Endocrine Abstracts

Introduction: Graves thyrotoxicosis can be life-threatening if uncontrolled. Resistant thyrotoxicosis is not uncommon and may require urgent intervention. We present a case with severe refractory thyrotoxicosis which required urgent total thyroidectomy following bridging plasma exchange.

Case History: A 35-year-old male with Grave’s disease presented with persistent thyrotoxic symptoms despite medical management for 10 months. Clinically he was hyperthyroid with a heart rate of 108 b.p.m and had mild thyroid eye disease. ECG revealed sinus tachycardia. The thyroid function tests with TSH of < 0.001 mIU/lwith FT4 of 7.77 ng/dL (Reference 0.89-1.76). Imaging of the neck showed features of Graves thyroiditis. He was titrated up with anti-thyroid medications and while on Carbimazole 60 mg daily, Lithium carbonate 250 mg BD, Propranolol 40 mg BD, Prednisolone 30 mg daily, and Cholestyramine 4 g TDS, his FT4 was 5.92 ng/dl. Presence of persistently elevated FT4 along with a thyrotoxic state, it was decided to proceed with urgent thyroidectomy as a curative option. However, to bring down the FT4 to a safer level before the surgery, a therapeutic plasma exchange (TPE) was offered, and the surgery was performed after 2 cycles of TPE.

Discussion: Resistant thyrotoxicosis can be treated with surgery or radioactive iodine ablation. However, a euthyroid state should be achieved prior to these treatment strategies to minimize the risk of complications including thyroid storm. Therefore, in patients with refractory thyrotoxicosis with maximum tolerable medical management, a therapeutic plasma exchange (TPE) can be offered to reduce the FT4 up to a safer level. TPE is a procedure that involves exchanging a patient’s plasma through an apheresis machine. It can be used in severe hyperthyroidism as it removes active thyroid hormones and thyroid receptor antibodies (1). Therefore, TPE in refractory thyrotoxicosis is an effective treatment option and a crucial bridge to the definitive treatment in challenging cases (2).

References: 1. Saïe C, et al., Therapeutic Plasma Exchange in Refractory Hyperthyroidism. Eur Thyroid J. 2021 Mar;10(1):86-92. 2. Tieken K, et al., Therapeutic plasma exchange as a bridge to total thyroidectomy in patients with severe thyrotoxicosis. AACE Clin Case Rep. 2020 Sep 26;6(1): e14-18.