Abstract
Thyroid storm (TS) is a rare and life-threatening medical emergency, most commonly caused by Graves’ disease (GD). GD can be induced by immune reconstitution therapy (IRT) such as alemtuzumab (ALZ), a humanized monoclonal antibody against CD52, which is shown to be effective in the treatment of relapsing-remitting multiple sclerosis (RRMS). Here, we present a rare case of TS developing in a 39-year-old female with ALZ-induced GD, managed with antithyroid medication followed by thyroidectomy. There is some evidence that ALZ-induced GD may behave less aggressively than conventional GD. However, physicians should be aware that severe thyrotoxicosis and thyroid storm can happen, which requires prompt recognition and aggressive therapy.