Biomarkers of Renal Injury in Cirrhosis: Association with Acute Kidney Injury and Recovery after Liver Transplantation

Background: To define urine or serum biomarkers in predicting renal function recovery after liver transplantation (LT). Methods: Adults listed for LT (February 2011-July 2014) and with modified diet for renal disease-6 (MDRD-6) <60 mL/min provided urine/blood samples at baseline and serially until LT for biomarkers in serum (pg/mL) and urine (pg/mg creatinine). Results: Of 271 LT listed patients (mean age 57 years, 63% males, median listing MELD 17.5), 1 year acute kidney injury (AKI) probability was 49%, with odds of 1.3-, 3.0-, 4.6-, and 8.5-fold times for listing MELD 16-20, 21-25, 26-30, and >30, compared to MELD <16. Thirty-seven people died over 1 year from the time of listing, with twofold increased odds with AKI. Among 67 patients with MDRD <60, only urinary epidermal growth factor was different comparing AKI (increase in serum creatinine ≥0.3 mg/dL from baseline within past 3 months) vs. no AKI (2,254 vs. 4,253, p = 0.003). Differences between acute tubular necrosis (ATN) and hepatorenal syndrome could not be ascertained for a small sample of 3 patients with ATN. Analyzing 15 of 43 receiving LT and MDRD-6 <30 prior to LT, biomarkers were not different comparing 5 patients recovering renal function (MDRD-6 >50 mL/min) at 6 months vs. 10 without recovery. Conclusions: AKI is common among LT listed patients, with a negative impact on transplant-free survival. Serum and urine biomarkers are not associated with the recovery of renal function after LT. Multicenter studies are suggested to (a) develop strategies to reduce the development of AKI and (b) derive novel biomarkers for use in accurately predicting renal recovery after LT.