The factors contributing to long-term remission in axial SpA (axSpA) are unclear. We aimed to characterize individuals with axSpA at the 5-year follow-up to identify baseline factors associated with remission.

We included all patients from the DESIR cohort (with recent-onset axSpA) with an available Ankylosing Spondylitis Disease Activity Score-CRP (ASDAS-CRP) at 5-year follow-up. Patients in remission (ASDAS-CRP < 1.3) were compared with those with active disease by demographic, clinical, biological and imaging characteristics. A logistic model stratified on TNF inhibitor (TNFi) exposure was used.

Overall, 111/449 patients (25%) were in remission after 5 years. Among those never exposed to TNFi, 31% (77/247) were in remission compared with 17% (34/202) of those exposed to TNFi. Patients in remission after 5 years were more likely to be male, HLA-B27+, have a lower BMI, and a higher education level. Baseline factors associated with 5-year remission in patients never exposed to TNFi included lower BASDAI [adjusted odds ratio (ORa) 0.9, 95% CI: 0.8, 0.9) and history of peripheral arthritis (ORa 2.1, 95% CI: 1.2, 5.3). In those exposed to TNFi, remission was associated with higher education level (ORa 2.9, 95% CI: 1.6, 5.1), lower enthesitis index (ORa 0.8, 95% CI: 0.7, 0.9), lower BASDAI (ORa 0.9, 95% CI: 0.9, 0.9) and lower BMI (ORa 0.8, 95% CI: 0.7, 0.9).

This study highlights the difficulty in achieving 5-year remission in those with recent-onset axSpA, especially for the more active cases, despite the use of TNFi. Socio-economic factors and BMI are implicated in the outcome at 5 years.