Medizym® T.R.A. human Determination of TSH receptor antibodies using enzyme immunoassay of the 3rd generation

ELISA for the determination of autoantibodies to TSH receptor
ELISA for the determination of autoantibodies to TSH receptor

Autoimmune hyperthyroidism is caused by the stimulation of the thyroid gland by autoantibodies. These autoantibodies bind to the TSH receptor and mimic the effect of TSH (Thyroid-stimulating hormone). The consequence is a permanent production and therefore an oversupply of the organism with the thyroid hormones thyroxine and triiodothyronine. The determination of TSH receptor antibodies (TRAb) differentiates non-autoimmune forms of hyperthyroidism.

The determination of TSH receptor antibodies (TRAb) is based on a competitive enzyme immunoassay. Autoantibodies in the patient sample bind to the immobilized TSH receptor. The bound TRAb inhibit the binding of the detection reagent. The content of antibodies in the sample is indirectly proportional to the measured signal.

The Medizym® T.R.A. human is a 3rd generation assay which utilizes a labelled monoclonal antibody against the TSH receptor as detection method.

Assay principle

Enzyme immunoassay

Assay size

96 determinations


Autoimmune thyroid disease


TSH Receptor Antibody


Anti-TSHR-Biotin, Streptavidin-POD




undiluted patient sample


quantitative (IU/l)

Incubation time

120 min - 20 min - 20 min - 20 min, RT


Tetramethylbenzidine (TMB), 450 nm

Sensitivity / Specificity

95 % / > 99 %



The Medizym® T.R.A. human (3rd generation enzyme immunoassay) consists of 96 determinations and allows for a cost-effective determination of the diagnostic marker for autoimmune hyperthyroidism. The assay is adapted for processing on open automated systems.

Kakinuma A, Morimoto I, Kuroda T, Fujihira T, Eto S, McLachlan SM and Rapoport B: Comparison of recombinant human thyrotropin receptors versus porcine thyrotropin receptors in the thyrotropin binding inhibition assay for thyrotropin receptor autoantibodies. Thyroid 1999; 9 (9): 849 - 855.

Kamijo, K: TSH-receptor antibody measurement in patients with various thyrotoxicosis and Hashimoto's thyroiditis: a comparison of two two-step assays, coated plate ELISA using porcine TSH-receptor and coated tube radioassay using human recombinant TSH-receptor. Endocr J. 2003 Feb; 50 (1):113-116.