Clinical Chemistry, Vol 33, 303-305, Copyright © 1987 by American Association for Clinical Chemistry

Value and limitations of a highly sensitive immunoradiometric assay for thyrotropin in the study of thyrotroph function

G Caldwell, SM Gow, VM Sweeting, GJ Beckett, J Seth and AD Toft

Using a highly sensitive and specific immunoradiometric assay for thyrotropin, we studied thyrotroph function in 232 new patients referred to a thyroid clinic and in 13 patients after treatment for hyperthyroidism. Significant thyrotroph responsiveness to thyroliberin (thyrotropin-releasing hormone, TRH) was found in all patients with values for basal thyrotropin greater than 0.1 milli-int unit/L. In no overtly hyperthyroid patient was any increment in thyrotropin recorded at 20 min after thyroliberin administration. In seven patients, four subclinically hyperthyroid and three who had received treatment, increments in thyrotropin from undetectable basal values were recorded, consistent with incomplete thyrotroph suppression. By use of assays with even higher sensitivity, one may be able to distinguish these patients from overtly hyperthyroid patients.

The following articles in journals at HighWire Press have cited this article:

				C. T. Sawin, A. Geller, M. M. Kaplan, P. Bacharach, P. W. F. Wilson, and J. M. Hershman Low Serum Thyrotropin (Thyroid-Stimulating Hormone) in Older Persons Without Hyperthyroidism Arch Intern Med, January 1, 1991; 151(1): 165 - 168. [Abstract] [PDF]

				A. Ouyang, T. Su, X. Pang, and J. M. Hershman Serum TSH, FT3, and FT4 Levels in Inhabitants of an Endemic Goiter Area in China Supplied Iodized Salt for Twenty-five Years Asia Pac J Public Health, October 1, 1989; 3(4): 301 - 305. [Abstract] [PDF]