Efficacy of rituximab and risk factors for poor prognosis in patients with childhood-onset refractory steroid-resistant nephrotic syndrome: a multicenter study

Abstract Background The efficacy of rituximab in refractory steroid-resistant nephrotic syndrome (SRNS) is controversial. We previously reported that rituximab in combination with methylprednisolone pulse therapy (MPT) and immunosuppressants was associated with favorable outcomes. We determined risk factors for poor response following rituximab treatment, which remains unknown. Methods This retrospective study included 45 patients with childhood-onset refractory SRNS treated with rituximab treatment across four pediatric kidney facilities. Treatment effects were categorized as complete remission (CR), partial remission (PR), and no remission (NR) at one year after rituximab treatment. Risk factors for poor response (non-CR) were calculated with multivariate logistic regression. Adverse events and the relationship between disease status at one year and long-term prognosis were evaluated. Results The rates of CR, PR, and NR at one year were 69%, 24%, and 7%, respectively. The median time from rituximab administration to CR was 90 days. In multivariate analysis, significant risk factors for poor response were the pathologic finding of focal segmental glomerular sclerosis and a long interval between SRNS diagnosis and rituximab administration. The rates of CR were 90.3% and 21.4% in patients receiving rituximab within and after 6 months following SRNS diagnosis, respectively ( p < 0.001). Five patients developed chronic kidney disease stage G5, including 2 of the 11 patients with PR and all 3 patients with NR, whereas none of the 31 patients with CR developed chronic kidney disease stage G5. Conclusions Early administration of rituximab in combination with MPT and immunosuppressants might achieve favorable outcomes in patients with refractory SRNS.