A healing balm for the brain? Infusions of umbilical cord blood seem to help people recover better after a stroke.
Strokes occur when blood can’t reach brain cells because of a blocked or burst blood vessel, causing them to rapidly starve and die.  at Duke University, North Carolina, and her colleagues wondered if young blood might help heal brains that have been damaged in this way.
Blood from babiesĚý˛ą˛Ô»ĺĚýteenagers has previously been shown to reverse brain ageing in older mice, and there are hints that young blood can also help people with Alzheimer’s disease. To test young blood as a stroke treatment, the team recruited 10 patients between the ages of 45 and 79, and gave them a one-off infusion of blood collected from new-born babies’ umbilical cords. The infusions were given between 3 and 10 days after each person had experienced a stroke.
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Three months later, all 10 volunteers showed improvements in their speech, vision, and movement, and were more independent in their daily lives. The results should be interpreted with caution because there was no placebo group, says Kurtzberg. However, the participants’ disability test scores improved more than would normally be expected for stroke patients, hinting at a positive effect, she says.
Suppressing inflammation
This fits with earlier studies in rats, which also found that infusions of human cord blood helped to fix stroke-damaged brains. “The animals recovered quicker, had better survival, and the areas of brain damage were smaller,” says Kurtzberg.
These animal studies revealed that stem cells in cord blood were responsible for the therapeutic effects. The stem cells secreted chemicals that encouraged the growth of new brain cells and reduced inflammation.
“After a stroke, the body has an inflammatory reaction that causes more damage to the brain,” says Kurtzberg. “So, by suppressing that, some of the damaged areas can be repaired.”
The researchers have now started a larger trial in 110 stroke patients to confirm their results. Half the participants will receive a single infusion of umbilical cord blood, while the rest will get a placebo.
Stem cell treatments
Several other groups are also working on cell treatments for stroke, including the US company SanBio, which has shown that injecting stem cells from bone marrow directly into the brain helps stroke patients walk again.
New drugs for stroke are urgently needed, says  at La Trobe University in Australia. “It’s a massive, massive problem – not only do a lot of people die, there are a lot who are left disabled,” he says.
Currently, the main treatment for stroke is a clot-busting drug that helps clear blockages to the brain. However, most people don’t get this treatment because it needs to be administered within 5 hours of a stroke, but many people don’t realise that they’ve had one within this time.
Sobey and his colleagues are studying the potential therapeutic effect of amnion epithelial cells, which have stem-cell like, anti-inflammatory properties. These surround the growing fetus in pregnant women, and are normally discarded at birth. “During pregnancy, they prevent the mother’s immune system from attacking the growing baby because it is foreign tissue,” says Sobey. In animal studies, they’ve been found to quieten down inflammation after stroke, he says.
Sobey’s team is set to begin a small clinical trial involving 15 people later this year.
Stem Cells Translational Medicine
