Evaluation of a Functional Lymphocyte Test (QuantiFERON Monitor®) as a Prognostic Marker for Acute Community-acquired Pneumonia

Inclusion criteria

GROUP OF PATIENTS WITH PNEUMONIA

• Patient with acute pneumonitis:

• Acute signs and symptoms of lung disease (new or worsening), including at least 2 of the following:
• Cough
• Dyspnea
• Purulent sputum
• Chest pain
• Temperature ≥ 38°C or < 35°C 2) and new radiological pulmonary infiltrate (X-ray or CT scan on admission)
• Community Acquired Pneumonia:
• Pneumonia present on admission or diagnosed within 48 hours of admission,
• Poor prognosis according to the new quick SOFA sepsis score; poor prognosis is defined if at least 2 of the following criteria are present:
• Systolic blood pressure ≤ 100 mm Hg,
• Respiratory rate ≥ 22,
• Altered consciousness (Glasgow score < 15). And/or need for mechanical ventilation (invasive or non-invasive). And/or need for use of vasopressors for hemodynamic failure.
• Patient of legal age who has given informed consent
• Patient affiliated to the national health insurance system
• For patients with "severe SARS-CoV-2 pneumonia":

• Respiratory specimen positive for SARS-CoV-2 (PCR)
• And without Gram-negative bacilli found on respiratory and blood samples.

CONTROL GROUP (HEALTHY VOLUNTEERS):

• No infection in the previous or current 30 days

• No fever reported in the previous 30 days
• No antibiotics taken in the previous 30 days
• Temperature < 37.8°C on the day of inclusion
• Absence of clinically suspected infection
• No surgery in the previous 30 days
• Patient over 18 years of age who has provided informed consent
• Patient affiliated to the national health insurance system

Exclusion criteria

• Person protected by law
• Minor
• Pregnant, parturient or breastfeeding woman
• Patient with a known primary or secondary immune deficiency (radiation therapy, chemotherapy, immunosuppressive therapy or systemic corticosteroid therapy (> 0.15 mg/kg/day of prednisone equivalent for more than 2 weeks or "bolus" higher than 2 mg/kg/day of prednisone equivalent in the 3 months prior to inclusion), HIV infection, primary cellular immune deficiency)
• Presenting a chronic disorder known to cause deep lymphopenia (Cirrhosis, lympho or myeloproliferative syndrome, solid cancer or active systemic lupus erythematosus) and/or a condition known to cause a substantial increase in INF-γ (active hepatitis B)
• Patient who was hospitalized in the 3 months prior to inclusion for sepsis according to the new SOFA quick criteria
• Decision to limit care
• Treatment with Interferon initiated prior to study sampling

Exclusion criteria

• For the pneumopathy group: Failure to take a sample for the QFM within 48 hours of admission.
• For the control group: CRP greater than 15 mg/L at the time of sampling