Early prediction of urinary tract infection with urinary neutrophil gelatinase associated lipocalin

Abstract

Neutrophil gelatinase associated lipocalin (NGAL) is a protein identified in human neutrophil granules. The aim of the study was to assess whether urine level of NGAL (uNGAL) could represent a novel, reliable marker of urinary tract infection (UTI) and to determine the optimal cutoff level for uNGAL to predict UTI in children. Sixty patients with symptomatic UTI and 29 healthy controls were enrolled the study. Urine NGAL was measured by enzyme-linked immunosorbent assay. A dimercaptosuccinic acid (DMSA) radionuclide scan was performed within 7 days in the patients with UTI in an attempt to distinguish pyelonephritis from cystitis. Mean uNGAL level was significantly higher in the UTI group than in the controls (91.02 ng/ml vs 14.29 ng/ml, p = 0.0001) and using a cutoff 20 ng/ml for uNGAL for diagnosis of UTI, sensitivity, and specificity were 97% and 76%, respectively [area under the curve (AUC): 0.979]. Mean uNGAL/creatinine ratio (uNGAL/Cr) was also significantly higher in the UTI group [201.81 ng/mg creatinine (Cr) vs 18.08 ng/mg Cr; p = 0.0001], and using a cutoff 30 ng/mg Cr for uNGAL/Cr for diagnosis of UTI, sensitivity and specificity were 98% and 76%, respectively (AUC: 0.992). In conclusion, both uNGAL and uNGAL/Cr can be used as a novel, sensitive marker for early prediction of UTI in the absence of acute kidney injury and chronic kidney disease, and the optimal cutoff value for prediction of UTI is lower than the values determined for acute kidney injury. Further investigations with larger patient groups are required to confirm our results.

Plasma neutrophil gelatinase-associated lipocalin predicts acute pyelonephritis in children with urinary tract infections

“…This was consistent with our previous findings (18,19). Conflicting data have shown that uNGAL is elevated in patients with renal scarring compared to the level in those without scarring (1,37). In patients diagnosed with VUR without evidence of current UTI, uNGAL levels were also significantly higher compared to those in controls (37).…”

“…Ichino et al (17) demonstrated experimentally that uNGAL levels in rats increased in both the early and extensive fibrosis stages of pyelonephritis, suggesting that uNGAL might also be useful as a marker of APN and renal scarring in humans. Indeed, we, and other investigators, have demonstrated that uNGAL can be a useful predictor for detecting UTIs in children (1,18). In patients with febrile UTIs, increased uNGAL levels were related to UTI severity, and levels decreased following antibiotic treatment.…”

“…u rinary tract infections (UTIs) are among the most common bacterial infections in children (1). Early detection and proper management of UTIs is important since UTIs involving the kidney may cause permanent renal scarring and be a risk factor for future development of renal insufficiency (2).…”

Urinary Neutrophil Gelatinase Associated Lipocalin for Early UTI Diagnosis

“…Recent studies from Korea [5] and Turkey [6] showed that NGAL might be a good marker for UTI diagnosis but studies suffer from small number of patients.…”

Urinary Tract Infection in Children: Diagnostic and Prognostic Utility of Biomarkers

“…Subsequently, novel biomarkers are emerging as alternative tools in the diagnosis of UTI (6)(7)(8)(9)(10)(11)(12)(13), and as predictors of its complications such as vesico-ureteric reflux (VUR) (14)(15)(16)(17)(18) as well as renal parenchymal injury (19)(20)(21)(22). Reports also show that febrile UTI in children activate an interleukin 6 (IL-6) and interleukin 8 (IL-8) responses, thus adding the estimation of these cytokines in the diagnostic trajectory of the disease (23,24).…”