Patient 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

Patient Exclusion Criteria

- Patients with respiratory distress syndrome with arterial partial pressure of oxygen / fraction of inspired oxygen (PaO2 / FiO2) <200 mm/Hg or - Patients in non-invasive ventilation or - Patients in invasive ventilation or presence of shock or presence of concomitant organ failure that requires admission to the Intensive Care Unit - Severe heart and kidney failure - Pregnant or breastfeeding patient - Patient who, in the opinion of the clinician or by the patient's express will, will not go to intensive care regardless of the evolution of the lung picture. - Known hypersensitivity to TCZ or its excipients - Patient being treated with immuno-depressors or anti-rejection drugs - Known active infections or other clinical conditions that contraindicate TCZ and cannot be treated or resolved according to the physician's judgment - glutamate-pyruvate transaminase (GPT) or glutamine oxaloacetic transaminase (GOT) > 5 times the upper limit of the norm - Neutrophils <500 /mmc - Platelets <50.000 /mmc - Diverticulitis or intestinal perforation - Suspicion of latent tuberculosis