Plasma Neutrophil Gelatinase-Associated Lipocalin as a Predictor of Renal Parenchymal Involvement in Infants With Febrile Urinary Tract Infection: A Preliminary Study.

Urinary tract infection (UTI) is the most common bacterial infection in infants. Renal parenchymal involvement is an important prognostic factor; however, early detection of parenchymal involvement in UTI may be difficult during infancy. This study aimed to assess whether a recently established biomarker of UTI, neutrophil gelatinase-associated lipocalin (NGAL), can serve as a useful marker for the detection of cortical defects (CD) and to determine the appropriate diagnostic cut-off value of NGAL in infants with febrile UTI. Infants hospitalized for febrile UTI were divided into two groups according to the presence of cortical defects on dimercaptosuccinic acid (DMSA) scintigraphy. Among 64 enrolled infants, 43 (67%) had CD (UTI-CD) and 21 (33%) had no CD (UTI-ND). The white blood cell count, C-reactive protein, and plasma NGAL (pNGAL) levels were determined before antibiotic therapy and compared between the two groups. pNGAL level was significantly higher in the UTI-CD group than in the UTI-ND group (340 μg/L vs 214 μg/L, P=0.002). Multivariate analysis showed that pNGAL level was the only independent predictor of CD (odds ratio 2.759, P=0.039). In the ROC curve analysis, pNGAL showed the highest area under the curve (0.745; 95% confidence interval, 0.561-0.821; P=0.014). The appropriate cut-off value of pNGAL was 267 μg/L (sensitivity, 72.1%; specificity, 71.4%). pNGAL was found to be a useful marker for early prediction of renal parenchymal involvement in infants with febrile UTI.