Improvement of immunologic abnormalities associated with hyperthyroidism of Graves' disease during methimazole treatment.

In an attempt to study the effects of methimazole treatment on immunologic abnormality of hyperthyroidism of Graves' disease, TSH receptor antibody (TRab), anti-DNA antibody and HLA-DR were measured in untreated patients with hyperthyroidism of Graves' disease and treated patients with methimazole for 2 years, using peripheral blood. In untreated patients, all 3 parameters elevated above normal. Three parameters decreased 2 years after methimazole treatment, but the magnitude of decrease was more in T3-suppressible patients than in T3-unsuppressible patients. However, both anti-DNA antibody and HLA-DR were significantly more in T3-suppressible patients than in normal subjects. It is suggested that immunologic abnormalities should largely be improved before remission of Graves' disease can be obtained.