[A study of vascular factor in the pathogenesis of polymyositis].

OBJECTIVE: To study ICAM-1, IL-1alpha expression in capillaries and to explore whether capillaries play a role in the pathogenesis of polymyositis. METHODS: Ten cases of patients with polymyositis and 6 patients with other myopathies were collected. CD34, ICAM-1 and IL-1alpha were selected for a quantitative measurement using an image analysis system, and results were presented as the percent of positive staining in the tissue area. RESULTS: We found that the percent of capillaries in tissues from polymyositis was significantly less than that from controls (P = 0.009). ICAM-1 and IL-1alpha expression in endothelial cells of capillaries were stronger in polymyositis patients. CONCLUSION: Our findings indicated that changes of capillaries might participate in the pathogenesis of polymyositis.