Repeatability and Response Study of Absorptive Clearance Scans

Study Overview
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Brief Summary
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The investigators are developing a new nuclear medicine imaging technique for measuring liquid absorption in the airways that can be applied to screen new medications being developed to treat cystic fibrosis (CF). The investigators believe that the absorption of the small molecule radiopharmaceutical Indium 111 diethylene triamine pentaacetic acid (In-DTPA) will indicate changes in liquid absorption in the airways and demonstrate whether new CF medications will be effective. In this study the investigators will determine whether the imaging technique will demonstrate similar results when it is repeated on different days. They will also determine how their results change when subjects utilize several common CF medications.

Detailed Description
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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.

Official Title
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Repeatability and Response Study of Absorptive Clearance Scans

Conditions
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Cystic Fibrosis

Intervention / Treatment
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* Other: Absorptive clearance scan
* Drug: inhaled hypertonic saline (7%)
* Drug: mannitol inhalation powder


Participation Criteria
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Eligibility Criteria
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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)

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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Design Details

Primary Purpose: Basic Science
Allocation: Non-Randomized
Intervention Model: Single Group Assignment
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Repeatability<br>Subjects perform two sequential absorptive clearance scans (within 30 days) to determine the repeatability of the technique. Subjects also perform a third scan two years later so that longitudinal change can be measured. | Other: Absorptive clearance scan<br>* Subjects inhale a nebulized mixture of the radiopharmaceuticals Indium 111-DTPA and Technetium 99m sulfur colloid.<br>|
| Experimental: Response<br>Subjects perform three different absorptive clearance scans. One is a baseline measurement while the other two measure absorptive clearance after an intervention (inhaled hypertonic saline, mannitol inhalation powder). | Other: Absorptive clearance scan<br>* Subjects inhale a nebulized mixture of the radiopharmaceuticals Indium 111-DTPA and Technetium 99m sulfur colloid.<br>Drug: inhaled hypertonic saline (7%)<br>* nebulized hypertonic saline (7%)<br>* Other names: Hypersal;Drug: mannitol inhalation powder<br>* mannitol inhalation powder<br>* Other names: Bronchitol;|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| absorptive clearance variability | The difference in absorptive clearance measured on two different study days in the same subjects as an indicator of measurement variability | 30 days | 
| absorptive clearance response | The change in absorptive clearance demonstrated in response to therapy when compared to baseline | 14 day | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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cystic fibrosis, mucociliary clearance, airway surface liquid, nuclear medicine, mannitol