Alzheimer's blood test could predict onset up to 20 years in advance

[nitpicker]

https://www.theguardian.com/society/2019/aug/02/alzheimers-test-predicts-onset-up-to-20-years-in-advance

Alzheimer’s blood test could predict onset up to 20 years in advance

Fri 2 Aug 2019 09.18 BST First published on Fri 2 Aug 2019 00.23 BST

A blood test that can detect signs of Alzheimer’s as much as 20 years before the disease begins to have a debilitating effect has been developed by researchers in the US. Scientists at the Washington University School of Medicine in St Louis in Missouri believe the test can identify changes in the brain suggestive of Alzheimer’s with 94% accuracy, while being much cheaper and simpler than a PET brain scan.

The results of the study, which was published in the journal Neurology on Thursday, represent a potential breakthrough in the fight against the disease.

“Right now we screen people for clinical trials with brain scans, which is time-consuming and expensive, and enrolling participants takes years,” said the senior author, Randall Bateman, a leading professor of neurology. “But with a blood test, we could potentially screen thousands of people a month. That means we can more efficiently enrol participants in clinical trials, which will help us find treatments faster, and could have an enormous impact on the cost of the disease as well as the human suffering that goes with it.”

The researchers said they had found a way to measure levels of the protein amyloid beta, a key indicator of Alzheimer’s, in the blood. They can then use such levels to predict whether the protein has accumulated in the brain.

That analysis could then be combined with two other major Alzheimer’s risk factors – age and the presence of the genetic variant APOE4 – to accurately identify the relevant changes in the brain.

The researchers said the clumps of protein begin to form in the brain up to two decades before the onset of the characteristic memory loss, suggesting the tests could be used to predict Alzheimer’s years in advance. However, the benefits of such testing would not be seen to their fullest extent until treatments to halt the disease are developed.
(snip)

[Bernardo de La Paz]

1. One of most interesting discoveries about Alzheimers is that it may be a reaction to nasal infection

There is a direct nerve route from the nasal sensors to the core of the brain; smell is that important and that ancient of a sense.

Apparently the brain puts the amyloid beta around intruding infectors, and that protects the brain. This is normal and natural. It seems to get out of control or not be well regulated in some people.

[littlemissmartypants]

2. Links, references? Thanks in advance. nt

[Bernardo de La Paz]

4. An immigrant: Dr Robert Moir at MassGenH.

For those who like interviews (or don't like reading), here is a 15 minute podcast with an interview of him:

https://www.cbc.ca/player/play/1391682115504


Here is a well-written long article, which is a good thing, and some excerpts:

https://www.statnews.com/2018/10/29/alzheimers-research-outsider-bucked-prevailing-theory/

Moir’s experience is notable, however, because it shows that, even as one potential Alzheimer’s drug after another has failed for the last 15 years (the last such drug, Namenda, was approved in 2003), researchers with fresh approaches — and sound data to back them up — have struggled to get funded and to get studies published in top journals. Many scientists in the NIH “study sections” that evaluate grant applications, and those who vet submitted papers for journals, have so bought into the prevailing view of what causes Alzheimer’s that they resist alternative explanations, critics say.

But something had long bothered him about the “evil amyloid” dogma. The peptide is made by all vertebrates, including frogs and lizards and snakes and fish. In most species, it’s identical to humans’, suggesting that beta-amyloid evolved at least 400 million years ago. “Anything so extensively conserved over that immense span of time must play an important physiological role,” Moir said.

Moir, a native Australian, isn’t sure where he gets his anti-establishment streak, but during his undergraduate days down under he took a microbiology course from Nobel laureate-to-be Barry Marshall, who bucked orthodoxy for years by believing that a bacterial infection (H. pylori) causes ulcers. Marshall even infected himself to prove the point. “Everyone thought he was crazy,” Moir recalled. “He was crazy, but he was also right.”

If so, then the plaques it forms might be the brain’s last-ditch effort to protect itself from microbes, a sort of Spider-Man silk that binds up pathogens to keep them from damaging the brain. Maybe they save the brain from pathogens in the short term only to themselves prove toxic over the long term.

One hint of what those approaches should be comes from a 2018 study in Taiwan. It found that people with a herpes virus infection are at 2.5-fold higher risk for dementia than similar people without that infection — and that those treated with anti-herpes drugs were 92 percent less likely to develop dementia than those whose infections were left untreated.

[Phoenix61]

3. Weird link between losing the ability to smell

peanut butter and Alzheimer’s.