Differential expression of adhesion molecules on infiltrating cells in inflammatory dermatoses.

Abstract

Adhesion molecules and their ligands are involved in coordination of the activities of the immune system. To evaluate whether adhesion molecules are relevant in the pathogenesis of inflammatory dermatoses, we analyzed the expression pattern of many of these molecules. The expression of 10 members of the integrin and immunoglobulin superfamilies was mapped by means of immunohistochemical techniques in biopsy specimens of psoriasis (n = 15), pityriasis lichenoides (n = 11), parapsoriasis en plaques (n = 11), contact dermatitis (n = 7), and lichen planus (n = 5). In all investigated skin diseases, almost every infiltrating cell expressed lymphocyte function-associated antigens 1 and 3 as well as very late activation (VLA) antigens 4 and 5. The subepidermal infiltrate differed with regard to the expression of VLA-1, VLA-3, and VLA-6, which was high in lichen planus and moderate or absent in the other dermatoses. The intraepidermal lymphocytes in psoriasis and pityriasis lichenoides were VLA-1 positive, whereas the subepidermal infiltrate lacked this marker. The differential upregulation of adhesion molecules in the mononuclear infiltrate and on keratinocytes demonstrates their importance in the pathogenesis of cutaneous inflammation.