SAT0026 Differential levels of il-7 expression in adventitia of non-ra and ra patients with coronary artery disease

Background Rheumatoid Arthritis (RA) patients have increased cardiovascular risk due to accelerated atherosclerosis (ATS), which significantly contributes to excess mortality in RA1. The increased cardiovascular risk cannot be fully explained by traditional risk factors and systemic chronic inflammation appears to play a crucial role. Interestingly, IL-7, a proinflammatory cytokine involved in RA pathogenesis, appears to play a role also in atherosclerosis2 but its effect on cardiovascular disease (CVD) in RA has not been studied yet. Objectives To examine serum IL-7 levels and expression of IL-7, IL-7R, CD3 and CD20 in aortic adventitia of RA and non-RA patients with coronary artery disease (CAD) and to search for relationships between systemic IL-7 levels and expression of vascular markers, cardiovascular risk factors including metabolic and inflammatory markers. Methods We examined 19 RA patients and 20 non-RA patients undergoing coronary artery bypass graft surgery included in the Feiring Heart Biopsy Study. Serum IL-7 levels were measured by chemiluminescence (MSD). Biopsies from the adventitia of thoracic aorta from a subset of patients (12 RA and 14 non-RA) were stained for IL-7, IL-7R, CD3 and CD20 by immunohistochemistry and scored per mm2 of tissue. Results Non-RA patients had lower IL-7 serum levels than RA (3.4±3.3 vs. 6.7±3.5, p The number of IL-7 +and IL-7R+cells/mm2 in adventitia were significantly higher in RA (134.2±45.5 and 144±49.9 respectively) than non-RA patients (46.9±22.8 and 54.4±20.2, p Conclusions Among patients with CAD, those with RA had higher serum IL-7 and a greater expression of both IL-7/IL-7R is aortic adventitia. Systemic levels of IL-7 were related to its vascular expression. Thus, the IL-7/IL-7R axis may play a role in the accelerated atherogenesis observed in RA; further studies are needed to elucidate the precise role of IL-7 and impact of potential IL-7R blockade in CV risk in RA. References [1] Kaplan MJ. Curr. Opin. Rheumatol2006;18(3):289–297. [2] Damas JK, et al. Circulation2003;107(21):2670–2676. Disclosure of Interest None declared