Psoriasis is a chronic, inflammatory, immune-mediated skin disease. Recently, several psoriasis-linked genetic loci have been reported; PSORS4 contains S100A8 (calgranulin A), and PSOR6 (19p13) locus harbors JunB (19p13.2). S100A8 is considered to be a marker of inflammation in a variety of diseases. The expression of JunB and c-Jun have been reported to be reduced in psoriatic lesions.
We attempted to assess the role and correlation of S100A8, JunB, and c-Jun in the pathogenesis of guttate psoriasis and psoriasis vulgaris by studying whether any difference of immunohistochemical expression existed.
Skin biopsy specimens from patients with psoriasis vulgaris (n=37) and guttate psoriasis (n=17), and a normal skin controls (n=9) were utilized in the study. Formalin-fixed and paraffin-embedded tissue sections were prepared and JunB, c-Jun, and calgranulin A were immunohistochemically stained in order to compare the expression of those three proteins in each group.
Reduced JunB expression was observed in patients with psoriasis vulgaris and guttate psoriasis, as compared to patients in the control group; however, c-Jun expression was reduced only in the psoriasis vulgaris group. The expression of S100A8 increased in the psoriasis groups as compared to the control group. In addition, the expression of S100A8 was different between the psoriasis vulgaris and guttate psoriasis groups; S100A8 was expressed more profoundly in the guttate psoriasis group (p<0.05).
Our results indicate that S100A8 contributes to the pathogenesis of guttate psoriasis, and it may be a good target for therapy for guttate psoriasis provoked by microorganisms.
Keywords: c-Jun, Guttate psoriasis, JunB, Psoriasis vulgaris, S100A8 (calgranulin A)