Rituximab in childhood steroid-dependent nephrotic syndrome: a single-center experience

Abstract Background Most children with idiopathic nephrotic syndrome are steroid-sensitive. However, the majority of them relapse. Unfortunately, 50–70% of relapsers will develop frequently relapsing nephrotic syndrome or steroid-dependent nephrotic syndrome (SDNS). This study focused on the effect and safety of rituximab in childhood SDNS. Methods This retrospective study included SDNS children who received rituximab from 1 January 2021 to 30 June 2023. Data were collected about age at onset of nephrotic syndrome, age at first rituximab dose, and details of infusions. The time until CD19+ B-cell repletion and the time until relapse post-rituximab, as well as the total dose of steroids administered per year and the duration of remission, 1 year before and 1 year after rituximab, were analyzed. Results Thirty SDNS patients received rituximab treatment at a median age of 9.75 years for the first dose. During a median follow-up of 19 months, only 16.7% developed complications, mainly allergic reactions, and 47.6% of patients relapsed. No significant correlation was found between the time to CD19+ B-cell reconstitution and the time to relapse. A significant positive correlation was observed between the time to relapse after rituximab and the duration of nephrotic syndrome before treatment. However, no similar correlation was seen with the age at the first rituximab dose or renal biopsy findings. The total steroid dose per year was significantly lower, and the duration of remission was significantly longer in the year after rituximab compared to the year before. Conclusion Rituximab significantly prolongs the duration of remission and decreases the total steroid doses needed. There is a positive correlation between the time until relapse post-rituximab and the duration of nephrotic syndrome before rituximab. There is no significant difference in relapse incidence with or without routine prophylactic rituximab retreatment after B-cell repletion.