. 2019 Jul 10;58(9):1534–1546. doi: 10.1093/rheumatology/kez230

Table 2.

Main biomarkers with clinical interest for SSc-ILD according to current literature

Serum biomarkers	Main clinical interest	Suggested cut-off values	Level of evidence	Main references
KL-6	SSc-ILD severity evaluation	≥923 UI/ml for: Restrictive lung disease (FVC <70%) De novo extensive lung fibrosis^a DLCO <60% Fibrosis extent on CT scan	Multiple small prospective cohorts One very large prospective cohort (n = 423)	[16]
SP-D	SSc-ILD diagnosis	Serum value needs to be associated with anti-topoisomerase antibody status for a better diagnostic accuracy^b	Large prospective cohort (n = 423) and small observational studies	[16]
CCL18	SSc-ILD prognosis	Serum value needs to be associated with patient sex and immunosuppressive drug use for a better prognosis evaluation^b	Small prospective studies One large prospective cohort (n = 423)	[16, 32]
CRP	SSc-ILD prognosi Survival	>8 mg/ml	Multiple large prospective cohorts	[57, 59]

Extensive lung disease defined as: fibrosis extent >20% on CT-scan or fibrosis extent 10–30% and FVC <70%.

According to Elhai et al. [16]. CCL18: chemokine ligand 18; FVC: forced vital capacity; KL-6: Krebs Von Den Lungen 6; SP-D: surfactant protein D; SSc-ILD: SSc-associated interstitial lung disease.