Introduction
Urinary Interleukin-6 (IL-6) a pleiotropic cytokine with pro-inflammatory and immune-regulatory functions is a key mediator of inflammation in children with Urinary tract infection (UTI).
 
Aim of the study
The aim of this study is to estimate the role of urinary IL-6 (UIL-6) in diagnosis of acute UTI in children and its usefulness in differentiation between upper urinary tract infection (UUTI) (pyelonephritis) and lower urinary tract infection (LUTI) (cystitis).
 
Patients & Methods
This study conducted on a total 56 children divided into 36 patients suffering from UTI with mean age 4.3 ± 3.1 and 20 apparently healthy children age and sex matched with the cases. All patients were subjected to routine investigation and urine IL-6 assay.
 
Results
Urinary IL-6 was significantly higher in patients with UTI than control group, Sensitivity was 94.4 %, specificity of 92.1%, positive predictive value was 85%, negative predictive value was 97.2% anddiagnostic accuracy was 92.8% and the best cut off value >17 pg/ml. Also Urinary IL-6 was significantly higher in acute pyelonephritis (APN) in comparison to lower UTI cases and there was a positive correlation between urinary IL-6 level and fever, CRP, and leukocyte count [r = 0.623 P = 0.006, r = 0.816, P < 0.001 and r = 0.688,    P < 0.002 respectively]
 
Conclusion
Urinary IL-6 level may considered as a reliable biochemical marker to determine the severity of renal injury in APN as well as outcome of pediatric patients