Effect of Anti-TNF (Alpha) Treatment on Vascular Stiffness in Ankylosing Spondylitis (AS)

Inclusion Criteria: * Men or women, 18 years of age or older * Fulfilled the modified New York diagnostic criteria for Ankylosing spondylitis (AS)for more than 3 months * Bath Ankylosing Spondylitis Disease Activity Index (BASDAI) ≥ 4 (0-10 point scale), Pain visual analog scale(VAS) ≥ 4 (0-10cm scale) * Inadequate response to at least two Nonsteroidal Antiinflammatory Drugs (NASID) on highest recommended doses for 3 months or unable to receive full 3-month course because of intolerance,toxicity or contraindications * Normal Chest X-ray within 3 months before baseline * Purified Protein Derivative(PPD) negative, or Latent Tuberculosis (TB) patients were required therapy for Tuberculosis (TB) before or simultaneously with first dose of study agent Exclusion Criteria: * Complete ankylosis of the spine * Concurrent with other inflammatory rheumatic disease * Serious infection (treatment with IV-infective) within 2 months before randomization * Active Tuberculosis (TB) or recent contact with a person with active Tuberculosis (TB) * An opportunistic infection within 6 months of screening * Known history of Hepatitis, Human Immunodeficiency Virus (HIV), Malignancy, a transplanted organ, multiple sclerosis, congestive heart failure * Currently on systemic immunosuppressives, DMARDS (other than Methotrexate, Sulfasalazine , or Hydroxychloroquine), or Leflunomide within 4 week before first study agent * Any previous use of Alefacept, Efalizumab, Rituximab, Golimumab or Natalizumab * Use of cytotoxic drugs, received intra-articular, intramuscular, or intravenous corticosteroids in the past 4 weeks before screening * Clinically significant renal disease (serum creatinine level ≥ 270µmol/L), alanine aminotransferase (ALT) ≥ 2 x upper limit of normal (ULN) * Hemoglobin level \< 8.5gm/dl, a white blood cell count \< 3.5x 109/liter, a platelet count \< 100x 109/liter * Female of childbearing potential, unwilling to use adequate contraception during the study * Pregnant or breastfeeding women