What is the evidence for mesenchymal stem cell therapy in COVID-19 patients?
Mesenchymal stem cells may exert antiviral mechanisms in the context of SARS-CoV-2 infection. The basal IFN-stimulated gene expression of mesenchymal stem cells is high. This enhances MSC responsiveness to IFN signaling, potentially inducing broad viral resistance. Mesenchymal stem cell therapy is being used in some centers but its efficacy in COVID-19 has not been proven. Data available are mainly experimental with few records in humans and no reports on its efficacy in randomized clinical trials.199
Are common anti-hypertensive drugs useful in the prevention and treatment of COVID-19? Common anti-hypertensive drugs inhibit ACE, but not ACE2. Importantly, ACE2 opposes ACE actions and lowers blood pressure by converting angiotensin-II (a vasoconstrictor peptide) into its metabolites- angiotensin (1–7) (vasodilators).200 Other common related antihypertensive drugs are angiotensin-2 receptors blockers, which block AT-1, a receptor for angiotensin-II, through which it exerts its vasoconstrictor effect. However, AT-1 is not known to be used by SARS-CoV-2 to infect cells. It was shown in animal models that ACE inhibitors might increase ACE2 expression, thus increasing susceptibility to infection. It has not been proven in humans but it raised the concerns during the COVID-19 pandemic200. Based on the data available to date, antihypertensive treatment with these medications should be continued.201