Prediction of Three-Year Outcome of Renal Transplantation from Optimal Donors versus Expanded Criteria Donors.

Background/Aims: The shortage in organ supply has required the use of expanded criteria donors (ECD) for kidney transplantation. Current pre-transplant evaluations of ECD organs are based on histological, clinical or mixed criteria. This monocentric study investigates the predictivity of Karpinski's histological score on 3-year graft function in renal transplant. Ex-post classification using Nyberg's score was carried out to assess the reliability of a purely clinical score and its applicability for organ allocation. Methods: We evaluated 407 deceased donors (251 optimal and 156 ECD) for renal transplants performed between 2001 and 2006. The differences in creatinine levels and MDRD-GFR at transplant and 1, 2 and 3 years post-transplant between optimal donors and ECD were recorded. Amongst ECD organs, the effect of different Karpinski score classes (0-1, 2, 3, 4, double transplants) on 3-year graft outcomes was analyzed. We then compared renal function over time across the Nyberg grades (A, B, C, and D). Results: Karpinski scores 0-1 and 2 and double transplants were associated with improved graft function compared to scores 3 and 4. Nyberg's clinical score shows a good fit with medium-term outcome and Karpinski's score, but among the donors with a high Nyberg grade (C and D), it fails to differentiate between allocable or non-allocable organs (due to Karpinski's score ≥7). Conclusions: Our data demonstrate a correlation of histological damage at the time of transplant with 3-year graft function, but at present we are unable to provide any supposition on the possible outcome of the discarded kidneys.