Changes in Alveolar Macrophage Function During Acute Lung Injury

Study Overview
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Brief Summary
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In this study, the investigators aim to observe the change in alveolar macrophage function during acute lung injury.

Detailed Description
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Alveolar macrophages are tissue-resident or recruited cells with key functions in recognition of pathogens, initiation of host defensive ang protective inflammation,and in clearance of pathogens from the airways. However, macrophages are also responsible for efficient clearance of apoptotic neutrophils, termed efferocytosis, which is a prerequisite for the timely resolution of inflammation. In this study, the investigators aim to observe the change in alveolar macrophage function during acute lung injury.

Official Title
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Changes in Alveolar Macrophage Function During Acute Lung Injury

Conditions
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Acute Lung Injury

Intervention / Treatment
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* Procedure: Bronchoscopy


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Patients in ICU with diagnosed ALI under mechanical ventilation Exclusion Criteria: Patients with cardiac dysfunction, using steroid drugs or other drugs can that affect efferocytosis

Ages Eligible for Study
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Minimum Age: 18 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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Accepts Healthy Volunteers

Study Plan
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How is the study designed?
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Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| acute lung injury<br>Patients with a diagnosis of acute lung injury (ALI) under mechanical ventilation.Patients will underwent bronchoscopy for bronchoalveolar lavage fluid. | Procedure: Bronchoscopy<br>* Bronchoscopy will be implemented under sedation in both groups.<br>|
| control<br>Patient under mechanical ventilation without any lung diseases. Patients will underwent bronchoscopy for bronchoalveolar lavage fluid. | Procedure: Bronchoscopy<br>* Bronchoscopy will be implemented under sedation in both groups.<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| alveolar macrophages (AMs) phagocytic index | AMs will be collected and cultured in vitro. Apoptotic neutrophils will then be cocultured with AMs for 1 hour. To measure phagocytosis of apoptotic neutrophils, AMs were further processed and phagocytosed apoptotic neutrophils were detected by confocal fluorescence microscopy as described below under Cell staining and confocal microscopy. The phagocytic index was calculated according to the following formula: phagocytic index = (total number of engulfed cells/total number of counted macrophages) × (number of macrophages containing engulfed cells/total number of counted macrophages) × 100. | 7 days after admission | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| 30 days mortality |  | 30 days after admission | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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efferocytosis, macrophage