Serum thyroglobulin and its autoantibody following subtotal thyroid resection of Graves' disease

Thyroid surgery leads to marked changes of the levels of serum thyroglobulin and its autoantibodies in the subsequent 3 postoperative weeks. Furthermore in Graves' disease progression of exophthalmos has sometimes been seen following thyroidectomy. Nineteen medically pretreated patients with Graves' disease and no signs of exophthalmos were studied systematically up to 6 months postoperatively. Nine patients had thyroglobulin antibodies. Mean values rose to 3.5 times pretreatment values within 2 months (P less than 0.001) followed by a gradual fall below pretreatment level after 6 months. None of the antibody negative patients reverted to positive or vice versa. Serum thyroglobulin (n = 10) was elevated preoperatively (mean 309 micrograms/l, SD 251), their values being normalized within 1-2 months (mean 19.4 micrograms/l, SD 7.3). The preoperative serum thyroglobulin correlated to the weight of the removed thyroid tissue (r = 0.87, P less than 0.01). Three patients showed elevated thyroid stimulating hormone after 1 month. Of these, two developed myxoedema, the third remained euthyroid with persistently elevated serum thyroglobulin. None showed recurrence or developed exophthalmos within the period of observation. In spite of rising levels of thyroglobulin antibodies in all patients with antibodies none developed exophthalmos and only one patient with thyroglobulin antibodies had clinical myxoedema.