Effect of rituximab on disease activity in latin American patients with anti-aquaporin-4 (+) neuromyelitis optica spectrum disorder.

OBJECTIVES: The aim of the present study is to explore the efficacy of rituximab in patients with Neuromyelitis Optica spectrum disorders (NMOsd) with positive AQP4-IgG serostatus. PATIENTS AND METHODS: In this single center retrospective study, we recruited seropositive anti-AQP4 NMOsd patients who received treatment with Rituximab (RTX) for at least 2 years. Demographics were described and annualized relapse rate (AAR) and survival analysis were performed for time to relapse with Rituximab. All p values ≤0.05 we considered statistically significant. RESULTS: A total of 15 patients (100 % female) were identified. Mean age of disease onset was 34 ±â€¯11 years, mean time of disease was 8.11 ±â€¯4.04 years and the median number of relapses was 5 (2-16). Ten patients received an immunosuppressive agent before RTX. Mean age of RTX initiation was 37 ±â€¯12 with a mean treatment duration of 52 ±â€¯28 months. The median ARR before and after treatment with RTX was 2.08 vs 0.00, respectively, with a difference of -2.08 (p < 0.001) CONCLUSIONS: This study shows a statistically significant reduction in the ARR and an increase in the relapse-free rate in AQP4-IgG NMOsd patients treated with RTX. These findings support the use of rituximab in our population, and indirectly suggests that its prompt use could modify the course of the disease.