title: A novel method for measuring TBAb activity in TSAb- and TBAb-positive serum.
abstract: We reported a conversion assay in which thyroid blocking antibody (TBAb) function as thyroid stimulating antibody (TSAb). TBAb-bound porcine thyroid cells (PTC) were made by incubating TBAb(+) serum and PTC for 1 hour. When these TBAb-bound PTC were incubated 4 h with rabbit anti-human (h) IgG antibody (Ab), cAMP production was high, but when incubated with normal rabbit serum (NRS) cAMP production was low. TBAb-Mnoclonal Ab (MoAb) (KI-70) showed similar conversion. However, when TSAb-MoAb(M22) was assayed, anti-hIgG Ab-produced cAMP was lower than NRS-produced cAMP. When a mixture of M22 and KI-70 was assayed, anti-hIgG Ab-produced cAMP was higher than NRS. Thus, it is possible to determine existence of TBAb in TSAb(+)serum when anti-IgG Ab-produced cAMP is higher than NRS-produced cAMP. In this assay TBAb activity in TSAb(+)serum was scored as positive, gray zone and negative when the difference [anti-hIgG Ab-produced cAMP(%)-NRS-produced cAMP(%)] was >100%, 50-100% and <±50%, respectively. In TSAb(+)sera of Graves' patients with no treatment or anti-thyroid therapy, positive TBAb was 9% (3/33 )and 6.9% (5/72), and gray zone was 18 % (6/33) and 25% (18/72), respectively. A low prevelance of TBAb and low TBAb activity (<200% as cAMP) was found in these Graves' patients. A radioisotope treated Graves' patient showed existence of both TSAb and TBAb at 5 months (NRS, 800% cAMP and anti-IgGAb,1,350% cAMP), and highly positive TBAb (NRS, 180% cAMP and anti-hIgG Ab, 3,200% cAMP) at 30 months. This conversion assay is useful principally for TBAb determination but is also useful for TBAb determination in TSAb(+)serum.
authors: Research Institute for Production Development, 15 Morimoto-cho, Simogamo, Sakyo-ku, Kyoto, 606-0805, Japan. k-y-ochi@blue.plala.or.jp.
authors: Yukio
authors: Y
authors: Ochi
authors: Takashi
authors: T
authors: Hachiya
authors: Naoko
authors: N
authors: Arata
mesh_terms: D000818:Animals; D000911:Antibodies, Monoclonal / Q000032:analysis / Q000378:metabolism; D015551:Autoimmunity; D002478:Cells, Cultured; D000242:Cyclic AMP / Q000378:metabolism; D018450:Disease Progression; D005260:Female; D006111:Graves Disease / Q000097:blood* / Q000276:immunology / Q000378:metabolism / Q000503:physiopathology; D006801:Humans; D007037:Hypothyroidism / Q000097:blood* / Q000276:immunology / Q000378:metabolism / Q000503:physiopathology; D018828:Immunoglobulins, Thyroid-Stimulating / Q000032:analysis / Q000096:biosynthesis / Q000097:blood*; D007202:Indicators and Reagents / Q000032:analysis / Q000378:metabolism; D008875:Middle Aged; D015203:Reproducibility of Results; D034421:Sus scrofa; D013961:Thyroid Gland / Q000166:cytology / Q000276:immunology / Q000378:metabolism
chemical_list: D000911:Antibodies, Monoclonal; D018828:Immunoglobulins, Thyroid-Stimulating; D007202:Indicators and Reagents; C000611459:KI-70 monoclonal antibody; C000611457:M33 monoclonal antibody; C118905:thyroid stimulation-blocking antibody; D000242:Cyclic AMP