IMMUNOHISTOCHEMICAL ASSESSMENT OF CD200 IN PSORIASIS VULGARIS

Abstract

Psoriasis vulgaris is a common, chronic immune-mediated skin disease characterized by red, scaly patches, papules, and plaques, which are usually itchy. The skin lesions seen in psoriasis may vary in the degree of severity from minor localized patches to complete body coverage. Psoriasis is estimated to affect 2-4% of the population. The rate of psoriasis occurrence varies according to age, gender, region and ethnicity with a combination of environmental and genetic factors thought to be responsible for these differences. Histologically, psoriasis is characterized by abnormal keratinocytes proliferation and infiltration of immune cells, predominantly T lymphocytic cell and dendritic cells in psoriatic lesions. Most of inflammatory cells and cytokines remain in the tissue, and a relatively small proportion can be demonstrated in the peripheral blood. CD200 is a type I transmembrane glycoprotein belonging to the immuno- globulin superfamily. It consists of extracellular, transmembrane, and intracellular domains. CD200 receptors involve CD200R1 to CD200R4, of which CD