Rituximab for Children With Difficult-to-Treat Nephrotic Syndrome: Its Effects on Disease Progression and Growth.

Since the early 2000s rituximab (RTX) has been thought of as an alternative treatment for steroid-sensitive nephrotic syndrome (SSNS) and steroid-resistant nephrotic syndrome (SRNS). This study aimed to determine the effects of RTX treatment on disease outcome and growth in pediatric SSNS and SRNS patients. The medical records of pediatric SSNS and SRNS patients that began RTX treatment at the mean age of 10.8 ± 5.1 years between 2009 and 2017 were retrospectively reviewed. Additionally, the effect of RTX on growth was evaluated based on patient height, weight, and BMI z scores. The study included 41 children, of which 21 had SSNS and 20 had SRNS. Mean age at diagnosis of NS was 5.8 ± 4.7 years. Mean duration of post-RTX treatment follow-up was 2.3 ± 1.6 years. Among the SSNS patients, 6 and 11 patients were steroid free and calcineurin inhibitor free at the last follow-up visit, respectively. The 1-year cumulative steroid and calcineurin inhibitor doses both decreased after RTX treatment, as compared to before RTX ( = 0.001 and = 0.015, respectively). The median height -score at the time of RTX initiation was -1.2 and the median height -score at the last follow-up visit was -0.6 ( = 0.044). The median BMI -score decreased from 1.6 (IQR; 0.9-3.0) at the time RTX was initiated to 1.1 IQR; [(-0.7)-2.5] at the last follow-up visit ( = 0.007). At the last follow-up visit 4 SRNS patients had complete remission and 4 had partial remission. The 1-year cumulative steroid dosage in the SRNS patients decreased significantly after RTX, as compared to before RTX ( = 0.001). The median height -score at the time of RTX initiation was -0.8 and the median height -score at the last follow-up visit was -0.7 ( = 0.81). The median BMI -score decreased from 0.3 at the time RTX was initiated to -0.1 at the last follow-up visit ( = 0.11). RTX has a more positive effect on disease outcome and growth in SSNS patients than in those with SRNS.