Background: Renal dysfunction measured by serum creatinine (>1.5 mg/dL) at 1 year post-transplant correlates with long-term kidney graft survival. The purpose of this study was to compare the risk factors for elevated serum creatinine (SCr) >1.5 mg/dL at 1 year post-transplantation, and for long-term graft failure.
Methods: Between 1988 and 1999, 117,501 adult kidney transplants were reported to Organ Procurement and Transplantation Network/United Network for Organ Sharing (OPTN/UNOS). Of these, 96,091 were functioning at 1 year and SCr was available on 85,135 transplants. Donor and recipient demographics (age, sex, and race), transplant [living vs. cadaveric, previous transplantation, panel reactive antibody (PRA), human leukoocyte antigen (HLA) mismatch, cold ischemic time (CIT) and post-transplant delayed graft function (DGF), use of azathioprone vs. mycophenolate mofetil (MMF), cyclosporine A (CsA) vs. tacrolimus (Tac)], induction antibody, acute rejection within 1 year variables were used in the logistic regression model to estimate odds ratio (OR) for elevated 1 year serum creatinine (SCr). A Cox proportional hazard model was used to estimate the relative risk (RR) for long-term kidney graft failure with and without censoring for death with a functioning graft.
Results: Five-year actuarial graft survival for living donor transplant with SCr >1.5 and </=1.5 mg/dL at 1 year post-transplant was 83% and 88.6% (P < 0.001). The corresponding values for cadaveric transplant grafts were 66.5% and 77.9% (P < 0.001). The overall prevalence of renal dysfunction at 1 year post-transplant (SCr >1.5 mg/dL) declined from 54.5% in 1988 to 42.3% in 1999. There was a strong concordance between the key variables, such as cadaveric transplant, increasing CIT, HLA mismatch, DGF, and acute rejection, recipient race (black), younger age, and nondiabetics status; and donor race (black) and older age for elevated SCr and long-term graft failure.
Conclusion: Donor (age), race (black), recipient race (black), immunologic variables (HLA mismatch, DGF, acute rejection) were identified as important risk factors for elevated SCr at 1 year post-transplantation and long-term graft failure. Elevated SCr should be used as a short-term marker for predicting long-term transplant survival.