The association between hypogammaglobulinemia severity and infection risk in rituximab-treated patients with childhood-onset idiopathic nephrotic syndrome

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

BACKGROUND

The efficacy of rituximab in 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 SRNS treated with rituximab 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. The primary outcome was the rate of CR, PR, and NR. Risk factors for non-CR were calculated with multivariate logistic regression. Adverse events and the relationship between disease status at one year and long-term prognosis were also 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. The median follow-up period after rituximab administration was 7.4 years. 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.

CONCLUSION

Early administration of rituximab in combination with MPT and immunosuppressants might achieve favorable outcomes in patients with SRNS.

Efficacy and safety of long-term repeated use of rituximab in pediatric patients with nephrotic syndrome

BACKGROUND

We aimed to investigate the efficacy and safety of repeated use of rituximab (RTX) in pediatric patients with nephrotic syndrome (NS).

METHODS

Retrospective review of 50 patients with steroid-dependent NS (SDNS) who had received more than three cycles of RTX was conducted; each consisted of one to four infusions until B lymphocytes were depleted.

RESULTS

The median age of starting the first RTX cycle was 12.4 years (interquartile ranges (IQR) 10.2-14.6). During a median follow-up period of 6.3 (IQR 3.6-8.6) years, patients received a median of 5.0 RTX cycles (IQR 4.0-7.3). The number of relapses decreased from a median of 2.0 relapses per year (IQR 1.0-3.0) to 0.2 relapses per year (IQR 0.0-0.5) after long-term RTX treatments (P < 0.001). Longer relapse-free periods were associated with more than four RTX cycles, longer B-cell depletion, older age at each RTX treatment, and lower cholesterol levels. B lymphocytes recovered to 1% at a median of 5.9 months (95% confidence interval 5.7-6.1) after RTX administration. Factors related to a longer period of B-cell depletion included more than five RTX cycles, a higher dose of RTX, older age at treatment, and concurrent use of antimetabolites. During repeated RTX treatments, 8.0%, 6.0%, and 2.0% of patients developed hypogammaglobulinemia, severe infection, and severe neutropenia, respectively.

CONCLUSIONS

Long-term repeated use of RTX may be effective and safe in pediatric NS patients. Furthermore, the redosing of RTX could be chosen by considering predictive factors for relapse-free and B-cell depletion periods.