Comparative analysis of immunosuppressive therapies for myelin oligodendrocyte glycoprotein antibody-associated optic neuritis: a cohort study

Aims The optimal immunosuppressive therapy (IST) in patients with myelin oligodendrocyte glycoprotein antibody-associated optic neuritis (MOG-ON) remains uncertain. This study aimed to observe the disease course of MOG-ON and evaluate the therapeutic efficacy and tolerability of conventional immunosuppressants through Chinese cohort analysis. Methods This bidirectional cohort study included 121 patients with MOG-ON between January 2015 and December 2018. The clinical features and annualised relapse rate (ARR) of patients with and without IST were analysed. Results The median age at onset was 17.5 years, and the sex ratio (F:M) was 1.24. Of 121 patients, 77 patients relapsed and 61 patients were younger than 18 years at disease onset. The overall median ARR of 63 patients in the non-IST group was 0.5, with 46.0% patients showing relapse at a median follow-up of 33.5 months. In the IST group, the ARR decreased from 1.75 pre-IST to 0.00 post-IST in 53 patients who received IST exceeding 6 months, with 20.8% patients showing relapse at a median follow-up of 23.8 months. The relapse rates of patients treated with rituximab (RTX) and mycophenolate mofetil (MMF) were not statistically different, but the rate of discontinuation was significantly lower in the RTX-treated group (18.2% vs 57.7%, p=0.0017). Conclusion This study provides Class III evidence that both MMF and RTX may lower disease activity in patients with MOG-ON, and RTX showed better tolerability than MMF. However, observation after a single attack remains a good option because less than half of patients not on treatment suffered a relapse.