Immunoperoxidase staining of skin in SSc patients compared with that in healthy controls. Skin sections from (a to c) healthy controls and (d to f) systemic sclerosis (SSc) patients were stained with anti-human-CD68, CD163 and CD204 antibody, respectively. A larger number of (d) CD68+ cells, (e) CD163+ cells and (f) CD204+ cells in SSc skin were distributed not only in the perivascular and periappendageal regions, but also between thickened collagen fibers compared with that in healthy control skin (a, b and c, respectively). Arrows indicate positively stained cells (brown); nuclei are counterstained with hematoxylin. Results are representative of 6 controls and 10 SSc patients. Bar = 100 μm.