Female gender and overestimation of glomerular filtration rate: independent predictors of acute kidney injury after liver transplantation

Acute kidney injury (AKI) in liver transplant (LT) setting is a recognized complication and is related to increased morbidity and mortality. Pre-LT renal function is difficult to estimate, in particular for the female gender. The aim of the study was to evaluate the incidence of post-LT AKI, its relationship with survival, and related risk factors. In a single-center retrospective study of consecutive LT patients (2008 - 2015), we assessed patient characteristics and intra-LT events, and post-operative data were collected. The occurrence of AKI post-LT was also evaluated (KDIGO guidelines). Data of 145 LT patients were analyzed. 45 (31.0%) patients showed an overestimation of glomerular filtration rate (over-GFR), defined as GFR > 120 mL/min/1.73m2; 83 patients (57.2%) developed post-LT AKI. The patients (n = 145) were divided into two groups: 123 (84.8%) patients with no-AKI & AKI stage 1 and 22 (15.2%) patients with AKI stages 2 and 3. Patients with AKI stages 2 and 3 were characterized by a significantly decreased 5-year survival (p < 0.001). On the multivariable analysis, female gender and over-GFR were significantly predictive for development of AKI stages 2 and 3. Female gender has already been reported as a discriminant factor for LT candidates. Altered estimation of renal function also needs to be considered in this setting, as this could mask the presence of an unknown compromised renal function.