Exosomes from MSCs Should Be Used in Place of MSCs Themselves for Treatment of “Cytokine Storm” and Severe Pneumonia in COVID-19, Yale Expert Argues; Also, Presence & Role(s) of Billions of Exosomes in Convalescent Plasma Need to Be Considered

In an “Urgent Opinion” pre-print (https://osf.io/zm3ch/) posted online on July 1, 2020, Philip Askenase (https://medicine.yale.edu/news-article/15415/) (https://medicine.yale.edu/profile/philip_askenase/), MD, Professor of Medicine (Clinical Immunology) at the Yale University School of Medicine in the Section of Rheumatology and Clinical Immunology, and former Chief of Allergy & Clinical Immunology at the Yale University School of Medicine, argues that exosomes released from mesenchymal stromal cells (MSCs), should be used instead of MSCs for treatment of the profound clinical “cytokine storm” and severe pneumonia that can occur in COVID-19. He also contends that the presence and role of the billions of exosomes present in convalescent plasma should be considered when using this treatment approach. With regard to the MSC exosomes, Dr. Askenase notes that, although MSCs are increasingly used in the treatment of cytokine storms and pneumonia in COVID-19, many reports in the literature have shown “definitively” that the release of exosomes from in vivo administered MSCs is actually responsible for the beneficial effects associated with the MSCs. In addition, Dr. Askenase noted that exosomes are superior, simpler, and clinically more convenient when compared to their parental MSCs. Furthermore, he pointed out that, in the context of COVID-19, the known tendency of MSCs to aggregate and to cause lung dysfunction might combine with the COVID-19 pneumonia tendencies to exacerbate, rather than help, lung problems associated with COVID-19. In addition, he suggested that the tendency of MSCs to form peripheral vascular micro-aggregates, might synergize with the vascular clots associated with COVID-19 to cause significant central and/or peripheral vascular insufficiency.