Optimal response to ocrelizumab (Ocrevus®) treatment is associated with increased levels of plasma acetate in patients with multiple sclerosis (MS) who have no gadolinium-enhancing lesions in the brain before the start of treatment, according to a new study presented at the 38th Congress of the European Committee for Treatment and Research in Multiple Sclerosis.
According to the authors of the study, this finding links gut microbiota and response to ocrelizumab treatment in patients with primary progressive MS (PPMS) with a low inflammatory profile. “Future studies are needed to confirm the relationship of microbiota composition and response to ocrelizumab in these patients,” they wrote.
To assess the role of short-chain fatty acids levels in plasma in the response to ocrelizumab in patients with PPMS, the team, led by Luisa Maria Villar, PhD, from Ramón y Cajal University Hospital, in Madrid, Spain, conducted a prospective multicenter study in 69 patients with PPMS who were being treated with ocrelizumab.
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They found that 62.5% of patients who had gadolinium-enhancing lesions in the brain before the start of treatment with ocrelizumab and 77.4% of those who had no gadolinium-enhancing lesions before treatment reached an optimal response.
Optimal response was associated with an increase in acetate levels in the plasma after the first dose of ocrelizumab only in patients who had low inflammation and no gadolinium-enhancing lesions in the brain. This correlated with an increase in the levels of IgA levels and the IgA/IgG ratio in the serum. There was no difference in patients who had gadolinium-enhancing lesions in the brain before the start of ocrelizumab treatment.
An optimal response is defined as no disability progression and no new magnetic resonance imaging lesions after 1 year of treatment.
Short-chain fatty acids such as acetate are derived from gut microbiota metabolism and have been shown to play a role in the gut-brain axis.
Fernández Velasco JI, Monreal E, Kuhle J, et al. Elevated acetate levels correlate with optimal response to ocrelizumab treatment in low inflammatory primary progressive MS patients. Poster presented at: Congress of the European Committee for Treatment and Research in Multiple Sclerosis; October 26-28, 2022; Amsterdam, the Netherlands.