Do Serum C-reactive Protein and Interleukin-6 Predict Kidney Scarring After Urinary Tract Infection?

To investigate if serum C-reactive protein (s-CRP) and interleukin 6 (s-IL6) provide information for predicting renal damage and for DMSA patient selection in children with urinary tract infection (UTI). This observational study was carried out in children with UTI. s-CRP and s-IL6 were measured at UTI diagnosis. Patients forming renal scarring were identified by DMSA scans. The usefulness of s-CRP and s-IL6 measurements for nephropathy scarring diagnosis was evaluated using diagnostic quality and efficiency indexes. Thirty-two children were included in the study. Eight showed renal scarring after the follow-up. The s-CRP was 110.23 +/- 59.69 mg/L and 52.46 +/- 63.13 mg/L for patients with and without renal scarring. The s-IL6 concentration was 18.34 +/- 11.80 pg/mL and 8.07 +/- 9.51 pg/mL respectively. The cut-off points for optimum nephropathy scarring diagnosis were 115 mg/L for s-CRP and 20 pg/mL for s-IL6. The value of highest sensitivity for s-CRP was > 5 mg/L (S:100 %) and greatest specificity was > 150 mg/L (Sp:95.83). The highest sensitivity for s-IL6 was > 4 pg/mL (S:100 %) and the maximum specificity was > 40 pg/mL (Sp:100 %). Results confirm that children who will develop renal scarring show higher levels of s-IL6 and s-CRP at UTI diagnosis. However, none of the techniques provide sufficient information for predicting renal damage in all patients and for DMSA patient selection.