Expression of OKM5 antigen on keratinocytes in some dermatoses.

Employing an avidin-biotin complex immunoperoxidase technique, it was found that there was OKM5 but no OKM1 antigen expression on the keratinocytes of the upper epidermis from all the studied specimens of seborrheic keratosis, verrucous nevus, Bowen's disease, BCC, SCC, MM, lichen planus, psoriasis vulgaris, condyloma acuminatum, and sporotrichosis as well as in two of eight cases of nevus pigmentosus. Our findings indicate that OKM5 antigen expression on epidermal keratinocytes is usually associated with dermal infiltration. It is assumed that human keratinocytes in cutaneous lesions, like the OKM1− OKM5+ monocyte/macrophage lineages, might play certain roles in immune responses and possibly function as antigen-presenting cells.