Therapeutic Plasma Exchange to Alleviate Hyperinflammatory Condition During Severe Covid-19 Infections

Inclusion Criteria: * Age ≥ 18 years * Hospitalized for COVID-19 confirmed by Reverse Transcriptase-Polymerase Chain Reaction (RT-PCR) or scanner * Patients with PaO2/FiO2 between 75 and 175 mmHg requiring non invasive ventilation or high flow oxygen * peripheral venous state allowing PE to be performed, according to the investigator's judgement, or possibility of placing a Sheldon-type veinous central line * At least two biological results suggesting a cytokine storm or hyperinflammatory condition state among : C-reactive protéine (CRP)\>50mg/L, Procalcitonin (PCT)\>1µg/L, Fibrinogen\>5g/L, D-dimer \>1000ng/mL, Ferritin \> 800ng/mL during the last 72 hours. * Treatment with corticosteroids (at least 2 intakes of dexamethasone 6 mg or equivalent with another form of corticosteroids) * Patient affiliated to a social security or similar scheme * Information and written consent from the patient or if not possible from a confident person Exclusion Criteria: * Ventilated intubated patients * Patient with advanced cancer and without curative possibility * Bacterial or viral (HIV) infection explaining the worsening (the main reason) * Body Mass Index \> 40 * Severe hemodynamic instability with mean arterial pressure \< 65 mmHg (whatever the noradrenaline dosage used) * Known Immunoglobulin A (IgA) deficiency with anti-IgA antibodies * Inclusion in another study that could interact with the Covidep study (investigator's judgement) * Patient under legal protection measure * Pregnan…