Association of cytomegalovirus disease and acute rejection with graft loss in kidney transplantation

Background. Cytomegalovirus (CMV) and acute rejection (AR) alone have been associated with an increased risk of graft loss in kidney transplantation. However, little is known about their association with graft loss when both affect the transplant recipient. Methods. By using the dynamic time-varying covariate approach to the Cox-proportional hazards model, we retrospectively analyzed the strength of association of AR and CMV disease on graft loss in a single-center kidney and simultaneous pancreas-kidney transplant population. Results. Between January 1990 and December 2000, 2,740 kidney and simultaneous pancreas-kidney transplants were performed at the authors' center. The overall 5-year incidence of biopsy-proven AR and CMV disease was 45.8% (n = 1,254) and 15.3% (n = 420), respectively. The risk ratio (RR) for graft loss was increased by the presence of AR (RR = 3.7; P < 0.0001), CMV disease (RR = 1.9; P = 0.0007), AR following CMV disease (RR = 6.6; P < 0.0001), and CMV disease following AR (RR = 3.3; P < 0.0001). In patients with AR and CMV disease the average time until AR occurred was longer (441 days) when AR followed CMV disease in comparison with when AR preceded CMV disease (47 days). After adjusting for time-dependent risk of AR for kidney graft loss, the order of AR and CMV disease had no association with graft loss (RR = 1.2; P = 0.5055). Conclusions. These results demonstrate the strength of AR and CMV disease as prognosticators of impeding kidney graft loss in transplant recipients. Although AR usually precedes CMV disease, the order of AR and CMV disease has no impact on kidney graft loss in kidney and simultaneous pancreas-kidney transplant recipients.