Analysis of perforin expression in peripheral blood and lesions in severe and mild psoriasis

Abstract

Perforin is a membrane-disrupting protein that allows the entry of granzymes into a target cell inducing degradation of target substances in the cytoplasm and nucleus thus leading to programmed cell death or apoptosis. Recent work demonstrated a possible involvement of perforin mediated cytotoxicity in immunopathogenesis of psoriasis. To investigate a difference in systemic (peripheral blood) and local (lesions) expression and distribution of perforin in psoriatic patients with severe and mild disease. Flow cytometry was used for simultaneous detection of intracellular (perforin) and cell surface antigens in peripheral blood lymphocytes. The expression of perforin in skin lesions was evaluated by immunohistochemistry. Significant increase of perforin expression in T lymphocytes, especially cytotoxic CD8+ cells was found in severe psoriasis compared to mild disease (p<0.01 and p<0.05, respectively). There was also an increase of CD56+P+ NK cells (p<0.05) in severe compared to mild psoriasis. The psoriatic plaque of both, severe and mild disease were abundant with perforin showing no significant difference on local level. Based on our results we suggest the association between perforin expression and disease severity.