Association between cumulative TNF inhibitor dose and spinal radiographic progression in radiographic axial spondyloarthritis in patients with modified stoke ankylosing spondylitis spinal score ≤24

Abstract

Background: Tumor necrosis factor inhibitors (TNFi) effectively manage radiographic axial spondyloarthritis (SpA), and dose reduction is often used for stable patients. However, its long-term impact on radiographic progression remains unclear.Objective: To analyze the correlation between cumulative TNFi dose and radiographic progression in radiographic axial SpA.Design: Single-center retrospective chart review.Methods: Electronic medical records of patients with radiographic axial SpA from January 2001 to December 2018 were screened. The TNFi percentage dose was calculated as the total prescribed dose divided by the standard dose at 2-year intervals. The relationship between TNFi percentage dose and modified Stokes Ankylosing Spondylitis Spinal Score (mSASSS) changes was assessed using linear mixed models, separated into three baseline mSASSS groups: mSASSS <= 24, mSASSS >24 to <= 48, and mSASSS >48.Results: In the initial linear mixed model, radiographic progression, defined as the change in mSASSS over 2-year intervals, was examined in three baseline mSASSS groups. In the baseline mSASSS <= 24 group, the cumulative TNFi dose showed a negative correlation with radiographic progression (beta = -0.888, 95% confidence interval (CI): -1.793 to 0.017, p = 0.055). In the group with 24 < baseline mSASSS <= 48, a positive but nonsignificant association was observed (beta = 1.688, 95% CI: -2.119 to 5.495, p = 0.379). Similarly, for the baseline mSASSS >48 group, no significant correlation was found (beta = 0.182, 95% CI: -0.832 to 1.196, p = 0.715). In the multivariable model of the baseline mSASSS <= 24 group adjusted for age and sex, the cumulative TNFi dose was negatively correlated with the mSASSS change (beta = -1.871, 95% CI: -1.871 to -0.059, p = 0.037).Conclusion: In patients with radiographic axial SpA and baseline mSASSS <= 24, the cumulative TNFi dose was negatively correlated with radiographic progression. Maintaining a standard TNFi dose may slow the progression of spinal structural changes in early stage SpA.