Disease activity in axial spondyloarthritis (axSpA), as determined by the Ankylosing Spondylitis Disease Activity Score (ASDAS), is associated with spinal radiographic progression, independent of treatment with tumor necrosis factor (TNF) inhibitors, according to a letter published in Rheumatology.
Data from the Outcome in Ankylosing Spondylitis International Study (OASIS) indicated a longitudinal association between ASDAS and spinal radiographic progression. However, treatment with TNF inhibitors was not commonly prescribed in this study population.
The objective of the current analysis was to determine the predictive association between ASDAS and the subsequent 2-year spinal radiographic progression in patients with axSpA, including those who received TNF inhibitors.
Radiographs of the spine were independently scored by 2 experts, using the modified Stoke Ankylosing Spondylitis Spine Score (mSASSS). Participants with a clinical diagnosis of axSpA fulfilling the modified New York classification criteria were included in the current prospective, observational study (ALBERTA FORCAST).
The study sample included 314 patients (74% men) with a mean baseline ASDAS of 2.7. Of these patients, 7% had previously received a TNF inhibitor and 68% received a TNF inhibitor during follow-up. Data on mSASSS, ASDAS, and TNF inhibitor exposure were available for all study participants.
The average progression was 1.33 mSASSS-units per 2-year interval. Statistical analysis showed that 2-year progression of mSASSS over time increased with higher levels of baseline ASADS, from inactive disease (β, 0.35; 95% CI, 0.21-0.50) to low disease activity (β, 0.45; 95% CI, 0.34-0.56) and high disease activity (β, 0.56; 95% CI, 0.44-0.68) to very high disease activity (β, 0.72; 95% CI, 0.52-0.93).
Furthermore, there was a longitudinal association between higher ASDAS and higher spinal radiographic progression with radiographic axSpA, independent of treatment with TNF inhibitors.
“Here we found significant progression of mSASSS even in patients with inactive disease, which is similar to what has been previously seen in OASIS,” the study authors wrote.
Disclosure: The ALBERTA FORCAST study was supported by Abbvie. Please see the original reference for a full list of authors’ disclosures.
Sepriano A, Ramiro S, Wichuk S, et al. Disease activity is associated with spinal radiographic progression in axial spondyloarthritis independently of exposure to tumour necrosis factor inhibitors. Rheumatology (Oxford). Published online, October 29, 2020. doi:10.1093/rheumatology/keaa564