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Updated: May 5, 2026
Imaging Features of Systemic Sclerosis-Associated Interstitial Lung Disease
Published on: June 16, 2020
Circulating monocytes from systemic sclerosis patients with progressive interstitial lung disease preferentially
Vanessa Smith1,2,3, Stefano Soldano4, Rosanna Campitiello4,5
1Department of Rheumatology and Internal Medicine, University Hospital Ghent, Ghent, Flanders, Belgium.
Objective:
To characterise phenotype and functional profibrotic M2 markers in circulating monocytes and cultured monocyte-derived macrophages (MDMs) from systemic sclerosis (SSc) patients (pts) with progressive interstitial lung disease (ILD) (prog-ILD), non-progressive ILD (no-prog-ILD) and without ILD (no-ILD).
Methods:
Fifty-five SSc pts and 20 age-matched healthy controls were evaluated. In 36 SSc pts, circulating monocytes expressing toll-like receptor-4 (TLR4, M1 marker) and M2 phenotype markers (CD204, CD206, CD163) were detected by flow cytometry. Moreover, MDMs of 29 SSc pts were analysed by quantitative real-time PCR and Western blotting for gene expression and protein synthesis with regard to the production of profibrotic mediators: transforming growth factor-ß1 (TGFß1), Mer tyrosine kinase receptor (MerTK) and arginase-1 (ARG1). Interleukin-6 and 4 (IL6, IL4), as well as C-C motif chemokine ligand 2 and 18 (CCL2/MCP1 and CCL18) from culture medium, were evaluated by enzyme-linked immunosorbent assay (ELISA).
Results:
Prog-ILD SSc pts showed a higher percentage of TLR4+CD204+CD206+CD163+ monocytes versus no-prog-ILD, and significantly higher compared with no-ILD SSc pts.Interestingly, MDMs from prog-ILD SSc pts showed a significantly higher gene expression and protein synthesis of TGFβ1, and a significantly higher protein synthesis of MerTK, CD206, IL4 and CCL18 compared with no-prog-ILD SSc pts. Finally, gene expression and protein synthesis of TGFβ1, TLR4, CD206, CD163, ARG1, MerTK and IL6 were significantly increased in prog-ILD SSc versus no-ILD SSc MDMs.
Conclusions:
Cultured MDMs from circulating monocytes in SSc pts with prog-ILD show markedly increased profibrotic biomarkers and mediator expression, indicating an enhanced fibrotic phenotype compared to non-prog and no-ILD SSc pts.
