IntroductionF: as (Apo-I /CD95) is a widely expressed membrane-anchored protein that induces apoptosis. Keratinocytes constitutively express the Fas antigen and Fas- mediated apoptosis may characterize several pathological conditions affecting human skin. Soluble Fas (sFas) has been demonstrated in serum by alternative mRNA splicing of Fas receptor. It can antagonize cell surface Fas function by downregulating Fas- mediated apoptosis and its level may be regulated by pro-inflammatory cytokines.
Rationale: The purpose of this study was to investigate the role of apoptotic inhibitors, sFas and Bcl-2 (B-cell lymphoma-2), and pro-inflammatory cytokine, interleukin-6 (IL-6), in patients with psoriasis vulgaris and their possible correlations to disease activity.
Methods: Sera from fifty patients with psoriasis vulgaris and twenty healthy controls were tested for sFas, Bcl-2, and IL-6 levels using ELISA assays. According to disease activity, psoriasis area severity index (PASI score), the patients were classified into mild (n=31), moderate (n=l 1) and severe (n=8) cases.
Results: Serum levels of sFas, Bcl-2 and IL-6 were significantly higher in patients than controls. Serum levels of sFas and IL-6 in severe cases were significantly higher than mild and moderate cases. Significant positive correlation between PASI score and both sFas and IL-6 and between IL-6 and sFas were shown. However, no significant correlation was observed between Bcl-2 and both sFas and IL-6.
Conclusions: Psoriasis vulgaris was associated with increased serum levels of sFas, Bcl-2 and IL-6. This may explain two major pathological features in psoriasis;
epidermal hyperplasia and inflammation. Therefore, we support the possibility of a role of sFas in the pathogenesis of psoriasis by downregulating Fas mediated apoptosis and thus potentiating the action ofIL-6. The lack of correlation between sFas and the Bcl-2 could be attributed to their different mechanisms of anti-apoptotic actions.