P1629THE COMBINATION OF KDRI AND THE HISTOLOGICAL SCORE IMPROVES THE RISK STRATIFICATION OF MARGINAL ORGANS IN KIDNEY TRANSPLANTATION

Abstract

Abstract Background and Aims The organ shortage has led to increase the procurement of kidneys from marginal donors, but the risk of graft failure is still object of debate. The aim of the study is to assess whether using both clinical and histological scores can better assess the risk for worse outcome for marginal organs. Method We analyzed 210 kidney transplant recipients from donors aged >50 years. We retrospectively calculated the Kidney Donor Risk Index (KDRI) for each donor and we divided the population according to the KDRI (-, if KDRI ≤ median; +, if KDRI > median) and the histological score (HS, -, if HS ≤ 3; +, if HS > 3) in 4 groups: KDRI-HS- (low KDRI and HS), KDRI-HS+ (low KDRI and high HS), KDRI+HS-(high KDRI and low HS) and KDRI+HS+ (high KDRI and HS). We compared graft function between groups at 2 years and Cox regression analysis was performed to assess the risk for end stage renal disease (ESRD) between groups. Results Overall, median KDRI was 1.44 (1.25-1.65), while mean total HS was 3.04±1.62. Median follow-up was 51.9 (26.4 – 99.4) months. Graft function at 2 years was significantly worse in groups with high KDRI (KDRI+HS- and KDRI+HS+) compared to those with low KDRI (p<0.001), while no differences were found according to the HS. By contrast, the best ROC curve in predicting the development of ESRD is for the model that included both KDRI and histological score (AUC 0.81, 95%CI 0.708-0.914, p<0.001). A Cox model adjusted for recipient age, gender, acute rejection, DGF and chronic allograft dysfunction, patients with high KDRI and high HS are more likely to develop ESRD compared to the other groups (OR 5.6, 95%CI 1.3 to 24.5, p=0.02)(Figure 1). Conclusion Patients with high KDRI and HS have worse outcome compared to patients with high KDRI but better histology. The integration of histology to clinical score may improve the assessment of the risk for graft failure in patients receiving organs from marginal donors.