Urinary interleukin-8 in acute pyelonephritis of children: a before-after study.

INTRODUCTION The aim of this study was to assess urinary interleukin-8 (IL-8) levels in pyelonephritis and its relation with the clinical course of the infection and of inflammatory changes detected by renal scintigraphy. MATERIALS AND METHODS In this quasi-experimental before-after study, we evaluated 91 children aged 1 to 144 months (mean 34.4 +/- 35.2 months) with pyelonephritis. Inflammatory markers including erythrocyte sedimentation rate, C-reactive protein, leukocyte count, and urinary IL-8, together with the results of ultrasonography, voiding cystourethrography, and dimercaptosuccinic acid renal scintigraphy were evaluated in these children. The ratios of urinary IL-8 to creatinine (IL-8/C) before and after the treatment were compared with each other. RESULTS Urinary IL-8/C levels were significantly higher after the empirical treatment in comparison with those before the treatment (0.19 +/- 0.21 versus 0.51 +/- 0.53, P < .001). No correlation was found between the urinary IL-8 levels and leukocyturia, urine culture results, other inflammatory markers, or findings of imaging examinations. CONCLUSIONS We found high urinary IL-8 levels in children with pyelonephritis. We also documented its increasing after the treatment. We conclude that evaluation of urinary IL-8 can be a noninvasive test for diagnosis of upper urinary tract infection and its response to treatment.