Predictive factors of long-term disease remission after rituximab administration in patients with childhood-onset complicated steroid-dependent nephrotic syndrome: a single-center retrospective study

Background: Despite the fact that rituximab (RTX)-associated adverse events may be relatively frequent in younger patients, recent studies have reported RTX as a suitable first-line steroid-sparing agent for maintaining remission in children with steroid-dependent nephrotic syndrome (SDNS). However, the impact of age at RTX initiation on the long-term outcome remains unknown in this cohort.

Methods: We retrospectively reviewed the clinical course of 61 patients with complicated SDNS who received a single dose of RTX (375 mg/m²) followed by maintenance immunosuppressive agents (IS) from January 2008 to March 2021. In patients who achieved > 12 months of prednisolone-free remission, IS tapering within 6 months was tried to achieve. The primary endpoint was the probability of achieving long-term treatment-free remission at the last follow-up.

Results: After RTX initiation, 52 patients (85.2%) relapsed after a median of 665 days, and 44 patients (72.1%) received additional RTX doses (total, 226 infusions). At the last follow-up (median observation period, 8.3 years; median age, 18.3 years), 16 patients (26.2%) achieved long-term remission. Multivariate analysis showed that older age at RTX initiation was the independent predictive factor for achieving long-term remission (odds ratio, 1.25; p < 0.05). The proportion of those who achieved long-term remission was significantly higher in patients aged ≥ 13.5 years than in those aged < 13.5 years at RTX initiation (52.6 vs 14.3%, p < 0.05). Persistent severe hypogammaglobulinemia did not develop in older children (≥ 13.5 years) at RTX initiation.

Conclusion: For older children with complicated SDNS, RTX appeared to be a suitable disease-modifying therapy without persistent adverse events.