Increased Ion Transport in Cultured Nasal Polyp Epithelial Cells

Objective: To measure transepithelial bioelectric properties of cultured human nasal polyp and turbinate epithelial cells to test the hypothesis that nasal polyps have increased rates of ion transport.

Design: Cohort study.

Setting: Private referral center.

Patients: Individuals undergoing surgery for symptomatic nasal obstruction due to polyps caused by cystic fibrosis, nonatopic rhinosinusitis, or allergic rhinosinusitis.

Methods: Epithelial cells were removed from separated polyp and turbinate samples by protease disaggregation and cultured on permeable collagen matrix supports. Transepithelial potential difference and resistance were measured daily. At the time of maximal transepithelial potential difference, the cultures were mounted in modified Ussing chambers and exposed to a sodium-positive channel blocker (amiloride hydrochloride) and to selected chloride-negative channel agonists (isoproterenol bitartrate, adenosine triphosphate).

Outcome Measures: Maximal transepithelial potential difference, resistance, and equivalent short-circuit current. Bioelectric responses to amiloride, isoproterenol, and adenosine triphosphate.

Results: Polyp cultures had higher transepithelial potential difference and equivalent short-circuit current than turbinate cultures. The mediator responses were greater for polyp than for turbinate cultures.

Conclusions: Polyp epithelia have increased Na+ absorption and Cl- permeability relative to turbinate epithelia. These results are consistent with the hypothesis that increased epithelial fluid absorption contributes to the development of nasal polyps.