Endocrine Abstracts

Use of therapeutic plasmapheresis in hyperthyroidism is mainly described in thyroid storm when traditional measures fail. Patients with hyperthyroidism who respond poorly or suffer adverse effects to conventional antithyroid therapies, which then need to be stopped, can have persistently high levels of thyroxine and at risk of a full blown thyroid storm. Hence an alternative treatment to achieve euthyroidism followed by thyroidectomy as definitive therapy is vital. We report here a case of a lady who as a result of multiple adverse effects from conventional antithyroid therapies, underwent therapeutic plasmapheresis as a last resort to achieve euthyroidism prior to thyroidectomy. A 35 year-old lady who was diagnosed with Grave’s hyperthyroidism 2 months earlier and treated with carbimazole presented with fever, sore throat and generalized body weakness. Blood investigations revealed leucopenia (total white cell - 1.50x10³/uL) and neutropenia (absolute neutrophil count 0.03x10³/uL). A diagnosis of carbimazole-induced agranulocytosis with neutropenic sepsis was made. Carbimazole was stopped. Intravenous antibiotics, antifungal prophylaxis and granulocyte colony-stimulating factors (GCSF) were instituted. Her neutropenia was fairly resistant and needed twice daily GCSF for a week to recover. Thus, it was deemed unsafe to challenge with prophylthiouracil. Oral cholestyramine and lithium were started as alternative treatment for her thyrotoxicosis. Two weeks later she developed widespread pruritic maculopapular rash attributed to lithium which was then withheld. She also could not tolerate cholestyramine fully and often vomited on taking the drug. We opted to rechallenge her with lithium at lower doses and administer oral cholestyramine via nasogastric tube in the ward. However, her FT4 remained above 100 pmol/l (12.3-20.2) five days later (Table 1). Eventually we resorted to using therapeutic plasmapheresis one week before her scheduled operation date. She underwent 2 sessions of plasmapheresis uneventfully. Short term Lugol’s iodine was started perioperatively along with steroid cover. She successfully underwent total thyroidectomy and is currently well on levothyroxine replacement. This case highlights the use of, plasmapheresis as an effective and safe alternative to achieve rapid restoration of euthyroidism prior to thyroidectomy when conventional measures fail, even before acute deterioration into thyroid storm.