Hwang MC, Lee M, Gensler LS, et al. - Four distinct patterns of spinal disease progression were distinguished by group-based trajectory modeling in the Prospective Study of Outcomes in Ankylosing Spondylitis cohort. The findings revealed that male gender, longer disease duration, elevated C-reactive protein, and smoking were correlated with higher spinal disease groups. There is a need for independent confirmation in other Ankylosing Spondylitis cohorts to validate these radiographic patterns.

• Researchers examined a total of 561 patients with 1618 radiographs. The optimum number of trajectory groups identified was four (BIC -4062).

• They subsequently classified groups as non-progressors (204 patients), late-progressors (147 patients), early-progressors (107 patients), and rapid-progressors (103 patients).

• It was shown that baseline modified Stoke Ankylosing Spondylitis Spinal Score (mSASSS), male gender, longer disease duration, elevated C-reactive protein, and smoking history were the baseline predictors correlated with higher spinal disease burden groups.

• The results showed that time-varying anti-TNF use per year was correlated with reduced mSASSS progression only in the rapid-progressor group.