Evaluation of epitopes specificity of antibodies to thyroid peroxidase in autoimmune thyroid disorders

The problem of the human antithyroid peroxidase autoantibodies epitopes heterogeneity diagnosed in case of Graves' disease and Hashimoto's thyroiditis has been researched using monoclonal antibodies to thyroid peroxidase. It was shown, that in the competition for the binding sites of thyroid peroxidase and autoantibodies taken from patients with Graves' disease and Hashimoto's thyroiditis sera participate 8 mAb to epitopes 1, 70, 82, 88, 2, 3, 77 and 79. The maxima of the binding inhibition has been marked for the conformation epitope mAb 3: in case of Graves' disease it amounts to 60.3 ± 12.7%, in case of Hashimoto's thyroiditis – 61.8 ± 32.2%. Moreover the level of the binding inhibition did not depend on the concentration of Ab to thyroid peroxidase in the sera of patient with Graves' as opposed to the serum of patients with Hashimoto's thyroiditis. Autoantibodies in the serum of the patientswith Hashimoto's thyroiditis inhibited the binding of mAb to epitope 77 much more effectively, than in the serum of the patients with: 36.3 ± 17.2 and 54.3 ± 9.6% (p ≤ 0.05).The obtained results represented the specific reaction of the autoantibodies to the certain thyroid peroxidase molecular patterns which corresponds to the literature data. It is possible to assume that the further research of the competitive interactions with other autoantibodies to monoclonal antibodies, not included in this trial, and widening of the different thyroid diseased patients' serum palette can expose new immunodominant thyroid peroxidase molecular patterns, forming antibodies for different diseases, and enable the development of diagnostics and control of the thyroid functions and applied therapy.