OBJECTIVETo investigate the values of combination of urinary liver-type fatty acid-binding protein (L-FABP) and neutrophil gelatinase-associated lipocalin (NGAL) in early diagnosis of acute kidney injury (AKI) after cardiac surgery in children.

METHODSA total of 97 children with congenital heart disease undergoing cardiopulmonary bypass surgery were enrolled. Serum and urine samples were collected before and after surgery. Levels of serum creatinine (Scr), urinary L-FABP, and urinary NGAL from AKI group (n=18) and non-AKI group (n=79) were measured, and the postoperative dynamic changes in these markers were compared between the two groups. The receiver operating characteristic (ROC) curve and the area under ROC curve (AUC) were used to assess the values of these markers alone or in combination in the prediction of postoperative AKI.

RESULTSThe levels of urinary L-FABP and NGAL in the AKI group were significantly higher than those in the non-AKI group at 2 and 6 hours after surgery, and the changes in their concentrations were earlier than Scr. The AUCs of urinary L-FABP alone in predicting AKI at 2 and 6 hours after surgery were 0.921 and 0.896 respectively, and those of urinary NGAL alone were 0.908 and 0.928 respectively. Those of their combination were 0.942 and 0.929 respectively.

CONCLUSIONSUrinary L-FABP and NGAL significantly increase in the early stage of AKI after cardiac surgery in children, which are significantly earlier than the changes in Scr. They can be used to predict the occurrence of AKI in the early stage. A combination of the two biomarkers can further improve the accuracy of diagnosis.