Intermediate early graft function is associated with increased incidence of graft loss and worse long-term graft function in kidney transplantation

Abstract

Introduction: Intermediate early graft function is associated with increased incidence of graft loss and worse long-term graft function in kidney transplantation.

Background: Delayed graft function (DGF) is associated with premature graft loss, increased rate of allograft function decline, and greater incidence of acute rejection episodes (ARE). Regarding early intermediate graft function (IGF), these prognostic observations have not been clearly made. Our objective was to investigate the impact of IGF as compared with excellent graft function (EGF) on these outcomes.

Methods: Retrospective analysis included all patients who underwent transplantation in a tertiary care center between 1989 and 2009. Definitions are as follows: DGF, need for dialysis in the first 7 days posttransplantation; EGF, serum creatinine (sCr) <3 mg/dL at 5 days posttransplantation; IGF, absence of dialysis need but with a sCr >3 mg/dL at 5 days posttransplantation. For univariate analysis we performed Student t test, Mann- Whitney test, or Chi-square test, as appropriate. For survival analysis we performed Kaplan-Meier method to determine survival curves and we used the log-rank test for comparison. Multivariate logistic regression analysis was used to determine independent predictors of IGF and of graft survival.

Results: Five hundred seventy patients were included: 69.0% had EGF, 22.6% had IGF, and 8.4% had DGF. Patients with IGF had worse graft survival at 5 and 10 years posttransplantation (75% vs 92% and 69% vs 85%, respectively; P < .001 for both comparisons) and higher incidence of ARE (41% vs 27%; P = .001), compared with EGF. In multivariate analysis, IGF was independently associated with an increased risk of graft loss compared with EGF (odds ratio [OR], 2.40; 95% confidence interval [CI], 1.32-4.35; P = .004]. Donor age (OR, 1.03 per year; 95% CI, 1.02-1.05; P < .001) was the strongest predictor of the occurrence of IGF. IGF was also associated with worse long-term graft function until 7 years posttransplantation (mean glomerular filtration rate [GFR] 48.3 ± 18.9 vs 57.4 ± 20.4 mL/min/1.73 m(2); P = .008).

Conclusions: IGF, as DGF, is associated with increased rates of graft loss and ARE, as well as worse long- term graft function. Donor age was the strongest risk factor for the occurrence of IGF. This is especially relevant regarding the increasing use of extended criteria donors.