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Investigating Mucinase Activity in Airway Disease (Mucinase)

This study has been completed.
National Heart, Lung, and Blood Institute (NHLBI)
Information provided by (Responsible Party):
University of California, San Francisco Identifier:
First received: January 2, 2008
Last updated: April 28, 2016
Last verified: April 2016
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.

Asthma Cystic Fibrosis

Study Type: Observational
Study Design: Observational Model: Case Control
Time Perspective: Cross-Sectional
Official Title: Investigating Mucinase Activity in Airway Disease

Resource links provided by NLM:

Further study details as provided by University of California, San Francisco:

Primary Outcome Measures:
  • rheological measurements (viscosity and elasticity) in sputum. [ Time Frame: 2-3 years ]

Biospecimen Retention:   Samples Without DNA

Enrollment: 211
Study Start Date: April 2003
Study Completion Date: April 2016
Primary Completion Date: December 2015 (Final data collection date for primary outcome measure)
People who have been diagnosed with Asthma
Cystic Fibrosis
People who have been diagnosed with Cystic Fibrosis
People who are non-asthmatic, non smokers with less than 10 pack years and who do not have 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.

Ages Eligible for Study:   18 Years to 70 Years   (Adult, Senior)
Sexes Eligible for Study:   All
Accepts Healthy Volunteers:   Yes
Sampling Method:   Non-Probability Sample
Study Population
Volunteers are recruited from community advertisements and health clinics

Inclusion Criteria:


  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


  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
  Contacts and Locations
Choosing to participate in a study is an important personal decision. Talk with your doctor and family members or friends about deciding to join a study. To learn more about this study, you or your doctor may contact the study research staff using the Contacts provided below. For general information, see Learn About Clinical Studies.

Please refer to this study by its identifier: NCT00596232

United States, California
UCSF Airway Clinical Research Center
San Francisco, California, United States, 94143
Sponsors and Collaborators
University of California, San Francisco
National Heart, Lung, and Blood Institute (NHLBI)
Principal Investigator: John V Fahy, M.D., M.Sc. University of California, San Francisco
  More Information

Additional Information:
Responsible Party: University of California, San Francisco Identifier: NCT00596232     History of Changes
Other Study ID Numbers: 11-05418
5P01HL107202-03 ( U.S. NIH Grant/Contract )
Study First Received: January 2, 2008
Last Updated: April 28, 2016

Additional relevant MeSH terms:
Cystic Fibrosis
Pancreatic Diseases
Digestive System Diseases
Lung Diseases
Respiratory Tract Diseases
Genetic Diseases, Inborn
Infant, Newborn, Diseases processed this record on August 21, 2017