Characterization of Airway Mucus in Bronchiectasis Patients and Healthy Controls

Analysis of mucus, mucin and DNA concentration, MUC5B/5AC ratio, rheology, osmotic pressure, cohesion and nucleotides in sputum on 30 individual samples of good quality in healthy individuals and those with bronchiectasis. (60 total)

Study Overview

Status

Completed

Detailed Description

In this study the investigators will investigate the mucus properties in individuals with idiopathic bronchiectasis and healthy individuals without a history of lung disease. In order to understand how mucus is abnormal in disease conditions, the investigators need to understand the mucus biochemical and biophysical properties in healthy individuals. In this study the investigators will prospectively recruit patients with bronchiectasis and healthy individuals from the community to provide airway sputum samples. In these samples the investigators will measure an array of mucus properties. This will help our understanding of the mucus-obstructive lung diseases and facilitate the development of appropriate and effective disease prevention strategies.

A key question is whether mucus is hyper-concentrated and has abnormal biophysical properties in individuals with mucus-obstructive lung disease. To answer this question, the investigators need to understand the properties of the mucus in individuals with idiopathic bronchiectasis and no history of lung disease. This study will allow us to collect airway mucus (sputum) from individuals with bronchiectasis and healthy individuals with no history of lung disease.

Study Type

Observational

Enrollment (Actual)

30

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Locations

    • North Carolina
      • Chapel Hill, North Carolina, United States, 27599
        • Center for Environmental Medicine Asthma and Lung Biology
      • Chapel Hill, North Carolina, United States, 27599
        • Marsico Research Institure at Meadowmont

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

18 years to 99 years (Adult, Older Adult)

Accepts Healthy Volunteers

Yes

Genders Eligible for Study

All

Sampling Method

Non-Probability Sample

Study Population

The proposed study will recruit 30 patients with bronchiectasis and 30 healthy individuals with no history of lung disease aged over the age of 18 years.

Description

Participants who meet all the following criteria are eligible for the study:

  • Written informed consent
  • Bronchiectasis patients: Available CT of the chest that shows evidence of dilated airways fulfilling radiographic criteria for bronchiectasis in more than one lobe and chronic cough.

Participants who meet any of the following criteria will not be eligible for the study:

  • Healthy individuals: A history of lung disease, current asthma symptoms or medication use, premature birth (<37 week gestation), a history of lung disease of infancy, or neurological or cardiovascular illness, current smoker or a history of smoking tobacco products.
  • Bronchiectasis patients: Premature birth (<37 week gestation), a history of lung disease of infancy, or neurological or cardiovascular illness.
  • Younger than 18 years of age

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

Cohorts and Interventions

Group / Cohort
control
healthy individuals with no history of lung disease
bronchiectasis patients
individuals with a diagnoses of bronchiectasis

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Mucus concentration (% solids)
Time Frame: 6 months
The percentage of solid content of sputum (an index of hydration) will be calculated my measuring the wet to dry weight ratio using a microbalance (mean percent solids ± standard deviation).
6 months

Secondary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Biophysical properties of mucus by rheology
Time Frame: 6 months
The rheological properties of the sputum will be assayed by macro-rheology (cone and plate) and microbead rheology. Macro-rheology provides measures of the viscosity (median log viscosity in Pascal (range)) and elasticity (median log elasticity in Pascal (range) of the sputum. Microbead rheology is performed by analyzing the diffusive motion of embedded 1μm tracer particles (6). The primary outcome measure from microbead rheology will be the mean square displacement MSD(Mean squared displacement) (median MSD cm2 s-1 (range)).
6 months
Mucin composition by mass spectroscopy
Time Frame: 6 months
We will use mass spectroscopy to determine the relative abundance of the two major polymeric mucin proteins, MUC5B(Mucin type 5B)and MUC5AC(Mucin type 5AC), which are responsible for the viscoelastic properties of mucus.
6 months
Sputum extracellular nucleotide analysis
Time Frame: 6 months
Sputum adenosine and adenine nucleotides will be ethenoderivatized and measured by HPLC(High performance liquid chromatography) analysis (7) (median nucleotide concentration in μg/ml (range)).
6 months
Osmotic Pressure
Time Frame: 6 months
The osmotic pressure of the mucus will be assessed by placing an aliquot of mucus onto an osmometer with a 10kDa (10 kilodaltons) molecular weight polyethersulfone membrane (Millipore) separating the test chamber and reference chamber filled with PBS (phosphate-buffered saline) (mean osmotic pressure in Pascal ± standard deviation).
6 months
Total mucin concentration
Time Frame: 6 months
Mucins will be quantitated using sepharose CL2B(Cross-linked derivative of Sepharose 2B) UPLC(Ultra performance liquid chromatography) coupled to an Optilab interference refractometer with a filter at 680 nm and parallel flow chambers for solvent and the solution (mean mucin concentration (μg/ml) ± standard deviation) (4). With this approach, we will ensure that the solute is at full Donnan equilibrium with the solution within the context of gel chromatography, which creates an accurate equilibration of solute and solvent. This procedure also separates the mucins from contaminating proteins, allowing the mucins to be isolated for biochemical studies. DNAse can be added if significant DNA is present.
6 months
polymeric DNA concentration
Time Frame: 6 months
The quantification of free DNA will be performed using the DNA Quant-iT PicoGreen assay (Molecular Probes, Inc., Eugene, OR, USA), which utilizes an ultra-sensitive fluorescent nucleic acid stain for quantitating double-stranded DNA (median log DNA concentration (μg/ml) (range)).
6 months

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Investigators

  • Study Chair: Richard Boucher, MD, University of North Carolina, Chapel Hill
  • Principal Investigator: Kathryn Ramsey, University of North Carolina, Chapel Hill

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Actual)

March 10, 2017

Primary Completion (Actual)

June 27, 2017

Study Completion (Actual)

June 27, 2017

Study Registration Dates

First Submitted

April 14, 2017

First Submitted That Met QC Criteria

April 18, 2017

First Posted (Actual)

April 24, 2017

Study Record Updates

Last Update Posted (Actual)

July 24, 2017

Last Update Submitted That Met QC Criteria

July 20, 2017

Last Verified

July 1, 2017

More Information

Terms related to this study

Other Study ID Numbers

  • 16-3142

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

NO

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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