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

Study Overview
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Brief Summary
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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.

Detailed Description
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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.

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

Conditions
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CRS

Intervention / Treatment
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* Other: EDSPD


Participation Criteria
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Eligibility Criteria
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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

Ages Eligible for Study
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Minimum Age: 18 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| CRS Patients<br>Endoscopically-directed sinus potential difference (EDSPD) will be conducted in either the operating room or in the rhinology clinic setting to quantify CFTR activity in the sinus cavities. The potential difference will be monitored in actively inflamed areas as judged by endoscopy in comparison to an agar-filled reference butterfly electrode placed in the volar aspect of the forearm. A stable potential with the mean value of a 10-s scoring interval after perfusion of each solution will be recorded by a blinded investigator. | Other: EDSPD<br>* The equipment & conditions for measuring bioelectric changes across the sinus mucosa are based on the standard NPD protocol, including use of agar-filled PE90 tubing for the probing electrode and limiting perfusion solutions to Ringer, Ringer + amiloride (100 µM), chloride-free gluconate with amiloride + isoproterenol (10 µM). The potential difference will be monitored in actively inflamed areas as judged by endoscopy in comparison to an agar-filled reference butterfly electrode placed in the volar aspect of the forearm. A stable potential with the mean value of a 10-s scoring interval after perfusion of each solution will be recorded by a blinded investigator.<br>|
| Control Patients<br>Endoscopically-directed sinus potential difference (EDSPD) will be conducted in either the operating room or in the rhinology clinic setting to quantify CFTR activity in the sinus cavities. The potential difference will be monitored in actively inflamed areas as judged by endoscopy in comparison to an agar-filled reference butterfly electrode placed in the volar aspect of the forearm. A stable potential with the mean value of a 10-s scoring interval after perfusion of each solution will be recorded by a blinded investigator. | Other: EDSPD<br>* The equipment & conditions for measuring bioelectric changes across the sinus mucosa are based on the standard NPD protocol, including use of agar-filled PE90 tubing for the probing electrode and limiting perfusion solutions to Ringer, Ringer + amiloride (100 µM), chloride-free gluconate with amiloride + isoproterenol (10 µM). The potential difference will be monitored in actively inflamed areas as judged by endoscopy in comparison to an agar-filled reference butterfly electrode placed in the volar aspect of the forearm. A stable potential with the mean value of a 10-s scoring interval after perfusion of each solution will be recorded by a blinded investigator.<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Ability to measure CFTR difference using EDSPD testing | To establish the relationship of EDSPD findings with other validated instruments and markers of CRS disease | 3 Years |