Leukocyte migration inhibition in vitro in untreated and methimazole-treated patients with Graves disease.

The leukocyte migration tests has been applied to investigate immune-reactivity of 43 untreated and methimazole-treated patients against thyroid crude antigen. A significant migration inhibition was observed in 21 untreated patients, while in 22 methimazole-treated patients the migration test was negative independently of T3 suppressibility. Migration inhibition against thyroid antigen and purified protein derivative (PPD) was reduced or abolished after preincubation with methimazole of leukocytes of untreated patients. It seems that methimazole-treatment influences not only thyroid iodine metabolism, but by means of a direct effect on lymphocytes it also decreases the pathological stimulation.