All patients over 18 years, with rheumatoid arthritis treated for the first time with conventional anti-TNF therapy, Abatacept, Tocilizumab, Rituximab or patients with spondyloarthritis treated for the first time with NSAIDs that may be associated with conventional background treatments for peripheral or biological (anti-TNF, Usketinumab) may be included. However, they must be subject to a Social Security scheme and will only be able to participate in the research if they give their consent in writing after receiving full information.