THU0113 Anti-Cyclic Citrullinated Protein Antibodies Act as Direct Inductors of the Inflammation and the Oxidative Stress Observed in Rheumatoid Arthritis, with Differential Effects in Each White Blood Cell Type
Authors: N. Barbarroja, P. Ruiz-Limon, C. Perez-Sanchez, M. A. Aguirre, R. Carretero-Prieto, A. Rodriguez-Ariza, P. Font, A. Escudero, E. Collantes-Estevez, C. Lopez-Pedrera
Journal: Annals of the Rheumatic Diseases (2013)

<h3>Background</h3> The anti-cyclic citrullinated protein antibodies (anti-CCPs) are the most specific auto-antibodies associated with Rheumatoid Arthritis (RA). To date, no study has evaluated the direct effect of the anti-CCPs in the leukocytes and their relationship with the atherogenesis and cardiovascular disease (CVD) observed in these patients <h3>Objectives</h3> To evaluate the effect of the in vitro treatment with anti-CCPs antibodies in the induction of the pro-oxidative and inflammatory state observed in RA leukocytes, and its relationship with the chronic inflammation and early atherogenesis that commonly characterize this disease <h3>Methods</h3> 53 RA patients and 31 healthy donors were included in this study. Carotid intima-media thickness (CIMT) was evaluated as atherosclerosis marker; other markers of CVD were also studied. Several pro-coagulant factors, leukocyte activation markers, peroxides and peroxynitrite levels, intracellular glutathione (GSH) and mitochondrial membrane potential (MMP) were analysed in monocytes, lymphocytes and neutrophils by flow cytometry. Oxidative stress (total antioxidant capacity, nitric oxide and protein tyrosine nitration) and inflammation plasma markers (several interleukins, IFNg, VEGF, MCP-1, MIP-a, MMP-13, sP-selectina and tPA) were analyzed. To elucidate the cellular origin of the inflammatory molecules altered in the plasma from RA patients, RT-PCR of the three cell populations was performed. Finally, anti-CCPs antibodies were isolated from plasma of RA patients and in vitro treatment of healthy monocytes, lymphocytes and neutrophils was conducted <h3>Results</h3> Inflammatory factors such as IL-2, IL-6, IL-8, IL-10, IL-17a, MCP-1, MIP-A, sP-selectin and nitric oxide levels were found greatly elevated in RA plasma versus controls. The antioxidant capacity and protein tyrosine nitration were lower in RA plasma compared to controls. Additionally, high titles of anti-CCPs were associated to an increased expression of the pro-thrombotic and inflammatory markers, high oxidative stress and pathological CIMT. RA monocytes and neutrophils had elevated levels of peroxynitrites and peroxides, considerable depolarization of the MM and lower GSH activity compared with controls. They also showed an increased membrane presence of the cellular activation markers. RT-PCR of the proinflammatory molecules showed that each cell subtype presented a specific expression pattern. The in vitro treatment with anti-CCPs antibodies from RA patients supported the results observed in vivo in RA patients and confirmed the different effects caused by the anti-CCPs in the leukocytes <h3>Conclusions</h3> 1)The anti-CCPs antibodies directly induce inflammation and oxidative stress in the leukocytes from RA patients. 2)The anti-CCPs effects are different depending on the cell type, being the monocytes the cell type most clearly involved in the thrombotic, oxidative and inflammatory status, while lymphocytes were mainly associated to the inflammation and neutrophils to the oxidative stress observed in RA 3)Understanding the specific effects induced by anti-CCPs antibodies would help to develop a cellular targeted therapy preventing the atherosclerosis and CVD in RA patients <h3>Acknowledgements</h3> Supported by: P08-CVI-04234, PI12/01511, Spanish Rheumatology Society <h3>Disclosure of Interest</h3> None Declared