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.