Table 1.

Circulating biomarkers for severity monitoring, specific manifestations, or prognosis

Reference	Biomarker	Population	Type of marker	Summary of findings
Beyer et al. [13]	Sonic hedgehog	European, multicenter	Severity monitoring	Correlation with mRSS, digital ulcers, PAP
Abignano et al. [15]	ELF score	European, multicenter	Severity monitoring	Correlation with mRSS (positive), lung function (negative)
McMahan et al. [16]	U11/U12 RNP (RNPC3) antibody	US Cohorts (Johns Hopkins, Pittsburgh)	Organ manifestation	Association with gastrointestinal dysmotility
Igusa et al. [17∎]	aSSc-associated autoantibodies	US Cohort (Johns Hopkins)	Cancer risk	RNA Pol III antibody: increased risk centromere antibody: decreased risk
Shah et al. [18∎]	RPA194 antibody	US Cohort (Johns Hopkins)	Cancer risk	RPA194 antibody: lower risk of cancer amongst patients with RPC155 antibody
Moxey et al. [19]	ANCA	Australian, multicenter	Prognostic	ANCA positivity associated with higher prevalence of ILD and increased mortality
Herrick et al. [20∎∎]	RNA Pol III antibody	European, multicenter	Prognostic	Earlier and higher peak in mRSS amongst patients with diffuse SSc
Ross et al. [21]	CRP	Australian, multicenter	Severity monitoring, prognostic	High CRP associated with high mRSS and decreased baseline FVC, and decline in longitudinal FVC

ANCA, antineutrophil cytoplasmic antibody; CRP, C-reactive protein; ELF, enhanced liver fibrosis; FVC, forced vital capacity; ILD, interstitial lung disease; mRSS, modified Rodnan skin score; PAP, pulmonary arterial pressure; SSc, systemic sclerosis.

^aAntitopoisomerase-I, anticentromere, and anti-RNA polymerase III.