Lymphocytic expression of Fas and FasL apoptotic markers in vitiligo

Background. Lymphocytic dermal infiltrations accompany the melanocytes loss in depigmenting vitiligo skin. These lymphocytes are incriminated during the pathogenesis of the disease. Fas receptor is a death receptor on the surface of cells that leads to programmed cell death (apoptosis) and FasL is its ligand. Fas/FasL system plays a crucial role in modulating apoptosis. Objectives. This study investigates the lymphocytic expression of apoptotic markers Fas/FasL in vitiligo. Methods. The present study was conducted on 45 vitiligo samples obtained from 15 vitiligo patients including 8 females (53.3%) and seven males (46.7%). Biopsies were obtained also from control volunteers. All specimens were routinely stained with Hematoxylin &Eosin and immunohistochemically for Fas & FasL apoptotic markers. Results. Fas & FasL were significantly expressed by infiltrating lymphocytes in vitiligo biopsies compared to control. Lymphocytic expression of Fas & FasL was higher on the edge biopsies than the center. Considerable lymphocytic infiltration and attack of B.M. were associated with higher lymphocytic Fas and FasL expression. During vitiligo activity lymphocytic Fas & FasL expression was also significantly higher. Conclusions. Lymphocytic Fas and FasL are significantly expressed in vitiligo patches which may trigger epidermal apoptosis and loss of melanocytes. At the same time these factors have a role in switching-off of the immune responses and cell mediated cytotoxicity.