SAT-476 Alemtuzumab Induced Graves Disease

Abstract Introduction: Immune reconstitution therapy (IRT) with the monoclonal antibody alemtuzumab (anti-CD 52) has been shown to be superior to β-interferon in relapsing-remitting multiple sclerosis. It can cause early hyper-population of immature B cells which increases the risk of autoimmune disorders. The most common autoimmune adverse effect is autoimmune thyroid disorder (AITD) which has not been well recognized by internists, especially primary care physicians. We present a case of alemtuzumab-related hyperthyroidism. Most of these cases are mild and can be easily managed. Case presentation: A 44-year-old female with history of multiple sclerosis (MS) presented to the office with a two-month history of fatigue, palpitations, tremors, weight loss and pruritus after completing a course of Alemtuzumab. Her symptoms started 1 month after completing 2 years of a consecutive series with IRT. Her thyroid function panel was not checked before starting IRT. She had no previous history of thyroid disease. Family history is positive for goiter in her mother. She had no exposure to contrast dye, steroids, amiodarone, supplements or biotin use. On exam, she had tachycardia, dry skin, tremors on outstretched hands and a non-tender goiter with no palpable nodules. Her initial labs showed a suppressed TSH (<0.005 mIU/L), elevated FT4 (>7.77 ng/dL), elevated T3 (647 NG/dL) and TSI of 338% (<140%), consistent with Graves’ Disease. She was started on methimazole. Two months into treatment, she became clinical and biochemical euthyroid without medication side effects. Discussion: This patient might have Graves’ disease before IRT which can be easily treated if TFTs were routinely checked; or her Grave’s disease was induced by IRT later. Lack of TFTs checked before, during and after IRT put those patients at risk of unawareness of thyroid abnormalities. Based on this case, we strongly recommend doing routine TFTs (TSH, free T4) check before starting IRT to rule out existing thyroid function abnormalities and provide treatment accordingly. We also recommend checking TSI, TPO antibody for high-risk patients (positive family history, past history) and thyroid US for those who have nodules or goiters before starting IRT. For those found to have abnormal TFTs, TSI or TPO, routine follow up with an Endocrinologist should be recommended during, and even after therapy completion. References: 1. Alemtuzumab-induced thyroid events in multiple sclerosis: a systematic review and meta-analysis. L. Scappaticcio et al. 2. Thyroid disorders in alemtuzumab-treated multiple sclerosis patients: a Belgian consensus on diagnosis and management. Decallone B et al. 3. 2019 European Thyroid Association Guidelines on the Management of Thyroid dysfunction following immune reconstitution therapy. Muller et al.