Kidney Survival in Children With Steroid-Resistant Nephrotic Syndrome Treated by Rituximab.

Area of Science:

• Pediatric Nephrology
• Immunosuppressive Therapy
• Glomerular Diseases

Background:

• Steroid-resistant nephrotic syndrome (SRNS) poses significant challenges in pediatric kidney disease management.
• The efficacy and long-term kidney outcomes following rituximab treatment in SRNS patients remain incompletely understood.

Purpose of the Study:

• To evaluate kidney survival rates in children with SRNS treated with rituximab after failure of calcineurin inhibitors (CNIs).
• To identify predictors of kidney outcomes in this patient cohort.

Main Methods:

• International retrospective cohort study involving 151 children with SRNS across 23 centers in 17 countries.
• Patients excluded genetic variants and had not responded to CNIs prior to rituximab administration.
• Primary outcome assessed was kidney survival, with analysis of baseline characteristics and treatment response.

Main Results:

• Overall kidney survival was 82.7% at 3 years, 75.8% at 5 years, and 72.3% at 7 years post-rituximab.
• Pre-existing chronic kidney disease (CKD) stage, lower baseline serum albumin, and focal segmental glomerulosclerosis (FSGS) were significant predictors of inferior kidney survival.
• Non-remission at 6 months post-rituximab was strongly associated with poorer long-term kidney survival compared to complete or partial remission.

Conclusions:

• Rituximab provides moderate kidney survival rates (70-80%) over 3-7 years for children with SRNS refractory to CNIs.
• Baseline CKD stage, low serum albumin, FSGS, and lack of early treatment response are critical factors influencing kidney outcomes.
• These findings highlight the importance of assessing baseline kidney function and early treatment response for prognostication in SRNS patients treated with rituximab.