Inclusion Criteria:  Consent of the patient. Patient who meets the definition of Ankylosing Spondylitis based on the 1984 Modified New York Criteria, has a diagnosis of active Ankylosing Spondylitis (BASDAI ≥ 4, Back pain ≥ 4). Patients who have indication of adalimumab. Patients on NSAIDs treatment need to be on a stable dose for at least 4 weeks.  Exclusion Criteria:  (1) Hepatitis B or tuberculosis patients