MORGANTOWN, W.Va. – A recent study conducted by neuroscientists from West Virginia University shows a potential step towards improving stroke therapy.
The study, which is believed to be the first, shows that blood substitution therapy rescues the brains of mice from ischemic damage. The idea is to eventually be able to use blood transfusions in humans who suffer from a stroke.
According to neuroscientists, most strokes (ischemic) occur when the blood supply to the brain is interrupted, usually by a blockage of the arteries leading to the brain. There is no known single medication for stroke, however, the only FDA-approved treatment for ischemic strokes is tPA, or tissue plasminogen activator, which dissolves the clot and improves blood flow.
Xuefang “Sophie” Ren, research assistant professor in the Department of Neuroscience and director of the WVU Experimental Stroke Core led the team in this study.
“What we were able to demonstrate is that if you remove part of the blood from a subject undergoing stroke, and replace that blood from a subject that’s never had a stroke, the outcomes of that stroke are profoundly improved,” said Ren.
While tPA typically has to be administered within three hours of the stroke, Ren’s research indicates that blood transfusions can take place beyond that limited window. With a blood transfusion, it can take up to seven hours and still have a positive impact.
According to release, the study showed that replacing 20 percent of the blood in a mouse was enough to show a profound reduction in damage to the brain. The average adult holds around one-and-a-half gallons of blood in the body.
“The idea is to change the immune response that happens after stroke,” said James Simpkins, co-author of the study and director of the Center for Basic & Translational Stroke Research.
Simpkins is also a professor of the Department of Neuroscience. Heng Hu, postdoctoral fellow and Experimental Stroke Core surgeon, also helped co-author the study.
Following a stroke, the makeup of a patient’s blood changes, causing disruptions in the brain and how the body responds, explained by researchers. A type of white blood cell that helps lead the immune system’s response, known as Neutrophils, play a role in increasing the levels of an enzyme called MMP-9, which can lead to blood-brain barrier leakage and degeneration in brain tissue.
The study concluded that blood replacement therapy removes inflammatory cells and decreases neutrophils and MMP-9 levels following a stroke.
“The immune system doesn’t recognize much of what’s happening when there’s a stroke. So the neutrophils go to the brain and try to clean up the damage that happens. But there’s too much in the brain and those same neutrophils release MMP-9, which then exacerbates the damage.
What we learn is that stroke is simply not a cerebral vascular event. It’s a whole-body event. Both the brain and the body get signals that something’s going on in the brain and as the immune system responds to try to help, it actually worsens the outcome. Therefore, by removing the blood and replacing it with the blood of those that have not experienced stroke, we get good outcomes.”Simpkins, director of the Center for Basic & Translational Stroke Research and professor of the Department of Neuroscience
Ren said that now, blood replacement therapy is a proven strategy that targets the pathological systemic responses to stroke, and could reduce the mortality of stroke patients.
“In an ideal circumstance, a person having a stroke would show up to Ruby (Memorial) or any hospital. They’d go through the proper protocol. We would remove their stroke blood and magically restore it with the right kind of blood that would tamp down this immune response they’re experiencing. If it works out, that’s good for all of us,” said Simpkins.
According to the Centers for Disease Control and Prevention, more than 795,000 Americans experience a stroke each year and 140,000 die from it.
“Blood indeed saves our brains and lives from stroke damage,” Ren said.