Endocrine Abstracts

Graves’ disease (GD) is an autoimmune disease with genetic predisposition. The link with the major histocompatibility complex determines the complexity of the excess thyroid hormones molecular action on immune system that may cause the divergence of autoimmune process in GD, functioning not only in peripheral immune cells, but also in the thyroid. Objective: to study the phenotypic composition of T- and B-lymphocyte subset patterns in peripheral blood and thyroid tissue in patients with GD. Materials and methods. The study included 43 women with GD, mean age 39.95±14.38, who were performed the epifascial thyroidectomy. Phenotypic composition of T – and B-lymphocytes was investigated by flow cytometry. Analysis of stained cells was performed on a flow cytometer FC-500 (Beckman Coulter, USA). Each sample was analyzed at least 50,000 lymphocytes. Results. The median level of thyroid stimulating hormone (TSH), free thyroxine and autoantibodies to TSH receptor was respectively 1,9 (0,9; 2,9) umol/ml, 16,8 (13,2; 19,0) and 15,8 (9,4; 24,2) IU/ml. In peripheral blood of GD patients compared with healthy controls identified the increased in 9.2% the relative number of total T lymphocytes (CD3+, P<0.001) and in 5.8% relative level of T-helper cells (CD3+CD4+, P=0.019), but decreased content of T-regulatory cells (CD3+CD4+CD127LowCD25High, P=0.048) and total activated T cells (P<0.001), T-helper cells (CD3+CD4+CD25+, P=0.045) and cytotoxic T-lymphocytes (CD3+CD8+CD25+, P=0.041). It is revealed that in the blood of GD patients increased in 35.9% the relative number of B2-lymphocytes (CD19+CD5+, P=0.003), while reducing the amount of activated total B cells (CD19+CD23+, P<0.001), B2 cells (CD19+CD5−, P<0.001), B2− simplet (CD19+CD5-CD27−, P<0.001) and B2-memory (CD19+CD5−CD27+, P<0.001) cells. In a comparative analysis of the phenotypic composition of T – and B-lymphocytes in peripheral blood and thyroid tissue revealed that in the tissues is 2.3 times higher relative content of total activated T cells (CD3+CD25+, P=0.037), in 5.1 times more of activated cytotoxic T-lymphocytes (P=0.023), 1.7 times increased the percentage of B2-memory (CD19+CD5−CD27+, P=0.028) cells. Conclusions. The reduction of activated T – and B-lymphocytes content in peripheral venous blood of patients with GD is determined by the migration of immune cells in thyroid tissue.