The clinical and immunological indices and their interaction with thyroid status in patients with Graves’ disease depending on thyrocytes peroxidase autoantibodies level

Abstract

The process of antibody production against thyroid peroxidase and their relation to the complement-mediated cytotoxicity have the most pronounced cytotoxic effect on thyrocytes in Graves’ disease.Aim.To study the clinical and immunological indices and their interaction with thyroid status in patients with Graves’ disease depending on thyrocytes peroxidase autoantibodies level.Material and methods.The study included 35 women aged 18 to 55 years, mean age of 39.1±7.2, with verified diagnosis of Graves’ disease for the first time, before antithyroid therapy. The clinical and immunological parameters and their relationship with thyroid status studied depending on the level of AT-TPO. The definition of thyroid hormones content was measured using immunoradiometricassay analysis with standard test kits. AT-TPO was assessed by ELISA. Population and subpopulation composition of blood lymphocytes was evaluated using the method of indirect immunofluorescence using monoclonal antibodies to CD3, CD4, CD8, CD16, CD19 and HLA-DR. The humoral subset pattern characterized by the relative synthesis of IgA/CD19+, Ig M/CD19+, IgG/CD19+.Results.The most significant changes in population and subpopulation composition of lymphocytes was found in patients with more than 100 IU/L AT-TPO level and characterized by an increase in absolute lymphocyte, relative and absolute number of CD19+ and HLA-DR+cells, and CD3+ and CD8+cells, as compared to the control range and the values identified in group with AT-TPO less than 100 IU/L. A strong negative relationship AT-TPO with the number of T-lymphocytes (r=–0.75; p<0.001) and moderate with the relative synthesis level of IgM (r=–0,53; p=0.017) have been revealed. In Graves’ disease patients with AT-TPO more than 100 IU/l levels the statistically significant relationships were not found.Conclusion.The immunopathogenesis of Graves’ disease is characterized by positive correlation in AT-TPO and indicators of b-cell immunity, and negative — with the parameters of T-cell immunity, regardless of thyrocytes peroxidase autoantibodies concentration.