Therapeutic plasma exchange for control of thyroid storm

Abstract

Therapeutic plasma exchange (TPE) for thyroid storm has recently been upgraded to a category II indication after decades though its recommendation level still remains at Grade 2C according to the American Society for Apheresis (ASFA). In the absence of prospective randomized controlled trials due to the rarity of thyroid storm, retrospective data from case series continue to elevate the clinical evidence supporting TPE as a life-saving modality for complicated thyroid storm patients. We report three cases of life-threatening thyroid storm from Graves' disease rescued by TPE via rapid reduction in circulating thyroid hormones. Each patient underwent TPE when it was judged that other thyroid storm treatment options were futile or unsafe. The first patient received 4 cycles of TPE while the second patient received 9 cycles of TPE, and the third patient received 2 cycles of TPE with satisfactory clinical improvement. Plasma FT4 and TSH receptor antibody levels of the first case declined by 41.3% and >50% respectively right after the first round of TPE; plasma FT4 of the second patient dropped by up to 31.6% during the course of TPE; plasma FT4 and TSH receptor antibody of the third patient declined by 66% and 56.2% respectively after the first cycle of TPE. This demonstrates the safety, efficacy, and feasibility of TPE in thyroid storm especially when other therapeutic interventions are contraindicated. TPE operates via the elimination of serum proteins-bound thyroid hormones, thyroid autoantibodies, cytokines, and catecholamines in addition to increasing unsaturated binding sites for thyroid hormones.