ANALYSIS OF ACTIVATED T CELLS IN PERIPHERAL BLOOD OF PATIENTS WITH SCLERODERMA BY TWO-COLOR FLOW CYTOMETRY

Abstract

The activation of peripheral T cells in patients with systemic scleroderma was examined by two-color flow cytometry. Twenty-eight patients with untreated scleroderma, satisfying the ARA criteria for scleroderma, were studied. As controls, 23 age-and sex-matched healthy persons were also studied. Mononuclear cells separated from heparinized peripheral blood by Ficoll-Paque gradient method, were stained with a panel of anti-human mouse monoclonal antibodies. In order to analyze activated T cells by two-color flow cytometry, cells were double-stained with FITC-CD3 -CD4, or -CD8 and PE-HLA-DR antibodies. Although the lymphocyte subpopulation (CD3+, CD4+, CD8+, CD19+ and CD 16+) was not changed, CD3+ HLA-DR+ cells (activated T cells) were increased in scleroderma patients as compared with healthy controls. An increase in CD3+ HLA-DR+ cells was observed in patients with scleroderma associated with dermatomyositis/polymyositis, CREST syndrome or diffuse scleroderma, whereas patients with acrosclerosis exhibited no significant increase in activated T cells. In addition, an increase in CD3+ HLA-DR+ cells was associated with a high frequency of bibasilar pulmonary fibrosis and positive anti-ENA antibody in patients. In contrast, the incidence of proximal scleroderma was significantly decreased in patients with high T cell activation levels. These results suggest that activated T cells may participate in the patho-mechanism of lung fibrosis, which might differ from that of skin sclerosis.