EXPRESSION OF CALGRANULINE-A AND CALGRANU LINE-B IN MIDDLE-EAR CHOLESTEATOMA

Cholesteatoma epithelium is characterised by a keratinocyte dysregulat ion with a hyperproliferative growth and altered differentiation. Kera tinocytes with a reduced turnover time show an increase of calcium bin ding proteins like calgranulin A and B. These proteins are highly link ed with the modulation of cell growth and differentiation. The express ion of calgranulin A and B was studied immunohistochemically using the monoclonal antibody F12 on cryosections of cholesteatoma biopsies. No rmal skin served as control. The staining in normal skin was confined to the highly proliferative activated follicular keratinocytes, wherea s most cholesteatomas showed a staining of all cell layers of the epit helium. Our findings show that the keratinocyte dysregulation of the c holesteatoma epithelium is reflected by variations of the expression o f calcium binding proteins.