Alemtuzumab Induced Thyroid Disease in Multiple Sclerosis: A Review and Approach to Management

Alemtuzumab, an anti-CD52 monoclonal antibody, was recently approved for treatment of MS in Canada, having shown to significantly reduce relapses and disability in patients, particularly those who relapsed despite first line treatment. Offsetting its benefit however, is the development of novel secondary autoimmune disease, particularly affecting the thyroid gland in up to 36% of patients. The incidence of Alemtuzumab induced thyroid dysfunction (AITD) will likely rise as alemtuzumab becomes more widely used for treating MS. We review the clinical and investigational cues that help delineate the aetiology and management of thyrotoxicosis and hypothyroidism in ATID. AITD can be easily managed and we present a simple approach for its evaluation and management by neurologists that should be implemented prior to considering a referral to an internist or endocrinologist for further opinion or treatment.