Clinical Features and Airways Inflammation in Never Smokers and Smokers With COPD

Completed

• Conditions: COPD; Airway Obstruction; Inflammation
• Interventions: Diagnostic Test: Analysis of induced sputum; Diagnostic Test: Lung Function test; Diagnostic Test: Enzyme-linked Immunosorbent Assay

• Registration Number: NCT03274791
• Lead Sponsor: Ministry of Scientific Research, Tunisia

Brief Summary

The aim of this study was to investigate the airway inflammatory profile and the clinical presentation of chronic obstructive pulmonary disease (COPD) in never smokers compared to smokers with COPD.

Detailed Description

40 COPD patients (21 smokers and 19 never smokers) and 28 healthy never smokers were included in the present study. Information about respiratory symptoms and comorbidities were collected. Subjects underwent pulmonary function tests and COPD was defined according to Global Initiative for Chronic Obstructive lung Disease spirometric criteria. Induced sputum was collected to determine total and differential inflammatory cells counts as well as inflammatory mediators (Interleukin-8 (IL-8) and tumor necrosis factor-alpha (TNF-α)). The Mann-Whitney U and the χ2 tests were used for results comparisons. Correlations between symptoms, spirometric parameters, cytokines levels, inflammatory cells and risk factors of COPD were examined with Spearman's rank correlation test.

Study Timeline

• Study Start: 2013-09
• Primary Completion: 2016-08
• Study Completion: 2017-01
• Study First Submitted: 2017-08-24
• Status Verified: 2017-09
• Study First Submitted QC: 2017-09-06
• Last Update Submitted: 2017-09-06
• Study First Posted: 2017-09-07
• Last Update Posted: 2017-09-07

Recruitment & Eligibility

• Status: COMPLETED
• Sex: All
• Target Recruitment: 68

Inclusion Criteria

• Subjects with COPD, according to GOLD criteria (smokers and never smokers). Moreover, inhaled short-acting β2-agonists were stopped at least 8h before the test and inhaled long-acting β2-agonist were stopped at least 48h before the test.
• Healthy control subjects : never smokers with normal spirometry and did not have a history of lung disease or chronic respiratory symptoms.

Exclusion Criteria

• COPD patients were excluded from the study if they had an exacerbation, a respiratory tract infection or if they used a systemic form of corticosteroid preparation (oral or intravenous injection therapy) or antibiotics within the two months prior to the study entry. Patients with other respiratory disorder like pneumonia, pulmonary emboli, congestive heart failure, lung cancer or tuberculosis were also excluded.

Study & Design

• Study Type: OBSERVATIONAL
• Study Design: Not specified

Arm && Interventions

Group	Intervention	Description
Healthy subjects	Lung Function test	Healthy non-smoking subjects were never smokers with normal spirometry and did not have a history of lung disease or chronic respiratory symptoms. Information about respiratory symptoms and comorbidities were collected. Healthy subjects underwent pulmonary function tests (Spirometry). Induced sputum was collected to determine total and differential inflammatory cells counts as well as inflammatory mediators (Interleukin-8 and tumor necrosis factor-alpha).
COPD Smokers	Enzyme-linked Immunosorbent Assay	Smokers were defined as persons who had smoked \> 20 packs of cigarettes in a lifetime and who continue smoking every day. Airflow limitation in COPD was defined as a post-bronchodilator forced expiratory volume in 1 second (FEV1) to forced vital capacity (FVC) ratio \<70% and FEV1 reversibility of \<12% and 200 mL from baseline values after inhalation of 400 µg of Salbutamol. Information about respiratory symptoms and comorbidities were collected. Smoking subjects with COPD underwent pulmonary function tests (Spirometry). Induced sputum was collected to determine total and differential inflammatory cells counts as well as inflammatory mediators (Interleukin-8 and tumor necrosis factor-alpha).
Healthy subjects	Enzyme-linked Immunosorbent Assay	Healthy non-smoking subjects were never smokers with normal spirometry and did not have a history of lung disease or chronic respiratory symptoms. Information about respiratory symptoms and comorbidities were collected. Healthy subjects underwent pulmonary function tests (Spirometry). Induced sputum was collected to determine total and differential inflammatory cells counts as well as inflammatory mediators (Interleukin-8 and tumor necrosis factor-alpha).
COPD Never smokers	Enzyme-linked Immunosorbent Assay	Never smokers referred to subjects who had never smoked Airflow limitation in COPD was defined as a post-bronchodilator forced expiratory volume in 1 second (FEV1) to forced vital capacity (FVC) ratio \<70% and FEV1 reversibility of \<12% and 200 mL from baseline values after inhalation of 400 µg of Salbutamol. Information about respiratory symptoms and comorbidities were collected. Never smoking subjects with COPD underwent pulmonary function tests (Spirometry). Induced sputum was collected to determine total and differential inflammatory cells counts as well as inflammatory mediators (Interleukin-8 and tumor necrosis factor-alpha).
COPD Smokers	Lung Function test	Smokers were defined as persons who had smoked \> 20 packs of cigarettes in a lifetime and who continue smoking every day. Airflow limitation in COPD was defined as a post-bronchodilator forced expiratory volume in 1 second (FEV1) to forced vital capacity (FVC) ratio \<70% and FEV1 reversibility of \<12% and 200 mL from baseline values after inhalation of 400 µg of Salbutamol. Information about respiratory symptoms and comorbidities were collected. Smoking subjects with COPD underwent pulmonary function tests (Spirometry). Induced sputum was collected to determine total and differential inflammatory cells counts as well as inflammatory mediators (Interleukin-8 and tumor necrosis factor-alpha).
Healthy subjects	Analysis of induced sputum	Healthy non-smoking subjects were never smokers with normal spirometry and did not have a history of lung disease or chronic respiratory symptoms. Information about respiratory symptoms and comorbidities were collected. Healthy subjects underwent pulmonary function tests (Spirometry). Induced sputum was collected to determine total and differential inflammatory cells counts as well as inflammatory mediators (Interleukin-8 and tumor necrosis factor-alpha).
COPD Never smokers	Analysis of induced sputum	Never smokers referred to subjects who had never smoked Airflow limitation in COPD was defined as a post-bronchodilator forced expiratory volume in 1 second (FEV1) to forced vital capacity (FVC) ratio \<70% and FEV1 reversibility of \<12% and 200 mL from baseline values after inhalation of 400 µg of Salbutamol. Information about respiratory symptoms and comorbidities were collected. Never smoking subjects with COPD underwent pulmonary function tests (Spirometry). Induced sputum was collected to determine total and differential inflammatory cells counts as well as inflammatory mediators (Interleukin-8 and tumor necrosis factor-alpha).
COPD Never smokers	Lung Function test	Never smokers referred to subjects who had never smoked Airflow limitation in COPD was defined as a post-bronchodilator forced expiratory volume in 1 second (FEV1) to forced vital capacity (FVC) ratio \<70% and FEV1 reversibility of \<12% and 200 mL from baseline values after inhalation of 400 µg of Salbutamol. Information about respiratory symptoms and comorbidities were collected. Never smoking subjects with COPD underwent pulmonary function tests (Spirometry). Induced sputum was collected to determine total and differential inflammatory cells counts as well as inflammatory mediators (Interleukin-8 and tumor necrosis factor-alpha).
COPD Smokers	Analysis of induced sputum	Smokers were defined as persons who had smoked \> 20 packs of cigarettes in a lifetime and who continue smoking every day. Airflow limitation in COPD was defined as a post-bronchodilator forced expiratory volume in 1 second (FEV1) to forced vital capacity (FVC) ratio \<70% and FEV1 reversibility of \<12% and 200 mL from baseline values after inhalation of 400 µg of Salbutamol. Information about respiratory symptoms and comorbidities were collected. Smoking subjects with COPD underwent pulmonary function tests (Spirometry). Induced sputum was collected to determine total and differential inflammatory cells counts as well as inflammatory mediators (Interleukin-8 and tumor necrosis factor-alpha).

Primary Outcome Measures

Name	Time	Method
Sputum induction and collection	6 months	Sputum induction was conducted by inhalation of nebulised sterile hypertonic saline solution followed by coughing and expectoration of airway secretions. For nebulisation, an ultrasound nebulizer was used for 5-20 min to provide an adequate amount of sample. The subject is asked to cough and expectorate at 5 min intervals.
Forced expiratory volume in one second (FEV1)	6 months	FEV1 was measured using a portable spirometer (Easy One ndd. Medizintechnik; Zurich, Switzerland) according to the American Thoracic Society criteria.
Weight measurement	6 months	Weight was measured in kilograms for all the participants.
Forced vital capacity (FVC)	6 months	FVC was measured using a portable spirometer (Easy One ndd. Medizintechnik; Zurich, Switzerland) according to the American Thoracic Society criteria.
Height measurement	6 months	Height was measured in meters for all the participants.

Secondary Outcome Measures

Name	Time	Method
Tiffeneau ratio (FEV1/FVC)	6 months	The calculation of FEV1/FVC allows the identification of obstructive ventilatory defect. A FEV1/FVC \< 70 % where FEV1 is reduced more than FVC signifies an obstructive defect.
BMI determination	6 months	Weight and height values were combined to report BMI in kg/m2
Sputum supernatant analyses	3 months	IL-8 and TNF-α sputum supernatant concentrations were measured in the sputum supernatant of the three studied groups using ELISA test.
Sputum cell counts	1 month	Four hundred non-squamous cells were counted by two technicians and the mean of the two scores was expressed as percentage of the total cell count. Sputum samples containing \>20% of squamous cells and/or with cell viability \<70% were excluded from analysis.