The type, duration, and severity of pretransplant kidney injury predict prolonged kidney dysfunction after liver transplantation.

Chronic kidney disease (CKD) is a major complication of liver transplantation (LT) associated with substantial morbidity and mortality. Knowing the drivers of post-LT kidney dysfunction-with a granular focus on the type, duration, and severity of pre-LT kidney disease-can highlight intervention opportunities and inform dual-organ allocation policies. We retrospectively analyzed predictors of safety net kidney after liver transplant (KALT) eligibility and kidney replacement therapy (KRT) for > 14 days after LT. Among 557 recipients of adult deceased-donor LT, 49% had normal kidney function, 25% had acute kidney injury (AKI), and 25% had CKD±AKI at the time of LT. A total of 36 (6.5%) qualified for KALT and 63 (11%) required KRT > 14 days. In univariable analysis, factors associated with KALT eligibility and KRT > 14 days, respectively, included stage 3 AKI (OR 7.87; OR 7.06), CKD±AKI (OR 4.58; OR 4.22), CKD III-V duration (OR 1.10 per week; OR 1.06 per week), and increasing CKD stage (stage III: OR 3.90, IV: OR 5.24, V: OR 16.8; stage III: OR 2.23, IV: OR 3.62, V: OR 19.4). AKI stage I-II and AKI duration in the absence of CKD were not associated with the outcomes. Pre-LT KRT had a robust impact on KALT eligibility (OR 4.00 per week) and prolonged post-LT KRT (OR 5.22 per week), with 19.8% of patients who received any pre-LT KRT ultimately qualifying for KALT. Eligibility for KALT was similar between those who received 0 days and ≤ 14 days of KRT after LT (2.1% vs. 2.9%, p = 0.53). In conclusion, the type, duration, and severity of pre-LT kidney dysfunction have unique impacts on post-LT kidney-related morbidity, and future research must use these novel classifications to study mitigation strategies.