Pulmonary Immune Cell-microbiome Interactions in the Healthy Lung: the ILLUMINA-2 Study
Trial Snapshot
- Phase
- Not Applicable
- Status
- Recruiting
- Sponsor
- Hvidovre University Hospital
- Enrollment
- 50
- Locations
- 1
- Primary Endpoint
- Lung microbiome
Study Overview
Brief Summary
The overall aim is to to provide a normal material for the composition and spatial heterogeneity of the following in the healthy lung: i) immune cell populations and their activation patterns, ii) the surrounding cytokine-chemokine milieu, including trans-compartmental fluxes of these mediators between the lung and bloodstream, and iii) the lung microbiome.
Main hypotheses:
- Absolute and relative immune cell counts in bronchoalveolar lavage fluid (BALF) are similar to those previously reported by other methods6,7.
- No trans-compartmental flux of cytokines between the lungs and bloodstream is present, but cytokine concentrations (notably IL-6 and IL-8) vary with the immune-cell-microbiome composition.
- Immune cell (mainly T cell) activation, differentiation, and gene expression patterns are expected to differ between blood and BALF in a manner that depends on the regional diversity of the pulmonary microbiome.
Detailed Description
The coronavirus disease 2019 pandemic, caused by severe acute respiratory syndrome coronavirus 2, has brought with it several studies on the local pulmonary immune system, which was until very recently largely a terra incognita. With these new methods, apparently fundamental aspects of lung disease have been uncovered, including pulmonary hyper inflammation. However, very little is currently known about the composition of the normal immune cell population in the human lung, including its interplay with the pulmonary microbiome, that is, the commensal microbiota of interacting bacteria and fungi that reside within the healthy lung
Overall design: In 50 patients (25 males, 25 females), intubated for elective surgery in general anaesthesia, an endotracheal aspirate and BAL fluid (BALF) from separate lung segments will be obtained. Furthermore, an oral and nasal swab and blood samples will be collected. This will be done immediately after intubation.
The following is obtained from the patient's electronic health record: diagnosis codes and medication (type and dosage), smoking history (current/previous/never smoker; pack years), type of operation; furthermore, the health record is screened for any exclusion criteria
Blood samples are drawn from the patient's peripheral venous catheter (inserted for clinical purposes) immediately before BALF collection.
Bronchoscopy with BALF collection: This procedure is performed in a standardized fashion according to current clinical guidelines. Immediately prior to the procedure, an oral swab, nasal swab and an endotracheal aspirate (ETA) are obtained. FIO2 is then increased to 1.0, and the bronchoscopy procedure is performed using a disposable videoscope with an outer diameter of 5.0 mm). Three successive 50-ml aliquots of prewarmed (37°C) isotonic saline are instilled in the medial segment of the right middle lobe, aspirated immediately with low negative suction pressure (< 100 cm H2O), and pooled into a sterile glass container on ice to obtain a BALF specimen.
Study Design
- Study Type
- Observational
- Observational Model
- Case Only
- Time Perspective
- Prospective
Eligibility Criteria
- Ages
- 40 Years to 75 Years (Adult, Older Adult)
- Sex
- All
- Accepts Healthy Volunteers
- No
Inclusion Criteria
- •Men and women
- •Age 40 to 75
Exclusion Criteria
- •Immune deficiency
- •Lung disease
- •Active cancer or infection
- •Absolute contraindications for bronchoscopy
- •Untreated malignant arrhythmia
- •Documented or suspected intracranial hypertension (intracranial pressure ≥ > 15 mmHg)
- •One-lung ventilation
- •Severe coagulopathy
Outcomes
Primary Outcomes
Lung microbiome
Time Frame: Day 0 (subsequent to study inclusion)
16S ribosomal RNA (rRNA) and 18S rRNA PCR for bacterial or fungal pathogen identification in bronchoalveolar lavage fluid
Lymphocyte populations
Time Frame: Day 0 (subsequent to study inclusion)
Cell populations and subpopulations evaluated by 10 colored flow cytometry (B cells, T cells, TCR subsets, Tregs/Th17, dendritic cells, myeloid cells and neutrophils) in bronchoalveolar lavage fluid and blood
Secondary Outcomes
- Auto-antibodies against tI-IFNs in blood(Day 0 (subsequent to study inclusion))
- Cell differential counts and cytomorphological analyses of BALF(Day 0 (subsequent to study inclusion))
- Trans-compartmental fluxes(Day 0 (subsequent to study inclusion))
- Cytokines(Day 0 (subsequent to study inclusion))
- White blood cells counts(Day 0 (subsequent to study inclusion))
- Number and characterizations of microorganisms(Up to 12 weeks)
- Number and characterizations of respiratory pathogens(Day 0 (subsequent to study inclusion))
Investigators
Ronni R. Plovsing
Associate professor, Senior Consultant of ICU
Hvidovre University Hospital