Evaluation of quantitative urinary CRP (C-reactive protein) level in children with urinary tract infection

Urinary tract infection (UTI) is a risk factor for kidney damage and end stage renal failure. In this study, the urinary C-Reactive Protein (CRP) level was compared between patients with UTI and patients with other infectious diseases and the role of the mean urinary CRP, as a predictive factor for renal involvement, was evaluated. Urine samples were collected from patients under 15 years of age with UTI in Shahid Motahari Children''s Hospital within 24 to 48 hours after hospital admission. Then, urine CRP was measured quantitatively using the ELISA method. The control group was selected among patients with various infectious diseases. Technetium Tc 99m Dimercaptosuccinic Acid (DMSA scan) and voiding cystouretrography (VCUG) were performed for children with UTI. Data were analyzed by using Mann-Whitney Test and P values less than 0.05 were considered statistically significant. A total of 50 patients with UTI as the study group and 20 patients as the control group were evaluated. The mean urinary CRP was 244.8 in the study group and 179.67 in the control group. There was no significant difference in urinary CRP between the cases and the controls (P value: 0.83). The mean urinary CRP was 83.4 ± 46.02 in 9 patients with DMSA scan class 1, 224.8±320.1 in 38 patients with class 2, and 399.53 ± 46.27 in the three patients with class 3. Mann-Whitney Test showed no significant differences in urinary CRP levels between normal and abnormal DMSA scans. Four patients were positive for VUR but there was no significant relationship between VUR and urinary CRP (P value= 0.56). According to our findings, urine CRP does not have a diagnostic value in urinary tract infections in children and cannot predict renal damage.