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

Abstract

Background:The identification of acute pyelonephritis (APN) is still a challenge. Methods: Patients admitted for their first urinary tract infection (UTI) were enrolled. Plasma neutrophil gelatinaseassociated lipocalin (NGAL) levels were measured at admittance and after treatment. Laboratory, clinical, and imaging results were compared between children with and without APN. results: A total of 123 patients were enrolled (53 APN and 70 lower UTI). After adjusting for age and gender, plasma NGAL levels were higher in the APN group than in the lower UTI group (233 (129-496) ng/ml vs. 71 (50.8-110) ng/ml, P < 0.001). NGAL levels were correlated with the serum levels of leukocytes, C-reactive protein, and creatinine, as well as fever duration (P < 0.05). Multivariable analysis revealed that logtransformed plasma NGAL was an independent predictor of APN (P < 0.05). Receiver operating curve analysis showed a good diagnostic profile of NGAL for identifying APN (area under the curve 0.864) with a best cut-off value of 102.5 ng/ml. The NGAL levels in both two groups decreased after treatment compared to levels before treatment (P < 0.001). conclusion: Plasma NGAL can be a sensitive predictor for identifying APN and monitoring the treatment response of pediatric UTI. 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). Establishing the diagnosis of acute pyelonephritis (APN) requires imaging with 99m Tc-dimercaptosuccinic acid (DMSA) scintigraphy to view renal parenchymal involvement (3). Although a DMSA scan is considered to be very sensitive in the assessment of renal damage, it is expensive, not readily available in all centers, and exposes the patients to radiation (4). Therefore, a more practical and accessible tool to determine the presence of renal parenchymal involvement could be helpful for the timely management of UTIs.Neutrophil gelatinase-associated lipocalin (NGAL), as a member of the lipocalin superfamily, is produced from the nephron in response to tubular epithelial damage (5). It has been identified as one of the earliest and potentially one of the most indicative biomarkers of acute kidney injury (AKI) from a diverse array of conditions and can differentiate between prerenal and intrinsic causes (6,7). Urinary NGAL (uNGAL) levels increase in patients with different causes of nephropathies (8,9) and might be a valuable tool in monitoring the treatment response of various renal diseases (10,11).As an iron-carrier protein derived from human neutrophils, NGAL also plays an important role in the innate immune response to bacterial infection (12). Experimentally, NGAL was capable of blocking Escherichia coli growth under ironpoor conditions, but NGAL with siderophore iron was not (13). NGAL-knockout mice demonstrated substantially increased mortality after intraperitoneal i...

Neutrophil gelatinase-associated lipocalin: utility in urologic conditions

“…While a study in adults found that uNGAL did not differentiate upper and lower tract infection, despite a significant difference in uNGAL between patients with UTI and controls, a pediatric study did report a difference in pNGAL levels between lower tract UTI and pyelonephritis [24, 25]. These results are consistent with the utility of pNGAL as a marker of inflammation and bacterial infection, while uNGAL is specific for localized infection with the genitourinary system.…”

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

“…Evolving biomarkers have been studied for non-invasive detection of APN in children with UTI [ 8 9 10 11 ]. Although several studies have revealed promising results for neutrophil gelatinase-associated lipocalin (NGAL) in children with UTI [ 9 10 11 ], only limited data are available for infants [ 12 13 ]. This study aimed to assess whether plasma NGAL (pNGAL) could be used as a reliable marker for renal parenchymal involvement and to determine the appropriate diagnostic cut-off value of NGAL for detection of renal parenchymal involvement in infants with febrile UTI.…”

Are Plasma Neutrophil Gelatinase Associated Lipocalin Levels Diagnostic in Uncomplicated Urinary Tract Infections?

“…We excluded patients with abnormal kidney function tests from the study group so that the NGAL values were not affected by any kidney pathology. In a study conducted by Sim et al (13) serum NGAL values in children who had UTI and developed pyelonephritis as a result were significantly higher than those with UTI but did not develop pyelonephritis, and the reason for that difference was the development of proximal tubular damage in the kidneys. However, this condition is not sufficient to explain the fact that controls' NGAL values were higher than the NGAL values of patients with UTI.…”