SAW Lung Microbiome Study in Smokers and Never-smokers

Research Center Borstel

Status: Completed

Conditions: Healthy; Microbial Colonization; Chronic Obstructive Pulmonary Disease (COPD); Smoking Cessation

Treatments: Behavioral: Smoking cessation

Study type: Interventional

Funder types: Other

Identifiers

NCT03562442

SAW Lungenmikrobiom-Studie

Details and patient eligibility

About

The trial aims to analyse changes in the microbiome of the lower airways after smoking cessation. Microbiome analyses (upper airway swabs, bronchoalveolar lavage, transbronchial brushing) are conducted in smokers before and 6 weeks after smoking cessation. Never smokers serve as a control group and undergo the same sampling procedures once.

Full description

The trial aims to analyze changes in the microbiome of the lower airways after smoking cessation. Microbiome analyses (upper airway swabs, bronchoalveolar lavage, transbronchial brushing) are conducted in healthy (and willing to quit) smokers before and 6 weeks after smoking cessation. Never smokers serve as a control group and undergo the same sampling procedures once.

Demographic and clinical data of the study subjects are obtained, aiming for homogeneous groups. All personal data are encrypted according to the standard operating procedures of the study site. Pharyngeal and deep nasal swabs are taken.

To avoid contamination of the lower airways from the oropharynx through the bronchoscope, standardized procedures are established according to the German guidelines for bronchoscopy. Before bronchoscopy, the endoscope is flushed with sterile saline which is analyzed for 16S ribosomal RNA (rRNA) to control for residual contaminating bacterial desoxyribonucleic acid (DNA). A 300ml bronchoalveolar lavage with warm normal saline solution is taken from the middle lobe. Three covered and "microbiologically protected" bronchial brushings are obtained from the right upper lobe. This sterile brush is sealed in wax and pushed through the wax just before taking the brushing. All samples are immediately frozen and stored at -80°C until further analyses. For cultivations, samples are kept at 4°C and rapidly processed.

Enrollment: 60 patients

Sex: All

Ages: 18+ years old

Volunteers: Accepts Healthy Volunteers

Inclusion criteria

• Cigarette consumption of at least five cigarettes per day
• Caucasian ethnicity

Exclusion criteria

• Continous passive smoking exposure
• Systemic steroid therapy during the previous month
• Chronic lung disease (exception COPD stage Global Initiative on Lung Disease (GOLD) 0/I/II)
• Diabetes mellitus
• Pregnancy or breast feeding
• active tuberculosis (currently or previously)
• respiratory infection in the previous month
• antibiotic therapy in the previous two months
• immunosuppression
• malignancy
• interstitial lung disease
• rheumatic disease with lung manifestation
• member of a collaborative group of the project

Trial design

Primary purpose: Basic Science

Allocation: Non-Randomized

Interventional model: Parallel Assignment

Masking: None (Open label)

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60 participants in 2 patient groups

Smokers

Experimental group

Description:

Healthy caucasian smokers who are willing to quit smoking are investigated before cessation (Visit 1) and 6 weeks after cessation (Visit 2). Intervention: Smoking cessation

Treatment:

Behavioral: Smoking cessation

Never-Smokers

No Intervention group

Description:

Healthy caucasian volunteers who never smoked are investigated once only (Visit 1)