Immune Alveolar Alterations During Pneumonia-Associated Acute Respiratory Distress Syndrome
Immune Alveolar Alterations During Pneumonia-Associated Acute Respiratory Distress Syndrome
Sepsis is a dysregulated host response to severe life-threatening infections, leading to
 organ failure and death in up to 40% of patients with septic shock. Pulmonary infections are
 the main cause of community-acquired sepsis and frequently lead to the development of acute
 respiratory distress syndrome(ARDS). Features of immunosuppression, including diminished cell
 surface monocyte human leukocyte antigen DR (mHLA-DR) expression, are strongly associated
 with hospital mortality. Such decrease in HLA-DR expression on antigen-presenting cells has
 been associated with impairment of microbial antigens to Tcells. Septic patients also show
 elevated expression of inhibitory receptors associated with cell exhaustion.. Yet,
 biochemical, flow cytometric and immunohistochemical findings consistent with
 immunosuppression have been observed in lungs and spleen of patients died of sepsis and
 multiple organ failure, demonstrating the relevance of studying these defects directly in
 organ tissues. A novel approach aimed to characterize the role and prognostic value of
 alveolar biomarkers measured directly in the injured lungs is warranted and supported by:
 -disappointing results of previous clinical trials attempting to restore the level of
 biomarkers measured on circulating cells; -evidences of regional immunosuppression in lungs
 of ARDS patients; -lung is the main site of hospital-acquired infections with a prevalence of
 ventilator-associated pneumonia in 30% over the course of Intensive Care Unit(ICU) stay in
 ARDS patients.

 Investigators speculate that biomarkers measured on alveolar leukocytes (AL) surface, are
 important predictors of outcome and potential therapeutic targets in ICU patients with
 pneumonia-associated ARDS.

 Investigators aim to explore whether biomarkers measured directly on AL from patients with
 pneumonia-associated ARDS are associated to regional pulmonary immunosuppression using
 leukocyte functional tests; and predictors of outcomes.

 Bronchoalveolar lavage fluid(BALF) and blood samples will be collected in ARDS patients.
 Leukocyte populations and cell membrane biomarkers will be quantified using flow cytometry.
 Leukocyte functional tests will be performed ex vivo on leukocytes collected from BALF and
 blood samples. Pharmacological interventions will be performed ex vivo.

 This project aims to identify biomarkers associated with outcomes and potential therapeutic
 targets.
Inclusion Criteria:

 -  Age ≥ 18 years

 -  Affiliated to a social security system

 -  Patient informed and have given his non opposition verbally (trustworthy or a family
 member non opposition is required if the patient is unable to give his non opposition)

 Groupe 1 :

 - Patient with ARDS secondary to pneumonia defined by following criteria: Intubation and
 mechanical ventilation for less than 48 hours Lung infection evolving since less than 7
 days Bilateral pulmonary radiological opacities compatible with edema pulmonary lesion PaO2
 / FiO2 ratio ≤ 300 mmHg with a positive expiratory pressure level ≥ 5 cmH2O

 - Absence of immunosuppression (No HIV infection, bone marrow or solid organ
 transplantation, post-chemotherapy aplasia, immunosuppressive therapy or corticosteroid
 therapy (>200 mg / day of hydrocortisone or equivalent in the 4 weeks prior to inclusion))

 Group 2 - Patient with ARDS secondary to pneumonia defined by following criteria:
 Intubation and mechanical ventilation for less than 48 hours Lung infection evolving since
 less than 7 days Bilateral pulmonary radiological opacities compatible with edema pulmonary
 lesion PaO2 / FiO2 ratio ≤ 300 mmHg with a positive expiratory pressure level ≥ 5 cmH2O

 - Previously known immunosuppression (patient with HIV, solid tumor, solid organ
 transplantation or under corticosteroids therapy since at least 4 weeks before inclusion)

 Group 3

 -  LBA indicated in usual care

 -  Absence of ARDS

 -  Absence of evolutionary infection

 -  Absence of infiltrative lung disease

 -  Absence of immunosuppression (No HIV infection, bone marrow or solid organ
 transplantation, post-chemotherapy aplasia, immunosuppressive therapy, corticosteroid
 therapy (> 200 mg / day of hydrocortisone or equivalent in the 4 weeks prior to
 inclusion))

 Exclusion Criteria:

 -  Chronic respiratory insufficiency treated by long-term oxygen therapy and / or
 long-term respiratory assistance

 -  Child-Pugh C cirrhosis

 -  Pulmonary fibrosis

 -  Active lymphoid and myeloid malignant hemopathies

 -  Neutropenia (neutrophils <1500 / mm3)

 -  Patient moribund the day of inclusion or having an IGS II score greater than 90

 -  Irreversible neurological pathology: cerebral involvement, encephalic death

 -  Decision to limit active therapies

 -  Deep hypoxemia (PaO2 / FiO2 <75 mmHg)

 -  Patient protected by law

 -  Pregnant or lactating woman