Vascular adhesion protein-1 (VAP-1) is overexpressed in psoriatic patients

BACKGROUND: Vascular adhesion protein (VAP)-1 is an adhesion molecule with an enzymatic activity that partakes in the migration process of lymphocytes. OBJECTIVES: The aim of this study was to investigate the expression of VAP-1 in the skin and serum of psoriatic patients. MATERIAL AND METHODS: Seventy-one patients suffering from psoriasis aged between 23 and 89 years were included in the study. The mean psoriasis severity assessed according to the psoriasis area and severity index was 14.2+/-9.6 points. The soluble VAP-1 serum concentration was evaluated by ELISA and VAP-1 expression in the skin (nine patients) immunohistochemically. RESULTS: The serum concentration of soluble VAP-1 was significantly higher in psoriatic patients than in healthy controls (403.4+/-130.8 ng/mL vs. 246.4+/-68.0 ng/mL; P<0.0001). No significant relationships were found between sVAP-1 concentration and studied clinical parameters, except the presence of pruritus. Mean number of VAP-1 positive vessels in psoriatic skin, both lesional (19.8+/-1.4) and non-lesional (9.4+/-1.4), was significantly higher than in healthy skin (5.4+/-1.5; P<0.005). Lesional psoriatic skin demonstrated significantly more VAP-1 positive vessels than non-lesional skin (P<0.01). CONCLUSIONS: Significant overexpression of VAP-1 in both lesional and non-lesional psoriatic skin and higher serum level of soluble VAP-1 in psoriatic patients may indicate the role of VAP-1 in chronic inflammation occurring in psoriasis. However, because of lack of correlation between soluble VAP-1 serum levels and psoriasis severity this hypothesis needs further investigation.