ODP523 Thyroid Storm in a Patient With Alemtuzumab Induced Graves’ Disease

BACKGROUND: Thyroid storm (TS) is a rare and life-threatening medical emergency, most commonly caused by Graves’ disease (GD). GD can beinduced 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). Evidence shows that ALZ induced GD may be less aggressive than conventional GD. Below we present a rare case of thyroid storm developing in a patient with ALZ induced GD. CLINICAL CASE: A 39 year-old female non-smoker, known to have RRMS, wasstarted on ALZ. Presented to our emergency room13months later with palpitation, diarrhea and oligomenorrhea. Found to have TSH of 0. 007 mIU/L (0.250-5), T4 50 pmol/L (11.5- 22.7), thyroid scan demonstrated diffusely enlarged thyroid gland with increased tracer uptake compatible withGD. Our impression was ALZ- induced GD (not in thyroid storm),she wasstarted on carbimazole and propranolol and discharged home. Neurology team gave hera second cycle of ALZas she was euthyroid on carbimazole. One month later, the patient presented to our emergency room with nausea and vomiting. On examination, she was febrile 38.2°C, tachycardic reaching 140 beats/min (regular). Her blood pressure was 138/87 mmhg. The patient was agitated, anxious, alert and oriented. She was diaphoretic with mild peripheral oedema and had pulmonary crackles. The thyroid was diffusely enlarged with no signs of graves’ ophthalmopathy, or pretibial myxedema. On the Burch-Wartofsky Point Scale for thyroid storm, she scored 60. The patient was admitted to the intensive care unit (ICU), with endocrinology and neurology consultation. Laboratory investigation revealed TSH of 0. 009 mIU/L, T3 26.5 pmol/L (3.39-5.82) T4 65 pmol/L, positive thyroid peroxidase antibody 183 units (>100 positive). Despite treatment with maximum dose of carbimazole, B-blocker, hydrocortisone, and potassium iodide her T4 was not improving, and her liver function was deteriorating. Finally, she underwent total thyroidectomy. Three days post total thyroidectomy, the patient clinically improved. Steroids were stopped and the B-blocker dose was gradually tapered. She was then maintained on Levothyroxine. CONCLUSION: It is thought that ALZ- induced GD behaves less aggressive than the conventional GD as spontaneous and/or drug-induced remission may be more likely. However, physicians should be aware that severe thyrotoxicosis and thyroid storm can happen which required prompt recognition and aggressive therapy. Presentation: No date and time listed