Abstract: Objective To explore the diagnostic value of urine neutrophil gelatinase-associated lipocalin (NGAL) in children with acute pyelonephritis. Methods A total of 104 children with urinary tract infection admitted to Tianjin Children’s Hospital from December 2016 to May 2017 were selected in this study, including 61 cases with acutepyelonephritis (group APN) and 43 with lower urinary tract infection (group non-APN). The serum levels of beta 2-Microglobulin (β2-MG), cystatin C (CysC), C-reactive protein (CRP), procalcitonin (PCT) and urine levels of NGAL were compared between two groups. Receiver operating characteristic (ROC) curves were drawn to evaluate the diagnostic values of serum β2-MG, CysC, CRP, PCT and urine NGAL. Results The serum levels of CRP, PCT, β2-MG and urinary NGAL were significantly higher in APN group than those in non-APN group (P < 0.05). There was no significant difference in serum CysC level between two groups (P > 0.05). The areas under the ROC curve (AUC) for serum CRP, PCT, and urinary NGAL were 0.838, 0.898 and 0.963. The optimal cutoff value of serum CRP was 22.6 mg/L, the sensitivity was 75.4% and the specificity was 83.7%. The optimal cutoff value of serum PCT was 0.285 μg / L, the sensitivity was 77.0%and the specificity was 93.0%. The optimal cutoff value of urine NGAL was 473 μg/L, the sensitivity was 82.0% and the specificity was 97.7%. Conclusion Urinary NGAL has high diagnostic value for APN in children, and which is helpful for the early identification of APN.

Key words: pyelonephritis, urinary tract infections, ROC curve, child, neutrophil gelatinase-associated lipocalin