Table 2.

Stratification of the clinical significance of the biomarkers discussed in this guideline.

Biomarkers	Diagnosis	Assessment of disease activity	Prediction of radiographic progression	Prediction/monitoring of therapeutic responses
HLA-B27	√
HLA-B27 subtypes	√
Polygenic risk score	√
Antibodies, including anti-CD74 antibodies, anti-sclerostin and anti-noggin antibodies, antibodies againts microbial targets
CRP	√	√	√	√
ESR		√	√	√
SAA		√
Leptin and HMW-APN		√	√
VEGF
Calprotectin		√
Inflammatory cytokines including IL-6, IL-17 and TNF-α		√
Peripheral lymphocyte subsets		√
Non-coding RNAs
Bone turnover markers, including sCTX and PINP			√
Sclerostin			√
DKK-1			√
OPG/RANKL/RANK
MMP-3
NSAIDs-related genes				√
SSZ-related genes				√
Anti-drug antibodies				√

The symbol √ indicates that results of the systemic literature review supports that this biomarker bears clinical significance in this field.