Endocrine Abstracts

It is known that thyroid peroxidase is expressed on the apical surface of thyrocytes, where catalyze the iodination of thyroglobulin and may, also, be a surface-cell antigen, which involves in the complement-dependent cytotoxicity reactions. Objective: to study the immune status indicies depending on thyroid peroxidase (anti-TPO) antibodies in patients with Graves’ disease (GD). Materials and methods. The study included 35 women aged from 18 to 55 years, mean age of 39.1±7.2, with manifestations of GD, before antithyroid therapy. Concentrations of thyroid hormones were measured by RIA. Anti-TPO concentrations was assessed by ELISA. The analysis of lymphocytes subset pattern were performed by indirect immunofluorescence using the FITC-marked monoclonal antibodies to CD3, CD4, CD8, CD16, CD19, HLA-DR. The Ig A, M, G concentrations were determined by ELISA. The CD4⁺/CD8⁺T cell ratio and the relative synthesis of IgA (IgA /CD19⁺), IgM (Ig M/CD19⁺) and IgG (IgG/CD19⁺) were also calculated. Results. The patients with more than 100 IU/L anti-TPO level were characterized by an increase in absolute lymphocytes, relative and absolute number of CD19⁺ and HLA-DR⁺cells, CD3⁺ and CD8⁺cells, compared to the control range and patients with anti-TPO less than 100 IU/L. In GD patients with at-TPO level more than 100 IU/l the leuko-T- and leuko-B-cell ratios reduction, along with the IgA and IgM relative synthesis decreasing were observed. The only difference of patients with anti-TPO less than 100 IU/l was the increasing of absolute lymphocytes number (P<0.05). But in this group relationship anti-TPO with relative and absolute content of B-lymphocytes (r=+0.50, P=0.026 and r=+0.47, P=0.39, respectively), and leuko-T-cell ratio (r=−0.58, P=0.007) have been appeared. Conclusion. The most significant changes of immunological indices in GD were found in patients with more than 100 IU/L anti-TPO level. In the case of anti-TPO level less than 100 IU/l the immunopathogenesis of GD is characterized by the appearance of positive relationships anti-TPO with B-, and negative with T-cell immunity indicies.