Three distinct precipitating antibodies in patients with thyroid diseases against the antigens in cytoplasmic fraction of human thyroid gland supernatant (HTS)

Autoantibodies in sera from patients with thyroid disease were detected by passive hemagglutination method (PHA) in general. However this method had serveral problems for the specificity and discrimination of them. In this study, autoantibodies against human thyroid gland were tentatively analyzed by double immunodiffusion (DID) method for the first step to evaluate these subjects. After analysis of 355 sera, three distinct and human-thyroid specific antibodies were observed against the antigens in cytoplasmic fraction of human thyroid gland supernatant (HTS). Antibodies to HTS-1 antigen appeared within 1 day and were absorved by HTS. All of the 14 sera containing antibodies to HTS-1 antigen showed positive at 1600 or greater dilution by PHA. Thirteen of 14 sera were found in patients with Hashimoto's thyroiditis. All the data suggested antibodies to HTS-1 antigen were the same as antibodies to thyroglobulin. Interestingly antibodies to HTS-1 antigen were thought to be heterogeneous because of these antibodies showing partial identity by DID method. Antibodies to HTS-2 antigen appeared after two days and were found in small percentage of patients with Hashimoto's thyroiditis and Graves’ disease. Antibodies to HTS-3 antigen weekly appeared against condensed HTS after one week. These antibodies were uncertain whether they were compatible with thyroid microsome antibodies or not. These antibodies were found in 52 patients with Hashimoto's thyroiditis or Graves’ disease.