New York, Jan 5 (IANS): A team of researchers has led a groundbreaking randomised controlled trial, using mesenchymal stem cells, that resulted in reduced risk of death and quickened time of recovery for the severest COVID-19 patients.

According to the researchers from the University of Miami, the treatment was safe with no infusion-related serious adverse effects.

"It was a double-blind study. Doctors and patients didn't know what was infused," said researcher of the study, Camillo Ricordi, Director of the Diabetes Research Institute (DRI) and Cell Transplant Center at the University of Miami.

"Two infusions of 100 million stem cells were delivered within three days, for a total of 200 million cells in each subject in the treatment group," Ricordi added.

The researcher said that treating COVID-19 with mesenchymal stem cells makes sense.

For the study, published in the journal Stem Cells Translational Medicine, the researchers involved 24 hospitalised patients with COVID-19 who developed severe acute respiratory distress syndrome. Each received two infusions given days apart of either mesenchymal stem cells or placebo.

Patient survival at one month was 91 per cent in the stem cell treated group versus 42 per cent in the control group. Among patients younger than 85 years, 100 per cent of those treated with mesenchymal stem cells survived at one month.

The team also found time to recovery was faster among those in the treatment arm.

The umbilical cord contains progenitor stem cells, or mesenchymal stem cells, that can be expanded and provide therapeutic doses for over 10,000 patients from a single umbilical cord.

"It's a unique resource of cells that are under investigation for their possible use in cell therapy applications, anytime you have to modulate immune response or inflammatory response," Ricordi said.

"We've been studying them with our collaborators in China for more than 10 years in Type 1 Diabetes, and there are currently over 260 clinical studies listed in clinicaltrials.gov for treatment of other autoimmune diseases," he added.

Mesenchymal cells not only help correct immune and inflammatory responses that go awry, they also have antimicrobial activity and have been shown to promote tissue regeneration.

"Our results confirm the powerful anti-inflammatory, immunomodulatory effect of UC-MSC. These cells have clearly inhibited the 'cytokine storm', a hallmark of severe Covid-19," said the lead author Giacomo Lanzoni, Assistant Research Professor at the Diabetes Research Institute.

"The results are critically important not only for COVID-19 but also for other diseases characterized by aberrant and hyperinflammatory immune responses, such as autoimmune Type 1 Diabetes," Lanzoni added.