Can KDPI score be a predictor of function and survival of kidneys from non-heart beating donors?

Abstract

Introduction: Circulatory death donors (CDD) are a growing source of kidney allografts amid current organ demand-supply imbalance. CDD grafts are subject to the added injury of warm ischemia time. The urge for as early as possible implantation precludes histological characterization of these grafts. Kidney Donor Profile Index (KDPI) is a well-established score for predicting the risk of graft failure in brain death donors. The aim of this study was to investigate the value of KDPI to predict graft function following kidney transplantation from CDD donors under extra-corporeal membrane oxygenation (ECMO). Methods: We retrospectively reviewed all cases of CDD kidney transplantation under ECMO performed at our institution between 1st January 2020 and 30th June 2022. The cases for which KDPI score could not be calculated due to missing data were excluded. Electronic health records and national transplantation registry were reviewed, and data was retrieved and analyzed. This study of approved by our institution's ethics committee. Data confidentiality was assured. Results: 36 DCC kidney transplants from donors under ECMO were performed during the timeframe of the study. Eleven were excluded due to lack of information precluding KDPI calculation. Median (IQR) donor age was 46 (20) years. Median (IQR) recipient age at transplant was 52 (20) and women represented 40% of allograft recipients. Mean (IQR) KDPI was 45 (42,5). Three (12%) allografts displayed immediate function (IF), 17 (68%) had delayed graft function (DGF) and 5 (20%) showed primary non-function (PNF). No differences could be found between KPDPI groups (<35; 35-85; >85) regarding allograft function or survival. Allograft KDPI was significantly higher in the group with PNF when compared with those with DGF (median 66 vs. 35, p=0,015). The IF group had an unexpectedly high median KDPI (93), probably due to the low number of patients in this group, therefore conclusions are limited. KDPI did not correlate with estimated glomerular filtration rate (EGFR) at 6 months (r=-0,439, p=0,056). Conclusions: In this pilot study, KDPI was significantly higher in the group of patients with primary non function. KDPI may be a valuable tool in the evaluation and allocation of kidney allografts from DCC donors under ECMO. Nevertheless, studies with a larger sample size are needed to establish its role.