KERATIN AND INVOLUCRIN EXPRESSION IN DISCOID LUPUS-ERYTHEMATOSUS AND LICHEN-PLANUS

In the present study, keratin and involucrin expression were studied i n cutaneous lesions of discoid lupus erythematosus and lichen planus i n order to gain a better understanding of the abnormal differentiation or maturation of the epidermal cells in these dermatoses, Ten specime ns each from discoid lupus erythematosus and lichen planus were analyz ed by immunohistochemical techniques, using a panel of monoclonal anti keratin antibodies and polyclonal anti-involucrin antibody, and five s pecimens each were analyzed by one-and two-dimensional gel electrophor esis and immunoblot analysis using three antikeratin antibodies, No si gnificant difference was found between the dermatoses, The expression of differentiation-specific keratins showed a similar pattern to that in normal epidermis, and involucrin was expressed even in the lower pa rt of the stratum spinosum, Keratins 6 and 16, which are characteristi c markers of hyperproliferative states, and keratin 17 were detected i n nonhyperproliferative and atrophic epidermis with hydropic degenerat ion and inflammatory infiltrates in the dermis, These results suggest that expression of keratins 6, 16 and 17 in discoid lupus erythematosu s and lichen planus may reflect a wound healing response to the damage to the basal cell layer, or may be under the control of cytokines pro duced by infiltrating inflammatory cells in the dermis.