Utility of renal resistive index measurement in juvenile systemic lupus erythematosus: a cross-sectional single-center study.

Although RRI was found significantly higher in juvenile SLE, it is not affected by GFR, proteinuria level, or the renal biopsy results, even the presence of proliferative nephritis. The underlying pathogenetic mechanisms of increased RRI in SLE should be clarified in further studies. Key Points • Renal resistive index (RRI) is a parameter derived from renal Doppler ultrasound imaging and shows the intrarenal arterial resistance. • This study reveals that RRI is increased in juvenile systemic lupus erythematosus. • RRI was previously related with renal involvement, particularly class 4 lupus nephritis in adults. However, RRI was not affected by the presence or degree of renal involvement in juvenile SLE patients in our study.