inclusion criteria: - age > 18 years - informed consent for participation in the study - real time polymerase chain reaction (pcr) diagnosis of sars-cov2 infection - hospitalization due to clinical / instrumental diagnosis (high resolution chest ct scan or chest x-ray or pulmonary ultrasound) - presence of acute respiratory distress syndrome with arterial partial pressure of oxygen / fraction of inspired oxygen (pao2 / fio2) between 200 and 300 mm/hg - presence of exaggerated inflammatory response defined by the presence of at least 1 of the following criteria: - at least one body temperature measurement >38° c in the past two days; - serum crp greater than or equal to 10 mg/dl; - crp increase of at least twice the basal value

inclusion criteria: - age > 18 years - informed consent for participation in the study - real time polymerase chain reaction (pcr) diagnosis of sars-cov2 infection - hospitalization due to clinical / instrumental diagnosis (high resolution chest ct scan or chest x-ray or pulmonary ultrasound) - presence of acute respiratory distress syndrome with arterial partial pressure of oxygen / fraction of inspired oxygen (pao2 / fio2) between 200 and 300 mm/hg - presence of exaggerated inflammatory response defined by the presence of at least 1 of the following criteria: - at least one body temperature measurement >38° c in the past two days; - serum crp greater than or equal to 10 mg/dl; - crp increase of at least twice the basal value