Comparison of IL-6 and CCL18 secretion levels in GM-CSF and M-CSF-derived MDMs from healthy donors and from SSc patients, with alveolar MΦ (AM) from patients with SSc-ILD. Primary human monocytes from healthy donors or SSc patients were differentiated into MDMs in vitro in the presence of GM-CSF (GM-MDM or GM-SSc) or M-CSF (M-MDM or M-SSc) for 6 days. Culture media were replaced at day 6 and, 24 h later, conditioned media were removed, stocked and ELISA were performed. Data are expressed as the mean of concentration in pg/mL + SEM from at least 5 healthy donors, or 7 SSc patients and four AM from patients with SSc-ILD. ANOVA followed by Newman–Keuls’ multiple comparison Test, ** p < 0.01.