Nasal polyp chitinolytic activity associated with smoking or allergy

Abstract

Cells of the innate immune system that are implicated in allergy and immunity bind to chitin during tissue infiltration in a process negatively regulated by vertebrate chitinases. Both acidic mammalian chitinase (AMCase) and chitotriosidase (ChT) exert chitinolytic activity. The levels of activities of these enzymes in nasal polyps (NPs) of subjects who smoke or who suffer from allergies are unknown. In the present work, we measured the activities of AMCase and ChT in NPs of smokers and allergic subjects. We report a prospective cohort study in a tertiary care facility. AMCase and ChT activities of NPs were measured in buffers of several pH values using the fluorogenic substrate 4-methylumbelliferyl-β-d-N,N',N″-triacetyl-chitotriose. The activities of AMCase and ChT in NPs did not differ significantly among smokers, nonsmokers, and ex-smokers. AMCase and ChT activities were significantly higher in NPs of allergic subjects than in NPs of those who did not suffer from allergy. Increased levels of chitinolytic activities in NPs were associated with the allergic rhinitis. We suggest that control of such rhinitis may help to prevent the development and growth of NPs.