The story told in the movie “Awakenings” could apply to dementia patients. Periodic, full blood plasma transfusions allow people with Alzheimer’s disease to temporarily regain consciousness to the point of interacting with others normally, as if they had conquered evil. According to various works under investigation, it occurs mainly in early stages of the disease. The problem at the moment is that after a while, a month or a little more, the effect of the therapy wears off and the patients return to the state in which they were at the beginning. Exactly the same as in the autobiography of neurologist Oliver Sacks, in which the late Robin Williams starred in the cinema.
“It is a very interesting experience that we are working on a project carried out from Spain, which is still in development”, explains Manuel Fernández, neurologist at Cruces Hospital, convinced that the research is on the right track. “At the moment, the effect obtained does not seem to be stable, but any research needs time. Many things that seemed impossible a few years ago are now routine clinical practice”, explains the specialist, professor at the Faculty Department of Neurosciences. of Medicine and Nursing from the University of the Basque Country (UPV/EHU).
The international publication ‘Molecular Psychiatry’ reported only a few days ago the encouraging results of a study on mice at the University of Texas, Houston (USA). This work recalls that the exchange of whole blood is presented as a “possible modifying therapy” of Alzheimer’s disease. Because? Because most of one of the two pathogenic proteins, beta-amyloid, circulates in the blood before being deposited in the brain. The “cleaning” of the blood circulation would prevent its accumulation. Until he gets infected again, of course.
It would be like hemodialysis
“We have proof of concept for the use of technologies commonly used in medical practice, such as plasmapheresis or blood dialysis. Both would ‘clean’ patients’ blood and reduce the accumulation of toxic substances in the brainThat’s how Claudio Soto, the study’s lead author and director of the George and Cynthia Mitchel Center for Alzheimer’s and other brain disorders, sees it. disease because it circulates in the blood before reaching the brain,” he says.
Research against Alzheimer’s has essentially followed two paths, marked by the two substances known to be most closely linked to the disease. One of them is this abnormal protein called beta-amyloid, which turns into plaques that deposit in the arteries of the brain. There is another, called tau, which causes what are called neural tangles, a kind of very damaging knots that prevent communication between neurons. What is not known, and this is important, is whether the two manifestations are the cause or the consequence of the disease.
Unknowns pending
Hence the interest of approaches that are a priori as revolutionary as that of plasma transfusions. Although not certain, science suspects that beta-amyloid is one of the most toxic to the brain and, “very likely”, the trigger of the disease. It settles in the cerebral vessels and between neurons and from there it begins its harmful work. Continuous blood transfusions, as this latest study showed, reduced the buildup of amyloid plaques in the brain by 40-80%. As a result, the mice’s spatial memory also performed better.
Grifols is working on this same idea with a plasma preparation containing albumin, which is the main protein in blood and in the human body. The “Ambar” project began in 2004 and its formula was tested in patients with a mild or moderate stage in 41 Spanish and American hospitals. Disease progression was reduced in them by up to 61% and clinical deterioration by 71%.
The problem, according to the UPV professor of neurology, is that the effect of the transfusion is not maintained. You have to find a formula that does it. And moreover, how many blood donations would be needed in Spain to meet the current demand of 800,000 patients? The investigation is not closed. The work continues.