The widening gap between supply and demand in kidney transplantation has lead to the increased use of kidneys from marginal donors, including those with acute kidney injury (AKI). Despite the organ shortage, donor kidneys with AKI are often declined or discarded. To determine if this policy is justified we have analysed outcomes of AKI in a large UK cohort.Methods
In a retrospective analysis of the UK transplant registry, adult deceased donors between 2003-2008 were evaluated. Donors were classified as no AKI, or AKI stage 1, 2 or 3 according to the AKIN criteria defined by change in creatinine between admission and donation. Relationship of AKI with DGF/PNF, eGFR and graft survival (GS) at 90d and 1y using risk adjusted Cox regression analysis.Results
11,244 kidneys were included in the analysis. 35% of AKI kidneys were not accepted or transplanted. There is evidence that the chance of graft failure (GF) at 1y is greater for donors with AKI than for those without (GS 89% v 91%, p=0.02; OR 1.20 (95% CI: 1.03-1.41)). The odds of DGF and PNF increase with donor AKI stage (p<0.005, p=0.04 resp). Analysis of association between donor AKI and recipient eGFR suggests risk of inferior eGFR with increasing AKI stage versus no AKI (p<0.005; OR 1.25 (95% CI: 1.08-1.31)).Discussion
This study shows that a significant number of donor kidneys with AKI are discarded. We report a small but significant reduction of 2% in 1y GS of kidneys from donors with AKI. The 20% increased risk of graft failure due to AKI in the donor is similar to the 17% increased risk of graft failure associated with dialysis vintage of 6 months when compared to pre-emptive transplantation, and is significantly lower than the 37% and 55% increased risk of graft failure when dialysing for longer than 1 or 2 years prior to kidney transplantation (Meier-Kriesche, 2005). In this analysis, over 1500 recipients received a donor kidney with AKI and still had a functioning graft at 1y. We conclude that donor kidneys with AKI stage 1 or 2 should not be discarded as they give comparable outcomes; due to its small sample size we cannot but advise to be cautious for AKI stage 3 donors.