Clinical implications of a new TSH-reteptor-antibody-assay (DYNOtest (R) TRAKhuman) in autoimmune thyroid diseases

Abstract

Aim: Conventional radioreceptor-antibody-assays (RAAs) foil 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(R) TRAK-human) which uses the human recombinant TSH-Receptor in the diagnosis of autoimmune thyroid disease. Methods: Sera from 142 consecutive patients (GO: 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(R) TRAKhuman-assay and a conventional RRA (TRAK-Assay(R)). Thyroid in vitro parameters and thyroid sonography were performed in ail patients. Results: The DYNOtest(R) 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 resort in patients with euthyroid goiter was found in the TRAK-Assay(R) as well as in the DYNOtest(R) TRAKhuman-Assay. Therefore the specifity of the DYNOtest(R) TRAKhuman was not inferior compared with the conventional assay. Conclusion: The DYNOtest(R) TRAK-assay is superior in the diagnostic work up of Groves' disease compared with a conventional TRAK-assay and offeres on equal specifity.