Darier's disease: an immunohistochemical study using monoclonal antibodies to human cytokeratins.

The pathogenesis of Darier's disease was investigated by immunohistochemical staining of skin biopsies from involved and uninvolved skin in 14 patients, using monoclonal antibodies specific for keratins expressed in simple epithelia, stratified squamous epithelia and during skin specific differentiation as well as keratins expressed in mucosa and some benign epidermal hyperproliferative states. Uninvolved perilesional skin from Darier's patients showed a normal profile of keratin expression, whereas in lesional skin there was apparent delay in the expression of the suprabasal skin specific keratins. Suprabasal keratins were not detected in basal cells, thus there was no true premature keratinization. The presence of hyperproliferative keratins was restricted to suprabasal cells in lesional skin. Four patients were receiving treatment with etretinate at the time of biopsy, but results in these patients did not differ from patients using topical treatments. Etretinate did not influence the profile of keratin expression in uninvolved or involved skin. The expression of type VII collagen was examined and was normal throughout uninvolved and lesional skin in Darier's disease.