The goal of this interventional pathophysiological exploratory, cohort, prospective, with a 6-month follow-up study is to characterize phenotypic and functional alterations of PolyMorphonuclear Neutrophils as well as monocytes/macrophages and dendritic cells in blood samples from rheumatoid arthritis patients. Investigators will perform prospective characterization of these myeloid cells before and after treatment to assess how the functional status of PMNs/myeloid cells affects the response to anti-TNFα (tumor necrosis factor alpha) in rheumatoid arthritis. This will identify key immune components potentially involved in the activation and/or recruitment of PolyMorphonuclear Neutrophils (PMN) (and other myeloid cells) that may play a role in the pathogenesis of Rheumatoid Arthritis and may help predict the response to anti-TNFα agents, thus guiding the decision-making of therapeutic strategies.