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

February 23, 2026 updated by: University Hospital, Limoges

Pilot Study Describing 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

Study Overview

Status

Not yet recruiting

Conditions

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.

Study Type

Observational

Enrollment (Estimated)

75

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Contact

Study Contact Backup

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

  • Adult
  • Older Adult

Accepts Healthy Volunteers

No

Sampling Method

Non-Probability Sample

Study Population

Patients of Limoges University Hospital admitted to emergency room

Description

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).

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

Cohorts and Interventions

Group / Cohort
Ventilator Associated Pneumonia (VAP)
Patient who developped Ventilator Associated Pneumonia (VAP) under mechanical ventilation
Without Ventilator Associated Pneumonia
Patient who did not develop Ventilator Associated Pneumonia (VAP) under mechanical ventilation

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
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.
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)

Secondary Outcome Measures

Outcome Measure
Measure Description
Time Frame
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
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)

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

University Hospital, Limoges

Investigators

  • Principal Investigator: Julien VAIDIE, Dr, University Hospital, Limoges

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Estimated)

January 31, 2026

Primary Completion (Estimated)

July 30, 2027

Study Completion (Estimated)

July 30, 2027

Study Registration Dates

First Submitted

December 12, 2025

First Submitted That Met QC Criteria

February 23, 2026

First Posted (Actual)

February 27, 2026

Study Record Updates

Last Update Posted (Actual)

February 27, 2026

Last Update Submitted That Met QC Criteria

February 23, 2026

Last Verified

February 1, 2026

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

  • 87RI25_0020 (OLYMPE)

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

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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