[Anti-thyroid peroxidase antibody].

Anti-thyroid peroxidase antibody(TPOAb) in patients with autoimmune thyroid diseases was identified with anti-microsomal antibody. Highly sensitive assays of TPOAb using radioimmunoassays and enzyme immunoassays have been developed following a hemagglutination assay technique. TPOAb is present in the serum of almost all patients with Hashimoto's thyroiditis, in more than 70% of those with Graves' disease, and, to a variable degree, in patients with nonthyroid autoimmune diseases and some normal subjects. There is a good correlation between the degree of lymphocytic infiltration of the thyroid gland and the titer of TPOAb. Postpartum thyroiditis, usually a transient disorder, occurs with high frequency in women who have TPOAb. TPOAb, in addition to anti-thyroglobulin antibody, was a clinically useful marker for defining autoimmune thyroid diseases and for detecting an underlying autoimmune process in the thyroid, however, its biological importance remains to be clarified at the present time.