Relation of thyroid-stimulating immunoglobulins to thyroid function and effects of surgery, radioiodine, and antithyroid drugs.

Thyroid-stimulating immunoglobulins (T.S.I.) have been detected in the serum of all patients with untreated Graves' disease, and in these patients the levels of T.S.I. correlated significantly with the early uptake of 131I by the thyroid. The frequency of T.S.I. in patients treated solely by antithyroid drugs, by radioiodine, or by partial thyroidectomy was 53 per cent, 50 per cent, and 17 per cent, respectively. The reduced frequency of T.S.I. in the serum of patients treated by drugs or radioiodine was probably due to spontaneous remission, but in the case of partial thyroidectomy the operation itself clearly had a dramatic effect on the serum-T.S;I. These results accorded well with the reported frequency of thyroid autonomy in similar groups of patients and suggested that thyroid-stimulating immunoglobulins were responsible for hyperthyroidism in Graves' disease.