Clinical Research Directory

Inclusion Criteria: * The patient should be given free and informed consent and signed the consent * The patient must be affiliated or beneficiary of a health insurance plan * patients aged 18 years and under 50 * inflammatory back pain (buttocks , lumbar or thoracic spine ) * fulfilling the criteria of Calin or Berlin (30,31) * duration of symptoms than three months and less than three years * symptoms suggestive of spondyloarthritis as assessed by the local investigator ( score≥5 on a numerical scale from 0 to 10 where 0 = no evocative and 10 = very suggestive of spondyloarthritis ) . Exclusion Criteria: * Another clearly defined spinal disease (eg discarthrose ) * history of treatment with biotherapy * taking glucocorticoids allowed only in low dose of less than 10mg of prednisone daily and stable for at least four weeks before inclusion * Current or history anomalies that could interfere with the validity of informed consent and / or prevent a patient's optimal adhesion to the cohort (eg , alcoholism , mental illness) .