We are searching data for your request:
Upon completion, a link will appear to access the found materials.
New theory on the development of Alzheimer's?
Alzheimer's affects many people around the world. The causes of the disease are still not fully understood. A new theory says that bacteria, viruses, or other infectious pathogens could play a role in the development of Alzheimer's.
In a recent discussion of the possible causes of Alzheimer's, researchers suspected that bacteria, viruses or other infectious pathogens are involved in the development of Alzheimer's. The results of the interesting discussion were published in the English-language journal "Nature Reviews Neurology".
What is the infection theory for Alzheimer's?
The idea that bacteria, viruses or other infectious pathogens could play a role in the development of Alzheimer's was discussed in a new discussion group. The concept, sometimes referred to as the infection theory of Alzheimer's disease, was first mentioned about 30 years ago. Since then, however, this idea has met with considerable resistance in the research community.
What has been the trigger for Alzheimer's so far?
So far, plaques of amyloid beta and accumulations of the tau protein have been the cause of the disease. The repeated failures of drugs that target amyloids, as well as recent research that supports a microbial link to Alzheimer's disease, have sparked new interest in viruses or other infectious pathogens as triggers.
New technology and methods lead to new approaches
"Accelerating the technology and methodology for profiling biological systems has really opened up new ways of understanding whether microbes could play a role in Alzheimer's disease," said Ben Readhead of Arizona State University in a press release.
Discussion should improve understanding about Alzheimer's
The Viewpoint article was a good opportunity for researchers with different opinions, key evidence, inconsistent results, and opportunities for new research to discuss that could help advance understanding of the role of microbes in Alzheimer's disease, the expert adds.
Plaques and tangles as triggers of the disease?
Since the first diagnosis of Alzheimer's disease in 1906, research has focused in particular on two features that keep appearing in Alzheimer's-damaged brains. These are clumps of plaques caused by amyloid beta and twisted forms of the tau protein called neurofibrillary nodes. Although plaques and so-called tangles are seen as diagnostic guides for Alzheimer's disease, many believe that they are not the primary cause of the disease.
Effect of experimental drugs has been studied
The experimental drugs gantenerumab and solanezumab were recently tested on a unique group of participants. These were still young and healthy at the time of the trials and all contained a rare mutation that guaranteed that they would develop dementia over time. They were therefore ideal candidates to test whether an anti-amyloid agent could prove beneficial.
Medicines did not prevent mental degradation
The results obtained confirmed that the drugs could not prevent or slow the mental decline associated with dementia. This speaks against the amyloid hypothesis - the prevailing theory that describes the mechanisms of onset and progression of Alzheimer's.
Do microorganisms trigger Alzheimer's?
Even before this notion, alternative theories of the disease have been proposed. A theory described in the Viewpoint discussion assumes that Alzheimer's is not caused by accumulations of lifeless proteins, but rather by microorganisms, as is the case with so many infectious diseases.
Are microbes a key player in the pathology of Alzheimer's?
Researchers examined the presence of various infectious agents that appear to be linked to Alzheimer's disease. The discussion highlights many of the indications that microbes can actually be key players in the pathology of Alzheimer's disease.
Relationship between Alzheimer's and herpes viruses has been investigated
In previous research, large data sets were used to investigate the prevalence of two common herpes viruses, some of which are found in Alzheimer's brain tissue. This study showed that three strains of the virus, HSV-1, HHV-6A and 7, were more common in brain samples from Alzheimer's patients compared to healthy brains. The viruses also appear to be linked to genetic networks of Alzheimer's disease, including cell death, amyloid-β accumulation, and the production of neurofibrillary tissue tension.
Reasons to reject the new theory
There are several reasons why the pathogen theory has so far been rejected. Researchers may have an inadequate microbiological background, or may associate pathogens inaccurately with acute rather than chronic diseases, although a number of microbial infections can actually remain asymptomatic in the body for decades.
Theory does not rule out the role of amyloid
In the discussion, the researchers emphasized that a microbial connection with Alzheimer's and the amyloid hypothesis can be complementary rather than exclusive. It is still possible that the deposition of amyloid triggers a process of neurological degradation, followed by opportunistic infections. It is also possible that exactly the opposite is the case, i.e. amyloid deposits represent a defense reaction against the infection and invasive microbes remain trapped in sticky concentrations of amyloid.
More research is needed
Of course, a lot of further research is needed to prove the infection theory of Alzheimer's pathology. However, based on encouraging advances, research funding and grants are now increasingly being made available on the subject. (as)
Author and source information
This text corresponds to the specifications of the medical literature, medical guidelines and current studies and has been checked by medical doctors.
Swell:
- Ruth F. Itzhaki, Todd E. Golde, Michael T. Heneka, Ben Readhead: Do infections have a role in the pathogenesis of Alzheimer disease ?, in Nature Reviews Neurology (published March 9, 2020), Nature Reviews Neurology
- Viewpoint: Could disease pathogens be the dark matter behind Alzheimer's disease?, Arizona State University (Published March 18, 2020), Arizona State University
