Immunohistochemical Expression of Perforin in Lichen Planus Lesions

BACKGROUND: Lichen planus (LP) is a chronic inflammatory papulosquamous skin disease characterized by epidermal basal cell damage and a particular band-like infiltrate predominantly of T cells in the upper dermis. It is characterized by the formation of colloid bodies representing apoptotic keratinocytes. The apoptotic process mediated by CD8+ cytotoxic T lymphocytes and natural killer cells mainly involves two distinct pathways: the perforin/granzyme pathway and the Fas/FasL pathway. So far, little is known regarding the role of perforin-mediated apoptosis in LP. AIM: Is to study the expression and distribution of perforin in the epidermis and dermis of lesional LP skin. MATERIALS AND METHODS: Skin biopsy specimens from lesional skin of 31 patients with LP and 10 healthy persons were analyzed by immunohistochemistry. RESULTS: Significant accumulation of perforin + cells was found in both epidermis and dermis of LP lesions compared with healthy skin. Perforin expression was significantly upregulated in the epidermis of LP lesions. CONCLUSION: Accumulation of perforin + cells in the epidermis of LP lesions suggest a potential role of perforin in the apoptosis of basal keratinocytes.