Abstract: Objective To study the role of the vascular endothelial cells in the pathogenesis of psoriasis. Methods ABC immunohistochemical technique was employed to study the expression of ICAM-1, CD34, HLA-DR, FⅧ RAg and CD36 antigens on the vascular endothelial cells in the lesions of patients with psoriasis vulgaris. Results There was a significantly stronger expression of ICAM-1, CD34 and HLA-DR antigens on the endothelial cells of superficial dermis of the lesions in progressive stage than in static stage, and in the lesional skin than in normal skin.However, no significant difference was found in the expression of FⅧ RAg and CD36 in progressive stage compared with in static stage. Conclusions Increased expression of ICAM-1, CD34 and HLA-DR antigens on the vascular endothelial cells might be related to the severities of psoriatic lesions. CD34 might participate in the adhesion and emigration of inflammatory cells.

Key words: Psoriasis, Endothelium, vascular, Intercellular adhesion molecule-1, Antigens, CD34 HLA-DR antigens