Do serum C-reactive protein and interleukin-6 predict kidney scarring after urinary tract infection?

Area of Science:

• Pediatric Nephrology
• Infectious Diseases
• Biomarker Research

Background:

• Urinary tract infections (UTIs) in children can lead to renal scarring and long-term kidney damage.
• Early identification of children at risk for renal scarring is crucial for timely intervention.
• Diagnostic imaging like DMSA scans are used to detect renal scarring, but patient selection can be challenging.

Purpose of the Study:

• To evaluate the predictive value of serum C-reactive protein (s-CRP) and interleukin 6 (s-IL6) for renal damage in pediatric UTI.
• To assess the utility of s-CRP and s-IL6 in selecting patients for dimercaptosuccinic acid (DMSA) scans.

Main Methods:

• An observational study involving children diagnosed with UTI.
• Measurement of s-CRP and s-IL6 levels at the time of UTI diagnosis.
• Identification of renal scarring using DMSA scans during follow-up.
• Analysis of diagnostic performance using quality and efficiency indexes.

Main Results:

• Children who developed renal scarring exhibited significantly higher s-CRP (110.23 mg/L vs 52.46 mg/L) and s-IL6 (18.34 pg/mL vs 8.07 pg/mL) levels compared to those without scarring.
• Optimal cut-off points for predicting scarring were identified as 115 mg/L for s-CRP and 20 pg/mL for s-IL6.
• While high sensitivity was observed for both markers (s-CRP >5 mg/L, s-IL6 >4 pg/mL), specificity varied (s-CRP >150 mg/L, Sp:95.83%; s-IL6 >40 pg/mL, Sp:100%).

Conclusions:

• Elevated s-CRP and s-IL6 at UTI diagnosis are associated with an increased risk of renal scarring in children.
• Despite their association, s-CRP and s-IL6 alone do not provide sufficient predictive information for all patients.
• These biomarkers are not adequate for definitive prediction of renal damage or for sole DMSA scan patient selection.