Immunity in Graves' disease at diagnosis: correlation between activated T cells and humoral immune factors

Activated T cells, T-cell subsets, thyrotropin receptor antibodies and immune complexes were evaluated in 31 patients with newly diagnosed Graves' disease. Activated T cells were assayed by monoclonal antibodies against early (4F2) and late activation surface lymphocyte antigens (different epitopes of class II antigens). In comparison with the normal population, Graves' patients showed a significant decrease in the suppressor cytotoxic T-cell subset. Significant increases of 4F2-positive cells (70% of patients studied), class II antigen-positive cells (65%), thyrotropin receptor antibodies (93%), Clq-immune complexeses (44%) and conglutinin-immune complexes (37%) were observed. A significant inverse correlation between the increase in 4F2-positive cells and thyrotropin receptor antibody values was also observed. Lymphocytes from Graves' patients were cultured in the presence of thyrotropin receptor antibody-positive or -negative sera, with or without mitogen stimulation. Thyrotropin receptor antibodies were shown not to interfere with the expression of activation antigens in cultured cells. The different patterns of humoral and cellular immune phenomena may indicate the existence of either different stages of Graves' disease or a heterogeneity of the immunopathogenesis in different patients.