Endocrine Abstracts

Introduction: Graves’ disease (GD) is organ-specific autoimmune-inflammatory disorder characterized by a complex pathogenesis. The inflammatory process is dominated by an imbalance of the antioxidant-oxidant mechanism, increased production of reactive oxygen species (ROS), which can potentiate the cytotoxicity of neutrophils and sustain the autoimmune process and perpetuate the disease. Aim: to study the level of ROS synthesis by peripheral blood neutrophils in patients with Graves’ disease depending on hyperthyroidism compensation.

Materials and methods: One hundred and twenty-six women with Graves’ disease, aged 18 to 65 years, divided in groups with compensated hyperthyroidism 93 (73.81%) and relapse of hyperthyroidism 33 (26.19%) were studied and compared concerning ROS production. All patients continuously treated with thiamazole about two months. The maintenance dose of thiamazole was 10 mg per day. The synthesis level of ROS in peripheral blood neutrophils was evaluated using a 36-channel chemiluminescence analyzer ‘BLM-3607’ (MedBioTech, Krasnoyarsk) and was characterized by Tmax – the rate of development of the chemiluminescent reaction, Imax – the maximum ROS synthesis and the area under the chemiluminescence curve (S – total synthesis of ROS for 90 minutes of measurement).

Results: Regardless for hyperthyroidism compensation the indicator S of spontaneous and zymosan-induced lucigenin-dependent chemiluminescence increases significantly relative to the control (р<0,001), but decreases the Tmax of zymosan-induced chemiluminescence (р<0,01). In GD relapse patients total synthesis of ROS during zymosan-induced chemiluminescence was higher up to 4,35 compared to euthyroid group (р<0,05). Antigenic stimulation of neutrophils in GD patients of both groups revealed an increase the Imax during luminol-dependent chemiluminescence (р<0,01). Samples with zymosan in GD relapse patients, also, demonstrated more than tenfold increase in the total synthesis of ROS relative to the control, but no statistically significant differences with euthyroid patients.

Conclusion: Violation of the ROS production by peripheral blood neutrophils in euthyroid patients mainly affects the production of primary ROS which is associated with hyperthyroidism compensation and the immunosuppressive effect of thiamazole. In patients with relapse of hyperthyroidism, there are more changes in the production of high-energy oxidants not only at initial oxidative reactions stage but also at the level of secondary ROS, indicating the activation of cellular response immunological mechanisms. Cytopathogenic effect of ROS neutrophils generation in patients with Graves’ hyperthyroidism determine the intracellular targets of immunotropic treatment of the disease.