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

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

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Key information

Conditions

Ventilator-associated Pneumonia Cross Infection Disease Attributes Healthcare-Associated Pneumonia Iatrogenic Disease Infections Lung Diseases Pathologic Processes Pathological Conditions, Signs and Symptoms Pneumonia Pneumonia, Ventilator-Associated Respiratory Tract Diseases Respiratory Tract Infections

Age range

18 year and older

Sex eligibility

All sexes

Study type

Observational

About this study

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.

Who can participate

Healthy volunteers accepted: No

Only the study team can determine whether someone qualifies for participation.

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).

Treatment and study plan

Primary outcomes

Qualitative description of B lymphocyte populations by flow cytometry analysis with specific antibodies

Time frame: 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 outcomes

Quantitative description of B lymphocyte populations by flow cytometry analysis with specific antibodies

Time frame: 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

Study contacts

Contact information is provided by the study sponsor or research team.

Abdeslam BEN TALEB

CONTACT

[email protected]

+33555058616

Safirah Akowanou

CONTACT

[email protected]

+33555058755

Sponsors and collaborators

Lead sponsor

University Hospital, Limoges

Other

Registry information

Official study title

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

Acronym: OLYMPE

Important dates

Study start: 2026
Primary completion: 2027
Study completion: 2027
First posted: Feb 27, 2026
Registry last updated: Feb 27, 2026

OpenTrials presents study information sourced from ClinicalTrials.gov. The official registry record should be consulted for the latest information.

View the official ClinicalTrials.gov record (opens in a new tab)

This listing is for discovery and informational purposes only. It is not medical advice, does not guarantee that a study is recruiting, and does not determine eligibility. Contact the study team and a qualified healthcare professional when considering participation.

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