title: [Inappropriately undetectable thyroglobulin after exclusion of interference from thyroglobulin antibodies].
abstract: Thyroglobuline (Tg) is a large molecule of high molecular weight mainly indicated in monitoring differentiated thyroid cancer (DTC), its measurement remains difficult. We report the case of a patient who underwent total thyroidectomy for a poorly differentiated thyroid insular carcinoma. Despite several (131)I treatments, a progressive elevation of serum Tg is observed. A control performed in another laboratory using an immunoradiometric assay (IRMA Cisbio) returns an undetectable value (< 0,2 mg/L). A new sample was simultaneously sent to different laboratories. Three nonisotopic immunometric assays showed high values of Tg while the IRMA assay, considered the gold standard, gave a result below the detection threshold. The absence of Tg antibodies and of anti-mouse antibodies was confirmed. The IRMA Kit manufacturer agreed to carry out an expertise. After changing their detection antibody, the presence of a high Tg was demonstrated, in agreement with non-isotopic techniques. The expertise conclusion was a lack of detection by the IRMA Tg assay. This incident was notified to AFSSAPS by the manufacturer.
authors: Laboratoire de biologie médicale, Centre hospitalier de Valence, Valence, France. pmunier@ch-valence.fr
authors: Perrine
authors: P
authors: Munier
authors: Françoise
authors: F
authors: Courtier
authors: Kildie
authors: K
authors: Barrial
authors: Karim
authors: K
authors: Chikh
authors: Francine
authors: F
authors: Claustrat
authors: Thierry
authors: T
authors: Le Bricon
authors: Jacques
authors: J
authors: Bronner
authors: Edgar
authors: E
authors: Sanabria
mesh_terms: D000368:Aged; D001323:Autoantibodies / Q000097:blood / Q000302:isolation & purification*; D002277:Carcinoma / Q000097:blood / Q000175:diagnosis / Q000276:immunology / Q000601:surgery; D003951:Diagnostic Errors; D003940:Diagnostic Techniques, Endocrine / Q000592:standards; D006801:Humans; D015592:Immunoradiometric Assay / Q000379:methods / Q000592:standards; D057230:Limit of Detection; D008297:Male; D012680:Sensitivity and Specificity; D013954:Thyroglobulin / Q000032:analysis / Q000097:blood* / Q000276:immunology*; D013964:Thyroid Neoplasms / Q000097:blood / Q000175:diagnosis / Q000276:immunology / Q000601:surgery; D013965:Thyroidectomy
chemical_list: D001323:Autoantibodies; C006606:anti-thyroglobulin; D013954:Thyroglobulin