Comparison of Alveolar Macrophages in Individuals With COPD Versus Smokers With Normal Pulmonary Function

December 12, 2014 updated by: Jeffrey L. Curtis, University of Michigan

Innate and Adaptive Immunity in COPD Exacerbations: Clinically-Indicated Bronchoscopies

The purpose of this study is to determine whether the alveolar macrophages (AMø) of patients with chronic obstructive pulmonary disease (COPD ) show abnormal responsiveness to bacterial and viral products, relative to smokers with normal pulmonary function. Participation in this study will be offered to patients already scheduled to undergo a bronchoscopy for clinical indications.

Study Overview

Detailed Description

BACKGROUND:

COPD is one of the most pressing healthcare problems facing our nation. Acute exacerbations of COPD (AE-COPD) are responsible for the bulk of healthcare costs, and much of the morbidity and decline in health status among individuals with this common disease. The lack of accepted animal models of AE-COPD necessitates novel approaches using human samples. Advances in the understanding of the pathogenesis have been slowed, in part, due to controversy as to how exacerbations should be defined. The prevailing paradigm has defined AE-COPD as event-based. Such definitions clearly identify groups of patients with accelerated loss of pulmonary function and increased mortality. However, limited data show that symptom-based definitions of AE-COPD also capture episodes inducing significant morbidity and functional decline, and hence of concern to patients. Fundamental mechanisms are lacking to explain AE-COPD defined by either means.

Controversy also surrounds triggers of AE-COPD. Bacteria and viruses are involved in some episodes, but the relative importance of each is intertwined with disputes over the definition of AE-COPD. Progress at linking specific pathogens to molecular pathogenesis has been slow, both due to their diversity, and to the high rates of bacterial colonization of patients with COPD, even in the stable state. Moreover, in many AE-COPD cases, no pathogen can be identified. Without negating the value of analyzing infections with specific species of pathogens, it appears that progress in molecular pathogenesis could be accelerated by focusing on unifying features of the pulmonary immune response during AE-COPD.

DESIGN NARRATIVE:

The purpose of this experiment is to determine whether the AMø of patients with COPD show abnormal responsiveness to bacterial and viral products, relative to smokers with normal pulmonary function. Specifically, the study will determine the dose-response characteristics of AMø from these two groups of subjects for production of interleukin (IL)-6, IL-18, and IL-23 (pro-inflammatory cytokines) on stimulation by purified Lipopolysaccharide, a synthetic lipopeptide (PAM3-Cys), or poly I:C. These stimuli mimic the response to Gram-negative bacteria, Gram-positive bacteria, and RNA viruses, respectively.

This research protocol involves adding a research bronchoalveolar lavage (BAL) to clinically indicated bronchoscopy that is being performed for evaluation of lung nodules suspected to possibly be malignant. The research BAL will be performed during the same procedure, but on the opposite lung from the radiographic lesion that motivated the bronchoscopy. Subjects will be COPD patients or smokers with normal pulmonary function recruited from the Pulmonary Clinic. Smoking history will be taken to mean at least 20 pack-years exposure, and could include current or ex-smokers. Bronchoscopy will be performed under conscious sedation using a fiberoptic bronchoscope, in almost all cases on outpatients (although stable inpatients could be considered for consent if they otherwise meet eligibility criteria). The setting is the Endoscopy suite at the Ann Arbor VA Hospital.

The procedures in this protocol involve the following upon enrollment: bronchoalveolar lavage (200 ml maximal instilled volume) and collection of blood for hematocrit, serum albumin, C-reactive protein, and IL-6.

Study Type

Observational

Enrollment (Actual)

32

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

    • Michigan
      • Ann Arbor, Michigan, United States, 48105
        • University of Michigan at Ann Arbor

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

40 years and older (Adult, Older Adult)

Accepts Healthy Volunteers

Yes

Genders Eligible for Study

All

Sampling Method

Non-Probability Sample

Study Population

Smokers with COPD or smokers with normal pulmonary function will be recruited from among subjects scheduled to undergo bronchoscopy for clinical indications.

Description

Inclusion criteria:

  • Diagnosis of COPD and/or chronic bronchitis (study group, following American Thoracic Society guidelines)
  • Willingness to participate in follow-up studies defined in the protocol
  • Ability to give informed consent
  • Already undergoing clinically indicated bronchoscopy

Exclusion criteria:

  • Unstable cardiovascular disease
  • Other systemic disease in which survival of more than 2 years is unlikely
  • Mental incompetence or active psychiatric illness
  • Currently taking more than 20 mg/day of Prednisone
  • Participation in another experimental protocol within 6 weeks of study entry
  • Asthma
  • Cystic fibrosis
  • Clinically significant bronchiectasis
  • Lung cancer
  • Other inflammatory or fibrotic lung disease

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
Intervention / Treatment
Healthy smokers
Smokers with normal pulmonary function
blood will be drawn at the time of starting the intravenous (IV) line for the procedure.
A small amount of liquid will be introduced and immediately sucked back out of portions of the lung, and the cells that are recovered will be analyzed in the laboratory. All test will be solely for research, and there will be no results reported to the subject from that fluid.
Other Names:
  • BAL
COPD patients
blood will be drawn at the time of starting the intravenous (IV) line for the procedure.
A small amount of liquid will be introduced and immediately sucked back out of portions of the lung, and the cells that are recovered will be analyzed in the laboratory. All test will be solely for research, and there will be no results reported to the subject from that fluid.
Other Names:
  • BAL

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Time Frame
alveolar macrophage functions in vitro
Time Frame: day of bronchoscopy
day of bronchoscopy

Collaborators and Investigators

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

Publications and helpful links

The person responsible for entering information about the study voluntarily provides these publications. These may be about anything related to the study.

General Publications

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

September 1, 2005

Primary Completion (Actual)

October 1, 2014

Study Completion (Actual)

October 1, 2014

Study Registration Dates

First Submitted

January 20, 2006

First Submitted That Met QC Criteria

January 20, 2006

First Posted (Estimate)

January 24, 2006

Study Record Updates

Last Update Posted (Estimate)

December 16, 2014

Last Update Submitted That Met QC Criteria

December 12, 2014

Last Verified

December 1, 2014

More Information

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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