DELAYED FUNCTION REDUCES RENAL-ALLOGRAFT SURVIVAL INDEPENDENT OF ACUTE REJECTION

Background. Mechanisms by which delayed allograft function reduces ren al allograft survival are poorly understood. This study evaluated the relationship of delayed allograft function to acute rejection and long term survival of cadaveric allografts. Methods. 338 recipients of cada veric allografts were followed until death, resumption of dialysis, re transplantation, loss to follow-up, or the study's end, whichever came first. Delayed allograft function was defined by dialysis during the first week following transplantation. Multivariate Cox proportional ha zards survival analysis was used to assess the relationship of delayed allograft function to rejection and allograft survival. Results. Dela yed allograft function, recipient age, preformed reactive antibody lev els, prior kidney transplantation, recipient race, rejection during th e first 30 days and rejection subsequent to 30 days following transpla ntation were predictive of allograft survival in multivariate survival models. Delayed allograft function was associated with shorter allogr aft survival after adjustment for acute rejection and other covariates (relative rate of failure [RR] = 1.72 [95% CI, 1.07, 2.76]). The adju sted RR of allograft failure associated with any rejection during the first 30 days was 1.99 (1.23, 3.21), and for rejection subsequent to t he first 30 days was 3.53 (2.08, 6.00). The impact of delayed allograf t function did not change substantially (RR = 1.84 [1.15, 2.95]) in mo dels not controlling for acute rejection. These results were stable am ong several subgroups df patients and using alternative definitions of allograft survival and delayed allograft function. Conclusions. This study demonstrates that delayed allograft function and acute allograft rejection have important independent and deleterious effects on cadav eric allograft survival. These results suggest that the effect of dela yed allograft function is mediated, in part, through mechanisms not in volving acute clinical rejection.