Lipopolysaccharide-binding protein: a potential marker of febrile urinary tract infection in childhood

Urinary tract infections (UTIs) are encountered frequently in children, and their early diagnosis and treatment are important. This study evaluates the diagnostic value of serum concentrations of lipopolysaccharide-binding protein (LBP), an acute-phase protein, in children with febrile UTI and compares it to those of the total white blood cell count (WBC), erythrocyte sedimentation rate (ESR), C-reactive protein (CRP), procalcitonin (PCT), and interleukin-6 (IL-6). The study population comprised 77 consecutive patients with a first-episode febrile UTI (33 boys) with a median age of 11 months [interquartile range (IQR), 5.5-33 months], 21 healthy controls (11 boys) with a median age of 10 months (IQR, 5-20.5 months) and 58 febrile controls with a fever due to other causes (28 boys) with a median age of 12.5 months (IQR, 7-30 months). LBP, IL-6, PCT, and CRP were measured for both patients and control groups. The serum levels of LBP (p < 0.001), CRP (p < 0.001), PCT (p = 0.001), IL-6 (p = 0.002), ESR (p = 0.020), and WBC (p < 0.001) were higher in patients with febrile UTI than in the healthy and febrile control groups. The LPB cut-off value for best sensitivity and specificity in patients with febrile UTI was > 43.23 mg/l. Furthermore, the area under the receiver operating characteristic curve was significantly greater for LBP than for CRP (p = 0.014), PCT (p < 0.001), ESR (p < 0.001), WBC (p = 0.002) and IL-6 (p = 0.006). The results of this study suggest that the serum LBP concentration constitutes a reliable biologic marker for the diagnosis of a febrile UTI in children.