and 74 retransplants were included in the study and followed prospectively until December 31, 2001. CMV infection (CMV pp65 antigenemia) and CMV disease were recorded once weekly during the first 100 days after transplantation. No CMV prophylaxis or preemptive therapy was given. In a multiple Cox proportional hazard model allowing time-dependent covariates, the effects of asymptomatic CMV infection and CMV disease, recipient age and gender, retransplantation, living donor, panel-reactive cytotoxid antibodies, acute rejection, and graft loss were tested on overall mortality beyond 100 days post-transplantation. In a similar analysis, the effect of asymptomatic CMV infection and CMV disease plus other factors were tested on death censored graft loss beyond 100 days.
Results: Median (range) follow up time was 66.6 (<1-86.9) months. The incidence of CMV infection and disease during the first 100 days was 62.8% and 23.4%, respectively. The number of total deaths was 96 (20%), 82 occurred after the first 100 days. Independent risk factors for overall mortality beyond 100 days were asymptomatic CMV infection, RR = 2.90 (95% CI 1.61-5.22) (P= 0.001), CMV disease, RR = 2.50 (95% CI 1.31-4.79) (P= 0.006), both compared to no infection or disease, recipient age, RR = 1.066 per year (95% CI 1.048-1.084) (P < 0.001), and graft loss in the whole study period RR = 7.88 (95% CI 4.75-13.08) (P < 0.001). Asymptomatic CMV infection and CMV disease were not independent risk factors for death censored graft loss, but they significantly reduced graft survival uncensored for death, (log rank P= 0.001, respectively).
Conclusion: Asymptomatic CMV infection and overt CMV disease during the first 100 days increase the risk of recipient mortality beyond 100 days. This raises the question whether CMV prophylaxis should be given routinely after kidney transplantation.