Urinary levels of interleukin-6 and interleukin-8 in children with urinary tract infections to age 2.

Background: The aim of this study was to assess relations between the clinical course of UTI, IL-6 and IL-8 levels, and the presence of inflammatory changes detected by renal scintigraphy using 99mTc-DMSA (DMSA).
Material/methods: We studied 33 children aged 1-24 months (mean 7.1+/-5.8 months) with first-time UTI. The subjects were divided in two groups: with fever (group I, n=10) and without fever (group II, n=23). Inflammatory markers (ESR, CRP, leukocyte count), urinary IL-6 and IL-8 level, and DMSA scan were evaluated in all children.
Results: Urinary IL-6 and IL-8 levels [IL-6, IL-8/creatinine (pg/mg)] were significantly higher in group I than in group II (Il-6 level: 39.4+/-41.1 vs. 6.3+/-13.7, p<0.01; IL-8 level: 791.1+/-1143.6 vs. 36+/-87.9, p<0.001). We found positive correlation between urinary IL-6 and IL-8 levels and ESR, CRP, and leukocyte count (IL-6: r=0.43, p<0.05; r=0.46, p<0.05; and r=0.59, p<0.001, respectively; IL-8: r=0.55, p<0.05; r=0.72, p<0.0001; and r=0.44, p<0.05, respectively). We found no relation between urinary cytokine levels and the presence of inflammatory changes detected by DMSA scanning, despite slightly higher mean urinary cytokine levels in children with inflammatory changes in DMSA scan.
Conclusions: We found significantly higher IL-6 and IL-8 levels in children with febrile UTI and elevated inflammatory markers. IL-6 and IL-8 levels do not differentiate between acute pyelonephritis and UTI in children to age 24 months.