AB0207 Calprotectin (S100A8/9) plasma levels decrease after abatacept therapy and correlate with disease activity in patients with rheumatoid arthritis

Background Calprotectin (S100A8/9) is a damage-associated molecular pattern molecule that is involved in the early phase of tissue injury. It is found mainly in circulating neutrophils, monocytes and macrophages of rheumatoid arthritis (RA) synovial tissue where it acts as a chemoattractant and induces production of proinflammatory cytokines. Several studies have reported its association with clinical disease activity and radiographic damage in patients with RA. Objectives The aim of our study was to analyse the plasma levels of calprotectin in patients with established RA after the abatacept treatment compared with healthy individuals, and to examine their potential association with disease activity and treatment response. Methods The plasma levels of calprotectin were determined by ELISA (BUHLMANN Laboratories AG) in 40 patients with established RA before and 3 months after initiation of abatacept treatment, and in 30 age–/sex-matched healthy subjects. Disease activity was evaluated by 28-joint Disease Activity Score (DAS28). The CRP levels and erythrocyte sedimentation rate (ESR) were determined by routine laboratory techniques. Data are presented as median ±IQR. Results Calprotectin levels at baseline were significantly higher in patients with established RA than in healthy individuals (1925 [741; 4093] vs. 506 [302; 754] p Conclusions We demonstrate here decrease in plasma levels of calprotectin after 3 months of abatacept therapy in patients with established RA, its association with disease activity and disease activity improvement over time. Acknowledgements Supported by the project of MHCR for conceptual development of research organisation 00023728, research project SVV 260 373. Disclosure of Interest None declared