[Characteristics of CD99 expression in the skin of psoriasis patients]

The pattern of CD99 expression in the skin was studied in 22 patients with disseminated psoriasis. The patients' skin biopsy specimens were immunohistochemically stained by the standard procedure using monoclonal antibodies to CD99. The progression of psoriasis was characterized by the increased expression of the protein in the dermis (lymphocytes and vascular endothelium) and epidermis (keratinocytes) with the antigen being located not only in the cytoplasm, but also in the membrane. In remission, the content of CD99-positive cells in the dermis and epidermis was significantly reduced with the prevalence of cytoplasmic localization in the epidermal keratinocytes. It is assumed that the expression of CD99 plays an important role in the pathogenesis of psoriasis, in the processes of emigration of leukocytes, and in their tropism toward to the epidermis.