Autoimmune thyroid disease following treatment with alemtuzumab for multiple sclerosis

Alemtuzumab, an anti-CD52 monoclonal antibody, is effective in the treatment of relapsing–remitting multiple sclerosis (RRMS). Common adverse effects include the development of autoimmune diseases, and Graves’ disease is one of the most frequent presentations. We report here a case of alemtuzumab-induced thyroid disease in a female patient who showed a phase of thyrotoxicosis with positive anti-thyroglobulin (anti-Tg) and anti–thyroid peroxidase (TPO) antibodies, but a negative TSH receptor antibody, spontaneously followed by hypothyroidism. The aim is to illustrate the clinical presentation, evaluation over time, and the possibility to consider a conservative management up to the spontaneous resolution of the thyrotoxicosis. All these are intended to emphasize the importance of pretreatment screening and follow-up in the management of treatment with alemtuzumab.