Koo BS, Lee S, Oh JS, et al. - In radiographic axial spondyloarthritis cases, a significant association exists between controlled C-reactive protein (CRP) achieved in response to initial treatment with non-biologic agents for 3 months and a slower rate of spinal radiographic change. In this disease condition, radiographic progression is well-predicted by CRP level at 3 months after initial non-biologic treatment.

• This study included radiographic axial spondyloarthritis patients observed for 18 years and initially treated with nonsteroidal anti-inflammatory drugs and/or conventional disease-modifying antirheumatic drugs for 3 months.

• Participants were assigned to two groups: the controlled CRP group (n = 351) comprising patients with a CRP level of <0.8 mg/dL or 50% of the baseline CRP at 3 months; and the uncontrolled CRP group (n = 452) with remaining patients.

• The controlled CRP group exhibited a slower increase in the modified Stoke Ankylosing Spondylitis Spinal Score compared with the uncontrolled CRP group (interaction term β = −.499, 95% confidence interval −0.699 to −0.300).