involucrin and Lupus-Erythematosus--Discoid

In the present study, keratin and involucrin expression were studied in cutaneous lesions of discoid lupus erythematosus and lichen planus in order to gain a better understanding of the abnormal differentiation or maturation of the epidermal cells in these dermatoses. Ten specimens each from discoid lupus erythematosus and lichen planus were analyzed by immunohistochemical techniques, using a panel of monoclonal antikeratin antibodies and polyclonal anti-involucrin antibody, and five specimens each were analyzed by one- and two-dimensional gel electrophoresis and immunoblot analysis using three antikeratin antibodies. No significant 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 part of the stratum spinosum. Keratins 6 and 16, which are characteristic markers of hyperproliferative states, and keratin 17 were detected in nonhyperproliferative and atrophic epidermis with hydropic degeneration and inflammatory infiltrates in the dermis. These results suggest that expression of keratins 6, 16 and 17 in discoid lupus erythematosus 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 produced by infiltrating inflammatory cells in the dermis.

Topics: Cell Differentiation; Cellular Senescence; Electrophoresis, Polyacrylamide Gel; Humans; Immunoblotting; Immunoenzyme Techniques; Keratins; Lichen Planus; Lupus Erythematosus, Discoid; Protein Precursors

Discoid lupus erythematosus lesions show hyperkeratosis and atrophy, which may reflect abnormal epidermal proliferation, differentiation, or both. In this investigation, markers for epidermal proliferation, differentiation and inflammation were studied in cutaneous lesions of discoid lupus erythematosus. Frozen sections of biopsy specimens from 20 patients were examined immunohistochemically regarding Ki-67 staining and keratin 16 expression (parameters for proliferation), and the expression of keratin 10, involucrin, and filaggrin (parameters for differentiation). The inflammatory infiltrate was characterized with the use of antibodies against T lymphocytes, monocytes/macrophages, and Langerhans cells. With these markers, epidermal proliferation was found to be increased in discoid lupus erythematosus. Keratin 10 expression, a marker for early differentiation, showed the pattern of normal skin. Involucrin and filaggrin, markers for terminal differentiation, were expressed already in the lower part of the stratum spinosum, whereas in normal skin these markers were restricted to the stratum granulosum and the upper layers of the stratum spinosum, and the stratum granulosum and stratum corneum, respectively. Infiltrate analysis revealed the well-established picture. We conclude that in cutaneous lesions of discoid lupus erythematosus, hyperproliferation is combined with normal early differentiation and premature terminal differentiation of keratinocytes.

Topics: Adult; Aged; Cell Differentiation; Cell Division; Cell Nucleus; Epidermis; Female; Filaggrin Proteins; Fluorescent Antibody Technique; Humans; Immunoenzyme Techniques; Immunohistochemistry; Intermediate Filament Proteins; Keratins; Langerhans Cells; Lupus Erythematosus, Discoid; Macrophages; Male; Middle Aged; Monocytes; Protein Precursors; Skin; T-Lymphocytes