Airway Macrophages and Sputum Milieu in Adult Subjects With Airflow Obstruction

Sponsor

University of Nebraska (Other)

Overall Status

Completed

CT.gov ID

NCT00871637

Collaborator

VA Nebraska Western Iowa Health Care System (U.S. Fed)

Enrollment

Location

Duration (Months)

Patients Per Site Per Month

Study Details

Study Description

Brief Summary

Airway macrophage impairment is a central feature in the immunopathogenesis of chronic obstructive pulmonary disease, regardless of smoking status.

Condition or Disease	Intervention/Treatment	Phase
Pulmonary Disease, Chronic Obstructive Bronchitis, Chronic Occupational Diseases Tobacco Use Disorder

Detailed Description

In the United States, a variety of farming operations can generate significant amounts of dust. Chronic organic dust exposure to workers in this industry can result in several respiratory health conditions including chronic bronchitis, chronic obstructive pulmonary disease (COPD), and exacerbations of asthma. Organic dust is a complex mixture containing particulate matter and microbial-associated components from gram positive and gram negative bacteria. Airway macrophages are key innate immune cells that are rapidly activated by exposure to inhaled toxins and organic dust.

The literature indicates that subjects with tobacco-induced chronic bronchitis/COPD have alveolar macrophages that have impaired function. It has been hypothesized that the impaired lung macrophage function may contribute to the increased susceptibility to infections and chronic bacterial colonization that is a central feature in subjects with chronic bronchitis/COPD. It is unknown at this time if impaired macrophage function is secondary to tobacco-induced effects, or is a central pathologic feature of chronic bronchitis/COPD.

We will explore the expression of innate immune cell surface molecule expression involved in antigen presentation, phagocytic ability, and ex vivo cytokine responses in airway macrophages obtained by induced sputum. We will also collect blood to determine if ex vivo stimulation of blood mimics the inflammatory responses observed with airway macrophages. Comparisons to our past findings in vitro studies, which demonstrated that repetitive organic dust exposure impairs monocyte derived macrophage immune cell surface markers and function, could then be made. This information could lead to future investigations centered on therapeutic interventions to prevent or reverse the underlying lung disease experienced by farmers in this industry.

Study Design

Study Type:

Observational

Actual Enrollment :

30 participants

Observational Model:

Case-Control

Time Perspective:

Prospective

Official Title:

Airway Macrophages and Sputum Milieu in Adult Subjects With Airflow Obstruction

Study Start Date :

Aug 1, 2008

Actual Primary Completion Date :

Jun 1, 2009

Actual Study Completion Date :

Jun 1, 2009

Arms and Interventions

Arm	Intervention/Treatment
Group One Healthy non-smoking controls
Group Two Smoking adults with chronic bronchitis/chronic obstructive pulmonary disease
Group Three Non-smoking adults with chronic bronchitis/chronic obstructive pulmonary disease

Outcome Measures

Primary Outcome Measures

Determine if airway macrophages from adult subjects with airflow obstruction demonstrate impaired innate immune cell surface marker expression and phagocytic ability compared to healthy controls. [One year]

Secondary Outcome Measures

Determine if airway macrophages from adult subjects with airflow obstruction demonstrate impaired cytokine responsiveness compared to healthy controls. [One year]
Determine if airway macrophage cytokine responsiveness is comparable to whole blood cytokine responsiveness. [One year]
To determine if airway sputum milieu for potential immunomodulators predict airway macrophage phenotype and function. [One year]

Eligibility Criteria

Criteria

Ages Eligible for Study:

50 Years to 75 Years

Sexes Eligible for Study:

All

Accepts Healthy Volunteers:

Yes

Inclusion Criteria:

Medically stable to participate in induced sputums
Group One: Smoked less than 100 cigarettes in their lifetime Quit smoking greater than 10 years ago Pre-bronchodilator FEV1/FVC > 70% Pre-bronchodilator FEV1 % predicted > 80%
Group Two: Greater than a 20-pack year tobacco history Smoked in the last two years Post-bronchodilator FEV1/FVC < 70%
Group Three:Have less than a 20-pack year tobacco history Quit smoking greater than 20 years ago Post-bronchodilator FEV1/FVC < 70%

Exclusion Criteria:

Personal history of lung cancer
Pregnancy
Personal history of autoimmune disease
Currently taking oral/parental corticosteroids
Personal history of upper or lower respiratory tract infection in the prior four weeks