The Role of IL-23 in Chronic Inflammatory Disease: Exploring the Cellular and Molecular Targets of IL-23 Signaling in Peripheral and Axial Spondyloarthritis

Inclusion Criteria: * Age : Adults (\>18 years) * Satisfying ASAS diagnostic criteria for SpA * Patient has active disease, defined by the presence of active synovitis, tendinitis, or dactylitis or significant inflammatory pain of the spine, judged by the examining clinician to be due to SpA. * Informed consent signed * Beneficiary of health insurance, except for the AME Only for patients of Group 1 • Patient is naïve to biological therapies Only for patients of Group 2 * Patient is affected by peripheral SpA (ASAS criteria) or psoriatic arthritis, with inflammation of peripheral joints * Patient requires aspiration, as part of standard care Non inclusion criteria: * Patient is minor * Patient is pregnant or breastfeeding * Patient is immunocompromised * Patient has received biological therapy with 2 or more biologics * Patient is receiving corticosteroid treatment \> 10 mg per day * Patient is under legal protection, curators, guardianship * Patient refuses consent * Previous history of alcoholism, drug addiction, psychological problems, severe concomitant conditions that could invalidate the patient's consent or limit the patient's compliance to the treatment protocol. * Beneficiary of the AME Only for group 1 • Patient has received biological therapy