Rituximab as a first-line therapy in children with new-onset idiopathic nephrotic syndrome

Background Idiopathic nephrotic syndrome (INS) in children, commonly treated with steroids, poses challenges due to associated side effects. Rituximab, known for its efficacy in reducing relapse frequency in difficult-to-treat cases, emerges a potential first-line therapy for pediatric new-onset INS.Method This is a single-center, retrospective, observational study to evaluate the efficacy and safety of rituximab as a first-line therapy for pediatric INS. The complete treatment strategy was weekly injections at a dose of 375 mg/m2 for four doses. Children with new-onset INS who received rituximab as a first-line monotherapy from 1 January 2022 to 31 December 2023 were included and followed until 31 May 2024.Results Seventeen patients (median age at diagnosis 4.8 years) were included. Twelve patients achieved complete remission within a median time of 19 days. Over a follow-up period ranging from 41 to 112 weeks, 11 patients maintained remission even after B-cell reconstitution, with one patient experiencing a relapse at 85 weeks. Three patients, who presented with hematuria, hypocomplementemia or renal injury at initial diagnosis, exhibited resistance to rituximab. No severe adverse events were noted.Conclusion Rituximab may be an effective and safe option as a first-line therapy for inducing and maintaining remission in newly diagnosed INS.