Pulmonary Immune Cell-microbiome Interactions in the Healthy Lung (ILLUMINA-2)

Pulmonary Immune Cell-microbiome Interactions in the Healthy Lung: the ILLUMINA-2 Study

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.

Study Overview

• Status: Recruiting
• Conditions: Healthy
• Intervention / Treatment: Procedure: Bronchoalveolar lavage

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.

Afterwards a mini-BAL is performed in the upper and lower lobe of the right lung with a single installation of 20 ml isotonic saline in each lobe with immediately aspiration into a sterile container.

Measurements: The composition of the immune cell population, as well as the function and differentiation of various cell lines will be investigated by single-cell RNA sequencing (scRNA-seq) on selected immune cells from BALF, ETA, and blood, and this will be supplemented by bulk RNA sequencing with sample barcoding and multiplexing, giving a detailed expression pattern of all samples.

The composition microbiome in BALF, ETA, and oral swabs will be assessed by targeted amplicon sequencing of the hyper-variable regions 1 through 3 of the 16S subunit of ribosomal RNA gene for bacteria.

Statistical analyses: will be performed using R statistical software version 4.1.1 (R Project for Statistical Computing) within RStudio statistical software version 1.4.1717 (RStudio), and p<0.05 considered statistically significant. Inspection of normality and variance homogeneity will be done by creating qq-plots and histograms. The statistical inference tools SPIEC-EASI and HeatMaps will be used, and based on correlational analyses, principal component analyses, including non-hierarchal cluster analysis, will be applied to identify traits.

• Study Type: Observational
• Enrollment (Estimated): 50

Contacts and Locations

• Study Contact: Name: Ronni Plovsing, MD, PhD; Phone Number: +45386220721; Email: ronni.thermann.reitz.plovsing.01@regionh.dk
• Study Contact Backup: Name: Katrine Schneider, MD; Phone Number: +4528118147; Email: katrine.schneider@regionh.dk

Study Locations

• Denmark
  • Hvidovre, Denmark, 2650
    • Recruiting
    • Hvidovre Hospital, University of Copenhagen
    • Contact: Katrine Schneider, MD; Phone Number: +4521524590; Email: katrine.schneider@regionh.dk
    • Contact: Ronni Plovsing, MD, phD; Email: ronni.thermann.reitz.plovsing.01@regionh.dk

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult; Older Adult
• Accepts Healthy Volunteers: No

• Sampling Method: Non-Probability Sample

Study Population

Patients referred for elective surgery requiring intubation at Hvidovre Hospital

Description

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

Study Plan

How is the study designed?

Number of groups / cohorts

2

Cohorts and Interventions

Group / Cohort	Intervention / Treatment
Women	Procedure: Bronchoalveolar lavage; Bronchoalveolar lavage in the middle lobe of the right lung and a mini-bronchoalveolar lavage in the upper and lower lobe of the right lung
Men	Procedure: Bronchoalveolar lavage; Bronchoalveolar lavage in the middle lobe of the right lung and a mini-bronchoalveolar lavage in the upper and lower lobe of the right lung

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Lung microbiome	16S ribosomal RNA (rRNA) and 18S rRNA PCR for bacterial or fungal pathogen identification in bronchoalveolar lavage fluid	Day 0 (subsequent to study inclusion)
Lymphocyte populations	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	Day 0 (subsequent to study inclusion)

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Number and characterizations of microorganisms	Growth of pathogenic microorganisms in body fluids (e.g. urine, blood, bronchoalveolar lavage fluid) in microbiological assays	Up to 12 weeks
Cell differential counts and cytomorphological analyses of BALF		Day 0 (subsequent to study inclusion)
Trans-compartmental fluxes	(calculated from plasma- and urea-adjusted BAL)	Day 0 (subsequent to study inclusion)
White blood cells counts	Total white blood cells, neutrocytes, lymphocytes, and monocytes in bronchoalveolar lavage fluid and blood	Day 0 (subsequent to study inclusion)
Cytokines	Multiplex assay for measuring cytokines in bronchoalveolar lavage fluid and plasma (e.g. IL-1-beta, IL-1RA, IL-2, IL-6, IL-8, IL-10, IL-17, IL-18, IL-33, IL-35, TGF-beta, TNF-alpha, HMGB1)	Day 0 (subsequent to study inclusion)
Auto-antibodies against tI-IFNs in blood	Measured in bronchoalveolar lavage fluid	Day 0 (subsequent to study inclusion)
Number and characterizations of respiratory pathogens	Respiratory film array PCR for testing for number of pathogens	Day 0 (subsequent to study inclusion)

Collaborators and Investigators

• Sponsor: Hvidovre University Hospital
• Investigators: Study Chair: Ronan Berg, MD PhD, Biomedical Science of Health, University of Copenhagen

Study record dates

Study Major Dates

• Study Start (Actual): April 17, 2023
• Primary Completion (Estimated): November 30, 2028
• Study Completion (Estimated): November 30, 2028

Study Registration Dates

• First Submitted: April 27, 2023
• First Submitted That Met QC Criteria: April 27, 2023
• First Posted (Actual): May 6, 2023

Study Record Updates

• Last Update Posted (Actual): March 25, 2025
• Last Update Submitted That Met QC Criteria: March 13, 2025
• Last Verified: March 1, 2025

More Information

Terms related to this study

• Keywords: healthy lung, lung microbiota, microbiome
• Additional Relevant MeSH Terms: Molecular Mechanisms of Pharmacological Action; Chelating Agents; Sequestering Agents; Dimercaprol
• Other Study ID Numbers: H-22046545

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: UNDECIDED

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No
• product manufactured in and exported from the U.S.: No