The objective of this study is to prove reasonability of registration in Russian federation this new indication (ankylosing spondylitis [AS]) through evaluation of safety and efficacy rate of Remicade 5mg/kg, given as an intravenous infusion over a 2-hour period followed by additional 5 mg/kg infusion doses at 2 and 6 weeks after the first infusion, then every 6 to 8 weeks (maximum 9 infusions).