Donor/recipient age index (DoRAIn) as an independent predictor of long-term living-donor renal graft function

Problem: The effect of donor/recipient age disparity on living-donor renal graft function is controversial. The objective of this study is to find new clinical predictors of renal graft function and evaluate the effect of donor/recipient age disparity in our series. Methods: A retrospective review of our institutional renal transplantation database was performed. We calculated the glomerular filtration rate of our patients with the Chronic Kidney Disease Epidemiology Collaboration formula. Our receptors were categorized using a cut-off of 60 ml/min calculated glomerular filtration rate. An index called "Donor/Recipient Age Index" was created based on the interaction between donor/recipient ages. Univariable and multivariable regression analysis were performed. The Mantel-Cox model was used for statistical analysis. Results: A total of 220 donor/recipient pairs were selected from January 2005 to August 2013. Only 186 pairs completed the one-year follow-up. The mean age of the donors was 35.3 +/- 10.4 years and 31.6 +/- 11.7 years for the recipients. The Donor/Recipient Age Index significantly predicted a glomerular filtration rate < 60 ml/min at one-year follow-up in univariable (p = 0.02) and multivariable (p = 0.033) regression models. Conclusion: We propose the Donor/Recipient Age Index as a significant predictor of long-term graft function.