Management of ankylosing spondylitis with infliximab

Ankylosing spondylitis (AS) is a systemic inflammatory rheumatic disease responsible for back pain, stiffness and progressive loss of functional capacity with limited therapeutic options. Regular physical exercises together with the use of nonsteroidal antiinflammatory drugs are the two recognized treatment options in AS. Infliximab is a chimeric anti-tumor necrosis factor-α monoclonal antibody that has been demonstrated to be highly effective in the treatment of AS, providing clinical amelioration at both axial and peripheral skeleton. Infliximab also improves quality of life, function, biological parameters (acute phase reactants) and inflammatory lesions of the spine as detected by magnetic resonance imaging. It is given at a 5 mg/kg dosage, as an infusion at weeks 0, 2, 6, and every 6 to 8 weeks after. Open-label and placebo-controlled trials have well demonstrated its high level of efficacy, with an improvement of the disease activity of at least 50% in 60%-80% of patients. In a large placebo-controlled trial, Assessment in Ankylosing Spondylitis Response Criteria (ASAS20) responders were observed in 61.2% of patients receiving infliximab compared to 19.2% of patients under placebo. Long-term efficacy is maintained when infliximab is administered every 6-8 weeks. Consensus international guidelines for the initiation and the use of this expensive treatment are available. Some questions remain, including the long-term safety, in particular the risk of lymphoma, and the potential influence of infliximab on radiological progression which is not currently demonstrated. Despite these concerns, infliximab has revolutionized the management of AS and represents a considerable therapeutic advancement in this disabling disease.