Cytokine profiles of pediatric patients treated with antibiotics for pyelonephritis: Potential therapeutic impact

Urinary tract infections are common in infants and children. Pyelonephritis may result in serious complications, such as renal scarring, hypertension, and renal failure. Identification of the timing of release of inflammatory cytokines in relation to pyelonephritis and its treatment is essential for designing interventions that would minimize tissue damage. To this end, we measured urinary cytokine concentrations of interleukin-1 beta (IL-1 beta) , IL-6, and IL-8 in infants and children with pyelonephritis and in healthy children. Children that presented to our institution with presumed urinary tract infection were given the diagnosis of pyelonephritis if they had a p ositive urine culture, pyuria, and one or more of the following indicators of systemic involvement: fever, elevated peripheral white blood cell count, or elevated C-reactive protein. Urine samples were obtained at the time of presentation prior to the administration of antibiotics, immediately after completion of the first dose of antibiotics, and at follow up 12 to 24 h a fter presentation. IL-1 beta, IL-6, and IL-8 concentrations were measured b y enzyme-linked immunosorbent assay. Creatinine concentrations were also de termined, and cytokine/creatinine ratios were calculated to standardize sam ples. Differences between preantibiotic and follow-up cytokine/creatinine r atios were significant for IL-1 beta, IL-6, and IL-8 (P < 0.01). Difference s between preantibiotic and control cytokine/creatinine ratios were also si gnificant for IL-1<beta>, IL-6, and IL-8 (P < 0.01). Our study revealed tha t the urinary tract cytokine response to infection is intense but dissipate s shortly after the initiation of antibiotic treatment. This suggests that renal damage due to inflammation begins early in infection, underscoring th e need for rapid diagnosis and intervention.