Absorptive Clearance in the Cystic Fibrosis Airway

The objective of this overall project is to develop a new aerosol-based technique for quantifying liquid absorption in the airways of subjects with cystic fibrosis(CF) that can be used to help develop new therapies. In CF, mutations in the CF gene result in dysfunction of the Cystic Fibrosis Transmembrane Conductance Regulator (CFTR) ion channel on the cells that line the airway epithelium, causing improper fluxes of ions such as sodium, chloride, and bicarbonate. The so called "low volume" hypothesis of CF pathogenesis contends that abnormal absorption of ions from the airways causes excessive absorption of liquid, resulting in an airway surface liquid layer that is dehydrated and difficult to clear. Here we are measuring the absorption rate of a radiolabeled small molecule (DTPA) from the lungs of cystic fibrosis patients and healthy controls. We hypothesize that the molecule will absorb more quickly in cystic fibrosis patients. Further studies will be performed to determine if DTPA absorption is related to liquid absorption in the airways.

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Key information

Conditions

Cystic Fibrosis Congenital, Hereditary, and Neonatal Diseases and Abnormalities Digestive System Diseases Genetic Diseases, Inborn Infant, Newborn, Diseases Lung Diseases Pancreatic Diseases Respiratory Tract Diseases

Age range

18 year and older

Sex eligibility

All sexes

Study type

Interventional

Phase

Not applicable

Primary location

University of Pittsburgh

Pittsburgh, Pennsylvania, 15213, United States

Who can participate

Healthy volunteers accepted: Yes

Only the study team can determine whether someone qualifies for participation.

Inclusion criteria

Cystic fibrosis subjects and healthy controls
Age ≥ 18 years
Diagnosis of cystic fibrosis as determined by sweat test or genotype and clinical symptoms (CF subjects)
Clinically stable as determined by the investigator (pulmonologist)

Exclusion criteria

Reactive airways disease
Tobacco smokers (regular smoking within 6 months of enrollment)
Positive urine pregnancy test on the day of testing
FEV1p value of < 50%
SaO2 < 92%, or if they require supplemental oxygen.
Subjects performing other radioisotope studies within the last 2 weeks will be excluded.
Healthy subjects with any history of lung disease will be excluded.
Women currently breastfeeding
Subjects not willing to stop treatments with inhaled hypertonic saline for 48 hours in advance of the study.

Treatment and study plan

Technetium [Tc-99m] sulfur colloid and Indium [In-111] DTPA

Other

Subjects perform a single nuclear medicine scan after inhaling an aerosol containing Technetium 99m sulfur colloid and Indium 111 DTPA.

Primary outcomes

Absorptive Clearance Rate

Time frame: single measurement

The absorptive clearance rate is the percentage of the radiolabeled small molecule DTPA that is cleared through absorption over a 60 minute period. Total DTPA clearance includes absorptive and mucociliary components. The mucociliary component is determined by measuring the clearance of a radiolabeled particle over the same period (Technetium 99m sulfur colloid; Tc-SC), and subtracted from total DTPA clearance in order to determine the absorptive component. Here we specifically report absorption from the central lung zone to capture the behavior within the airways.

Secondary outcomes

Mucociliary Clearance Rate

Time frame: single measurement

Mucociliary clearance rate represents the rate at which the lungs clear an inhaled particulate. Here it specifically represents the percentage of inhaled Technetium 99m sulfur colloid cleared from the lungs over a 60 minute period. This is reported based on "whole lung" areas to allow comparisons with previous studies.

Sponsors and collaborators

Lead sponsor

University of Pittsburgh

Other

Registry information

Important dates

Study start: 2007
Primary completion: 2008
Study completion: 2008
First posted: Oct 10, 2007
Registry last updated: Aug 24, 2017

OpenTrials presents study information sourced from ClinicalTrials.gov. The official registry record should be consulted for the latest information.

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This listing is for discovery and informational purposes only. It is not medical advice, does not guarantee that a study is recruiting, and does not determine eligibility. Contact the study team and a qualified healthcare professional when considering participation.

Published trials that share one or more normalized conditions with this study.

Completed