- any other cause of acute respiratory distress not attributable to sars-cov-2. - rt-pcr of sars-cov-2 negative. - multi-organ failure (more than three organs) - severe respiratory failure requiring extracorporeal support (ecmo) grave moderate severe copd requiring chronic home oxygen therapy, need for prior home oxygen therapy for any reason. - pregnancy, lactation and women of childbearing age but who do not take effective contraceptive measures. - active tumor disease. - previous immunosuppressive treatment. - allergy or hypersensitivity to the administered products. - history of deep vein thrombosis or pulmonary embolism in the last 3 years. - participation in other clinical trials during the 3 months prior to the initial visit.

- any other cause of acute respiratory distress not attributable to sars-cov-2. - rt-pcr of sars-cov-2 negative. - multi-organ failure (more than three organs) - severe respiratory failure requiring extracorporeal support (ecmo) grave moderate severe copd requiring chronic home oxygen therapy, need for prior home oxygen therapy for any reason. - pregnancy, lactation and women of childbearing age but who do not take effective contraceptive measures. - active tumor disease. - previous immunosuppressive treatment. - allergy or hypersensitivity to the administered products. - history of deep vein thrombosis or pulmonary embolism in the last 3 years. - participation in other clinical trials during the 3 months prior to the initial visit.