Alba Suárez EM, Tallón Barranco A, Puertas Muñoz I, Chamorro Hernández B, Robles Marhuenda Á. Non-late-onset neutropaenia following treatment of multiple sclerosis with ocrelizumab. Neurologia. 2021 13:S0213-4853(21)00026-8. Late-onset neutropaenia (loss of neutrophils which are our first line against infection) is defined as an absolute neutrophil count of <1.5×103cells/μL starting>4 weeks after the last dose of rituximab, in the absence of other identifiable causes. Late-onset neutropaenia is a rare adverse reaction to rituximab (observed in approximately 5% of patients). Rheumatic diseases constitute the main indication for rituximab; in these patients, neutropaenia appears after a mean of greater than 28 days. Ocrelizumab is another monoclonal antibody that binds to CD20 (a glycosylated phosphoprotein mainly expressed on the membranes of B-lymphocytes); in January 2018, it was approved for the treatment of relapsing-remitting and primary progressive multiple sclerosis. We present a case of neutropaenia following intravenous infusion of ocrelizumab in a patient with primary progressive multiple sclerosis who presented with neutropaenic fever, herpetic stomatitis ( is a viral infection of the mouth that causes sores and ulcers), and ecthyma gangrenosum (a type of skin lesion characterized by vesicles or blisters which rapidly evolve into pustules and necrotic ulcers with undermined tender erythematous border. “Ecthyma” means a pus forming infection of the skin with an ulcer, “gangrenosum” refers to the accompanying gangrene or necrosis), only 20 days after infusion.
Many MS drugs can have an impact on neutrophils but this is unusual. Why does it happen as one guesses neutrophils do not express CD20. However, they may be triggered buy the B cell killing mechanisms. I am guessing these will get checked as part of you standard blood tests. It further shows that you immune system is there to get rid of infections removing large chunks of it with drugs can have consequences and a reason why you dont want to do it forever.
Marked neutropenia: Significant but rare in people with multiple sclerosis after alemtuzumab treatment. Baker D, Giovannoni G, Schmierer K.Mult Scler Relat Disord. 2017 Nov;18:181-183.
Neutropenia has been reported with cladribine when used within the cancer setting and is one of the major problems with HSCT, which is associated with loss of neutrophils and severe and sometimes fatal infection risk .
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