[Determination and clinical significance of anti-idiotypic antibody--in model experiments of thyroglobulin and TSH].
Anti-idiotypic (anti-ID) antibody in test serum was determined by the direct binding assay using 125I-anti-human thyroglobulin (hTg). Several positive cases were found in Graves' disease and thyroiditis chronica. Positive anti-ID antibodies could be classified into two types. Type 1 showed the positive anti-hTg antibody and high Tg levels by RIA using double antibody method. Type 2 showed the positive anti-hTg antibody but low Tg levels by RIA. The binding of 125I-hTg to anti-hTg antibody was displaced by anti-ID antibody in type 1, but was not anti-ID antibody in type 2. A case of coexistence of autoantibody to hTSH and auto-anti-ID antibody to anti-hTSH antibody was found. She showed normal thyroid function (T4, T3), but TSH level showed discrepancy by different assay methods. Both autoantibodies for hTSH and for anti-hTSH antibody were demonstrated by the reaction of patient's antibody with both 125I-hTSH and 125I-anti-hTSH (MoAb). These two autoantibodies belong to the polyclonal IgG. The autoantibody for hTSH recognized only the beta-subunit of hTSH. Neither stimulating type of TSH receptor antibody (TRAb) nor blocking type of TRAb interfered with the binding of patient's anti-ID to 125I-anti-hTSH. This binding reaction could be inhibited by the unlabeled hTSH. This anti-ID might represent the internal image of the non-biological active site of TSH molecule, because of absence of thyroid stimulating activity. These anti-ID antibodies may provide evidence supporting a network theory of the immune system.
Central Clinical Laboratory, Shiga University of Medical Science, Otsu.
T
T
Inui
Y
Y
Ochi
M
M
Morishima
D000293:Adolescent; D000328:Adult; D005260:Female; D006111:Graves Disease / Q000175:diagnosis*; D006801:Humans; D007130:Immunoglobulin Idiotypes / Q000032:analysis*; D008297:Male; D008875:Middle Aged; D011933:Reagent Kits, Diagnostic; D013954:Thyroglobulin / Q000276:immunology*; D013960:Thyroid Function Tests / Q000379:methods; D013966:Thyroiditis / Q000175:diagnosis*; D013972:Thyrotropin / Q000276:immunology*
D007130:Immunoglobulin Idiotypes; D011933:Reagent Kits, Diagnostic; D013972:Thyrotropin; D013954:Thyroglobulin