Novel biomarkers of acute kidney injury following living donor liver transplantation

Urinary biomarkers such as neutrophil gelatinase-associated lipocalin (NGAL) and renalase were recently studied for their potential role in the early detection of acute kidney injury (AKI) in patients with cirrhosis. Our study was conducted on 50 patients with end-stage liver disease undergoing living donor liver transplantation. The patients were divided into two groups: Group I contained 23 patients with AKI who had undergone liver transplantation and Group II included 27 non-AKI patients who had undergone liver transplantation. Serum renalase and NGAL levels were measured by ELISA; renalase was measured on day 1, day 7, and three months after liver transplantation. NGAL was measured on day 1 postliver transplantation. There was an improvement in liver function, kidney functions, hemoglobin level, platelet count, and C- reactive protein levels in patients at three months posttransplantation when compared to day 1, day 3, and day 7 (P < 0.01). Comparison of the renalase level at day 1, day 7, and three months showed that there was a highly significant decline at three months in the AKI group compared to the non-AKI group (P < 0.01). Regarding the NGAL level at day 1, there was no significant difference between the AKI and non-AKI groups (P > 0.05). The receiver operating characteristic curve for the renalase biomarker showed a borderline significant change between the AKI and non-AKI groups at day 1 [area under the curve (AUC): 0.54, P = 0.08], day 7 (AUC: 0.605, P = 0.08), and three months (AUC: 0.605, P = 0.08). However, the NGAL biomarker level was not significantly different between the AKI and non-AKI groups. Our study suggests that renalase showed a better predictive value and a higher accuracy in identifying postliver transplantation patients with AKI than NGAL.