the main objectives are

1. to study the pathophysiological role of KIR3DL2 in axSpA and its relationship with Th17 immunity in HLA-B27 + and HLA-B27- patients and
2. to assess the effect on the pro-inflammatory immune response of a cytotoxic monoclonal antibody IPH4102 (anti-KIR3DL2) in these patients.

The study will be carried out on blood samples from 24 patients with axSpA, 12 HLA-B27 + and 12 HLA-B27-, without any drug injection nor direct therapeutic benefit for the participating patients and 12 healthy controls.

Inclusion Criteria:

• Informed consent of the patient signed before any procedure planned to the protocol
• SPA axial according to the criteria of the ASAS (international Assessment of SpondyloArthritis Society)
• Known Status HLA B27
• Disease activates with a score of BASDAI = 4/10. The BASDAI (Bath Ankylosing Spondylitis Disease Activity Score) is a composite indication(index), validated, used in the therapeutic essays and in current practice for the evaluation of the activity of the SPA.
• Naive Patients of thorough treatment
• Patients of 18 and more years old

Exclusion Criteria:

• Minors
• Pregnant or breast-feeding Women
• Adults under guardianship
• People staying in a sanitary or social establishment
• People in emergency situation
• Not profitable People of a national insurance scheme
• Private persons of freedom
• Treatment by corticoids during the last 30 days before the inclusion
• Treatment by anti-TNF or quite different biomedicine
• Treatment by sulfasalazine
• Reached concomitant by another active chronic inflammatory disease
• Infection chronicles by VHB, VHC or HIV
• Patients included in another study of clinical trial