T-lymphocytes phenotypic composition of peripheral blood in patients with Graves’ disease undergoing conservative therapy with thiamazole

Abstract

BACKGROUND: Effective control of autoimmune inflammation in Graves’ disease determines necessity to study the T helper (Th) and cytotoxic T-lymphocytes dysfunction, as well as the level of regulatory T-cells (Treg) activation in patients with Graves’ disease on thyrostatic medication, which will clarify the immunomodulatory effects of long-term thiamazole treatment serve as targets for more specific therapies.AIM: To study the phenotypic composition of T-lymphocytes in the peripheral blood of patients with Graves’ disease to assess the direction of immune response depending on thimazole-induced euthyroidism duration.MATERIALS AND METHODS: A single-center, cohort, continuous, open-label, controlled trial was conducted to assess the phenotypic composition of T-lymphocytes in peripheral blood in women with Graves’ disease on long-term thiamazole treatment. The phenotypic composition of T-lymphocytes was determined by flow cytometry using direct immunofluorescence with conjugated FITC monoclonal antibodies depending on the duration of thimazole-induced euthyroidism of long-term thiamazole treatment.RESULTS: The study included 135 women with Graves’ disease, mean age 43.09±12.81 years, 120 (88.91%) with a relapse of the disease and 15 (11.09%) with newly diagnosed hyperthyroidism. An increase of activated CD3+CD4+CD25+ was found in patients with Graves’ disease with a duration of thimazole-induced euthyroidism 5–8 months and 9–12 months, respectively, Me=0.94 (0.48–1.45), p=0.020) and Me=0.95 (0.41–1.80), p=0.025), in control group — Me=0.12 (0.03–0.68). Compared to the control an increase of CD4+CD25+CD127Low (Treg) was found in patients with a duration of thimazole-induced euthyroidism 5–8 and 9–12 months. The content of Treg in peripheral blood in Graves’ disease patients with a duration of thimazole-induced euthyroidism more than 12 months decreases, but remains elevated relative to the control.CONCLUSION: In patients with Graves’ disease with a duration of thimazole-induced euthyroidism 5–8 months and 9–12 months the level of Treg has been increased. The increase of activated Th (CD3+CD4+CD25+) persists independently of thimazole-induced euthyroidism. In patients with Graves’ disease with a duration of thimazole-induced euthyroidism for more than 12 months, there is a compensatory increase in regulatory T-lymphocyte, and the total number of T-helpers is restored to the control.