The Rate of Decline of Glomerular Filtration Rate Is a Predictor of Long-term Graft Outcome After Kidney Transplantation

Abstract

Background. To improve the long-term outcome of kidney transplantation (KT), it is important to identify and take active steps to reduce the number or severity of novel risk factors. We investigated whether changes in estimated glomerular filtration rate over the first year after KT (Delta eGFR(12-3)) was associated with long-term renal allograft function and survival. Methods. Four hundred twenty-eight allogaft recipients transplanted between 1990 and 2001 underwent Delta eGFR(12-3) calculation using the equation: Delta eGFR(12-3) = ([eGFR at 12 months post-KT - eGFR at 3 months post-KT]/[eGFR at 3 months post-KT]) x 100%. Recipients were divided into 3 groups according to their Delta eGFR(12-3): group I (n = 150), Delta eGFR(12-3) >= 10%; group II (n = 151), 10 > Delta eGFR(12-3) >= -10%; and group III (n = 127), Delta eGFR(12-3) < -10%. Multiple linear regression analysis was used to adjust for confounding variables that may affect long-term renal allograft function, and Kaplan-Meier analysis, to compare allograft survival. Results. At a mean follow-up of 120 +/- 58 months, we observed 112 renal allograft losses. The Delta eGFR over 10 years post-KT (Delta eGFR(120-3)) was significantly associated with the serum uric acid levels at 3 months post-transplantation and Delta eGFR(12-3). Group III showed poor renal allograft survival; group I, 194 +/- 8 months; group II, 197 +/- 7 month and; group III, 163 +/- 4 months; (log-rank test, P < .05). A Cox proportional hazard model revealed Delta eGFR(12-3) to be independently associated with future renal allograft loss (hazard ratio, 0.981; 95% confidence interval, 0.974-0.992). Conclusion. Our results suggested that Delta eGFR(12-3) may be an independent predictor of kidney allograft survival. Routine application of eGFR is strongly recommended to identify patients at risk for chronic allograft dysfunction.