AB0572 REDUCED ENZYMATIC ACTIVITY OF ANTIOXIDANT SYSTEM IN SCLEROSIS.
Authors: N. Emelyanov, I. Gontar, O. Emelyanova, O. Rusanova
Journal: Annals of the Rheumatic Diseases (2020)

Background: The antioxidant system is a natural barrier to the pathologic effect of reactive oxygen intermediate (ROI) on the tissues of patients with systemic scleroderma (SSD). It is comprised of enzymatic links, of which the cascade of enzymes like superoxide dismutase (SOD), glutathione peroxidase (GP), glutathione reductase (GR) and others are most important. Autoantibodies to enzymes of the antioxidant system can bring about a reduction in their biochemical activity. Objectives: Studying the effect of production of antibodies to antioxidant system enzymes SOD, GP and GR in patients with SSD using immobilized magnetocontrolable adsorbents. Methods: We observed 40 patients with SSD and 30 apparently healthy individuals. Degree I of activity was established in 15 patients (37,5%), degree II – in 24 patients (60%), degree III – in 1 patient (2,5%). Patients with subacute and acute course of the disease, degree of activity II and III were united in one group due to their small number. Antibodies to SOD, GR and GP were determined in blood serum of patients upon admission and discharge using immobilized antigen forms of enzymes (Gontar I.P., 2001). Commercial preparations served as antigens when determining antibodies to SOD, GR and GP. Results: A study of blood sera from healthy individuals showed SOD antibodies level of 0,06±0,004, GP antibodies – 0,045±0,003, GR antibodies – 0,05±0,01. The total activity of SOD in the group of healthy people was 38,2±1,2 IU; GP – 0,153±0,007, GR – 114,3±3,7. Upon admission to hospital patients showed a reliably reduced activity of SOD and GR (p&lt;0,002), and unreliably reduced activity of GP (р&lt;0,02). Among patients with SSD antibodies to SOD were detected in 15 people (37,5%), antibodies to GP – in 14 (35%), antibodies to GR – in 16 (40%). With degree I of activity, high levels of SOD antibodies were detected in 4 patients (26,7%), antibodies to GP – in 4 patients (20%), to GR – in 6 (40%). When SSD was degree of activity II and III, the patients showed a reduced activity of SOD, GR and GP (р&lt;0,05) compared with healthy people, and higher antibody levels (р&lt;0,002). We noted an increase in the number of patients whose serum showed high antibody levels: antibodies to SOD in 11 people (44%), to GP – in 11 (44%), antibodies to GR – in 12 (48%). In the group of SSD patients who showed high levels of SOD, GR and GP antibodies, we observed a reliable reduction in enzymatic activity (р&lt;0,05). SOD activity was reliably reduced both in chronic and subacute course of the disease (р&lt;0,02). In the group of patients with high levels of enzyme antibodies we noted a reliable reduction in enzymatic activity. A test for antibodies to SOD, GR and GP in SSD patients with involvement of various organs and systems showed their reliably elevated level in all clinical groups (р=0,032, р=0,034 and р=0,025). Conclusion: Production of antibodies to antioxidant system enzymes plays an important role in pathogenesis of SSD involving internal organs and tissues and aggravating the course of the disease on the whole. Disclosure of Interests: None declared