Table 1.

Panel of biomarkers used in the study

Biomarker	Description of the biomarker	Implication	Previously assessed in axSpA or AS
C1M	MMP-2/9/13-degraded type I collagen	Interstitial matrix degradation	Yes
C2M	MMP (multiple)-degraded type II collagen	Cartilage degradation	Yes
T2CM	Collagenase-degraded type II collagen	Cartilage degradation	No
C3M	MMP-9-degraded type III collagen	Interstitial matrix degradation	Yes
C4M	MMP (multiple)-degraded type IV collagen	Primarily basal lamina disruption	Yes
C6M	MMP-degraded type VI collagen	Microfibril degradation	Yes
C10C	Cathepsin-K-mediated degradation of type X collagen	Chondrocyte activity	No
COL10NC	NC1 domain of type X collagen	Chondrocyte activity	No
PROM	MMP-cleaved prolargin	Interstitial matrix degradation	No
VICM	Citrullinated and MMP-degraded vimentin	Inflammation	Yes
CRPM	C-reactive protein metabolite	Inflammation	Yes
PRO-C2	Type II collagen N-terminal pro-peptide	Cartilage formation	Yes
PRO-C3	Type III collagen N-terminal pro-peptide	Fibrosis	No
PRO-C4	Type IV 7S domain collagen	Basement membrane formation	No
PRO-C6	Type VI collagen C5 domain	Fibrosis	No