SAT0018 Blood chemokine system profile associated with disease activity in rheumatoid arthritis

Background Chemokine receptors and their chemokine ligands (chemokine system), key mediators of inflammatory and immune cell trafficking, are involved in the pathogenesis of rheumatoid arthritis (RA). There is still limited information of blood chemokine system signature associated with disease activity. Objectives To identify RA-associated chemokine system signature using highly sensitive multiplex Proximity Extension ImmunoAssay (PEA) in serum together with analysis of CCR5, CCR6 and CXCR3 expression in blood cell subsets and assess its relationship with disease activity as evaluated by activity score (DAS28). Methods We investigated the serum levels of 92 inflammation-related proteins in 78 Czech patients with RA by PEA (Proseek Multiplex, Olink Bioscience, Sweden). Disease activity was assessed by means of DAS28 and subgroups were formed based on the disease activity, where DAS28 of ≥3.2 was taken as active RA (inactive RA, n=40; active RA, n=38). The expression of CCR5, CCR6 and CXCR3 receptors were analysed using 6-colour flow cytometry (BD FACSCanto II) on T and B lymphocytes, NK, dendritic cells, and monocytes in peripheral blood from 11 patients with active RA and 9 age-matched healthy control subjects. Statistical tests (Mann-Whitney U test, Spearman correlation) were performed using GenEx (Sweden) and GraphPad Prism 5.01 (CA, USA). P-value≤0.05 was considered as significant. Results In patients with active RA, 16 serum proteins were upregulated (Pcorr ≤0.05). Top-ranked proteins distinguishing active and inactive RA were CCL20, CXCL9, CCL7, CXCL10, IL-6, sCDCP1, and CXCL1 (Pcorr 0.30, p Conclusions We identified the blood chemokine system signature associated with disease activity in RA further supporting a critical role of CCL20/CCR6 axis in the ongoing inflammation related to the disease activity in RA. Acknowledgements Grant support: MZ CR VES15–28659A, IGA_LFUP_2018_16 Disclosure of Interest None declared