Introduction: Severe thyrotoxicosis is particularly difficult to manage when antithyroid drugs are contraindicated. Therapeutic plasma exchange (TPE) is an adjunctive option in complicated hyperthyroidism, including thyroid storm and refractory thyrotoxicosis, through the rapid removal of circulating thyroid hormones, hormone-binding proteins, cytokines, and thyroid autoantibodies. However, its precise role and indications remain incompletely defined. We report two patients with Graves’ disease complicated by carbimazole-induced agranulocytosis in whom TPE was used as bridging therapy before total thyroidectomy. Cases: The first patient was a 32-year-old female who developed carbimazole-induced agranulocytosis 1 month after the diagnosis of hyperthyroidism. Biochemical control remained unsatisfactory despite second-line therapy with high-dose lithium, cholestyramine, propranolol, corticosteroids, and 5 days of Lugol’s iodine. Over 8 days, free thyroxine (fT4) increased by 13%, necessitating TPE for preoperative stabilization. Following three cycles over 4 days, fT4 decreased by 20%, from 52 to 41 pmol/L, enabling successful total thyroidectomy. The second patient was a 26-year-old female who presented with neutropenic sepsis and severe agranulocytosis 2 months after being diagnosed with Graves’ disease. She received second-line therapy, and neutrophil recovery occurred only after 7 days of granulocyte colony-stimulating factor. TPE, together with Lugol’s iodine, was then initiated as bridging therapy before surgery. After 5 days of Lugol’s iodine and three TPE cycles, fT4 decreased by 43%, from 58 to 33 pmol/L, permitting total thyroidectomy. Conclusion These cases highlight TPE as a useful bridging strategy in Graves’ thyrotoxicosis when antithyroid drugs are precluded by agranulocytosis, and conventional secondline therapy fails to achieve adequate biochemical control. TPE may facilitate timely stabilization and safe progression to definitive surgical treatment.
Plasma Exchange ; Agranulocytosis ; Graves Disease