All participants received oral Methotrexate(MTX), starting at 7.5 mg/week. In patients with persistent tender or swollen joints, the dose was escalated in a graduated manner (2.5 mg/week every 1-2 weeks) to 15 mg/week by week 4 or 20 mg/week by week 8 Patients in combination group receive infliximab 3mg/kg at weeks 0, 2, and 6 and every 8 week thereafter. Comprehensive assessment will be made on week 0, 12, 24.