Use of rituximab to treat a patient with coexistence of rheumatoid arthritis and ankylosing spondylitis: 18 months follow-up.

Coexistence of rheumatoid arthritis (RA) and ankylosing spondylitis (AS) is rare. Tumor necrosis factor (TNF) inhibitor has been highly successful in controlling inflammation in many patients with AS or RA. Rituximab, which is a chimeric anti-CD20 monoclonal antibody, has been proven effective in RA. Whether rituximab may be effective in AS is presently unclear. Here we report the 18 months follow-up result of a coexisting AS and RA TNF inhibitor failed patient that was treated successfully with rituximab.