title: Immunoradiometric assay of thyroglobulin in patients with differentiated thyroid carcinomas: need for thyroglobulin recovery tests.
abstract: As interference from thyroglobulin autoantibodies appears to have been overcome in new commercial thyroglobulin assays by the use of monoclonal antibodies, the need for thyroglobulin recovery tests became uncertain. Sera (n=45) from patients with differentiated thyroid carcinomas were selected on the basis of a thyroglobulin recovery value below 70% in the Dynotest Tg immunoradiometric assay (Brahms) routinely used in our laboratory. Serum thyroglobulin levels were then measured using three other commercial immunoradiometric assays: thyroglobulin ERIA (Pasteur), HTGK (Sorin) and ELSA HTG (Cis Bio International). Thyroglobulin autoantibodies were measured using the Thyrak assay (Brahms). Although many patients were thyroglobulin antibodies-negative (< 200 U/ml, n=26), most immunoradiometric assays failed to detect thyroglobulin in patients with evidence of recurrence. Low thyroglobulin values associated with low thyroglobulin recovery in thyroglobulin antibody-negative patients appear to be more biologically relevant than a single low thyroglobulin value, which can lead to lack of medical intervention. We conclude that the thyroglobulin recovery test is a prerequisite for the correct interpretation of serum thyroglobulin levels determined with immunoradiometric assays in the follow-up of thyroglobulin autoantibody-negative patients treated for differentiated thyroid carcinomas.
authors.affiliation: Department of Nuclear Medicine, CHU, Toulouse, France.
authors.forename: F
authors.initials: F
authors.lastname: Bourrel
authors.forename: M
authors.initials: M
authors.lastname: Hoff
authors.forename: H
authors.initials: H
authors.lastname: Regis
authors.forename: P
authors.initials: P
authors.lastname: Courrière
authors.forename: P
authors.initials: P
authors.lastname: Caron
mesh_terms: D002454:Cell Differentiation; D005260:Female; D006801:Humans; D015592:Immunoradiometric Assay / Q000379:methods*; D008297:Male; D008875:Middle Aged; D013954:Thyroglobulin / Q000097:blood* / Q000276:immunology; D013964:Thyroid Neoplasms / Q000097:blood* / Q000473:pathology
chemical_list: D013954:Thyroglobulin