The impact of cytomegalovirus infection and disease on rejection episodes in renal allograft recipients

Cytomegalovirus (CMV) infection and disease are potential risk factors for acute allograft rejection in renal transplant recipients. The present study specifically addresses this issue. From October 1994 to July 1997, 477 consecutive renal allograft recipients (397 first transplants and 80 retransplants) were included in the study. CMV infection (cytomegalovirus pp65 antigen in leukocytes) and disease (infection and clinical symptoms or signs of disease) were examined prospectively for 3 months. No CMV prophylaxis was given, and CMV disease was treated with intravenous (i.v.) ganciclovir. The retransplantation of four patients transplanted twice during the study and 22 patients receiving kidneys from human leucocyte antigen (HLA)-identical siblings were excluded from statistical analysis. Rejections were evaluated clinically [277(61%)] and 173 (38%) also had a biopsy verified rejection. CMV infection occurred in 64% of the patients and 24% experienced CMV disease. In a multiple time-dependent Cox analysis, CMV infection and CMV disease were independent significant predictors for clinical acute rejections, RR = 1.6 (1.1-2.5, p = 0.02) and RR = 2.5 (1.2-5.1, p = 0.01), respectively. Among 173 patients with biopsy verified rejection, 72% of the patients had tubulointerstitial rejection whereas 28% had a vascular rejection. CMV disease, but not CMV infection was a predictor of tubulointerstitial rejection, RR = 3.1 (1.1-9.3, p = 0.04). CMV infection and disease are independent risk factors for clinical acute rejection in kidney allograft recipients. CMV disease is an independent risk factor for biopsy verified acute tubulointerstitial rejection in kidney allograft recipients.