Abstract
Objective
To determine whether the effects of anti–tumor necrosis factor α (TNFα) in reducing the signs and symptoms of ankylosing spondylitis (AS) coincide with a reduction in spinal inflammation as detected by magnetic resonance imaging (MRI).
Methods
Pre‐ and postgadolinium T1 and STIR MR images of the spine were acquired at baseline and at week 24 in patients with AS who participated in a multicenter, randomized, double‐blind, placebo‐controlled study. Patients were randomly assigned at an 8:3 ratio to receive infusions of infliximab (5 mg/kg) or placebo at weeks 0, 2, and 6 and then every 6 weeks thereafter. MR images were obtained and evaluated independently by 2 readers who were blinded to the treatment allocation and time sequence of the images.
Results
A total of 194 patients in the infliximab group and 72 patients in the placebo group had evaluable images at baseline and week 24. About 80% of the patients had at least 1 active spinal lesion at baseline, as assessed by MRI. The improvement in the MRI Activity Score after 6 months was significantly greater in the patients who received infliximab (mean 5.02, median 2.72) than in those who received placebo (mean 0.60, median 0.0) (P < 0.001). Almost complete resolution of spinal inflammation was seen in most patients who received infliximab, irrespective of baseline activity.
Conclusion
Patients with AS who received infliximab therapy showed a decrease in spinal inflammation as detected by MRI, whereas those who received placebo showed persistent inflammatory spondylitis.