TORONTO -- Two Canadian research centres are gearing up for a clinical trial to determine if a type of stem cell can help alleviate the symptoms of multiple sclerosis.

Researchers at the Ottawa Hospital and Winnipeg's Health Sciences Centre will each recruit 20 MS patients for the trial that will test whether mesenchymal stem cells can reduce inflammation and even help repair damage already caused by the disease.

MS is thought to be an autoimmune disease that creates inflammation in the central nervous system, resulting in injury to myelin, the protective sheath that covers nerves. This damage can create a host of symptoms, leading to varying degrees of physical disability and cognitive impairment.

Mesenchymal stem cells, which are found in bone marrow, fat, skin tissue and umbilical cord blood, have the ability to modify the immune system and reduce inflammation, said neurologist Dr. Mark Freedman of the Ottawa Hospital Research Institute, who is leading the clinical trial.

Freedman said researchers want to determine if these stem cells can demonstrate anti-inflammatory properties in patients with MS.

"But that's not why we're doing it," he said of the study, called MESCAMS ("MEsenchymal Stem cell therapy for CAnadian MS patients"). "We have lots of drugs that can control inflammation in multiple sclerosis -- that's what all the new medicines do."

"The ultimate hope is that we will be able to exploit some of their other very important biological properties, which is to promote repair."

The two research centres are ready to begin enrolling patients for the trial, which has specific acceptance criteria. While most of those accepted will likely have the relapsing-remitting form of the disease, Freedman said some people with more severe primary- or secondary-progressive MS may also be eligible if they fit the criteria.

The study protocol can be accessed at www.clinicaltrials.gov/show/NCT02239393. It will later be posted on the website of the MS Society of Canada, which along with the Multiple Sclerosis Scientific Research Foundation has provided a $4.2-million grant for the study.

To conduct the trial, half the patients will be randomly assigned to receive their own mesenchymal stem cells within weeks of them being extracted from the bone marrow and grown in the lab; the remainder of the participants will instead be infused with a mock stem-cell solution, and won't receive their actual stem cells for about six months. The two groups will then be compared.

While mesenchymal stem cells have the ability to give rise to virtually any cell type in the body, Freedman said it's their tendency to migrate to areas of injury that researchers hope to capitalize on.

"And it doesn't matter where the injury is in the body," he said. "So they have a potential obviously for treating many different types of illnesses."

In MS patients, it's thought the stem cells would zero in on damaged areas of the brain, spinal cord and other nerve tissue. Once at their destination, the stem cells are known from animal studies to release chemical factors "to mobilize the local repair crew that's sitting on their butts and not doing what they're supposed to," he said.

"They can mobilize these cells to actually start the repair process and overcome whatever barriers there were to repair that had been left behind, probably by the ongoing inflammation."

Dr. James Marriott, the neurologist leading the Winnipeg arm of the trial, said his team is excited to be able to offer Manitoba MS patients the opportunity to participate. The province has one of the highest rates of multiple sclerosis in the country.

"This is a promising area and we hope this study will demonstrate the safety and feasibility of this therapy, and ultimately lead to further research and new treatments," Marriott said in a release.

Margo Murchison of Ottawa was diagnosed with relapsing-remitting MS at age 27. Now 60, the former primary French immersion teacher is in a wheelchair and no longer able to work.

"There is nothing they've ever been able to do for me," said Murchison, explaining that drug treatments did not arrest her MS, which is now classified as the much more debilitating secondary-progressive form of the disease.

"This is why this is so exciting," she said of the research trial.

While she does not meet the selection criteria for the trial, Murchison said that doesn't mean the stem cell therapy wouldn't work for her in the future if the trial proves it can repair nerve damage.

"I'm really hopeful about stem cell research ... We don't know until we try."

Freedman and Ottawa Hospital colleague Dr. Harry Atkins pioneered a different kind of stem cell therapy for MS that uses hematopoietic stem cells to replace a patient's defective immune system with a new one that no longer attacks the brain and spinal cord.

"Our experience with hematopoietic stem cell transplantation has been very encouraging, but the therapy has serious risks and it is only appropriate for a very small percentage of people with aggressive early MS," said Freedman.

"On the other hand, we really don't know what the effect of mesenchymal stem cell therapy will be in people with MS," he said. "It involves a different treatment approach that does not require the use of chemotherapy and therefore has fewer risks compared with hematopoietic stem cell transplantation.

"Mesenchymal stem cell therapy, if successful, might offer a future treatment option for a larger group of patients."

An estimated 100,000 Canadians have multiple sclerosis, and Canada is believed to have the highest per capita rate of the disease in the world, according to the MS Society.

The Canadian study is part of a larger nine-country clinical trial of mesenchymal stem cells in MS patients, co-led by Freedman and Dr. Antonio Uccelli at the University of Genoa in Italy.