Site and Mechanism(s) of Expiratory Airflow Limitation in COPD, Emphysema and Asthma-COPD Overlap

Overview

The purpose of this cross-sectional, observational study is to evaluate the site and mechanism(s) for expiratory airflow limitation in chronic, treated, current or former smokers (\>15 pack years) with COPD, Emphysema, and Asthma-COPD Overlap with mild to severe expiratory airflow limitation. Treatment may include short and long acting inhaled beta2agonists, short and long acting inhaled muscarinic receptor antagonists, inhaled and or oral corticosteroid, oral antibiotic, supplemental oxygen, and PDE type 4 inhibitor. In some cases, the patient may have had a history of asthma preceding the development of COPD (Asthma COPD Overlap).

Detailed description

The investigators are interested in determining the predominant site of expiratory airflow limitation including large central airways vs small peripheral airways/alveoli. In mild to moderate obstructive airways disease and emphysema, I believe routine spirometry including FEV 1(L), FVC (L), and FEV 1/FVC % may be normal, despite expiratory airflow limitation in lung peripheral airways. I also want to determine whether the mechanism(s) of expiratory airflow limitation are related to measured loss of lung elastic recoil or intrinsic obstruction of small peripheral airways or both. It is also important to determine the extent and distribution of emphysema using high resolution, thin section lung CT with voxel quantification. If available pathological analysis of lung surgical specimens and also formalin inflated lungs obtained at autopsy will also be studied. Blood studies will include but not limited to CBC, serum IgE, complete metabolic panel, and alpha 1 antitrypsin levels. Extensive lung function testing will also include spirometry tests before and after inhaled albuterol bronchodilation, lung volumes measured in a plethysmograph, diffusing capacity, measurement of lung elasticity that requires placement of an esophageal balloon, measurement of airflow after breathing a mixture of 80% helium-20%oxygen for 7-10 minutes, and measurements of exhaled nitric oxide. CAT scans of the lungs will be obtained to evaluate the presence, extent and distribution of emphysema and bronchiectasis. In some cases, bronchoscopy may be requested.

The above tests may be uncomfortable but should cause no harm.

Interventions

• Other As above: diagnosis: COPD, Emphysema, Asthma-COPD Overlap

Primary outcome measures

• Site and Mechanism(s) of Expiratory Airflow Limitation [Time frame: 4 years]

Eligibility criteria

Inclusion criteria

• asthma- copd overlap
• emphysema in smokers with smoking history > 15 pack years
• COPD/ bronchitis and bronchiectasis in smokers with smoking history
• >15 pack years

Exclusion Criteria:other pulmonary or systemic diagnosis

• non smokers
• any other pulmonary diagnosis
• pulmonary fibrosis

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

Healthy volunteers: Yes

Study design

Observational model

Case-only

Study locations

United States · 2 centers

• Arthur F Gelb MD — Lakewood
• Arthur F Gelb MD — Lakewood

Publications

• Qaseem A, Wilt TJ, Weinberger SE, Hanania NA, Criner G, van der Molen T, Marciniuk DD, Denberg T, Schunemann H, Wedzicha W, MacDonald R, Shekelle P; American College of Physicians; American College of Chest Physicians; American Thoracic Society; European Respiratory Society. Diagnosis and management of stable chronic obstructive pulmonary disease: a clinical practice guideline update from the Amer PMID 21810710
• Alcaide AB, Sanchez-Salcedo P, Bastarrika G, Campo A, Berto J, Ocon MD, Fernandez-Montero A, Celli BR, Zulueta JJ, de-Torres JP. Clinical Features of Smokers With Radiological Emphysema But Without Airway Limitation. Chest. 2017 Feb;151(2):358-365. doi: 10.1016/j.chest.2016.10.044. Epub 2016 Nov 3. PMID 27818328
• Mannino DM, Make BJ. Is it time to move beyond the "O" in early COPD? Eur Respir J. 2015 Dec;46(6):1535-7. doi: 10.1183/13993003.01436-2015. No abstract available. PMID 26621878
• Rennard SI, Drummond MB. Early chronic obstructive pulmonary disease: definition, assessment, and prevention. Lancet. 2015 May 2;385(9979):1778-1788. doi: 10.1016/S0140-6736(15)60647-X. PMID 25943942
• Harvey BG, Strulovici-Barel Y, Kaner RJ, Sanders A, Vincent TL, Mezey JG, Crystal RG. Risk of COPD with obstruction in active smokers with normal spirometry and reduced diffusion capacity. Eur Respir J. 2015 Dec;46(6):1589-1597. doi: 10.1183/13993003.02377-2014. Epub 2015 Nov 5. PMID 26541521
• Johns DP, Walters JA, Walters EH. Diagnosis and early detection of COPD using spirometry. J Thorac Dis. 2014 Nov;6(11):1557-69. doi: 10.3978/j.issn.2072-1439.2014.08.18. PMID 25478197
• Woodruff PG, Barr RG, Bleecker E, Christenson SA, Couper D, Curtis JL, Gouskova NA, Hansel NN, Hoffman EA, Kanner RE, Kleerup E, Lazarus SC, Martinez FJ, Paine R 3rd, Rennard S, Tashkin DP, Han MK; SPIROMICS Research Group. Clinical Significance of Symptoms in Smokers with Preserved Pulmonary Function. N Engl J Med. 2016 May 12;374(19):1811-21. doi: 10.1056/NEJMoa1505971. PMID 27168432
• Rodriguez-Roisin R, Han MK, Vestbo J, Wedzicha JA, Woodruff PG, Martinez FJ. Chronic Respiratory Symptoms with Normal Spirometry. A Reliable Clinical Entity? Am J Respir Crit Care Med. 2017 Jan 1;195(1):17-22. doi: 10.1164/rccm.201607-1376PP. No abstract available. PMID 27598473

Identifiers

NCT: NCT03263130 · 1234567

Primary sources (government registries)

• ClinicalTrials.gov (US NIH)

View this study on ClinicalTrials.gov ↗