A144

Existing methods for the preoperative detection of metastases in thyroid cancer have low efficiency and highly invasive. Therefore, the searches for laboratory markers that will indicate the presence of metastases including hidden with high reliability in cancer of the thyroid gland are relevant. Immune system is one of the key mechanisms for regulation of tissue proliferation. Autoreactive lymphocytes restrict the growth and proliferation of tissues. In turn autoreactive lymphocytes are controlled by idiotypic lymphocytes. Abnormalities in the regulation system can be the cause of tumor growth, such as excess activity of anti-idiotypic lymphocytes. Previously we conducted a comparative analysis of the level of autoantibodies to various antigens (thyroglobulin, thyroid stimulating hormone receptor, native DNA, anionic proteins vascular endothelium), as well as anti-idiotypic antibodies to thyroglobulin in thyroid cancer patients with metastases and without metastases. Significant differences between investigated groups were found in the level of anti-idiotypic antibodies against antibodies to thyroglobulin. Therefore, the aim of this study was to analyze the feasibility of using anti-idiotypic antibodies against antibodies to thyroglobulin as a marker of metastatic thyroid cancer. All studied patients with thyroid cancer were hospitalized at Primushko Regional Clinical Oncology Center of the Ministry of Health of the Udmurt Republic, Izhevsk. Blood was taken from patients before surgery. The level of anti-idiotype antibodies (AIAT) against autoantibodies to thyroglobulin (Tg) and the level of autoantibodies (AUAT) to thyroglobulin were determined in the blood plasma using the test system manufacturing MRC ”Immunkulus”. To determine the AIAT against AUAT to Tg, we used the principle of competitive inhibition of the binding reaction with antibodies to thyroglobulin in the presence of analyzed serum. As a source of antibodies to thyroglobulin, we used serum from patients with autoimmune thyroiditis in effective dilutions for competition. Analyzed samples were previously depleted by antibodies to thyroglobulin. The level of the test antibodies was expressed in conventional unit (CU) - optical density of the reaction of antibody binding to the antigen. We found that AIAT against AUAT to Tg were not defined in 43% of thyroid cancer patients with metastases (group I), 57% revealed a relatively high level of AIAT against AUAT to Tg – 0.343 ± 0.027 CU (Group II). I