Cell adhesion molecule expression in cutaneous lesions of dermatomyositis

Chronic inflammation seems to play a major role in skin and muscle cell damage in dermatomyositis. Adhesion molecules and their ligands are fundamental in regulating inflammation. We have carried out an immunohistochemical analysis of different activation-inducible adhesion markers in 15 biopsy specimens from dermatomyositis skin lesions. Consistent findings were the increased expression of intercellular adhesion molecule-1 (ICAM-1) on endothelial cells, inflammatory cells and focally grouped keratinocytes in contact with subepidermal inflammatory infiltrates. Immunoreactivity for vascular cell adhesion molecule-1 (VCAM-1) was predominant on endothelial cells of the upper reticular dermis and dermal stellate-shaped cells. E-selectin (endothelial leukocyte adhesion molecule-1) immunoreactivity was less extensive, detected mostly on segments of vessels of the papillary dermis and upper reticular dermis, and sometimes independent of inflammation. This pattern of adhesion molecule expression is similar to that described in other immune-mediated dermatoses. The up-regulation of the adhesion molecules appears to play a role in the development and perpetuation of dermatomyositis skin lesions.