[Evaluation of immunological tests in thyroid diseases].

We evaluated immunological tests for autoimmune thyroid diseases. Although both humoral and cellular immunity are correlated to the onset and pathophysiological progression of these diseases, the major tests employed in daily clinic belong to the former. We measured the anti-TSH receptor antibody (TRAb, TBII), circulating immune complex (CIC), thyroid growth stimulating immunoglobulin (TGSI) and interleukin-2 (IL2) levels in patients with Graves' disease (GD) and chronic thyroiditis (CT). The normal range of TRAb in 190 healthy controls was from -10.9 to +10.3% calculated from the mean +/- 2SD. Sixty eight out of 78 untreated cases of GD (87.2%) showed a higher TRAb than the upper normal level (positive), 92 out of 131 cases of GD under treatment (70.2%) were positive and only 5 out of 57 cases of treated GD (8.8%) were positive. Three neonates out of 12 GD mothers had a positive TRAb and one of them developed neonatal GD. Nine out of the 45 CT (20%) had positive TRAb, but about half were euthyroid and goitrous. In untreated GD, CIC was distributed widely from the normal range to high levels. CIC showed a significantly negative correlation with TRAb. TGSI correlated with goiter size and CIC in GD revealed autologous inhibition on TGSI. Three cases showed markedly decreased levels of TRAb which was found to be due to anti-TSH antibodies. Production of IL2 in GD was impaired, but it was improved by treatment of GD.(ABSTRACT TRUNCATED AT 250 WORDS)