Urinary Liver-Type Fatty Acid-Binding Protein Linked with Increased Risk of Acute Kidney Injury after Allogeneic Stem Cell Transplantation

•This study showed the utility of urinary biomarker in allogeneic stem cell transplantation.•Antecedent subclinical kidney injury may contribute to acute kidney injury after allogeneic stem cell transplantation.•Urinary liver-type fatty acid-binding protein is a biomarker to detect subclinical kidney injury.•Increased urinary liver-type fatty acid-binding protein before transplantation is linked with acute kidney injury after allogeneic stem cell transpslantation.•Urinary liver-type fatty acid-binding protein is a noninvasive and easy measurement to predict acute kidney injury after allogeneic stem cell transplantation.

Stem cell transplantation (SCT) involves a great risk of acute kidney injury (AKI). Urinary liver-type fatty acid-binding protein (uL-FABP) is a sensitive biomarker to detect kidney damage before an increase in serum creatinine (Cr); however, the utility of uL-FABP is not fully understood in the platform of SCT. A prospective study was conducted in 84 allogeneic SCT recipients to ascertain a link between the uL-FABP level before preparative procedures and AKI incidence after SCT. The association between them was analyzed using Gray's method and a multivariate Fine-Gray proportional hazards regression model. The recipients were stratified into high and low uL-FABP groups, according to the reference value for healthy subjects (8.4 μg/g Cr). AKI developed more frequently in the high (n = 20) than low (n = 64) group (55.0% versus 26.6% at day 30, P = .005), and high uL-FABP was an independent risk for the emergence of AKI (hazard ratio, 2.78; 95% confidence interval, 1.24 to 6.22, P = .01). In conclusion, increased baseline uL-FABP, which may indicate previous incipient kidney injury, is linked with a high risk of AKI after allogeneic SCT.