Combination Of Changing Trends In Renal Function Within The First Year Post-transplantation And One-year Glomerular Filtration Rate Predicting Long-term Renal Allograft Survival

BackgroundLong-term survival for renal allograft mostly depends on maintaining stable allograft function after transplantation.One-year eGFR post-transplantation was reported as a predictor for long-term survival.However,few studies have examined the predictive value of changing trends in renal function within the first year post-transplantation.Our objective is to explore the predictive effectiveness on long allograft survival of their combination.MethodsWe retrospectively reviewed 1,062 recipients who underwent renal transplantations from cadaveric donors between January 1992 and June 2003 in our kidney disease center.The slopes of the changing eGFR between 3-month and 1-year after the operation were measured by least-squares-fitted.The cut-off values of 1-year eGFR (ml/min) and slopes(ml/min/month) were derived from Kaplan-Meier analysis of groups based on their means±SD.Subsequently,recipients were stratified into 4 groups:(a) 1-year eGFR＜45 ml/min & slope＜-2 ml/min/month,(b) 1-year eGFR＜45 ml/min & slope＞-2 ml/min/month,(c) 1-year eGFR＞45 ml/min & slope＜-2 ml/min/month,(d) 1-year eGFR＞45 ml/min & slope＞-2 ml/min/month.Allograft survival with or without censoring for death with a functioning graft was assessed by Kaplan-Meier analysis.Significance of related variables was assessed by Cox proportional hazard model.ResultsBoth slope of eGFR changes and 1-year eGFR were significantly associated with long-term survival in univariate analysis.Hazard ratios(HR) of graft loss was 2.645 when 1-year eGFR＜45 ml/min(1.623 - 4.310;P＜0.001) after adjusting for other related variables.The risk increased to 7.438(4.433 - 12.478;P＜0.001),when combined with slope＜-2 ml/min/month.Patients with 1-year eGFR＜45 ml/min & slope＞-2 ml/min/month have similar 5-,10-year rates to those with 1-year eGFR＞45 ml/min(P＞0.05).ConclusionsLong-term graft survival was significantly related to both 1-year eGFR and changing trends of eGFR within the first year post-transplantation.Combination of them has a more discriminatorily predictive value.