Correlation Between Radioimmunological and Biological Human Thyrotropin Measurements[*]

Abstract

Human thyrotropin (HTSH) was measured by McKenzie bioassay (B) and by radioimmunoassay (I), in the sera (63 cases) and in the pituitaries (48 cases) of patients affected with various thyroid diseases, principally asymptomatic thyroiditis, and in controls. Results were expressed in terms of MRC Research Standard A for both assays. For the pttuitaries, a positive correlation was found between B and I TSH levels, when the results were analysed together or separately (controls, patients with thyroiditis). The mean ratio of the absolute values obtained by B and I (B/I) was 0,47 for the controls and 0,86 for the thyroiditis patients. For the sera, again, a positive correlation between B and I TSH levels was demonstrated. The B/I ratios for the measurable TSH values showed also a difference between the thyroiditis patients and the other cases. The reported data demonstrate a parallelism in B and I determinations. The constant different B/I ratio for the thyroiditis patients suggests the possible existence of a different TSH in this disease.

Key words

Human Thyrotropin (HTSH) - Radioimmunoassay - Bioassay - Asymptomatic Thyroiditis

1 Work partially carried out under contract of the Ministère de la Politique Scientifique within the framework of the Association Euratom-University of Brussels-University of Pisa, and under contract of the Fonds de la Recherche Scientifique Médicale n° 20013.

1 Work partially carried out under contract of the Ministère de la Politique Scientifique within the framework of the Association Euratom-University of Brussels-University of Pisa, and under contract of the Fonds de la Recherche Scientifique Médicale n° 20013.