Abstract
Background and Aims
Acute kidney injury (AKI) during organ procurement represents an important cause of discarded kidneys. In the context of organ shortage, the evaluation of such grafts is needed in order to enlarge the donor pool. Although many studies showed an increased risk of delayed graft function when donors present with AKI, long-term impact on graft survival remains controversial. A recent large US registry study concluded that AKI during organ procurement had no deleterious effect on graft survival. However the definition of AKI in this latter study is questionable. Indeed the donor baseline serum creatinine (SCr), according to KDIGO recommendations, is often not available. In this situation, the KDIGO guidelines suggest to estimate the baseline SCr using the MDRD equation, assuming a baseline glomerular filtration rate at 75 mL/min/1.73m?
This method was applied in the present study to assess the impact of donor kidney failure on long term kidney allograft survival.
Method
We analyzed the French national allocation system CRISTAL (Agence de la Biomédecine) data of all the recipients who received a deceased donor kidney graft from 2006 to 2017. 26786 transplant patients from 14899 deceased kidney donors were included. The donors were categorized into four groups. Ongoing AKI at the time of kidney procurement: n=1880 (3373 transplantations, AKI group), AKI with total recovery (normal SCr) at the time of kidney procurement: n=1332 donors (2392 transplantations, recovery group), elevated SCr all along the procedure: n=952 donors (1745 transplantations, unclassified AKI/CKD group) and normal SCr all along the procedure: n=10735 donors (19276 transplantations, no-AKI group). The main outcome was death censored graft survival.
Results
4458 graft losses occurred during the study period (648 in the AKI group, 411 in the recovery group, 297 in the unclassified AKI/CKD group and 3102 in the no-AKI group) after a median follow-up time of 5.7 years (3 - 8.9). Multivariate analysis showed a significant increase risk of graft loss for each group when compared to the no-AKI group: HR 1.18 (1.04-1.34), HR 1.15 (1.04-1.28) and HR 1.22 (1.12-1.34) for the unclassified AKI/CKD, recovery and AKI groups, respectively. Regarding the AKI group, the risk of graft loss increased according to the AKI stage (KDIGO 2012): HR 1.20 (1.08-1.32) for stage I AKI and HR 1.31 (1.13-1.53) for stage II-III AKI.
Conclusion
Donor AKI represents a significant risk factor of graft loss, independently of SCr at the time of procurement. Stage II-III AKI carries a higher risk than stage I AKI suggesting a “dose-effect”. However, considering organ shortage, further studies are required to better allocate these sub-optimal kidneys.
Uncovering a Long-term Graft Survival Advantage Afforded by Infant Renal Transplants—An Organ Procurement and Transplantation Network Database Analysis
