Assessment of perforin expression in peripheral blood lymphocytes in psoriatic patients during exacerbation of disease.

There are very few data concerning the role played by cell-mediated cytotoxicity, particularly at the molecular level, in the course of psoriasis. Both cytotoxic T lymphocytes (CTL) and natural killer cells contain in their granules the cytolytic protein perforin, a mediator in cell-mediated cytotoxicity reactions. The aim of this study was to analyze perforin expression in various sets and subsets of perforin-positive peripheral blood lymphocytes in 17 patients with chronic psoriasis vulgaris in the exacerbation phase. The results were compared with those of an age- and sex-matched healthy control group (n = 21). Perforin (intracellular antigen) and cell surface antigens were detected using the simultaneous double-staining method. We found a significant increase in perforin (P) expression in the patient group for CTL (CD3+P+ cells), which are located mostly in the CD8+ population of T lymphocytes (CD8+P+).