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Characterizing Asthma Sputum Elasticity in the UCSF Severe Asthma Research Program (CAESAR)

The safety and scientific validity of this study is the responsibility of the study sponsor and investigators. Listing a study does not mean it has been evaluated by the U.S. Federal Government. Know the risks and potential benefits of clinical studies and talk to your health care provider before participating. Read our disclaimer for details. Identifier: NCT02103348
Recruitment Status : Recruiting
First Posted : April 3, 2014
Last Update Posted : February 1, 2022
Information provided by (Responsible Party):
University of California, San Francisco

Brief Summary:
This study is designed to characterize subjects in terms of their sputum phenotype. The purpose of this study is to learn more about the impact of having abnormally elastic sputum on asthma severity by comparing subjects with severe as well as mild/moderate asthma to healthy controls. The characterization will include medical history, pulmonary function testing, imaging of the lungs and biospecimen collection.

Condition or disease

Detailed Description:

Asthma is a heterogeneous disease characterized by airway hyperreactivity and chronic airway inflammation. Published literature from the last few years has shown that asthma does not behave like a single disease but is more of a syndrome with vast heterogeneity in pathogenesis, severity, and treatment response. Various clinical phenotypes and endotypes have been described that advance our understanding of these differences and the mechanisms underlying them. We propose there is a subgroup of asthmatic patients that have sputum with abnormal biophysical properties. Healthy airway mucus is composed of a lightly cross-linked gel that is easily transported by the mucociliary apparatus, coughed and expectorated or swallowed. Pathologic mucus has, in contrast, abnormally high elasticity. This is due to a more cross linked structure which gives the sputum the properties of solid and makes sputum difficult to mobilize. Increased sputum elasticity makes expectoration of sputum more difficult and leads to airflow obstruction. Pathologic mucus contributes to airflow obstruction and airway infection in multiple lung diseases, including asthma. Mucus plugs are a particular problem in asthmatic patients with allergic bronchopulmonary aspergillosis (ABPA)The identification of phenotype of severe asthma with pathologic mucus contributing to disease severity may change how we think about severe asthma, moving towards therapies targeting mucus clearance such as in other conditions such as cystic fibrosis. Pathologic mucus in severe asthma is characterized by cellular inflammation, high concentrations of mucins and DNA polymers. Knowledge of specific cellular and biochemical constituents of pathologic mucus in severe asthma can guide targeted mucolytic treatment with n-acetylcysteine, rhDNAse, or novel mucolytic agents.

As part of the Severe Asthma Research Program (SARP), UCSF is in a unique position to recruit a large number of severe asthmatic subjects within which we expect a portion will demonstrate high sputum elasticity. We will also through CAESAR recruit additional subjects with moderate to severe airflow obstruction. We will perform rheological measurement on all subjects that are recruited to our site and from this identify a group of asthmatic cases that have an elastic modulus of ≥1 or <1 and compare properties of sputum from these subjects to healthy controls.

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Study Type : Observational
Estimated Enrollment : 75 participants
Observational Model: Cohort
Time Perspective: Cross-Sectional
Official Title: Characterizing Asthma Sputum Elasticity in the UCSF Severe Asthma Research Program
Study Start Date : September 2015
Estimated Primary Completion Date : April 2022
Estimated Study Completion Date : June 2023

Resource links provided by the National Library of Medicine

MedlinePlus related topics: Asthma

Mild-to-Moderate Asthma
Those with mild-to-moderate persistent asthma as defined by the NAEPP EPR-3 guidelines.
Severe Asthma

Major Criteria: (1 required)

  1. Treatment with oral corticosteroids for at least 6 of the previous 12 months
  2. Treatment with high-dose inhaled corticosteroids for at least 10 of the previous 12 months

Minor Criteria: (2 required)

  1. Daily treatment with an asthma controller medication in addition to inhaled, or
  2. Asthma symptoms requiring short-acting bronchodilator use on a daily or near daily basis (defined as at least 5 of 7 days), or
  3. Persistent airway obstruction with baseline FEV1 <80% predicted, or
  4. ≥ 1 urgent visits for asthma in the previous 12 months, or
  5. ≥ 3 systemic corticosteroid bursts in the previous 12 months, or
  6. Prompt deterioration with a reduction in oral or inhaled corticosteroid dose, or
  7. A near-fatal asthma event (i.e., intubation) in the past.
Healthy Controls
Those without asthma or other chronic lung disease.

Primary Outcome Measures :
  1. Lung function [ Time Frame: Cross sectional over 4-6 weeks ]
    Lung function as a measure of asthma severity.

Secondary Outcome Measures :
  1. Inflammatory cellular markers [ Time Frame: Cross sectional over 4-6 weeks ]
    Changes in inflammatory cellular markers in sputum and blood. We will measure various indicators of airway inflammation and compare them with various phenotypic characteristics.

Other Outcome Measures:
  1. CT Chest [ Time Frame: Cross sectional over 4-6 weeks ]
    Examining CT chest in asthmatics for evidence of retained mucus.

Biospecimen Retention:   Samples With DNA
Samples of induced sputum and blood for DNA and RNA extraction, plasma, and serum will be banked in the UCSF Airway Tissue Bank.

Information from the National Library of Medicine

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, Learn About Clinical Studies.

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Ages Eligible for Study:   18 Years to 65 Years   (Adult, Older Adult)
Sexes Eligible for Study:   All
Accepts Healthy Volunteers:   Yes
Sampling Method:   Non-Probability Sample
Study Population
A diverse sample of subjects with asthma is needed to gain better understanding of asthma and its endotypes. CAESAR will therefore enroll subjects between 18 and 65 years with a physician diagnosis of asthma as well as a group of healthy subjects. The target recruitment goal for UCSF is 50 adults with asthma and 25 healthy controls (age 18 and older). Within the asthma group, an attempt will be made to enroll 60% of subjects with severe with the rest of the subjects mild to moderate asthma.Within the cohort, an attempt will be made to enroll at least 50% females and 10% minorities.

Inclusion Criteria:

  • FEV1 bronchodilator reversibility ≥12% or airway hyperresponsiveness reflected by a methacholine PC20 ≤16 mg/mL
  • An exception will be made for enrollees whose FEV1 is < 50% predicted (<70% in children aged 6 to 17 years), precluding methacholine challenge testing. If bronchodilator reversibility is <12% in these participants, a diagnosis of asthma acceptable to the investigator is sufficient for inclusion in CAESAR.

Exclusion Criteria:

  • Pregnancy,
  • Current smoking,
  • Smoking history > 10 pack years if ≥30 years of age, or smoking history > 5 pack years if <30 years of age,
  • Other chronic pulmonary disorders associated with asthma-like symptoms, including (but not limited to) cystic fibrosis, chronic obstructive pulmonary disease, chronic bronchitis, vocal cord dysfunction (that is the sole cause of respiratory symptoms and at the PI's discretion), severe scoliosis or chest wall deformities that affect lung function, or congenital disorders of the lungs or airways,
  • History of premature birth before 35 weeks gestation,
  • Planning to relocate from the clinical center area before study completion,
  • Any other criteria that place the subject at unnecessary risk according to the judgment of the Principal Investigator and/or attending physician(s) of record, or
  • Currently participating in an investigational drug trial.

Healthy Controls:

Inclusion criteria: Healthy subjects between the age of 18y and 65y. At least 3 of the 7 subjects per center should be aged 35y or older.

Exclusion criteria

  • History of chronic diseases that affect the lungs.
  • A history suggestive of allergic rhinitis, eczema or chronic sinusitis.
  • An improvement in FEV1 of more than 12% following 4 puffs of albuterol.
  • Smoking history > 10 pack years if ≥30 years of age, or smoking history > 5 pack years if <30 years of age, or any smoking within the past year.
  • Respiratory tract infection within the past 4 weeks.
  • Pregnancy.
  • History of premature birth (<35 weeks).

Information from the National Library of Medicine

To learn more about this study, you or your doctor may contact the study research staff using the contact information provided by the sponsor.

Please refer to this study by its identifier (NCT number): NCT02103348

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Contact: Xavier Orain, BS 415-502-3472

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United States, California
University of California, San Francisco Recruiting
San Francisco, California, United States, 94143
Contact: John V Fahy, M.D. M.Sc    415-502-4849      
Sponsors and Collaborators
University of California, San Francisco
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Principal Investigator: John V Fahy, M.D. M.SC. University of California, San Francisco
Additional Information:
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Responsible Party: University of California, San Francisco Identifier: NCT02103348    
Other Study ID Numbers: 14-13242
First Posted: April 3, 2014    Key Record Dates
Last Update Posted: February 1, 2022
Last Verified: January 2022

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Studies a U.S. FDA-regulated Drug Product: No
Studies a U.S. FDA-regulated Device Product: No
Keywords provided by University of California, San Francisco:
Severe asthma
Additional relevant MeSH terms:
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Bronchial Diseases
Respiratory Tract Diseases
Lung Diseases, Obstructive
Lung Diseases
Respiratory Hypersensitivity
Hypersensitivity, Immediate
Immune System Diseases