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AB1118 THE ROLE OF ANGIOPOETHIN-LIKE PROTEIN 4 TYPE IN PROGRESSION OF INFLAMMATORY CHANGES IN RHEUMATOID ARTHRITIS

Background Angiopoietin-like protein 4 (ANGPTL4) is actively involved in the processes associated with inflammation, angiogenesis and lipid metabolism in rheumatoid arthritis (RA). Objectives To study of the effect of ANGPTL4 on the features of the inflammatory process in RA. Methods The study included 36 RA patients (aged from 33 to 64 years old). A control group (12 people) comprised healthy individuals aged 28 to 52 years old, 28 patients with osteoarthritis (OA) aged 48 to 70 years and 14 people with ankylosing spondylitis (AS) aged 39 to 62 years. Levels of ANGPTL4 in serum were determined by the enzyme immunoassay using the commercial test systems «Human Angiopoietin-like Protein 4 ELISA» from «Bio Vendor» (Czech Republic). Serum C-reactive protein (CRP) levels, erythrocyte sedimentation rates (ESR), rheumatoid factor (RF) titers, and anti-cyclic citrullinated peptide antibody (anti-CCP) were also measured in patients with RA. Results The following results were obtained: the level of ANGPTL4 was significantly higher in patients with RA than in patients with OA, AS, and healthy individuals (p = 0.04, p = 0.021, p = 0.038, respectively). A strong positive correlation was found between the level of ANGPTL4 and the activity of RA according to DAS28 (r = 0.71, p = 0.002). There is no reliable association between ANGPTL4 and anti-CCP (p> 0.05). The ANGPTL4 level in the serum was correlated with levels of ESR (r = 0.42, p = 0.019), CRP (r = 0.49, p = 0.007) and the Sharp score of radiologic change (r = 0.39, p = 0.045) in RA. Hypervascularization rates were significantly correlated with ANGPTL4 in patients with RA (r = 0.38, p = 0.002) according to Doppler data. ANGPTL4 can activate proliferation processes in the synovial membrane by binding to integrin-αvβ3. Besides, the concentration of mast cells is increased in the synovium of affected joints. Mast cells significantly influence angiogenesis through the production of proangiogenic cytokines, including ANGPTL4. Conclusion Changes of the level of ANGPTL4 in the serum of patients with RA may be a potential biomarker of disease activity, severity of neovascularization, inflammation and development of bone erosion. Disclosure of Interests None declared