Fas (Apo-1/CD95) ts a widely expressed mem brane-anchored protein that induces apoptosis. Keratinocytes constitutively express 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 re ceptor. It can antagonize cell surface Fas func tion by downregulating Fas-mediated apoptosis and its level may be regulated by pro inflammatory cytokines. Therefore, the purpose of this study was 10 investigate the role of apoptotic inhibitors, slias and Bcl-Z (B-cell lvmphoma
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-2), and pro-inflammatory cytokine, interleukin-6 (IL-6), in patients with psoriasis vulgaris and their possible correlations to disease activitv. Sera from fiftv patients with psoriasis vulgaris and 20 healthy controls were tested for slias. Bcl-2 and IL-6 levels using ELISA assays. According to disease activity, psoriasis area severity index (PASI score), the patients were classified info mild (11=3 I), moderate (n= 11) and severe (11=8) cases. Serum levels of slias. 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. In conclusion, these results suggest that the psoriasis vulgaris was associated with increased serum levels of slias, Bcl-2 and IL-6 . This may explain two major pathological features in psoriasis: ep idermal 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 of !L-6. The lack of correlation between sFas c111d Bcl-2 could be attributed to their different mechanisms of anti-apoptotic actions.