To evaluate allogeneic human mesenchymal stem cell exosomes (hMSC-Exos) in the treatment of acute respiratory distress syndrome (ARDS)

According to the 2012 Berlin diagnostic criteria, there are currently more than 3 million ARDS patients worldwide, accounting for about 10% of patients in the intensive care unit (ICU). In recent years, the incidence of ARDS has increased significantly, which has significantly increased the social and economic burden. The impact of ARDS can even be compared with tumors, AIDS or myocardial infarction. There are the basic clinical treatments, such as using various ventilation methods to improve hypoxia and choosing alternative therapies to improve renal insufficiency. Therefore, there is still a lack of specific treatment measures.

Exosomes are naturally occurring nanosized vesicles and comprised of natural lipid bilayers with the abundance of adhesive proteins that readily interact with cellular membranes. Studies have confirmed that MSC-Exos can improve most of the pathological changes caused by lung infection, reduce pulmonary edema, reduce protein exudation, reduce alveolar inflammation, and clear bacterial infections. Thus, it brings new hope for the treatment of ARDS.

The purpose of this study is to evaluate allogeneic human mesenchymal stem cell exosomes (hMSC-Exos) in the treatment of acute respiratory distress syndrome (ARDS)

Inclusion Criteria:

1. The subjects themselves or their family members voluntarily participate in this study and sign the informed consent form;
2. 18-70 years old, male or female;
3. Definitely diagnosed as acute respiratory distress syndrome (ARDS) (according to the Berlin definition and diagnostic criteria of ARDS);
4. Course of disease <96 hours after diagnosis;
5. Chest X-ray showed bilateral infiltration with pulmonary edema; no clinical manifestations of left ventricular hypertension, or pulmonary artery wedge pressure (PAOP) ≤18mmHg.

Exclusion Criteria:

1. Patients with severe allergic constitution;
2. Moderate to severe liver failure (children Pugh score > 12);
3. Patients with severe chronic respiratory diseases, PaCO2 > 50mmhg, and need home oxygen therapy;
4. Severe trauma occurred within 14 days before screening;
5. History of malignant tumor (patients with skin basal cell carcinoma in the past can be included);
6. They are undergoing hemodialysis or peritoneal dialysis;
7. The patients who had deep venous thrombosis or pulmonary embolism within 90 days;
8. Acute myocardial infarction occurred within 30 days;
9. Neuromuscular diseases that result in impaired natural ventilation include, but are not limited to, C5 or higher spinal cord injury, amyotrophic lateral sclerosis, Guillain Barre syndrome, and myasthenia gravis;
10. Obesity (BMI > 28);
11. Lung transplantation;
12. Bone marrow transplantation;
13. Active immunosuppression is defined as receiving immunosuppressive drugs or having a medical condition associated with immunodeficiency. These included: 1) HIV (AIDS or CD4 < 200 cells / mm3); 2) chemotherapy within 6 weeks before randomization; 3) immunosuppressive therapy, including maintenance glucocorticoid therapy (> 40) Results: 1) short term systemic steroid therapy (intravenous or oral) for less than 1 week, topical steroid for skin diseases; 4) absolute neutrophil count < 500 / mm3;
14. Patients undergoing extracorporeal circulation support (ECMO) or high frequency oscillatory ventilation;
15. They were not willing to receive lung protective ventilation (minimum tidal volume 6ml / kg pbw) or liquid management treatment;
16. Have a history of epilepsy, need continuous anticonvulsant therapy, or have received anticonvulsant therapy in the past 3 years;
17. The estimated survival time was less than 30 days;
18. Hepatitis B, hepatitis C, AIDS, syphilis patients;
19. Women of childbearing age are pregnant, lactating or pregnant within one year;
20. Those who could not understand the study protocol;
21. According to the judgment of the researchers, there were other situations in which the patients were not suitable to participate in the study (for example, there were factors to reduce the follow-up compliance, and the patients did not receive relevant supportive treatment, etc.).

No plan to make individual participant data (IPD) available to other researchers