Endocrine Abstracts

Although NICE guidelines recommend that radioiodine is the first-line treatment for Graves disease, carbimazole is often used initially to get control of the hyperthyroidism. This patient was exquisitely sensitive to carbimazole initially, and despite initial recurrence, he cannot be treated with radioiodine as he now has intermittent hypothyroidism.

Case: A 42-year-old male was diagnosed with Grave’s disease and initially treated for twelve months with low-dose carbimazole. One year later, he relapsed with biochemical evidence of hyperthyroidism (TSH: <0.01 milliunit/l, Free T4 = 32 pmol/l, Free T3 = 14.2 pmol/l) and an elevated TSH antibody level of > 30 unit/l, necessitating the initiation of therapy. Three months into treatment, he developed hypothyroidism, requiring the withdrawal of carbimazole due to a rise in thyroid-stimulating hormone (TSH) to 65 mu/l and a drop in Free T4 to 5.4 pmol/l. The table demonstrates the exquisite sensitivity the patient had to carbimazole despite his high antibody titre throughout the follow-up period. At present, he continues to exhibit biochemical signs of hypothyroidism (TSH: 47.9 milliunit/l, free T4: 8.6 pmol/l, and free T3: 2.9 pmol/l), despite being on no treatment for five months Despite the significant level of TSH receptor antibodies, the development of hypothyroidism is suggestive of the existence of inhibiting antibodies. He remains at risk of subsequent recurrence, and we are now ready to offer definitive treatment as soon as he has a recurrence.

Conclusion: This case would emphasize the need for an individualized treatment approach, close monitoring of thyroid function, and long-term follow-up.