Urinary Biomarkers for Screening for Renal Scarring in Children with Febrile Urinary Tract Infection: Pilot Study

Purpose: Recurrent febrile urinary tract infections during infancy cause renal scarring, which is characterized by progressive focal interstitial fibrosis and may lead to renal failure. Renal scarring can be diagnosed through scintigraphy, although it seems impractical to perform renal scintigraphy for all infants with febrile urinary tract infections. Therefore, it is important to search for a biomarker to identify the presence of renal scarring. We hypothesized that urinary biomarkers of nephropathy may increase in infants with renal scarring following febrile urinary tract infections. Materials and Methods: A total of 49 infants who underwent renal scintigraphy for febrile urinary tract infections were enrolled in the study. Several measurements were performed using urine samples, including total proteins, beta2-microglobulins, N-acetyl-beta-D-glucosaminidase, neutrophil gelatinase associated lipocalin, liver-type fatty acid binding protein and angiotensinogen. Values were corrected by creatinine and compared between patients with and without renal scarring. Results: Among urinary biomarkers only angiotensinogen in patients with scarring (median 14.6 mu g/gm creatinine) demonstrated significantly higher levels than in patients without scarring (3.6 mu g/gm creatinine, p < 0.001). Conclusions: Urinary angiotensinogen may be useful for diagnosing the presence of renal scarring.