MONONUCLEAR CELLULAR INFILTRATES IN CLINICALLY INVOLVED SKIN FROM PATIENTS WITH SYSTEMIC-SCLEROSIS OF RECENT-ONSET PREDOMINANTLY CONSIST OFMONOCYTES MACROPHAGES

Systemic sclerosis (SSc) is a generalized autoimmune disorder characte rized by immunological abnormalities, microvascular dysfunction, and t issue fibrosis. This study evaluated the inflammatory processes occurr ing in skin of 7 patients with SSc of recent onset (average disease du ration of 10 +/- 3 months) to assess the involvement of monocytes/macr ophages during the early stages of SSc. All SSc skin biopsies displaye d inflammatory microvascular endothelial cell activation and fibrosis. Increased numbers of infiltrating inflammatory leukocytes were presen t in affected skin of recent onset SSc (p < 0.01) mainly consisting of CD14-positive monocytes/macrophages (p < 0.02). CD3 T lymphocytes wer e only slightly elevated in SSc skin (84 +/- 39) compared to normal (5 1 +/- 12), but the differences were statistically not significant. The ratio of CD14/CD3 cells was substantially higher in affected skin of recent onset SSc (4.0 +/- 2.0) than in normal skin (1.4 +/- 0.5, p < 0 .01). Monocytes/macrophages, therefore, are the predominant infiltrati ng mononuclear cell in skin lesions of recent-onset SSc. These results strongly suggest that CD14-positive monocytes/macrophages play an imp ortant role during the early stages of SSc pathogenesis.