Reduced immunohistochemical expression of adhesion molecules in vitiligo skin biopsies

Because defects in adhesion impairment seem to be involved in the etiopathogenesis of vitiligo, this study aimed to compare the immunohistochemical expression of several adhesion molecules in the epidermis of vitiligo and non lesional vitiligo skin. Sixty-six specimens of lesional and non lesional skin from 33 volunteers with vitiligo were evaluated by immunohistochemistry using anti-beta-catenin, anti-E-cadherin, anti-laminin, anti-beta1 integrin, anti-collagen IV, anti-ICAM-1 and anti-VCAM-1 antibodies. Biopsies of vitiligo skin demonstrated a significant reduction in the expression of laminin and integrin. The average value of the immunohistochemically positive reaction area of the vitiligo specimens was 3053.2μm², compared with the observed value of 3431.8μm² in non vitiligo skin (p=0.003) for laminin. The immuno-positive area was 7174.6μm² (vitiligo) and 8966.7μm² (non lesional skin) for integrin (p=0.042). A reduction in ICAM-1 and VCAM-1 expression in the basal layer of the epidermis in vitiligo samples was also observed (p=0.001 and p<0.001, respectively). However, no significant differences were observed with respect to the expression of beta-catenin, E-cadherin, and collagen IV between vitiligo and non lesional skin. Our results suggest that an impairment in adhesion exists in vitiligo skin, which is supported by the diminished immunohistochemical expression of laminin, beta1 integrin, ICAM-1 and VCAM-1.