ISOLATION AND CHARACTERIZATION OF TRYPSIN-LIKE AND CHYMOTRYPSIN-LIKE PROTEINASES FROM HUMAN CHOLESTEATOMA

The mast-cell-specific proteolytic enzymes tryptase and chymase were i dentified in and isolated from cholesteatoma in a ratio similar to tha t found in human skin. We assume that this ratio reflects a similar di stribution of tryptase-containing and tryptase/chymase-containing mast cells in both these tissues. It seems conceivable that mechanisms abl e to trigger excessive and/or continuous mast cell degranulation in th e middle ear might be causative for the formation of cholesteatoma eit her directly or via primed chronic inflammatory reactions. By their ab ility to amplify degranulation of mast cells, mast cell proteinases, i n particular chymase, may contribute to the chain of events leading to the formation of cholesteatoma.