Liver fibrosis is associated with cutaneous inflammation in the imiquimod-induced murine model of psoriasiform dermatitis.

ABSTRACT

BACKGROUND: Psoriasis exhibits several extracutaneous manifestations. Little is known about hepatic parameters specifically associated with psoriasis. OBJECTIVES: To study whether psoriasiform dermatitis is associated with liver injury. METHODS: We studied liver parameters of inflammation and fibrosis in a murine model of psoriasiform dermatitis induced by topical application of imiquimod for 9 weeks. RESULTS: Topical treatment with imiquimod induced a form of psoriasiform dermatitis reminiscent of the human disorder, characterized by thickened and scaly skin, psoriasiform epidermal hyperplasia, altered keratinocyte differentiation and cutaneous overexpression of interleukin-17A. Mice with dermatitis displayed hepatitis, as shown by elevation of plasma transaminase levels, as well as portal and periportal hepatitis, characterized by T-lymphocyte (CD3ε+ ) and polymorphonuclear cell (Gr1+ ) infiltrates. The hepatitis progressed towards liver fibrogenesis, as shown by excessive Sirius red staining, which is consistent with the expression of α-smooth muscle actin by hepatic stellate cells. CONCLUSIONS: These results indicate that liver inflammation and fibrosis are associated with experimental psoriasiform dermatitis. Our results suggest that psoriatic inflammation may be associated with specific liver injury.