Session Information
Session Type: ACR Concurrent Abstract Session
Session Time: 2:30PM-4:00PM
Background/Purpose:
Antiphospholipid syndrome (APS) is characterized by the presence of arterial and venous thrombosis, and by recurrent abortions, in patients with persistent presence of autoantibodies against phospholipid-binding proteins (aPL), such as β2-Glycoprotein I (β2GPI). Arterial thrombosis has been also related to accelerated atherosclerosis in experimental models, however contrasting findings have been reported in clinical studies of patients with primary APS regarding an increased number of plaques or an abnormal arterial wall thickness. In spite of that, aPL predicts adverse arterial outcomes (Hollan et al Autoimmun Rev 12:1004;2013). Aim of the study was to investigate the role of the anti-β2GPI immune response in atherosclerotic lesions.
Methods:
We investigated the cytokine production induced by β2GPI, and its domains (DI, DII, DIII, DIV, DV) in activated T cells that infiltrate in vivo atherosclerotic lesions of patients with primary APS atherothrombosis. We also examined the helper function of β2GPI-specific T cells for monocyte matrix metalloproteinase (MMP)-9 and tissue factor (TF) production, as well as their cytolytic potential and their helper function for antibody production.
Results:
We report that APS patients with atherothrombosis harbor in vivo activated CD4+ T cells that recognize β2GPI in atherothrombotic lesions. We characterized the submolecular specificity of plaque infiltrating T cells and found that the majority of them recognize their epitopes within the DI domain. β2GPI and its domains induce T cell proliferation and expression of IFN-g in plaque-derived T cell clones. β2GPI-specific T cells display helper function for monocyte MMP-9 and TF production, and promote antibody production in autologous B cells. Moreover, plaque-derived β2GPI-specific CD4+ T lymphocytes express both perforin-mediated and Fas-FasLigand mediated cytotoxicity.
Conclusion:
β2GPI, and especially DI domain, drive a local Th1 inflammatory response, with subsequent plaque instability which eventually favors atherothrombosis. This finding may explain the association between aPL and arterial thrombosis in spite of the lack of the evidence for surrogate markers of atherosclerosis – such as number of plaques and increased arterial wall thickness – in primary APS patients with high prevalence of arterial events.
To cite this abstract in AMA style:
Meroni PL, Benagiano M, Gerosa M, Romagnoli J, Mahler M, Borghi MO, Grassi A, Della Bella C, Emmi G, Amedei A, Silvestri E, Emmi L, Prisco D, D'Elios MM. Immune Response Against  β2GPI Drives Th1 Inflammation in Atherosclerotic Plaques of Patients with Primary Antiphospholipid Syndrome [abstract]. Arthritis Rheumatol. 2015; 67 (suppl 10). https://acrabstracts.org/abstract/immune-response-against-a-i%c2%b22gpi-drives-th1-inflammation-in-atherosclerotic-plaques-of-patients-with-primary-antiphospholipid-syndrome/. Accessed .« Back to 2015 ACR/ARHP Annual Meeting
ACR Meeting Abstracts - https://acrabstracts.org/abstract/immune-response-against-a-i%c2%b22gpi-drives-th1-inflammation-in-atherosclerotic-plaques-of-patients-with-primary-antiphospholipid-syndrome/