Urine neutrophil gelatinase associated lipocalin (uNGAL) as predictor of renal scarring

Abstract

Urine Neutrophil gelatinase associated lipocalin (uNGAL) is a novel protein expressed in injured epithelia. The aim of our study was to assess whether uNGAL could represent a novel biomarker of renal scarring and to determine the optimal cut-off level for uNGAL to predict the presence of renal scars in children. Forty-four patients with renal scarring and 44 patients without renal scarring on dimercaptosuccinic acid scan were enrolled in the study. Serum urea and creatinine levels were normal in all children in the study. Urine NGAL was measured by ELISA. The mean uNGAL level was significantly higher in children with scars than in those without scars (14.92 ng/mL vs 5.71 ng/mL, p=0.001). According to receiver operating curve (ROC) analysis, the optimal cut-off level was 4ng/mL for uNGAL to predict renal scars. Using a cut-off 4ng/mL for uNGAL for prediction of scars, sensitivity and specificity were 68% and 68%, respectively. The positive and negative predictive values of this cut-off point were 68% and 68%, respectively. The area under the curve (AUC) was found to be 0.69 for uNGAL. In conclusion, the uNGAL level was higher in children with renal scars than in without scars. However, uNGAL has low sensitivity and specificity as a marker for prediction of renal scarring.