NCT05474430 · Philip Polgreen
Estimating Risk of Respiratory Infections Attributable to CFTR Heterozygosity
What this study is about
A research team member will brush the inferior surface of the subjects' middle turbinate (nasal cavity) using a cytology brush to obtain the cells needed to perform our functional respiratory assays. An individual trained in phlebotomy will draw one 3 ml lavender top tube of blood to test c-reactive protein, calprotectin, and lactoferrin.
View original scientific description
A research team member will brush the inferior surface of the subjects' middle turbinate (nasal cavity) using a cytology brush to obtain the cells needed to perform our functional respiratory assays. An individual trained in phlebotomy will draw one 3 ml lavender top tube of blood to test c-reactive protein, calprotectin, and lactoferrin. They will also draw a 5 ml gold top serum separator tube of blood to test fibroblast growth factor-19. The participant will answer questions from the baseline survey and report their current medications interview-style with the research team member.
Primary outcome measures
Comparison of Chloride Transport Values
Time frame: At baseline
Comparison of chloride transport values in cystic fibrosis carrier group vs control group via t-test.
Comparison of Bicarbonate Transport Values
Time frame: At baseline
Comparison of bicarbonate transport values in cystic fibrosis carrier group vs control group via t-test.
Comparison of Airway Surface Liquid pH Values
Time frame: At baseline
Comparison of airway surface liquid pH values in cystic fibrosis carrier group vs control group via t-test.
Comparison of Mucous Viscosity Values
Time frame: At baseline
Comparison of mucous viscosity values in cystic fibrosis carrier group vs control group via t-test.
Comparison of Bacterial Killing Values
Time frame: At baseline
Comparison of bacterial killing values in cystic fibrosis carrier group vs control group via t-test.
Who can participate
This study lists these criteria on ClinicalTrials.gov. A study coordinator reviews eligibility during screening — this page does not determine whether you qualify.
Inclusion criteria
- Previously tested and shown to be a CF carrier
- English-speaking Control Group Inclusion Criteria:
- Previously tested and shown to not be a CF carrier or CF patient
- English-speaking
Exclusion criteria
- Currently sick with a respiratory infection
- Prisoner Status
- Unable to provide own written, informed consent
Where
- Iowa City, Iowa
Collaborators
National Institutes of Health (NIH), National Institute of Allergy and Infectious Diseases (NIAID)
Related conditions & keywords
Frequently asked questions
What is a clinical trial?
A clinical trial is a research study that tests new medical treatments, drugs, devices, or procedures to determine their safety and effectiveness. Trials are carefully designed and monitored to protect participants while advancing medical knowledge.
Is it safe to participate?
Clinical trials follow strict safety guidelines and ethical standards. Trials must be reviewed and approved, and participants are closely monitored by medical professionals throughout the study. You can withdraw at any time if you choose.
Will I be compensated?
Many clinical trials offer compensation for your time, travel expenses, and inconvenience. The specific compensation varies by study and will be discussed during the screening process. All study-related medical care is typically provided at no cost to participants.
Will I receive a placebo instead of treatment?
When effective treatment exists, participants typically receive either the standard treatment plus the study intervention, or the standard treatment plus placebo. You would not be denied effective care. Placebos are primarily used when no proven treatment is available, or in addition to standard care. Your trial consent form will clearly explain what treatments you may receive.
Can I leave a trial if I change my mind?
Absolutely. Participation in clinical trials is completely voluntary. You have the right to withdraw from the study at any time, for any reason, without penalty or loss of benefits to which you are otherwise entitled.
How long does a clinical trial last?
Trial duration varies widely depending on the study design and purpose. Some trials last just a few weeks, while others may continue for months or years. The study coordinator will provide specific timeline information during your screening call.
Data: ClinicalTrials.gov · synced Jan 7, 2026 · Source of record for eligibility and locations