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

Abstract

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. © 2007 Oxford University Press.