Evaluate the Safety and Efficacy of Allogeneic Umbilical Cord Mesenchymal Stem Cells in Patients With COVID-19

Exclusion criteria

• . Pregnancy, lactation, and those who are not pregnant but did not, or unwilling to, take effective contraceptives measures 4 weeks before and after the treatment.
• . Patients with malignant tumors or other serious systemic diseases.
• . Patients with hemoglobin \< 10 g, alanine aminotransferase (ALT) ≥ 5 × ULN, aspartate aminotransferase (AST) ≥ 5 × ULN, alkaline phosphatase (ALP) ≥ 5 × ULN, total bilirubin (TBILI) ≥ 2 × ULN, serum creatinine \> 2.5 mg/dl, platelet counts \< 100,000/μL, WBC \< 3,000 cells/μL, or neutrophil counts \< 1,000/μL at screening.
• . Presence of barotrauma or hemodynamic instability defined as hypotension with diastolic blood pressure \< 90 mmHg or mean arterial pressure (MAP) \< 70 mmHg despite fluid expansion, and vasoactive support or pneumothorax at screening.
• . Uncontrolled hypertension with systolic blood pressure \> 170 mmHg and diastolic blood pressure \> 100 mmHg which, in the investigator's judgment, would not make participation appropriate.
• . Recent history of (within 2 years) ischemic heart disease or cerebrovascular attack, such as myocardial infarction, unstable angina, or stroke.
• . Recent history (within 2 years) of hypercoagulable disorder, antiphospholipid syndrome, pulmonary embolism, or deep venous thrombosis.
• . Condition other than COVID-19 that is projected to limit lifespan to ≤ 1 year.