Timely antibiotic initiation for acute pyelonephritis (APN) can prevent renal complications. We investigated whether urine heparin binding protein (UHBP), a cytokine released from activated neutrophils, was a useful diagnostic tool for APN. Febrile children with presumed APN were prospectively enrolled between January and September 2013, and divided into two groups based on urine cultures. UHBP levels were measured at enrollment in all children and 1 month after antibiotic treatment in children with APN. UHBP levels in children with APN at baseline and 1 month versus controls were 47.0 ± 8.4 and 16.6 ± 3.8 vs. 15.0 ± 2.9 ng/mL, respectively (p < 0.001). Test performance characteristics were calculated against a gold standard of positive urine cultures and compared with leukocyte esterase (LE) and nitrite measured by dipsticks and pyuria by microscopy. The sensitivity and specificity for UHBP levels ≥34 ng/mL were 100 and 100 %. Spearman's rank coefficient was used to assess the associations between routine laboratory tests and UHBP levels. Significant positive correlations were found with pyuria grade (Spearman's rho = 0.62; p < 0.001), neutrophil count (rho = 0.38; p = 0.03), and platelet count (rho = 0.39; p = 0.03).
Conclusions: UHBP is a valid adjunctive diagnostic tool for aiding clinicians in making rapid treatment decisions for APN.