부산대학교 도서관

Lichen planus is a condition characterized by the development of intensely itchy skin lesions. This skin disorder is associated with the activation of immune cells which act against the epidermal cells located in the outer layer of the skin. Immune CD4 T cells and antigen-presenting cells, such as Langerhans cells and macrophages, accumulate within the dermal and epidermal skin layers. A skin condition similar to lichen planus occurs in bone marrow transplant patients who develop graft-versus-host disease, a pathological reaction between the recipient and transplanted tissue. This suggests that an autoimmune reaction, in which immune cells attack body tissues or cells, may contribute to the disease process in lichen planus. CD4 T cells may interact with the Langerhans cells or macrophages, resulting in the production of T cells that destroy keratinocytes, skin cells that produce the tough protein called keratin in the skin. The drug cyclosporine counteracts the activity of CD4 T cells and may be beneficial in treating lichen planus. Previous studies have shown that oral cyclosporine is effective in treating severe lichen planus. The effect of cyclosporine on immune cells within the skin lesions of five patients with severe lichen planus was examined. Cyclosporine, given orally in low doses for 15 days, decreased the total number of T cells and immune cells containing the receptor site for interleukin 2, a substance that activates the growth of T cells. These changes were associated with an improvement in the symptoms of the patients. These findings are consistent with CD4 T cells and antigen-presenting cells having a role in the disease process of lichen planus. The effectiveness of cyclosporine in treating lichen planus may be related to the ability of cyclosporine to inhibit CD4 T cells. (Consumer Summary produced by Reliance Medical Information, Inc.)