Detection of autoantibodies to thyroid peroxidase in autoimmune thyroid diseases by micro-ELISA and immunoblotting.
Serum autoantibodies to thyroid peroxidase (TPO) in patients with thyroid autoimmune diseases were studied by micro-ELISA and immunoblotting. Twenty-four patients, 15 with Graves' disease and 9 with Hashimoto's thyroiditis, whose serum titers were greater than 3200 on the microsomal hemagglutination test (except for 1 patient with a titer of 800) had autoantibodies to TPO. Both immunoglobulin G and M classes of autoantibodies were detected, with the former being more prominent. When TPO and thyroid microsomes were used as a target in a competitive binding inhibition test, the results suggested that TPO was a major thyroid microsomal antigen. On the other hand, immunoblotting analysis showed 3-4 bands in the 45-60K region stained by patients' sera in addition to human TPO with mol wt of 100K and 107K; only the latter 2 bands stained with antiporcine TPO antibody. In the majority of sera, TPO bands were clearer than others, although some sera showed the clearest band with a mol wt of 55K. These results indicate that patients with autoimmune thyroid disease often have autoantibodies to TPO that can be detected by micro-ELISA and immunoblotting, and that TPO is a major component of the thyroid microsomal antigen.
D000818:Animals; D001323:Autoantibodies / Q000032:analysis*; D001327:Autoimmune Diseases / Q000276:immunology*; D001667:Binding, Competitive; D003101:Collodion; D004591:Electrophoresis, Polyacrylamide Gel; D004797:Enzyme-Linked Immunosorbent Assay / Q000379:methods; D006386:Hemagglutination Tests; D006801:Humans; D007120:Immunochemistry; D007074:Immunoglobulin G / Q000378:metabolism; D007453:Iodide Peroxidase / Q000276:immunology*; D008861:Microsomes / Q000201:enzymology / Q000276:immunology; D011817:Rabbits; D013552:Swine; D013959:Thyroid Diseases / Q000276:immunology*; D013961:Thyroid Gland / Q000201:enzymology / Q000276:immunology
D001323:Autoantibodies; D007074:Immunoglobulin G; D003101:Collodion; D007453:Iodide Peroxidase