Lesional upregulation of SLURP1 immunostaining parallels disease severity in psoriasis vulgaris patients

Background and objectives: The exact pathogenesis of psoriasis is still unclear. SLURP1 is vital for the normal differentiation of keratinocytes, and could therefore be involved in psoriasis. In this study we investigated the immunohistochemical staining reaction of SLURP1 in psoriasis vulgaris patients and its possible relation to disease pathogenesis. Patients and Methods: 20 patients with psoriasis vulgaris, 20 patients with psoriasiform dermatitis and 20 normal skin samples were studied. Psoriasis severity was measured with a combination of PASI and DLQI scores. Lesional and non-lesional sites were biopsied for each psoriasis patient. A single biopsy sample was taken for cases with psoriasiform dermatitis and for controls. All sections were immunostained for SLURP1 according to the manufacturer's protocol. Results: Significant differences were noted in SLURP1 immunostaining between lesional and non-lesional biopsies of psoriasis patients and between lesional biopsies of psoriasis patients and lesional sites of psoriasiform dermatitis. However, the differences between non-lesional biopsies of psoriasis patients and normal controls were not significant. Furthermore, the grading of SLURP1 immunostaining paralleled the degree of psoriasis severity. Conclusions: SLURP1 immunostaining is significantly increased in lesional skin of psoriasis vulgaris and not in psoriasiform dermatitis, which demonstrates the role of SLURP1 in the pathogenesis of psoriasis. SLURP1 could be used as a biological marker for psoriasis severity, and this hypothesis warrants further investigation.