Evaluation of risk factors for acute pyelonephritis and permanent renal damage (renal scarring) in children under 2 years of age with a first febrile urinary tract infection.

BACKGROUND

The aim of this study was to evaluate possible predictive factors for acute pyelonephritis (APN) and renal scarring in children ≤2 years of age hospitalized with a first febrile urinary tract infection (UTI).

METHODS

Sixty patients and 63 age-matched controls were prospectively included in the study. On admission, work-up including cystatin C, vitamin 25OHD, and urine angiotensinogen (U-AGT) was conducted. Children with UTI had an acute DMSA scan (technetium 99m-dimercaptosuccinic acid scan) and were grouped in those with a normal DMSA and those with APN findings on DMSA scanning. The patients with APN had a follow-up DMSA scan after 6 months to evaluate for renal scarring.

RESULTS

The children with APN (53 %) had significantly higher CRP and ESR and lower 25OHD levels compared with normal DMSA group. The correlation between 25OHD level and APN remained significant after adjusting for age, fever duration and CRP/ESR level. Cystatin C and U-AGT levels did not differ significantly between patients and controls. Renal scaring was found in 33 % of children with APN. CRP levels >100 mg/L during APN and vesicoureteral reflux (VUR) grade ≥3 were found more frequently in children with renal scarring, comparing to those without scarring (p < 0.01).

CONCLUSION

Vitamin D levels could be an independent predictor of acute renal damage in children with febrile UTI. Cystatin C and U-AGT were not found to be predictive factors for renal damage. CRP levels >100 mg/L during APN and VUR grade ≥3 were associated with renal scarring.