Assessment of Urinary and Serum Neutrophil Gelatinase-Associated Lipocalin (NGAL) Levels as Novel Predictors for Vesicoureteral Reflux Diagnosis in Children with Febrile Urinary Tract Infection

The invasive, expensive, and time-consuming nature of radiological examinations for vesicoureteral reflux (VUR) has compelled researchers to search for new markers to predict VUR. This study was designed to evaluate the usefulness of serum and urine concentrations of neutrophil gelatinase-associated lipocalin (NGAL) in predicting the existence of VUR. This cross-sectional study involved all patients with a first febrile urinary tract infection (UTI) referred to Ali Asghar Children's Hospital. Each patient included in the study had clinical symptoms of pyelonephritis and a positive urine culture. The patients were divided into 2 groups: VUR and non-VUR. The serum and urinary NGAL levels were calculated in both groups. The receiver operating characteristic (ROC) curve was used to look for serum and urinary NGAL cut-points that differentiated the VUR group from the non-VUR group. Among the 40 children in the study, 23 belonged to the VUR group. The median age was 2.5 years (range, 0.3-8 years), and 35 patients were girls. ROC curve analysis showed that only the urinary NGAL level was significantly related to VUR. There was no association between serum NGAL levels and VUR. According to the ROC curve, a urinary NGAL level cut-off value of 15 ng/mL was likely to be diagnostic of VUR with 82.6% sensitivity and 58.8% specificity. The urinary NGAL level, specifically with a cut-off value of 15 ng/mL, can indicate the existence of VUR in patients with UTI with near-acceptable levels of sensitivity and specificity.