[Biological treatment of ankylosing spondylitis]

All of the three well-known TNF alpha inhibitors (infliximab, adalimumab and etanercept) have a rapidly occurring and long-lasting effect in ankylosing spondylitis (AS). The IL-1 antagonist, anakinra, has been investigated in two open label studies with partially conflicting results. Apart from infusion reactions and local reactions which rarely are of clinical importance, infections appear significantly more often in the TNF alpha inhibitor groups compared to placebo groups. Most of the infections observed have been minor, but serious infections, including tuberculosis, have been described.