Very late antigen-1 in psoriasis: an immunohistochemical study

Background Currently, psoriasis is thought to be an inflammatory response to an antigenic stimulation, in which angiogenesis plays a fundamental role. Very late antigen‐1 (VLA‐1) is a β₁ integrin collagen receptor that is up‐regulated in many angiogenic processes. Data on its role in psoriasis are sparse. Objective In a prospective study, we evaluated the staining of VLA‐1 in lesional skin from patients with psoriasis and atopic dermatitis. Material and methods Frozen sections from skin biopsies of patients with chronic plaque‐type psoriasis (n = 18) and chronic atopic dermatitis (n = 7) were stained with a monoclonal antibody to VLA‐1. The number of blood vessels stained with VLA‐1 and the staining intensity were evaluated. These were correlated with the histologic features. Results The absolute number of blood vessels was found to be similar in the atopic and psoriatic samples. However, the number of vessels stained with anti‐VLA‐1, as well as the staining intensity, was shown to be significantly higher in the psoriasis group (P < 0.05). Differences between psoriatic lesions showing typical histological features of psoriasis and those showing features that overlap with dermatitis were found as well. Conclusions Expression of VLA‐1 was found significantly higher in lesional dermal blood vessels of psoriatic patients compared with atopic patients. These findings suggest a possible role for VLA‐1 in the pathological angiogenesis of psoriasis. It may be an additional tool for establishing the diagnosis of psoriasis and provide a basis for new strategies in the treatment of psoriasis.