Abstract
An homogeneous phase radioassay (HRA) for antithyroglobulin autoantibodies (TgAb) in serum was investigated. In this method TgAb is allowed to react with 125l-Tg in solution and the immune complexes formed are separated by precipitation with sheep anti-human gammaglobulin. HRA proved to be suitable for the screening of sera prior to thyroglobulin (Tg) radioimmunoassay; being both sensitive, and unaffected by high endogenous levels of Tg. HRA was more sensitive than either of two commercial TgAb kits; a hemagglutination assay (Wellcome Australia Ltd.) and a solid phase radioassay (CIS France). Positive responses were obtained with 4 out of 42 normal subjects (titers up to 1/10), 24 out of 31 with untreated Graves’ disease (titers up to 1/10,000) and all out of 18 with Hashimoto’s thyroiditis (titers up to 1/10,000). Binding of 125l-Tg was displaceable with added unlabelled Tg, but in no case could it be abolished with less than 1,000 μg/l. Some sera exhibited more than one class of binding site and variation in both affinity and capacity for Tg was observed. It was concluded that the use of an assay standard for the reporting of results in units of concentration is invalid, although units of TgAb activity may be used as long as the analytical method is specified. Serum levels of TgAb may also be reported in semi-quantitative terms, such as in this report where a binding titer is used, or alternatively, antigen binding capacity may be reported.
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Doniach D. Humoral and genetic aspects of thyroid autoimmunity. Clin. Endocrinol. Metab. 4: 267, 1975.
Mori T., Kriss J.P. Measurements by competitive binding radioassay of serum antimicrosomal and antithyroglobulin antibodies in Graves’ disease and other thyroid disorders. J. Clin. Endocrinol. Metab. 33: 688, 1971.
Salabè G.B., Salabè H., Dominici R., Davoli C., Andreoli M. Radioimmunoassay for human antithyroglobulin antibodies. II. Determination of antigen binding capacity. J. Clin. Endocrinol. Metab. 39: 1125, 1974.
Bayer M.F., Kriss J.P. A solid phase, sandwich-type radioimmunoassay for antithyroglobulin: elimination of false positive results and semi quantitative measurement of antithyroglobulin in the presence of elevated thyroglobulin. J. Clin. Endocrinol. Metab. 49: 565, 1979.
Van Herle A.J., Vassart G., Dumont J.E. Control of thyroglobulin synthesis and secretion, Pt. II. N. Engl. J. Med. 307: 307, 1979.
Bridgman M.C., Cooper R.A., Luttrell B.M., Reeve T.S., Stiel J.N., Wilmshurst E.G., Hales I.B. Evaluation of serum thyroglobulin levels in the follow-up of thyroid cancer following ablative therapy. In: Stockigt J.R., Nagataki S. (Eds.), Thyroid Research VIII. Australian Academy of Science, Canberra, 1980, p. 483.
Schneider A.B., Pervos R. Radioimmunoassay of human thyroglobulin: effect of antithyroglobulin autoantibodies. J. Clin. Endocrinol. Metab. 47: 126, 1978.
Pinchera A., Mariotti S., Vitti P., Tosi M., Grasso L., Pacini F., Buti R., Baschieri L. Interference of serum thyroglobulin-in the radioassay for serum antithyroglobulin antibodies. J. Clin. Endocrinol. Metab. 45: 1077, 1977.
Peake R.L., Willis D.B., Asimakis Jr. G.K., Deiss Jr. W.P. Radioimmunologic assay for antithyroglobulin anti bodies. J. Lab. Clin. Med. 84: 907, 1974.
Bodlaender P., Arjonilla J.R., Twomey S.L. Sensitive radioimmunological screening test for antithy roglobulin autoantibodies. Clin. Chem. 24: 272, 1978.
Feldt-Rasmussen U., Petersen P.H., Date J., Madsen C.M. Sequential changes in serum thyroglobulin (Tg) and its autoantibodies (TgAb) following subtotal thyroidectomy of patients with pre-operatively detectable TgAb. Clin. Endocrinol. (Oxf.) 12: 29, 1980.
Date J., Feldt-Rasmussen U., Petersen P.H., Bech K. An improved co-precipitation assay for determination of thyroglobulin antibodies. Scand. J. Clin. Lab. Invest. 40: 37, 1980.
Van Herle A.J., Ulier R.P., Matthews N.L., Brown J. Radioimmunoassay for the measurement of thyroglobulin in human serum. J. Clin. Invest. 52: 1320, 1973.
Scatchard G. The attraction of proteins for small molecules and ions. Ann. N.Y. Acad. Sci. 52: 660, 1949.
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Henniker, A.J., Luttrell, B.M., Ward, P. et al. The measurement of antithyroglobulin autoantibodies in the presence of thyroglobulin. J Endocrinol Invest 6, 277–285 (1983). https://doi.org/10.1007/BF03347590
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DOI: https://doi.org/10.1007/BF03347590