[New assays of TSH-receptor antibodies: analytical and clinical performances in the diagnosis of Graves' disease].
Graves' disease autoimmunity is attributable to the presence of serum antibodies (Ab) directed against the TSH receptor (TSHR) measured by a second generation (2G) assay using the human TRAK (hTRAK) with a high sensitivity in the diagnosis of Graves' disease. In this study, we have compared both analytical and clinical performances of hTRAK with those of five new methods using a porcine TSHR: two 2G methods and three assays using the monoclonal M22 directed against the TSHR pocket. We showed a bad reproducibility of these new methods with inter assay CVs higher than 10%. High clinical sensitivity and specificity that appeared similar to those of the hTRAK and next to 100% were observed except for a 2G method that failed to detect five Graves' patients. All these new methods should be avoided since they display a high variability despite their calibration against the same International Standard 90/672. The TRAKh using a human TSHR should be still used for a correct interpretation of results in the follow-up of Graves' disease.
Massart
C
C
Unité fonctionnelle d'hormonologie, CHU de Rennes, Centre d'investigation clinique, Inserm 0203, Université de Rennes 1, France. catherine.massart@chu-rennes.fr
Sapin
R
R
Gibassier
J
J
Agin
A
A
d'Herbomez
M
M
D000293:Adolescent; D000328:Adult; D000368:Aged; D000818:Animals; D001327:Autoimmune Diseases / Q000175:diagnosis; D004797:Enzyme-Linked Immunosorbent Assay / Q000379:methods; D005260:Female; D006111:Graves Disease / Q000175:diagnosis* / Q000276:immunology*; D006801:Humans; D018828:Immunoglobulins, Thyroid-Stimulating / Q000032:analysis*; D008297:Male; D008875:Middle Aged; D011989:Receptors, Thyrotropin / Q000032:analysis; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D013552:Swine; D055815:Young Adult
D018828:Immunoglobulins, Thyroid-Stimulating; D011989:Receptors, Thyrotropin; C094372:thyrotropin-binding inhibitory immunoglobulin