Epidermal expression of the calcium binding surface antigen 27E10 in inflammatory skin diseases.

The expression of the heterodimeric complex of the calcium-binding proteins MRP-8 and MRP-14 was investigated in various inflammatory dermatoses using immunohistochemical staining with the monoclonal antibody 27E10. In addition to the inflammatory infiltrate, a positive staining was repeatedly found in the involved epidermis from patients with lichen planus, lupus erythematosus and psoriasis vulgaris, but not in normal skin epidermis and/or in epidermis from leucocytoclastic vasculitis patients. The keratinocytic expression of the 27E10 antigen was dissimilar to that of the MHC class-II molecules and the adhesion molecule ICAM-1. These data indicate that the 27E10 antigen is a distinct activation marker of inflammatory keratinocytes and may have proinflammatory properties.