REGULATORY EFFECTS OF 1-ALPHA,25-DIHYDROXYVITAMIN D-3 ON INFLAMMATORYRESPONSES IN PSORIASIS

Topical application of 1 alpha, 25-dihydroxyvitamin D-3 (VD3) is thoug ht to be beneficial in psoriasis because of its action in regulating k eratinocyte proliferation and inflammation mediated by various cytokin es. Wt: assessed the effect of VD3 on the production levels of interfe ron (IFN)-gamma, interleukin (IL)-6, IL-8 and tumor necrosis factor (T NF)-alpha in mitogen-stimulated peripheral blood mononuclear cells (PB MC) of psoriatic patients. The results demonstrated that VD3 significa ntly inhibited IFN-gamma, IL-6, and IL-8 levels produced by concanaval in A (Con A)-stimulated PBMC of psoriatic patients in a dose-dependent manner, and reduced mRNA expression or IFN-gamma and IL-8. These find ings suggest that in addition to the direct anti-proliferation effect on keratinocytes, VD3 may down-regulate the inflammatory cytokine prod uction by infiltrating cells in psoriatic lesions.