B Lymphocyte Populations in the Pulmonary Microenvironment of Patients Under Mechanical Ventilation With or Without VAP (Ventilator-Associated Pneumonia)

Pilot Study Describing B Lymphocyte Populations in the Pulmonary Microenvironment of Patients Under Mechanical Ventilation With or Without VAP (Ventilator-Associated Pneumonia)

Status

Not yet recruiting

Phases

Unknown

Study type

Observational

Source

ClinicalTrials.gov

Registry ID

NCT07436780

Acronym

OLYMPE

Enrollment

Registered

2026-02-27

Start date

2026-01-31

Completion date

2027-07-30

Last updated

2026-02-27

For informational purposes only — not medical advice. Sourced from public registries and may not reflect the latest updates. Terms

Conditions

Ventilator-associated Pneumonia

Keywords

ventilator-associated pneumonia, Intensive care medicine, host-pathogen interaction, humoral immunity

Brief summary

Diagnosis of VAP relies on a set of non-specific clinical, biological, and imaging criteria. Understanding host-pathogen interactions and the mechanisms of deregulations leading to infection of pulmonary tissue appears essential. The aim is to qualitatively describe the B lymphocyte populations present in the pulmonary microenvironment of patients admitted to intensive care and requiring invasive mechanical ventilation

Detailed description

The study of the immune system and host-pathogen interactions is the subject of extensive research to improve the understanding of pathophysiology, leading to more precise diagnostic criteria, and considering preventive or curative treatments while limiting the use of anti-infective molecules. Understanding host-pathogen interactions and the mechanisms of deregulations leading to infection of pulmonary tissue seems essential. The study of T lymphocyte populations has already been the focus of numerous investigations. However, regarding the humoral immune response, B lymphocyte populations and their roles have so far been little explored in this context. Nevertheless, the presence of B lymphocytes in pulmonary tissue has been proven, particularly in infectious, postinfectious, or postvaccination contexts, but currently, there are no published studies regarding the B lymphocytes role in the pathophysiology of VAP (Ventilator-Associated Pneumonia). Respiratory samples (endotracheal aspirates) will be collected from patients under mechanical ventilation on the day of intubation (D0), the day before extubation (Dext), and the day of VAP diagnosis (DVAP) for patients who will develop it. The samples will be stored and then analyzed by flow cytometry.

Interventions

None listed

Study design

Observational model

OTHER

Time perspective

PROSPECTIVE

Eligibility

Sex/Gender

ALL

Age

18 Years to No maximum

Healthy volunteers

Inclusion criteria

* Adult patients (≥18 years old), admitted to intensive care under mechanical ventilation for an estimated duration of at least 5 days.

Exclusion criteria

* Patients admitted for an infectious pneumonia or presenting with acute respiratory distress syndrome (ARDS). Patients in aplasia (leukocytes \< 0.5 gigal/L).

Design outcomes

Primary

Measure	Time frame	Description
Qualitative description of B lymphocyte populations by flow cytometry analysis with specific antibodies	At the inclusion (T1), at diagnosis (T2 on the day of VAP diagnosis for patient who will develop it, on average 72 hours after the inclusion), at the end of the study (T3 on the day before extubation, on average 5 days after the inclusion)	To qualitatively describe the B lymphocyte populations in the endotracheal aspirates of patients admitted to intensive care and requiring invasive mechanical ventilation. B lymphocyte subpopulations will be described using a flow cytometry method using antibodies targeting the following markers: CD93, CD62L, CD14, CXCR4, CD32, CD27, CD38, CD138, CD3, CD10, CD19, CD20, kappa light chains, lambda light chains.

Secondary

Measure	Time frame	Description
Quantitative description of B lymphocyte populations by flow cytometry analysis with specific antibodies	At the inclusion (T1), at diagnosis (T2 on the day of VAP diagnosis for patient who will develop it, on average 72 hours after the inclusion), at the end of the study (T3 on the day before extubation, on average 5 days after the inclusion)	To quantitatively describe the B lymphocyte populations in the endotracheal aspirates of patients admitted to intensive care, requiring invasive mechanical ventilation, and presenting ventilator associated pneumonia (VAP). B lymphocyte subpopulations will be described using a flow cytometry method using antibodies targeting the following markers: CD93, CD62L, CD14, CXCR4, CD32, CD27, CD38, CD138, CD3, CD10, CD19, CD20, kappa light chains, lambda light chains

Contacts

CONTACTSafirah Akowanou

safirah.akowanou@chu-limoges.fr+33555058755

CONTACTAbdeslam BEN TALEB

abdeslam.bentaleb@chu-limoges.fr+33555058616

PRINCIPAL_INVESTIGATORJulien VAIDIE, Dr

University Hospital, Limoges

Outcome results