The impact of acute kidney injury with or without recovery on long-term kidney outcome in patients undergoing living liver transplantation

Background Acute kidney injury (AKI) is associated with an increased incidence of poor liver graft and renal outcomes in patients who have undergone liver transplantation (LT). To date, no comprehensive study has compared patients with and without post-LT AKI and analyzed patients who recovered from AKI versus those who did not. Methods Patients who received living LT between January 2003 and January 2019 were enrolled. We diagnosed and classified AKI patients based on AKI-KDIGO guidelines by increment of creatinine after surgery when compared with serum creatinine on the day of surgery. The recovered AKI subgroup included recipients whose estimated glomerular filtration rate (eGFR) recovered more than 90% of baseline eGFR within 90 days after surgery. The risk of chronic kidney disease (CKD; eGFR <60 mL/min/1.73 m(2)) was investigated. Results A total of 392 patients, 77.3% men and mean +/- standard deviation age 54.1 +/- 8.4 years, met the eligible criteria and were divided into two groups (AKI vs non-AKI) and 243 (62%) patients developed AKI within 7 days after surgery. Compared with the non-AKI group, the AKI group was associated with an adjusted hazard ratio of 1.55 (95% CI 1.12-2.14) for the risk of incident CKD. Among AKI patients, 160 (65.8%) patients recovered renal function and 83 (34.2%) patients did not. Compared with the non-AKI group, the AKI non-recovery group was associated with an adjusted hazard ratio of 2.87 (95% CI 1.95-4.21) for the risk of incident CKD, while the AKI recovery group had no significant difference in the adjusted risk of incident CKD. Conclusions Post-LT AKI is associated with subsequent risk of CKD development. Taking into account recovery status, AKI was no longer associated with a higher risk of CKD if renal function recovered within 90 days after surgery. Identification and implementation of targeted and individualized therapies for patients at risk for AKI, particularly non-recovery AKI, is of paramount importance to reduce incident CKD during follow-up.