Comparison of early renal function parameters for the prediction of 5-year graft survival after kidney transplantation.

BACKGROUND: Early graft function (EGF) has an enduring effect on the subsequent course after kidney transplantation. This study compares quantitative parameters of EGF for the prediction of graft survival. METHODS: We involved 300 consecutive transplant recipients from deceased donors from 1989 to 2005. Urine output during 24 h post-transplant (UO), and serum creatinine after 1 week (Cr7) were taken for explanatory variables. We generated Kaplan-Meier (K-M) estimates of graft survival, by quintiles of the explanatory variable. Cox regression was applied to control for various recipient factors. RESULTS: K-M survival estimates indicate a threshold effect of UO and Cr7, which can dissect the risk of graft failure. The thresholds referring to the 2nd quintile correspond to a UO >630 ml and a Cr7 <2.5 mg/dl and were associated with a proportional hazard ratio of 0.52 (95% CI 0.33-0.84) and 0.34 (95% CI 0.18-0.65), respectively. Combining both of the parameters predicted a 5-year graft survival probability >90%, according to a hazard ratio of 0.21 (95% CI 0.09-0.46). Requirement of dialysis post-transplant lost its discriminatory power and was not a significant explanatory variable in the multivariate analysis. CONCLUSION: Routine parameters for monitoring of EGF display a threshold effect allowing accurate prediction of 5-year graft survival at the earliest point in time. The quantitative threshold levels for an optimum discriminatory power require validation in a larger, preferably multicentre database.