[Clinical implications of a new TSH receptor antibody assay (DYNOtest TRAKhuman) in autoimmune thyroid diseases].
OBJECTIVE
Conventional radioreceptor-antibody-assays (RAAs) fail in the detection of TSH-receptor antibodies (TRAKs) in 10-30% of patients with Graves' disease (GD). The aim of this study was the evaluation of the diagnostic and clinical impact of a new RRA (DYNOtest TRAKhuman) which uses the human recombinant TSH-Receptor in the diagnosis of autoimmune thyroid disease.


METHODS
Sera from 142 consecutive patients (GD: n = 50, autoimmune thyroiditis/AIT: n = 92) and from 55 controls (31 patients without any thyroid disease and 14 with euthyroid goiter) were evaluated both with the DYNOtest TRAKhuman-assay and a conventional RRA (TRAK-Assay). Thyroid in vitro parameters and thyroid sonography were performed in all patients.


RESULTS
The DYNOtest TRAK-assay was significantly superior to the conventional RRA in the diagnosis of GD (p < 0.00012), especially in those who were treated by thionamides (p < 0.003) and in the diagnosis of TRAK-positive patients with AIT (p < 0.003). The majority of TRAK-positive AIT-patients suffered from hypothyroidism. One false positive result in patients with euthyroid goiter was found in the TRAK-Assay as well as in the DYNOtest TRAKhuman-Assay. Therefore the specificity of the DYNOtest TRAKhuman was not inferior compared with the conventional assay.


CONCLUSIONS
The DYNOtest TRAK-assay is superior in the diagnostic work up of Graves' disease compared with a conventional TRAK-assay and offers an equal specificity.
Meller
J
J
Abt. Nuklearmedizin, Georg-August-Universität Göttingen, Deutschland. jmeller@med.uni-goettingen.de
Schreivogel
I
I
Bergmann
A
A
Morgenthaler
N
N
Hüfner
M
M
Becker
W
W
D005260:Female; D006042:Goiter / Q000097:blood / Q000276:immunology*; D006111:Graves Disease / Q000097:blood / Q000276:immunology*; D006801:Humans; D018828:Immunoglobulins, Thyroid-Stimulating / Q000097:blood*; D008297:Male; D008875:Middle Aged; D011863:Radioimmunoassay / Q000379:methods; D011933:Reagent Kits, Diagnostic; D011989:Receptors, Thyrotropin / Q000276:immunology; D011994:Recombinant Proteins / Q000276:immunology; D012016:Reference Values
D018828:Immunoglobulins, Thyroid-Stimulating; D011933:Reagent Kits, Diagnostic; D011989:Receptors, Thyrotropin; D011994:Recombinant Proteins