Simultaneous early-onset immune thrombocytopenia and autoimmune thyroid disease following alemtuzumab treatment in relapsing-remitting multiple sclerosis

Objective: We report two cases of patients with relapsing-remitting multiple sclerosis with early-onset thrombocytopenia and autoimmune thyroid disease after the first treatment course with 60-mg alemtuzumab. Methods: Case series and review of the literature. Results: Both patients showed severe thrombocytopenia with platelet counts of 2x10(9) and 11x10(9)/L, respectively, as well as increased thyroid antibodies within only a few months after initiating alemtuzumab treatment (11 and 9months). Both patients responded considerably well to medical therapy including corticosteroids and intravenous immunoglobulins with slow platelet recovery over several weeks. Interestingly, both patients were previously treated with fingolimod and showed a marked lymphocytopenia that led to discontinuation. Conclusion: These cases emphasize the necessity of careful clinical surveillance and proper education of patients treated with alemtuzumab as proposed by the safety-monitoring program. Previous severe lymphocytopenia under therapy with other disease-modifying therapies may be a risk factor for the development of immune thrombocytopenia.