Investigating Mucinase Activity in Airway Disease (Mucinase)

The purpose of this study is to investigate how mucus (phlegm or spit) is broken down once it forms in the airways (bronchial tubes) of people with lung disease. This research study will also examine whether blood groups have an effect on lung function or the type of mucus found in the lung. This study is not designed to be a treatment for asthma, emphysema, cystic fibrosis, or other lung disease. It is designed to help the investigators learn more about the causes of airway disease.

Study Overview

• Status: Completed
• Conditions: Asthma; Cystic Fibrosis

Detailed Description

Accumulation of mucus in the airway involves the process of overproduction and reduced clearance of mucin glycoproteins. To date, little attention has been focused on mechanisms of mucin clearance from the airway. We hypothesize that there is enzymatic degradation of mucins ("mucinase activity") in the airway, which acts to break down mucins and facilitate their clearance. We further hypothesize that glycosidases function as mucinases by removing peripheral monosaccharides from oligosaccharides, including oligosaccharides on mucins. Removal of terminal or capping sugars on mucin side chains may be an important mechanism in mucin degradation and clearance from the lung. If mucinase activity exists in the airway then mucus collected from human subjects should demonstrate evidence of mucin degradation ex vivo, especially at 37º celsius. As part of our protocol we propose to examine changes in airway mucus ex vivo under different experimental conditions. Our primary readout will be measures of sputum rheology, namely viscosity and elasticity. Our consultant for this methodology will be Dr Susan Muller (Chemical Engineering, University of California, Berkeley). In order to conduct experimental studies in this way we will need multiple samples from the same subjects. Thus, up to 10 or more sputum samples per subject will be collected on different days. In addition, we are interested in the biochemical properties of sputum and saliva, specifically the composition of mucin molecules found in these fluids.

• Study Type: Observational
• Enrollment (Actual): 211

Contacts and Locations

Study Locations

• United States
  • California
    • San Francisco, California, United States, 94143
      • UCSF Airway Clinical Research Center

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 18 years to 70 years (Adult, Older Adult)
• Accepts Healthy Volunteers: Yes
• Genders Eligible for Study: All

• Sampling Method: Non-Probability Sample

Study Population

Volunteers are recruited from community advertisements and health clinics

Description

Inclusion Criteria:

Asthma:

1. Male and female subjects aged 18 - 70 years
2. Medical history consistent with asthma
3. PC20 (provocative concentration causing a 20% fall) methacholine ≤ 8 mg/ml for subjects not taking inhaled corticosteroids
4. PC20 methacholine ≤ 16 mg/ml for subjects taking inhaled corticosteroids
5. Ability to provide informed consent

Cystic Fibrosis:

1. Male and female subjects aged 18-55 years
2. Prior diagnosis of cystic fibrosis
3. Ability to provide informed consent

Healthy:

1. Male and female subjects aged 18-70 years
2. No current smoking history
3. No history of asthma or allergic rhinitis
4. FEV1 (forced expiratory volume in 1 second) > 80% predicted
5. Ability to provide informed consent

Exclusion Criteria:

1. Recent heart attack or stroke
2. Known aortic or cerebral aneurysm
3. Uncontrolled hypertension
4. Pregnancy
5. Lactation
6. Lung disease other than asthma,cystic fibrosis, or chronic obstructive pulmonary disease (COPD)/emphysema/chronic bronchitis
7. Upper- or lower-respiratory tract infection 6 weeks prior to study enrollment
8. Significant asthma exacerbation 6 weeks prior to study enrollment
9. Increasing hyposensitization therapy for the past 3 months

Study Plan

How is the study designed?

Number of groups / cohorts

3

Cohorts and Interventions

Group / Cohort
Asthma; People who have been diagnosed with Asthma
Cystic Fibrosis; People who have been diagnosed with Cystic Fibrosis
Healthy; People who are non-asthmatic, non smokers with less than 10 pack years and who do not have cystic fibrosis

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Time Frame
rheological measurements (viscosity and elasticity) in sputum.	2-3 years

Collaborators and Investigators

• Sponsor: University of California, San Francisco
• Collaborators: National Heart, Lung, and Blood Institute (NHLBI)
• Investigators: Principal Investigator: John V Fahy, M.D., M.Sc., University of California, San Francisco

Publications and helpful links

Helpful Links

• Airway Clinical Research Center website

Study record dates

Study Major Dates

• Study Start: April 1, 2003
• Primary Completion (Actual): December 1, 2015
• Study Completion (Actual): April 1, 2016

Study Registration Dates

• First Submitted: January 2, 2008
• First Submitted That Met QC Criteria: January 15, 2008
• First Posted (Estimate): January 16, 2008

Study Record Updates

• Last Update Posted (Estimate): May 2, 2016
• Last Update Submitted That Met QC Criteria: April 28, 2016
• Last Verified: April 1, 2016

More Information

Terms related to this study

• Additional Relevant MeSH Terms: Digestive System Diseases; Respiratory Tract Diseases; Lung Diseases; Infant, Newborn, Diseases; Genetic Diseases, Inborn; Pancreatic Diseases; Cystic Fibrosis
• Other Study ID Numbers: 11-05418; 5P01HL107202-03 (U.S. NIH Grant/Contract)