Thursday, March 25, 2021

Stem cells from umbilical cords might be the answer for severely ill COVID patients: Canadian researchers

Tom Blackwell 
2/24/2021
© Provided by National Post Dr. Duncan Stewart of Ottawa Hospital Research Institute, who is conducting a trial using a type of stem cell obtained from umbilical cords to treat patients made severely ill by COVID-19.

More than a year into the COVID-19 pandemic, medical science is still struggling to cope with the worst manifestation of the disease.

When out-of-control immune systems attack patients’ lungs and sap their ability to breathe, health care has no sure-fire response. Even with some improvement in treatment, as many as 40 per cent of COVID patients in the intensive-care unit never make it out.

But researchers in Canada and elsewhere believe there’s potential lurking inside an unlikely source: a byproduct of child birth.

Discarded umbilical cords are a particularly rich font of mesenchymal stromal cells (MSCs), a type of stem cell that scientists hope could reset that berserk immune system and tamp down damaging inflammation.

At least two clinical trials are in the works in Canada and dozens more in other countries to test the idea on the sickest of COVID patients.

Results of randomized, controlled tests of the cells’ efficacy are still to come, but early signs are promising. A small handful of “case series” — observational studies that lack a placebo group for comparison — have had good results, including one just published by an Iranian team.

The Ottawa Hospital Research Institute has completed a phase one safety trial of the cells on 11 patients, showing the treatment was well tolerated.

“The results are encouraging, they definitely support moving forward into a larger randomized trial,” said Dr. Duncan Stewart, the institute’s CEO. “This is a population that has extremely poor outcomes, so anything that can reduce the severity of the disease and improve survival and recovery is really, really important.”

At McGill University, a team led by Dr. Inés Colmegna plans to test another MSC product derived from umbilical cord blood, produced by a Swedish company.

“The idea here is that you’re using a cell that is capable … of reversing the damage caused by a huge activation of the immune system,” she said. “In a way, you are bringing some order and direction to the immune system.”

Some experts actually describe COVID-19 as like two different diseases. The first sees the virus itself triggering various symptoms, which clear up in most patients. The second occurs when the immune system goes hyperactive, triggering massive inflammation and assailing the cells of the lung, strangling their ability to shift oxygen to the bloodstream.

The result can be acute respiratory distress syndrome (ARDS), the most dangerous symptom of COVID-19, when many patients end up on ventilators fighting for their lives.

Various potential treatments for the condition have been tried, none proving to be a home run.

With their ability to transform into other types of cells, MSCs were originally investigated as a way to regenerate damaged or diseased tissue. The results weren’t encouraging, but the cells did seem proficient at “modulating” the immune system, re-adjusting it so it fights off disease but doesn’t turn on the body itself, said Stewart.

Unlike single-molecule treatments, they also have a unique ability to multi-task, to target a number of factors causing damage, said Colmegna.

“You really are trying to tackle more than one thing at once.”

How the cells accomplish all that is not entirely clear, but they are associated with small blood vessels that play a key role in healing after injury, said Stewart.

Before the pandemic, the Ottawa team had completed a phase one trial using MSCs to treat ARDS caused by septic shock. A Chinese group reported in October on a study of 61 patients suffering from ARDS due to H7N9 flu. Significantly fewer of the 17 that received the stem cells — 17.6 per cent — died than those who did not get the treatment (55 per cent).

The cells can be found throughout the body but efforts to harvest them have largely focused on bone marrow and umbilical cords. The latter are the richest source and give up younger cells, Stewart said.

He believes his team’s MSC product has an advantage over others as it is derived fresh from living cultures, and is likely more potent than others that are frozen and then thawed.

But the frozen cells are “off-the-shelf” products that provide more flexibility in emergency cases when speed is of the essence, said Colmegna.

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