The propose of this study is implement adjuvant therapy with adipose tissue derived-mesenchymal stem cells (MSCs) for critical COVID-19 patients admitted to the intensive care unit of the Regional Hospital Lic. Adolfo López Mateos of the Institute for Social Security and Services for State Workers to reduce cytokine storm and contribute to the favorable resolution of respiratory insufficiency and multiple organic failure.

Within the epidemic context of phase 3 that currently exists in Mexico, implementation of new treatments that have shown to be beneficial for patients in a critical state in other countries is an urgent need. Adipose tissue derived-mesenchymal stem cells for could favor the regulation of patient immune system to reduce the proinflammatory state and promoting the regeneration of damaged tissues.

Patients diagnosed COVID-19 and confirmed positive with the virus by PCR, will be treated with two intravenous infusions MSCs on the day 1 (D1) and the day 3 (D3) of the treatment consisting of 1X106/kg each.

We will assess the pulmonary lesion area by chest x-ray or computed axial tomography at baseline and days 2, 3, 5, 10, 15, 20, and 25.

Days to clinical improvement (to be evaluated on days 2, 3, 5, 10, 15, 20, 25), considering temperature and other vital signs measurement, arterial oxygen saturation, blood chemistry (including liver function tests), creatine phosphokinase, C reactive protein, immune cells (CD3+, CD4+, CD8+, CD16+, CD19+, and CD56+ lymphocytes), pro-inflammatory cytokines (IL-1β, IL- 2, TNF-α, ITN-γ, IL-4, IL-6, IL-10), immunoglobulins (IgA, IgG, IgM, and IgE), HLA profile expression, and weaning from mechanical ventilation.

Inclusion Criteria:

• Aged between 18 and 65.
• RT-PCR positive for SARS-CoV-2 (Berlin protocol).
• Moderate to severe acute respiratory insufficiency (100 mmHg \