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

Fluctuations of Estimated Glomerular Filtration Rate Outside Kidney Disease Improving Global Outcomes Diagnostic Criteria for Acute Kidney Injury in End-Stage Liver Disease Outpatients and Outcome Postliver Transplantation.

BACKGROUND: Renal dysfunction in end-stage liver disease (ESLD) results from systemic conditions that affect both liver and kidney with activation of vasoconstrictor systems. In this setting, estimated glomerular filtration rate (eGFR) may undergo variations often outside Kidney Disease Improving Global Outcomes criteria for acute kidney injury (AKI) diagnosis, whose meaning is not clear. The aim of this study was to evaluate eGFR variations in ESLD outpatients listed for liver transplant (liver Tx) and the association with post-Tx outcome. METHODS: Fifty-one patients with ESLD were retrospectively evaluated from listing to transplant (L-Tx time), intraoperatively (Tx time), and up to 5 years post-Tx time. Variations between the highest and the lowest eGFR occurring in more than 48 hours, not satisfying Kidney Disease Improving Global Outcomes guideline, were considered as fluctuations (eGFR-F). Fluctuations of eGFR greater than 50% were defined as eGFR drops (DeGFR). Early graft dysfunction, AKI within 7 days, chronic kidney disease, and short- and long-term patient survivals were considered as outcomes. RESULTS: All patients presented eGFR-F, whereas DeGFR were observed in 18 (35.3%) of 51 (DeGFR+ group). These patients presented higher levels of Model for End-stage Liver Disease score, pre-Tx bilirubin and significantly greater incidence of post-Tx AKI stages 2 to 3 compared with patients without drops (DeGFR-). DeGFR was the only independent predictive factor of the occurrence of post-Tx AKI. The occurrence of AKI post-Tx was associated with the development of chronic kidney disease at 3 months and 5 years post-Tx. CONCLUSIONS: Drops of eGFR are more frequently observed in patients with a worse degree of ESLD and are associated with a worse post-Tx kidney outcome.