Diagnosis of medullary carcinoma of the thyroid (MCT) by calcitonin assay using monoclonal antibodies: criteria for the pentagastrin stimulation test in hereditary MCT

• Published in: The journal of clinical endocrinology and metabolism Vol. 71; no. 4; p. 1064
• Main Authors: Guilloteau, D, Perdrisot, R, Calmettes, C, Baulieu, J L, Lecomte, P, Kaphan, G, Milhaud, G, Besnard, J C, Jallet, P, Bigorgne, J C
• Format: Journal Article
• Language: English
• Published: United States 01.10.1990
• Subjects: Adolescent; Adult; Aged; Antibodies, Monoclonal; Biomarkers, Tumor - analysis; Calcitonin - analysis; Calcitonin - immunology; Carcinoma - genetics; Carcinoma - immunology; Carcinoma - surgery; Female; Humans; Immunoradiometric Assay; Male; Middle Aged; Pentagastrin; Radioimmunoassay; Thyroid Function Tests; Thyroid Neoplasms - genetics; Thyroid Neoplasms - immunology; Thyroid Neoplasms - surgery
• ISSN: 0021-972X
• DOI: 10.1210/jcem-71-4-1064

A new calcitonin (CT) immunoradiometric assay, using anti-11-7 and anti-24-32 CT fragment monoclonal antibodies was evaluated and compared to classical RIA. The sensitivity was 2.5 ng/L, the normal basal level (n = 83) was lower than 10 ng/L, the response to pentagastrin stimulation in control subjects was absent in nine and between 10-30 ng/L in nine others. (mean, 15.4). In patients with renal failure the basal level was increased between 10-52 ng/L. In patients with medullary thyroid carcinoma (MTC; n = 28), the basal level was between 189-28,900 ng/L. A pentagastrin test was performed as screening for familial MTC in eight patients with confirmed MTC at subsequent surgery; the calcitonin peak was equal or greater than 38 ng/L. Large differences exist between CT levels measured by RIA and immunoradiometric assay. The latter method provides a greater sensitivity to pentagastrin test and allows a better identification of microcarcinoma in hereditary cases of MTC.