The state of antioxidant defense system in young persons with gastroesophageal reflux disease and autoimmune thyroiditis

Aim of research was assessment of the levels of antioxidant biomarkers associated with mitochondrial function in young patients with gastroesophageal reflux disease (GERD) and autoimmune thyroiditis (AIT). This study included 165 patients of them 120 patients with GERD and AIT - the main group, 45 patients with isolated GERD - the comparison group. The examined contingent was presented by students aged 18 to 25 years. The control group consisted of 20 healthy individuals of corresponding gender, age and social status (students). Total antioxidant activity (TAS-TAC) was determined in blood serum of study persons with enzyme immunoassays (ELISA, Elabscience, USA), levels of manganese superoxide dismutase (MnSOD) – with enzyme immunoassays (ELISA, Elabscience, USA) and Klotho protein - with enzyme immunoassays (ELISA, Elabscience, USA). Statistical data processing by the Statistica Basic Academic 13 for Windows En local was made. In examined patients with esophageal and thyroid pathologies the decline of total antioxidant activity has been revealed. The MnSOD level in patients with comorbidity of GERD and AIT and isolated GERD was significantly higher as compare to control group. Significant increasing of Klotho protein in serum of young patients was observed. We assessed imbalance between decline of extracellular antioxidants and activation of mitochondrial antioxidants which is more pronounced in combination of diseases. The increase of biomarkers of mitohondrial antioxidant defense system with non-specific citoprotection mechanism in patients with GERD provides the basis to consider MnSOD and Klotho protein as prognostic indicator of clinical outcome of disease in young age. Under combination of GERD and AIT the tendency to overexpression of MnSOD and depression of total antioxidant activity has been revealed, this may cause the deterioration of mitochondrial function.