Studies of the effects of salicylate in hyperthyroidism

The aetiology and pathogenesis of hyperthyroidism

Studies of thyroid stimulating activity of serum from thyrotoxic patients has revealed an abnormal prolonged response in the mouse present in 40-60% of patients depending on the criteria used. This agent designated long acting thyroid stimulator (LATS) is a 7S globulin. Transplacental passage of LATS accounts for neonatal thyrotoxicosis—a self-limited disease. LATS is also more readily detected in patients with large goitre, exophthalmos, pretibial myxoedema and recurrence following therapy. Thyroid ablation is usually followed by a fall in the level of LATS. A fall may also be produced by steroid therapy or immunosuppressive agents. LATS probably arises from lymphoid tissue which accounts for the non-suppressibility of the hypersecreting thyroid. Its discovery provides strong evidence that hyperthyroidism is often, though not always, a disorder of immunological tolerance.