Patients with ankylosing spondylitis who are male, have evidence of spinal damage, or have higher levels of inflammatory markers may be at higher risk of disease progression, a study has found.
“Assessment of AS-related structural changes longitudinally is essential for understanding the natural course of progression and its underlying factors,” Ismail Sari, MD, of the University of Toronto and coauthors wrote in Arthritis Care & Research. “This could help identify the mechanisms responsible for progression and thereby personalizing treatment.”
The researchers found that nearly one-quarter (24.3%) of 350 individuals with ankylosing spondylitis in a longitudinal cohort study showed radiographic evidence of progression, defined as a change of 2 units on the modified Stoke Ankylosing Spondylitis Spinal Score (mSASSS) in 2 years. Overall, 76% of the group were males, and the group had a mean age of about 38 years with a mean symptom duration of nearly 15 years.
Over the 6-year follow-up, the mean mSASSS increased from 9.3 units at baseline to 17.7 units, with more progression seen in the cervical spine than the lumbar segments. During the first 2 years, the total mSASSS increased by a mean of 1.23 units; in years 2-4, it increased by a mean of 1.47 units, and from 4 to 6 years, it increased by a mean of 1.52 units.
Male sex was associated with more than double the risk of radiographic progression (hazard ratio, 2.46; 95% confidence interval, 1.05-5.76), while individuals with radiographic evidence of spinal damage at baseline had a nearly eightfold higher risk of progression (HR, 7.98; 95% CI, 3.98-16). The risk for disease progression also increased with higher levels of C-reactive protein.
The investigators also found that patients who had used tumor necrosis factor inhibitor therapy for at least 1 year had an 18% reduction in the rate of spinal progression.
However, other factors including symptom duration, presence of HLA-B27, smoking status, presence of radiographic hip disease, or use of disease-modifying antirheumatic drugs or NSAIDs did not appear to influence the risk of disease progression.
No funding or conflicts of interest were declared.
SOURCE: Sari I et al. Arthritis Care Res. 2019 Nov 1. doi: 10.1002/acr.24104.