The outbreak of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), has become pandemic. To date, no specific treatment has been proven to be effective. Promising results were obtained in China using Hyperimmune plasma from patients recovered from the disease.The investigators plan to treat critical Covid-19 patients with hyperimmune plasma.

Apheresis from recovered donors will be performed with a cell separator device , with 500-600 mL of plasma obtained from each donor. Donors are males, age 18 yrs or more, evaluated for transmissible diseases according to the italian law. Adjunctive tests will be for hepatitis A virus, hepatitis E virus and Parvovirus B-19. All donors will be tested for the Covid-19 neutralizing title. Each plasma bag obtained from plasmapheresis will be immediately divided in two units and frozen according to the national standards and stored separately.

Based on experience published in literature 250-300 mL of convalescent plasma will be used to treat each of the recruited patients at most 3 times over 5 days.

Inclusion Criteria:

• age >=18 yrs
• positive for reverse transcription polymerase chain reaction (RT-PCR) severe acute respiratory syndrome (SARS)-CoV-2
• Acute respiratory distress syndrome (ARDS) moderate to severe, according to Berlin definition, lasting less than10 days
• Polymerase chain reaction (PCR) increased by 3.5 with respect to baseline or >1.8 mg/dl
• need for mechanical ventilation or continuous positive airway pressure (CPAP)
• signed informed consent unless unfeasible for the critical condition

Exclusion Criteria:

• Moderate to severe ARDS lasting more than 10 days
• proven hypersensitivity or allergic reaction to hemoderivatives or immunoglobulins
• consent denied

will be decided