American researchers reveal a surprising link between a common virus, present in most octogenarians, and a specific form of Alzheimer’s disease.
- Human cytomegalovirus (CMV), a viral infection that affects nearly 80% of adults over the age of 80, appears to play a key role in a unique subtype of Alzheimer’s disease.
- Researchers identified an association between the presence of specific immune cells and a high proportion of Alzheimer’s patients (47%, compared to 25% in unaffected individuals).
- The study shows that in the laboratory, CMV infection in artificial brain tissue accelerates the formation of amyloid plaques and phosphorylated tau, worsening symptoms.
What if the key to the fight against Alzheimer’s was ultimately found in our intestinal microbiota? In the bowels of certain patients there may indeed be hidden an unexpected suspect: a very common virus which could silently contribute to neurodegenerative disease. If the role of microbes in this pathology has long been suspected, a new study highlights an unprecedented association between human cytomegalovirus (CMV) and a particular form of Alzheimer’s.
A subtype of Alzheimer’s involving a common virus
CMV, a viral infection that affects nearly 80% of adults over the age of 80, appears to play a key role in a unique subtype of the disease. Researchers at Arizona State University (United States) have identified an association between the presence of specific immune cells and a high proportion of patients with Alzheimer’s (47%, compared to 25% in non-Alzheimer’s individuals). affected). These key cells were more common in subjects with both CMV and increased levels of an antibody called immunoglobulin G4 (IgG4) in the colon, vagus nerve and brain tissue.
Published in the journal Alzheimer’s and Dementiathe study offers a unique approach by examining several body systems: the intestine, the brain and the vagus nerve which connects them. This allowed researchers to establish biological correlations between the virus, immune responses, and distinctive features of the disease, such as amyloid plaques and tau protein tangles. “We believe we have identified a unique biological subtype of Alzheimer’s, potentially affecting between 25% and 45% of patients”assure the scientists in a press release.
The intestine, a key player in the fight against Alzheimer’s?
In the laboratory, artificial brain tissue infected with CMV showed rapid progression of key disease markers, such as amyloid beta-42 and phosphorylated tau. By reinforcing the hypothesis of an active role of CMV in certain cases of Alzheimer’s, these observations could open up new therapeutic perspectives against this still incurable neurodegenerative disease.
In particular, the researchers plan to develop a blood test to detect chronic CMV infections in the intestine, to better identify patients likely to benefit from specific antiviral treatments. Ultimately, this approach could revolutionize the diagnosis and prevention of this subtype of Alzheimer’s.