Mechanism(s) of Airflow Limitation During Exacerbation of Asthma

Official title

Evaluation of Mechanism(s)Limiting Expiratory Airflow in Chronic, Stable Asthmatics Who Are Non-smokers

Overview

The purpose of this study is to evaluate the site and mechanisms responsible for expiratory airflow limitation in chronic, treated, non-smoking, stable asthmatics with moderate to severe persistent expiratory airflow obstruction. Treatment will include inhaled corticosteroids and long acting beta2agonists. The investigators are interested in determining whether the large and/or small airways are the predominant site of airflow limitation. The investigators are also interested in determining whether intrinsic small airways obstruction and/or loss of lung elastic recoil is responsible for expiratory airflow limitation. The investigators are also interested to evaluate the role of varying doses of inhaled corticosteroids to suppress large and small airway inflammation using exhaled nitric oxide as surrogate markers of inflammation. For comparison purposes, spirometry and measurements of exhaled nitric oxide will also be obtained if possible during a naturally occurring exacerbation of asthma.

Detailed description

In addition we will also obtain above studies in asthmatics during naturally occuring exacerbation of asthma and following treatment. If available, results of lung function studies including measurements of lung elastic recoil will be compared to pathologic analyses of formalin fixed, air inflated lungs obtained at autopsy in asthmatics who die from asthma related or non-asthma related death. This kind of lung structure-function study will provide potential mechanism(s) to explain the loss of lung elastic recoil in acute and chronic asthmatics who are non-smokers. We will also obtain voxel quantification of high resolution thin section CT of lung obtained without IV contrast. Also, we will use fiberoptic bronchoscopy to obtain optical coherence tomography in stable asthmatics with mild to moderate to severe expiratory airflow limitation to assess integrity of the lung parenchyma.

Interventions

• Drug fluticasone/salmeterol in all asthmatics
  budesonide 80ug/formoterol 4.5ug, 2 inhalations bid X 20-60 days or fluticasone 100ug/salmeterol 50ug, 1 inhalation bid X 20-60 days
• Drug budesonide/formoterol or fluticasone/salmeterol in all asthmatics
  budesonide 160ug/formoterol 4.5ug, 2 inhalations bid or fluticasone 250ug/salmeterol 50ug, 1 inhalations bid

Primary outcome measures

• Exhaled nitric oxide [Time frame: 20-60 days]

Secondary outcome measures (2)

• Mechanism(s) of expiratory airflow limitation [Time frame: 1 to 5 years]
• Presence of unsuspected emphysema by autopsy or explanted lung [Time frame: 1-5 years]

Eligibility criteria

Inclusion criteria

• Current non-smoking (<10 pack yr smoking history)
• Stable, treated asthmatics
• Age 10-80 yr
• post 180ug albuterol by MDI: FEV 1/FVC < 70% and FEV 1 <80% predicted

Exclusion criteria

• Pregnancy

Criteria are shown verbatim from the registry (in English). Final eligibility is always assessed by the study center.

Healthy volunteers: No

Study design

Allocation

N/A

Model

Single group

Masking

Open label

Primary purpose

Basic science

Study locations

United States · 1 center

• Arthur F Gelb Medical Corporation — Lakewood

Publications

• Gelb AF, Zamel N. Unsuspected pseudophysiologic emphysema in chronic persistent asthma. Am J Respir Crit Care Med. 2000 Nov;162(5):1778-82. doi: 10.1164/ajrccm.162.5.2001037. PMID 11069812
• Gelb AF, Licuanan J, Shinar CM, Zamel N. Unsuspected loss of lung elastic recoil in chronic persistent asthma. Chest. 2002 Mar;121(3):715-21. doi: 10.1378/chest.121.3.715. PMID 11888951
• Gelb AF, Gutierrez CA, Weisman IM, Newsom R, Taylor CF, Zamel N. Simplified detection of dynamic hyperinflation. Chest. 2004 Dec;126(6):1855-60. doi: 10.1378/chest.126.6.1855. PMID 15596684
• Gelb AF, Flynn Taylor C, Shinar CM, Gutierrez C, Zamel N. Role of spirometry and exhaled nitric oxide to predict exacerbations in treated asthmatics. Chest. 2006 Jun;129(6):1492-9. doi: 10.1378/chest.129.6.1492. PMID 16778266
• Gelb AF, Taylor CF, Nussbaum E, Gutierrez C, Schein A, Shinar CM, Schein MJ, Epstein JD, Zamel N. Alveolar and airway sites of nitric oxide inflammation in treated asthma. Am J Respir Crit Care Med. 2004 Oct 1;170(7):737-41. doi: 10.1164/rccm.200403-408OC. Epub 2004 Jun 30. PMID 15229098
• Gelb AF, Zamel N, Krishnan A. Physiologic similarities and differences between asthma and chronic obstructive pulmonary disease. Curr Opin Pulm Med. 2008 Jan;14(1):24-30. doi: 10.1097/MCP.0b013e3282f197df. PMID 18043272
• Gelb AF, Yamamoto A, Verbeken EK, Schein MJ, Moridzadeh R, Tran D, Fraser C, Barbers R, Elatre W, Koss MN, Glassy EF, Nadel JA. Further Studies of Unsuspected Emphysema in Nonsmoking Patients With Asthma With Persistent Expiratory Airflow Obstruction. Chest. 2018 Mar;153(3):618-629. doi: 10.1016/j.chest.2017.11.016. Epub 2017 Nov 29. PMID 29197547
• Gelb AF, Moridzadeh R, Singh DH, Fraser C, George SC. In moderate-to-severe asthma patients monitoring exhaled nitric oxide during exacerbation is not a good predictor of spirometric response to oral corticosteroid. J Allergy Clin Immunol. 2012 Jun;129(6):1491-8. doi: 10.1016/j.jaci.2012.03.036. Epub 2012 May 2. PMID 22560478

Identifiers

NCT: NCT01225913 · 20070934A

Primary sources (government registries)

• ClinicalTrials.gov (US NIH)

View this study on ClinicalTrials.gov ↗