Rituximab in multiple sclerosis: A tertiary hospital experience

Background and aims: B-lymphocytes play an important role in the pathophysiology of MS. As with other anti- CD20-antibodies, there is evidence that Rituximab may be effective and safe in this disease. Methods: Retrospective study in MS patients treated with Rituximab between 2017-2021. Demographic, clinical, radiologic and laboratory variables were analyzed. Results: 45 patients were included (60% males, mean age 48.3±8;84.4% presented SPMS;median baseline EDSS 6.0, IQR 4-6.5;mean follow-up 22.69±8.75 months). After one year of treatment, there was a significant reduction of relapses (ARR 0.51 vs 0.1, p=0.002), new/enlarged T2 lesion (60% vs 10%, p<0.001) or gadolinium-enhancing lesions (40% vs 0%, p<0.001) on MRI. EDSS, T25FWT, 9HPT or SDMT did not significally change. 33.3% presented confirmed disability progression (CDP). 56.4% achieved NEDA-3. Retreatment was guided by B-lymphocytes count. Mean B-cells count was 285.7, 1.553, 4.456, 54.35, 10.47 at baseline, 3, 6, 9 and 12 months, respectively. Mean time to retreatment was 9.05±3.14 months. Lipidospecific IgM-OCB were associated with CDP (adjusted OR 6.33, p=0.047). At first dose, 31.1% presented an infusion reaction, with fewer cases with retreatment. 28.8% presented infections of any kind, including three cases of Covid19 (only one case of severe infection was reported). No cases of hypogammaglobulinemia were reported. Conclusion: B-lymphocytes count guiding retreatment with Rituximab among patients with MS may favor a good safety profile, while being effective in reducing inflammatory activity. CDP was associated with lipidospecific IgM-OCB.