Activity of axial spondyloarthritis after one year of anti-tumor necrosis factor therapy among patients with inflammatory bowel diseases.

The disease activity of axSpA after initiating anti-TNF agents for inflammatory bowel diseases (IBD) is poorly understood. We sought to examine the disease activity of axial spondyloarthritis (axSpA) after initiation of anti-tumor necrosis factor (TNF) agents among patients with IBD. This retrospective cohort study included adults with IBD and axSpA who initiated anti-TNF agents between 1/1/2012-10/1/2021 at a large academic center. The primary outcome was symptom resolution (SR) of axSpA at 12 months ("0/10 pain" or "no pain" or "controlled pain" with no morning stiffness and no use of daily NSAIDs). The secondary outcome was clinical remission (CR) of IBD at 12 months (simple clinical colitis activity index <3, Harvey-Bradshaw Index <5, or provider assessment with no use of oral/IV steroids for 30 days). Associations between baseline characteristics and SR of axSpA were examined using logistic regression. 82 patients with axSpA and IBD initiated anti-TNF agents. At 12 months, 52% and 74% achieved SR of axSpA and CR of IBD, respectively. IBD duration <5 years (OR 3.0, 95% CI 1.2-7.5) and adalimumab use (reference: all other anti-TNFs; OR 2.7, 95% CI 1.002-7.1) were associated with SR of axSpA at 12 months. 52% of patients with axSpA and IBD achieved SR of axSpA at 12 months after initiating anti-TNF therapy. Shorter disease duration and adalimumab use may be associated with higher odds of SR. Larger studies are needed to confirm these findings, examine additional clinical predictors of SR, and identify more effective therapeutics for this population.