Chemokine (C-C motif) ligand 18 concentrations induced by immunoglobulin G of systemic sclerosis patients (SSc-IgG) in supernatants correlate with clinical features of SSc-IgG donors. (A) Correlation of measured chemokine (C-C motif) ligand 18 (CCL18) concentrations with the time since lung fibrosis onset (13 patients with reported lung fibrosis onset). (B) Association of measured CCL18 concentrations in supernatants with the incidence of vascular complications (25 patients with reported vascular status). CCL18 concentrations were measured by enzyme-linked immunosorbent assay. Statistical analyses were done by two-tailed Spearman's correlation (A) and Mann–Whitney U test (B). Data in (B) are shown as box-and-whisker plot (Tukey’s test). *P < 0.05.