# Role of renal doppler in children with idiopathic nephrotic syndrome

## TL;DR

This study shows that renal Doppler measurements can help predict steroid resistance in children with nephrotic syndrome, aiding early clinical decisions.

## Contribution

The study demonstrates that renal resistive index (RI) can predict steroid resistance and disease outcomes in pediatric nephrotic syndrome patients.

## Key findings

- Higher renal RI at diagnosis is associated with steroid resistance in nephrotic syndrome.
- Renal RI after 3 months can predict short-term disease outcomes with high sensitivity and specificity.
- Estimated GFR is significantly lower in steroid-resistant cases after 6 months.

## Abstract

Renal Doppler can measure intrarenal vascular resistance and may help determine the degree of intrarenal damage, as well as predict subsequent kidney function impairment. However, its utility in children with an underlying kidney disease such as nephrotic syndrome has not been widely examined. This work aimed to measure serial renal resistive index (RI) in pediatric patients with idiopathic nephrotic syndrome to assess its predictive value for steroid resistance and disease outcome.

This prospective cohort study included 60 patients with idiopathic nephrotic syndrome aged 5 to < 18 years. Renal Doppler was performed on all children, and renal RI was measured at diagnosis, after 1, 3, and 6 months of diagnosis.

The average interlobar renal RI of the right and left kidneys at diagnosis, during follow-up at 1, 3, and 6 months, was significantly higher in steroid-resistant nephrotic syndrome than in the steroid-sensitive nephrotic syndrome. Meanwhile, the estimated glomerular filtration rate (GFR) was significantly lower in steroid-resistant nephrotic syndrome than in steroid-sensitive nephrotic syndrome after 6 months, with no significant difference at diagnosis, after 1 month, or 3 months. The average interlobar RI at diagnosis can predict steroid resistance at a cutoff > 0.60 with 92.31% sensitivity and 85.32% specificity. Moreover, the average interlobar RI after 3 months of follow-up can predict short disease outcome at a cutoff > 0.63 with 84.62% sensitivity and 82.98% specificity.

Renal RI might be an effective non-invasive tool for early prediction and risk stratification of steroid resistance in pediatric patients with idiopathic nephrotic syndrome. Its utility lies in supporting earlier clinical decisions rather than replacing established diagnostic methods.