[Anti-thyroglobulin and anti-thyroid microsomal antibodies in thyroid disorders]

Serum anti-thyroglobulin antibody (TgAb) and anti-thyroid microsomal antibody (McAb) in 213 cases of thyroid disorders and 32 cases of non-thyroid disorders were studied. The antibodies were checked by commercial tanned red cell hemagglutination kits (Thymune-T and Thymune-M) purchased from Wellcome Reagents, Limited, England. The positive rates of TgAb and McAb in patients with untreated toxic diffuse goiter (45 cases) were 25.6% and 74.4%, respectively; 22.2% and 44.4% in toxic diffuse goiter on antithyroid therapy (36 cases); 42.9% and 71.4% in hyperthyroidism after thyroidectomy (7 cases); 60% and 80% in Hashimoto's thyroiditis (10 cases) and 100% and 50% in idiopathic primary hypothyroidism (2 cases). In hyperthyroidism and Hashimoto's thyroiditis, the positive rates of McAb were much higher than those of TgAb. The positive rates of TgAb and McAb in non-toxic nodular goiter were 11.7% and 10.4%, respectively; 6.1% and 3.0% in non-toxic diffuse goiter and 3.1% and 3.1% in non-thyroid disorders, There were 13 cases whose TgAb titers were 80 x (dilution factor) or higher and 25 cases whose McAb titers were 1600 x or higher. All of them belonged to the autoimmune thyroid diseases. It is, therefore, concluded that patients with autoimmune thyroid diseases have not only higher positive rates of TgAb and McAb but also higher titers of such antibodies, and determinations of TgAb and McAb by using the tanned red cell hemagglutination technique are of help in the diagnosis of autoimmune thyroid diseases.