Following a post-mortem study, researchers discovered that brains with Alzheimer’s disease contained twice as many strains of the herpes virus as brains free of the neurological disease.
“We observed an increase in human herpes virus 6A (HHV-6A) and human herpes virus 7 (HHV-7) in subjects with Alzheimer’s disease compared to controls.” This quote, taken froma new study published in the journal Neuron, supports a controversial theory that Alzheimer’s disease may be triggered by one or more viruses affecting the brain.
“We constructed multi-scale networks of the Alzheimer’s disease-associated virome, integrating genomic, transcriptomic, proteomic and histopathological data in four brain regions from post-mortem human tissues”, explain the researchers. In other words, the team analyzed almost 1000 post-mortem brains of people affected or not by Alzheimer’s disease.
“A rather old idea”
Result: two different strains of herpes virus were present in 40 to 50% of the tissues, herpes 6A and herpes 7 (almost everyone carries strains of herpes, only at the origin of eruptions in young children, Editor’s note). In addition, brains with Alzheimer’s disease contained twice as many of these strains as brains without the neurological disease. These findings were replicated in two other independent and geographically dispersed cohorts.
“The theory that viruses or other pathogens could play a role in the development of Alzheimer’s disease is a fairly old idea,” rightly recalls Dr. Benjamin Readhead, assistant professor at Arizona State University. (United States). Because the viruses have been found in both “Alzheimer’s” and “non-Alzheimer’s” tissue, scientists cannot simply say that infection with these viruses causes Alzheimer’s disease, and further testing is needed. .
Outstanding issues
But “one of the real outstanding questions is to try to determine to what extent what we see could be a causal factor of the disease”, concludes Benjamin Readhea. Alzheimer’s and related dementias affect approximately one million patients in France. 100,000 to 150,000 new cases are reported every year.
Alzheimer’s disease has been in the spotlight recently, with Health Minister Agnès Buzyn announcing the controversial reimbursement of certain drugs by social security. “I confirm the delisting of anti-Alzheimer’s drugs, and it is absolutely not for budgetary reasons. It is because these drugs have been shown by the HAS to be harmful and cause many side effects, with fractures and falls. We de-reimburse so that people no longer use them”, she explained, Wednesday, May 30, on the set of “19/20” of France 3.
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