stem cell therapy in Covid-19

INTERVENTION: Intervention 1: Intervention group: Group receiving mesenchymal stem cells. In this group, patients in 3 times (1, 3 and 6 days) are received 1 million Umbilical core‐derived MSCc/BW by intravenous injection ( Through the catheter and the Central vein and from the superior vena cava vein ). Also, in addition to cell therapy,Other common treatments will be given to patients according to the physician's supervision.Mesenchymal Stem cells had an ISCT standard and were given from a healthy donor. Blood samples were given from patients on days 0, 2, and 7, as well as 14 days after the second injection and patients will follow for 20 days (in terms of clinical and immunological parameters).It should be noted that of all patients at the beginning of the study conscious consent form will be received. Intervention 2: Control group: Receiving common therapies (without stem cell). In this group, patients are received other common treatments including antiviral drugs and etc In accordance with the physician's opinion and do not receive stem cells. CONDITION: Covid‐19 disease. ; Severe Acute Respiratory Syndrome coronavirus RA01.0 PRIMARY OUTCOME: Cell markers and populations. Timepoint: In onset of study and days 2, 7 and 14 after the second injection. Method of measurement: Using Flow cytometery technique. Evaluation of IFN‐?,IL4,TGF‐ß,IL1‐ß , IL‐6 and TNF‐a cytokine levels in patients blood. Timepoint: In onset of study and days 2, 7 and 14 after the second injection. Method of measurement: Using Elisa kits. Respiratory symptoms and pulmonary function in patients. Timepoint: In onset of study and days 2, 7 and 14 after the second injection. Method of measurement: Using CT scan image , physical examination , Oxygen saturation Percentage. INCLUSION CRITERIA: Covid‐19 patient with acute respirstory infectious symptoms and severe lung involvement Pulmonary compliance more than 40 Age category 18‐70 years PI02/FIo2 between 100 ‐ 300