The purpose of this study is to measure mucociliary clearance (MCC) in groups of subjects with the disease Primary Ciliary Dyskinesia (PCD) caused by mutations in different genes, and compare to healthy subjects. Some of these genes are associated with a milder clinical phenotype. This study seeks to determine if the milder phenotype is a result of mutations in a set of specific genes. The hypothesis is that subjects with PCD caused by mutations in the milder group will maintain a low, but significant rate of mucociliary clearance, while patients with mutations in genes in the more severe group will have a complete absence of mucociliary clearance. These studies will help inform future treatment strategies.
Participants will undergo screening with basic physical exam and lung function testing at the start of the study. Participants will then inhale a radiolabeled substance and undergo medical imaging to measure the clearance of mucus in the airways. Albuterol will be administered after the first imaging is completed. Lung function testing will be repeated. Finally, medical imaging will be repeated two more times to further look at clearance of mucus in the lungs. The study will be completed in one day and will last about 6 hours.
Study Type
INTERVENTIONAL
Allocation
NON_RANDOMIZED
Purpose
BASIC_SCIENCE
Masking
NONE
Enrollment
27
Albuterol HFA Metered Dose Inhaler (90mcg/puff). Subjects to use 4 puffs one time.
Aerosolized radiolabeled Tc99m-sulfur colloid will be delivered using a modified Pari-LC Star nebulizer. The activity of Tc99m-SC loaded in the nebulizer will be adjusted to provide an estimated 40 microcurie (µCi) deposited in the lung for the MCC/CC scan. Patients between the age 12-18 years old will receive three quarters of the adult dose to account for the smaller lung volume.
University of North Carolina Chapel Hill
Chapel Hill, North Carolina, United States
Baseline MCC (Ave60Clr; Average Clearance Over 60 Minutes)
The average percent clearance in subjects with Primary Ciliary Dyskinesia (PCD) caused by mutations associated with mild and severe clinical phenotypes. Prior to each MCC study, a transmission Co57 scan will be performed to define the lung boundaries, to assign regions of interest, and to normalize these regions for lung volume differences. Radiolabeled Tc99m-sulfur colloid will be delivered using a modified Pari-LC Star nebulizer. The subject will then (within a minute of final inhalation maneuver) be seated in front of a large-field-of-view gamma camera to begin acquiring consecutive 2 minute images. The first two-2-minute images will provide initial, time zero activity (i.e. 100% retention) followed by the same imaging at the start of every 10-minute period until 1 hour has passed to assess baseline MCC. Clearance will be determined by measuring the decrease in radiolabeled Tc99m-sulfur colloid in the lungs over time.
Time frame: 60 minutes
Change in MCC (Ave120Clr-Ave60Clr;Average Clearance Between 60 and 120 Minutes)
The change in average percent clearance after the administration of albuterol in subjects with PCD caused by mutations associated with mild and severe clinical phenotypes PCD patients with mild disease compared to PCD patients with more severe disease. A transmission Cobalt57 scan will be performed to define the lung boundaries. Radiolabeled Tc99m-sulfur colloid (Technetium99m) will be delivered using a modified nebulizer. The subject will be seated in front of a large-field-of-view gamma camera to begin consecutive 2 minute images. The first two-2-minute images will provide initial, time zero activity followed by the same imaging at every 10-minute period until 1 hour. Subjects will then inhale 4 puffs of albuterol from the Metered Dose Inhaler (MDI) and consecutive 2 minute imaging continues for the next hour to assess the effect of albuterol on MCC. Clearance will be determined by measuring the decrease in radiolabeled Tc99m-sulfur colloid in the lungs over time.
Time frame: 120 minutes
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