Transepithelial Potential Difference Measurements in Patients with Unusual Variants of Cystic Fibrosis

Principal Investigator

Kelvin MacDonald

Study Purpose

This purpose of this research study is to test the ability of the cells lining the nose to regulate the movement of salt and water in four types of persons: 1) adults and children with Cystic Fibrosis (CF), 2) adults and children with Cystic Fibrosis who have pancreatic sufficiency or were diagnosised after the age of five years 3) those adults that do not have CF, called reference subjects, and 4) those adults and children with some features of CF in whom the diagnosis is not entirely clear. We will be studying salt and water movement by a technique called nasal transepithelial potential difference (TEPD or NPD) which gives us information about the function of cells lining the inner surfaces of the nose.
The CF protein (CFTR) controls the movement of salt and water by these cells. The TEPD measurements may be very different in people with CF, atypical CF, and other people with diseases that affect the movement of salt and water, then they are in people who do not have these diseases. By looking at these different groups of people, we may be able to better characterize salt and water movement in these distinct groups.

Medical Condition(s)

Cystic Fibrosis and Cystic Fibrosis like conditions

Eligibility Criteria

Inclusion Criteria and Study Population
There is no age limit for nasal potential difference measures, however, subjects 10 years old and above tolerate it best.
Inclusion criteria include individuals with Cystic Fibrosis, Cystic Fibrosis carriers, those individuals in which a diagnosis of Cystic Fibrosis is unclear and non Cystic Fibrosis individuals. Individuals in whom standard diagnostic genotyping and sweat chloride are inconclusive for a diagnosis of Cystic Fibrosis are included.

Exclusion Criteria and Study Population
Normal infants and normal children less than 18 years of age are excluded from participation. Children in whom the diagnosis of CF is inconclusive are eligible. Additional exclusion criteria include acute rhinorrhea or onset of upper respiratory infection, epistaxis, or sinusitis.

Age Range

10 - 90

Healthy Volunteers Needed


Duration of Participation

About one hour.

Minors Included



Kelvin MacDonald, MD 503-494-8023


Recruitment End


Compensation Provided


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