Prognostic impact of early recovering acute kidney injury following liver transplantation: a multicenter retrospective study.

BACKGROUND Acute Kidney Injury (AKI) is a common complication after liver transplantation (LT) but the specific impact of rapidly resolving AKI is not elucidated. This study investigates the factors associated with early recovery from AKI and its association with post-LT outcomes. METHODS Retrospective analysis of 441 liver transplant recipients with end-stage liver disease without pretransplant renal impairment. AKI was defined according to KDIGO criteria and early renal recovery by its disappearance within 7 days post-LT. RESULTS 146 patients (32%) developed a post-LT AKI, of whom 99 (69%) recovered early and 45 (31%) did not. Factors associated with early recovery were KDIGO stage 1 (OR:14.11; 95%CI:5.59-40.22; P 50 % (OR:4.50; 95%CI:1.67-13.46; P=0.003) and AST peak value <1000 U/L (OR:4.07; 95%CI:1.64-10.75; P=0.002) within 48h post-LT. Patients with early recovery had a renal prognosis similar to that of patients without AKI with no difference in estimated glomerular filtration rate between D7 and one year. Their relative risk of developing CKD was 0.88 (95% CI: 0.55-1.41; P=0.6) with survival identical to patients without AKI and better than patients without early recovery (P<0.0001). CONCLUSIONS Most patients with post-LT AKI recover early and have a similar renal prognosis and survival to those without post-LT AKI. Factors associated with early renal recovery are related to the stage of AKI, the extent of liver injury and the early graft function. Patients at risk of not recovering may benefit the most from perioperative protective strategies, particularly those aimed at minimising the adverse effects of CNI.