Ivacaftor for Acquired CFTR Dysfunction in Chronic Rhinosinusitis (EDSPD Protocol)

The purpose of this study is to establish the novel endoscopically-directed sinus potential difference (EDSPD) assay as an endpoint for therapy of sinus disease.

The purpose of this study is to establish the novel endoscopically-directed sinus potential difference (EDSPD) assay as an endpoint for therapy of sinus disease. This assay provides a means to measure Cl- secretion across the sinus epithelium in human subjects with chronic rhinosinusitis (CRS) and test the relationship between this data and endoscopic findings of inflammation. The technique is appropriate for investigating acquired CFTR dysfunction in sinus epithelium and examining the therapeutic potential of CFTR potentiators for CRS.

Patient eligibility criteria are designed to limit enrollment otherwise healthy individuals who are scheduled for standard-of-care nasal endoscopy in the clinic or sinus/skull base surgery. Inclusion criteria: * Age \> 18 years * Able to give consent * A diagnosis of CRS, as determined by the Sinus and Allergy Health Partnership criteria * Has cultured out at least one gram negative bacteria (e.g. Pseudomonas aeruginosa, Escherichia coli, Stenotrophomonas maltophila) within the previous month * Is scheduled for either routine endoscopic surgery or has previously undergone endoscopic surgery and presents to clinic for routine endoscopic evaluation Exclusion criteria: * Age \< 18 years * Unable to give consent * Active diagnosis of cancer, autoimmune disease, or any know immunodeficiency * Women who are pregnant or breastfeeding