The diagnosis of febrile urinary tract infection in children may be facilitated by urinary biomarkers.

Background: We prospectively assessed the feasibility of two urinary markers of renal injury as potential diagnostic tests for acute febrile urinary tract infection (UTI) and subsequent renal scarring.

Methods: The patient cohort comprised children aged 0 to 4 years who visited the emergency room. The children were divided into three groups, namely, a febrile UTI (fUTI), febrile control (FC) and a non-febrile control (NFC) group, respectively, which were matched for sex and age. An enzyme-linked immunosorbent assay for neutrophil gelatinase-associated lipocalin (NGAL) and kidney injury molecule-1 (KIM-1) was performed on urine collected from each child. The urine levels of both markers were compared between the three groups, and the diagnostic accuracy was determined based on the area under the receiver-operator characteristic curve (AUC). In the fUTI group, the predictability of subsequent renal scarring was assessed by associating urinary levels with dimercaptosuccinic acid findings 6 months after an UTI episode.

Results: Significantly elevated levels of urinary NGAL and KIM-1 were observed in the fUTI group, as well as with increased urine esterase, serum C-reactive protein, and pyuria. The AUC was 72 % for KIM-1 and 96 % for NGAL. The AUC of KIM-1 for the prediction of scarring was 71 % (p < 0.05).

Conclusions: The diagnosis of febrile UTI and the prediction of subsequent scarring may be facilitated by assaying urine biomarkers with acceptable accuracy.