Anti-thyroglobulin autoantibodies in sera from patients with chronic thyroiditis and from healthy subjects: differences in cross-reactivity with thyroid peroxidase.
A significant portion (about 12.7%) of healthy subjects was found to contain anti-thyroglobulin (anti-Tg) antibodies in their sera. We compared the binding activities of these antibodies and of anti-Tg autoantibodies from sera of patients with chronic thyroiditis with human thyroid peroxidase (TPO). The results obtained by ELISA indicated that out of 10 healthy subjects with anti-Tg antibodies, only four had anti-Tg antibodies capable of binding to TPO, whereas anti-Tg autoantibodies from almost all patients with chronic thyroiditis possessed high binding activities to TPO. By use of the immunoprecipitation method, it was also shown that although all anti-Tg autoantibodies from patients precipitated TPO, a majority of anti-Tg antibodies from healthy subjects could not precipitate TPO. Such findings cannot be ascribed to the differences in levels of anti-Tg autoantibodies and anti-TPO autoantibodies in sera and the differences in avidities of anti-Tg antibodies in sera between healthy subjects and patients with chronic thyroiditis. Thus, it can be concluded that anti-Tg antibodies from healthy subjects differ from those of patients with chronic thyroiditis with respect to TPO binding, probably due to difference in fine specificities of these anti-Tg antibodies.
Naito
N
N
Faculty of Pharmaceutical Sciences, Chiba University, Japan.
Saito
K
K
Hosoya
T
T
Tarutani
O
O
Sakata
S
S
Nishikawa
T
T
Niimi
H
H
Nakajima
H
H
Kohno
Y
Y
D000293:Adolescent; D000328:Adult; D000888:Antibodies, Anti-Idiotypic / Q000276:immunology*; D000918:Antibody Specificity; D003429:Cross Reactions; D005260:Female; D006801:Humans; D007453:Iodide Peroxidase / Q000276:immunology*; D008297:Male; D013954:Thyroglobulin / Q000037:antagonists & inhibitors*; D013967:Thyroiditis, Autoimmune / Q000276:immunology*
D000888:Antibodies, Anti-Idiotypic; D013954:Thyroglobulin; D007453:Iodide Peroxidase