Repeatability and Response Study of Absorptive Clearance Scans

Cystic Fibrosis (CF) is an autosomal recessive genetic disease, caused by mutations of the
Cystic Fibrosis Transmembrane Conductance Regulator (CFTR) that impairs ion transport at
epithelial surfaces. This results in the accumulation of dehydrated secretions in the airways
and chronic infection and inflammation in the lungs, leading to significant morbidity and
mortality. The investigators understanding of CF pathogenesis has increased substantially and
many new targeted therapies are being developed to treat this disease, however, the
measurements of clinical efficacy used to evaluate these therapies require long trials to
demonstrate an effect. New translational techniques are needed to assess changes in the most
basic aspects of the disease and allow for the rapid screening of disease-altering therapies.
The investigators have recently developed a novel aerosol-based imaging technique to measure
liquid absorption in the airways - a central pathophysiological process related to CFTR
dysfunction. The investigators propose that airway liquid hyper-absorption is a key link
between cellular defects in ion and fluid transport and progressive airway dysfunction in CF.
Thus The investigators technique may provide a measure of disease severity and rapid
indication of therapeutic correction in advance of currently available outcome measures.

Inclusion Criteria:

- subjects 18 years old or older with a diagnosis of cystic fibrosis as determined by
sweat test or genotype and clinical symptoms who are clinically stable as determined
by a physician co-investigator

Exclusion Criteria:

- one second forced expiratory volume (FEV1) <50% of predicted

- nursing mother

- positive urine pregnancy test or unwilling to test

- cigarette smoker

- unwilling to stop hypertonic saline therapy for 72 hours prior to each test day

- are intolerant to hypertonic saline (response only)

- are intolerant to any inhaled therapies (response only)

- fail mannitol tolerance testing (response only)

- have a history of excessive (uncontrollable) coughing after an osmotic stimulus
(response only)

- have a history of hemoptysis (response only)