Abstract
Biopsy specimens of involved and uninvolved skin were studied in 16 patients with lichen planus using murine monoclonal antibodies against several cell surface markers of effector and/or accessory cells of the immune system. In contrast to uninvolved skin, keratinocytes were found to express HLA-DR, OKM5, Leu-8 and Leu-11b antigens in all biopsies from involved skin. We demonstrate here for the first time the in vivo expression of several effector and/or accessory cell markers on keratinocytes in lichen planus.