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

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