Table 5

Longitudinal associations between biomarker levels and ASDAS, BASDAI and CRP

ASDASBASDAICRP
Estimate (95% CI)p ValueEstimate (95% CI)p ValueEstimate (95% CI)p Value
CRP1.16 (1.05 to 1.28)0.004
IL-61.30 (1.21 to 1.38)<0.0001*1.20 (1.07 to 1.34)0.0022.23 (2.01 to 2.46)<0.0001
VEGF1.13 (1.04 to 1.23)0.0031.17 (1.02 to 1.35)0.031.60 (1.36 to 1.90)<0.0001
YKL-401.05 (0.93 to 1.19)NS1.03 (0.84 to 1.26)NS*1.45 (1.12 to 1.88)0.005
CTX-II1.02 (0.93 to 1.12)NS1.06 (0.91 to 1.23)NS*1.06 (0.89 to 1.27)NS
Aggrecan0.99 (0.76 to 1.30)NS1.05 (0.67 to 1.65)NS*0.44 (0.25 to 0.79)0.006
MMP-31.13 (1.03 to 1.23)0.0091.09 (0.94 to 1.28)NS*1.67 (1.38 to 2.01)<0.0001
COMP0.78 (0.54 to 1.12)NS*0.95 (0.51 to 1.77)NS*0.35 (0.16 to 0.73)0.006
CTX-I0.88 (0.77 to 1.00)NS*0.89 (0.71 to 1.09)NS0.93 (0.71 to 1.22)NS
Osteocalcin0.69 (0.55 to 1.17)0.0008*0.71 (0.49 to 1.04)NS0.40 (0.25 to 0.65)0.0003
  • Results from multivariate linear mixed model analyses adjusted for gender, diagnosis (axial spondyloarthritis with vs without psoriasis), age and anti-TNFα therapy. The analyses included data from baseline, weeks 2, 6, 14 and 22.

  • * Age p<0.05.

  • Age p<0.01.

  • Gender significant (p<0.05 but p>0.01).

  • ASDAS, ankylosing spondylitis disease activity score; BASDAI, Bath ankylosing spondylitis disease activity index; COMP, cartilage oligomeric matrix protein; CI, confidence interval; CRP, C-reactive protein; CTX-I, C-terminal cross-linking telopeptide of type I collagen; CTX-II, C-terminal crosslinking telopeptide of type II collagen; IL-6, interleukin 6; MMP-3, matrix metalloproteinase 3; NS, non-significant; VEGF, vascular endothelial growth factor.