INCREASED M1 INFLAMMATORY PHENOTYPE OF CIRCULATING MONOCYTES IS ASSOCIATED WITH HISTORY OF CARDIOVASCULAR EVENTS IN RA PATIENTS

Background: Cardiovascular (CV) Disease is the main cause of death in Rheumatoid Arthritis (RA). Current tools like Framingham or European SCORE underestimate CV risk in RA patients. Efforts to improve the assessment including RA biomarkers (disease activity) have been only partially successful. There is a need for better biomarkers to identify AR patients at high risk for CV disease. Monocytes have an important role in plaque development. Monocytes differentiates into 2 main phenotypes M1 and M2 (1). In RA and in post-MI patients M1 monocytes are expanded (2). mTORC influences monocyte phenotype in vitro and has been associated with development of atheromatous plaque (3). Objectives: To evaluate the phenotype of circulating monocyte in RA patient with or without previous CV events (RA-CV(-)RA-CV(+)), and its possible association with mTORC activity. Methods: 9 RA-CV(+)patients aged between 18 and 65 yo with RA (EULAR/ACR 2010 criteria), were paired with RA-CV(-)patients. 6 healthy individuals (HI) were also studied. Pairing criteria were classic CV risk factors (AHA 2018), sex, age, years since RA diagnosis, comorbidities, number of DMARDs previously used and use of bDMARDS. M1 and M2 circulating Monocytes were evaluated in PBMC obtained from patients and controls by flow cytometry analysis. Intracellular inflammatory cytokines (IL1, Il6) and phosphorylated S6R (P-S6R) as a measure of mTORC activation was also evaluated. M1 was defined as CD14+HLA-DR+CCR2+ and M2 CD14+CD163+CCR2-. DAS28-RCP, DAS28-ESR and Lipid profile was also measured. The differences among groups was analysed using Mann–Whitney U nonparametric. The relationship between variables with Spearman rank correlation test. Results: There were no differences in demographic, RA characteristic and CV risk factors between RA-CV (+) and RA-CV (-) patients. Male/Female 4/5, age 62±3 and 63±2 respectively. HI were younger than RA patients (32.5±7). CV events were 8 patients with MI and one Stroke. DAS28-RCP was 2.96±0.23 and 2.88±0.43 respectively. One patient in each group had failed to more than 2 sDMARDs and one in each group was receiving bDMARD. M1 circulating monocytes were expanded in RA as compared to HI. This difference was at RA-CV (+) expense. RA monocytes had higher Intracellular levels of IL-1b and IL-6 as compared to HI. M1 from RA-CV (+) had higher intracellular levels of IL-1b and IL-6 than RA-CV (-). M1 monocytes have higher levels of inflammatory cytokines than M2. P-S6R protein, (mTORC activation), was higher in RA patients than HI. The highest levels of P-S6R was observed in M1 monocytes from RA-CV(+) population. Conclusion: RA-CV+ patients, have a significantly higher number of pro-inflammatory circulating monocytes, using a multiparametric classification method. These monocytes also express higher levels of inflammatory cytokines and higher activation of mTORC, which also participate in the development of atheromatous plaque, suggesting that these monocytes could be a key element in the non-clarified-yet, excess of CV risk of RA patients. References: [1] Fukui S, et al. M1 and M2 Monocytes in Rheumatoid Arthritis: A Contribution of Imbalance of M1/M2 Monocytes to Osteoclastogenesis. Front Immunol. 2017;8:1958.2. Zhuang J, et al. Comparison of circulating dendritic cell and monocyte subsets at different stages of atherosclerosis: insights from optical coherence tomography. BMC Cardiovasc Disord. 2017 Oct 18;17(1):270. Disclosure of Interests: None declared