PREDICTORS OF RENAL SCARRING FOLLOWING FIRST FEBRILE URINARY TRACT INFECTION IN CHILDREN: A PROSPECTIVE COHORT STUDY

Abstract

Objective: Renal scarring is a serious long-term complication of febrile urinary tract infection (UTI) in children and may predispose affected individuals to hypertension, proteinuria, and chronic kidney disease. Early identification of children at high risk is essential for timely intervention and prevention of permanent renal damage. This study aimed to identify clinical, laboratory, microbiological, and radiological predictors of renal scarring following the first episode of febrile UTI in children.

Study Design and Duration of Study: A prospective cohort study. Lady Reading Hospital from June 2023 to May 2024.

Method: A total of 172 children aged 2 months to 12 years with a first documented febrile UTI completed six months of follow-up. Demographic, clinical, laboratory, microbiological, and imaging findings were recorded. Renal scarring was assessed using follow-up dimercaptosuccinic acid (DMSA) scintigraphy performed six months after the acute infection. Univariate and multivariable logistic regression analyses were performed to identify independent predictors of renal scarring.

Results: Renal scarring developed in 39 children (22.7%). Children with renal scarring had significantly longer fever duration before antibiotic initiation, higher C-reactive protein levels, more frequent abnormal renal ultrasonography, acute DMSA abnormalities, and high-grade vesicoureteral reflux (all p<0.05). Multivariable analysis demonstrated that delayed antibiotic therapy beyond 48 hours (adjusted odds ratio [aOR] 3.41, 95% CI: 1.52–7.67), elevated C-reactive protein (aOR 1.18 per 10 mg/L increase, 95% CI: 1.06–1.31), abnormal renal ultrasonography (aOR 2.96, 95% CI: 1.24–7.05), acute DMSA abnormalities (aOR 5.82, 95% CI: 2.11–16.08), and high-grade vesicoureteral reflux (aOR 6.47, 95% CI: 2.18–19.21) were independent predictors of renal scarring.

Conclusion: Permanent renal scarring occurred in nearly one-quarter of children after their first febrile UTI. Early diagnosis, prompt antimicrobial treatment, and risk-based imaging may facilitate early identification of high-risk children and reduce long-term renal morbidity.