Increased sensitivity of a new assay for anti-thyroglobulin antibody detection in patients with autoimmune thyroid disease.
OBJECTIVE
To verify the cut-off values and to determine the clinical sensitivity of antithyroglobulin (TgAb) determinations using our routine RIA and the new electrochemiluminescent Elecsys assay.


METHODS
We used the DYNOtest anti-Tgn manual RIA from BRAHMS and the new automated Elecsys electrochemiluminescent immunoassay from Roche Diagnostics. We analyzed 452 sera from the following subjects: 193 euthyroid controls, 163 with treated and untreated autoimmune thyroid diseases (AITD) (108 Graves' disease and 55 thyroiditis), 50 with differentiated thyroid carcinoma, 13 with nonautoimmune thyroid disease and 33 with type 1 diabetes mellitus.


RESULTS
As expected, using the proposed thresholds (BRAHMS 60 kIU/L, Elecsys 115 kIU/L) approximately 6% of the control subjects were positive for TgAb with both methods. In AITD patients, the sensitivity of TgAb determination was significantly higher with the Elecsys assay (51.5%) than with the BRAHMS assay (39.3%). This difference was not observed in the other patient groups.


CONCLUSIONS
The Elecsys assay can be preferred not only because it is automated and rapid, but also because of its better clinical performance in AITD patients.
Sapin
Rémy
R
Laboratoire Universitaire de Biophysique, Unité d'Analyses Endocriniennes, ULP/CNRS UMR 7004, Faculté de Médecine, 67085 Strasbourg Cedex, France. sapin@ipb.u-strasbg.fr
d'Herbomez
Michèle
M
Gasser
Françoise
F
Meyer
Laurent
L
Schlienger
Jean-Louis
JL
D000328:Adult; D001323:Autoantibodies / Q000097:blood*; D004563:Electrochemistry; D005260:Female; D006111:Graves Disease / Q000097:blood / Q000276:immunology*; D006801:Humans; D007118:Immunoassay / Q000379:methods; D008163:Luminescent Measurements; D008297:Male; D008875:Middle Aged; D012680:Sensitivity and Specificity; D013954:Thyroglobulin / Q000097:blood / Q000276:immunology*; D013967:Thyroiditis, Autoimmune / Q000276:immunology*
D001323:Autoantibodies; C006606:anti-thyroglobulin; D013954:Thyroglobulin