Anti-bovine TSH antibodies in patients with Graves' disease and primary myxedema.
Three patients with Graves' disease and one patients with primary myxedema had serum TSH-binding immunoglobulins of high affinity detected by the TSH binding inhibition immunoglobulin (TBII) assay. These IgGs bound 61%, 33%, 60% and 53% of radiolabeled TSH, respectively, higher than the maximal specific binding (25%) in the TBII assay. Such binding was detected even in the absence of TSH receptor with only small differences in the precipitable radioactivity (61%, 28%, 61%, 54%, respectively, in comparison with the assay non-specific binding 11.3%). The 125I-bTSH binding of IgGs was competitively inhibited by the addition of bTSH, but not inhibited by hTSH. Moreover IgG binding to bTSH was not inhibited by the addition of serial dilutions of TBII positive pooled Graves' IgG (0.1-10 mg/ml) from different untreated patients. The titers of these TSH binding antibodies were not changed during the treatment of Graves' disease. Following guinea pig fat cell membrane receptor purification, the IgG of one patient with Graves' disease revealed TBII activity of 43.7% inhibition of 125I-bTSH binding to the TSH receptor without binding activity of 125I-bTSH in the absence of the TSH receptor. These studies suggest that anti-TSH antibodies and TSH receptor antibodies are present independent of one another in sera of some patients with autoimmune thyroid diseases and anti-TSH antibodies result in false TBII assay results.
Cho
B Y
BY
Department of Internal Medicine, College of Medicine, Seoul National University, Korea.
Shong
Y K
YK
Lee
H K
HK
Koh
C S
CS
Min
H K
HK
D000328:Adult; D000368:Aged; D000818:Animals; D000906:Antibodies / Q000032:analysis*; D001323:Autoantibodies / Q000032:analysis; D002417:Cattle; D005260:Female; D006111:Graves Disease / Q000276:immunology*; D006358:Hot Temperature; D006801:Humans; D007074:Immunoglobulin G / Q000302:isolation & purification / Q000378:metabolism; D018828:Immunoglobulins, Thyroid-Stimulating; D007457:Iodine Radioisotopes; D008297:Male; D008403:Mass Screening / Q000379:methods*; D008875:Middle Aged; D009230:Myxedema / Q000276:immunology*; D011485:Protein Binding; D011989:Receptors, Thyrotropin / Q000276:immunology; D013972:Thyrotropin / Q000276:immunology*
D000906:Antibodies; D001323:Autoantibodies; D007074:Immunoglobulin G; D018828:Immunoglobulins, Thyroid-Stimulating; D007457:Iodine Radioisotopes; D011989:Receptors, Thyrotropin; D013972:Thyrotropin