OVEREXPRESSION OF EXTRACELLULAR-MATRIX RECEPTORS (VLA-3, VLA-5 AND VLA-6) ON PSORIATIC KERATINOCYTES

The potential role of adhesion molecules in the pathophysiology of psoriasis was investigated and the pattern of expression of the cell-surface receptors ICAM-1, LFA-3, and VLA-1, 2, 3, 4, 5 and 6 was determined in biopsies of skin from patients with psoriasis (n = 12) and from normal skin (n = 12). There were no differences in the intensity or localization of the adhesion molecules VLA-1, 2 and 4 and LFA-3. In contrast, VLA-3 and VLA-6, which are restricted to the basal keratinocytes in normal skin, were overexpressed in the spinous cells in psoriatic skin. ICAM-1 and VLA-5, which are not expressed by keratinocytes in normal skin, were focally induced, especially in cells above elongated rete ridges and where there was an infiltrate with intraepidermal granulocytes and lymphocytes.