Blood Test for Alzheimer’s Disease? Researchers Release New Findings

Blood-based test to identify proteins linked to AD

The team identified 18 proteins in the blood that appeared to be associated with changes linked to Alzheimer’s disease or mild cognitive impairment, according to the abstract. They then developed an 18-protein panel to identify Alzheimer’s disease or mild cognitive impairment. They found that the panel was able to classify the two conditions in two different cohorts with more than 90% accuracy.”

Experts agree measuring blood proteins is an effective approach when it comes to early detection of AD.

The research has not yet been published in a peer-reviewed journal.

“These findings are definitely promising as it is always helpful to be able to detect diseases early,” said Dr. Andrew Newberg, neuroscientist and director of research at the Marcus Institute of Integrative Health and a physician at Jefferson University Hospital. “The main issue is that since a truly effective therapy to stop AD is not available, it is less clear what we can do with such an earlier diagnosis.”

Newberg was not part of the study.

Evidence suggests that living a healthy lifestyle with good nutrition, exercise and sleep are the best current practices to prevent the development and progression of AD. But they do not stop it, Newberg added.

Along with helping with early diagnosis, this blood-based test can detect biological pathways that may be involved in the development of Alzheimer’s disease.

“The ability to measure hundreds of proteins simultaneously in the blood and determine patterns associated with risk for Alzheimer’s disease is promising both for increasing early diagnosis and for identifying biological pathways that may be implicated in the risk and progression of the disease, which is particularly relevant for developing treatments,”Adam Brickman, PhD, professor of neuropsychology at Columbia University Vagelos College of Physicians and Surgeons, stated.

Brickman was not part of the research.

Men experience more rapid cognitive and brain volume declines 

The other key finding in new research relates to cognitive and brain volume decline rates among men versus women.

This research has not yet been published in a peer-reviewed journal.

The abstract reports that in a study of 76 older adults, the male individuals had a faster accumulation of protein biomarkers of Alzheimer’s disease and more rapid declines in cognition and brain volume than women.

Neurologists state further research is needed to understand the underlying reasons why this is the case.

“There is a lot of debate about whether the biological profile and course of AD differ between men and women,” said Brickman. “We do not know whether reported differences reflect true biological differences or whether they are attributable to selection bias or differential survival in research studies.”

Newberg explained, “It is unclear at the present time whether this is related to genetics, hormones, or some other factors that lead to the male brain being different than females in terms of how it responds to the process of AD.”

It’s also important to understand what cognitive decline and atrophy look like among AD patients.

“Cognitive decline refers to the loss of memory and the progressive inability to perform daily life activities such as balancing a checkbook, going to the market, or even maintaining occupation activities,” said Newberg. “Atrophy refers to the overall amount of brain tissue.”

The average brain weighs about 3 pounds but as atrophy sets in, that can reduce by up to 5% per year while a normal person will only have their brain reduced in size by less than 1% per year. Alzheimer’s also affects specific regions more such as the hippocampus which is one of the main memory areas, Newberg added.

More specifically, “individuals with Alzheimer’s disease typically have a progressive, gradual decline in their cognitive abilities over several years, which usually begins with memory and then progresses to other cognitive domains, like language and executive functioning,” said Brickman.

“Brain atrophy in Alzheimer’s disease, usually measured with magnetic resonance imaging (MRI), follows a similar pattern, first affecting the medial temporal lobe, which houses important structures for learning and memory, and then spreading throughout the cortex,” Brickman explained.

Why early detection is crucial

“It will be more likely that at some point we can find a way to stop the progression of dementias such as AD rather than rebuild brain tissue that has already been destroyed by the disease process,” said Newberg. “So, the earlier we detect these neurodegenerative disorders, the more brain tissue we can protect and the less severe will be the cognitive impairment.”

In fact, these disease processes likely begin 5-10 years before people notice the changes. If we can detect people even before they become symptomatic and lose any of their cognitive function, we can treat them and help them maintain their brain function at a relatively normal level. But that all requires us to ultimately figure out what is causing these disorders and how to stop it.

“The current thinking is that early detection could lead to earlier treatment, hopefully arresting the disease before it progresses to the point where treatment would no longer be helpful,” Brickman stated. “The earliest detection of the disease could also help us understand the various biological pathways are operative and different stages.”

Takeaway

Research presented at Neuroscience 2023 showed new methods of detecting Alzheimer’s disease early.

First, researchers developed a blood-based test that can detect blood proteins linked to Alzheimer’s disease and mild cognitive impairment.

Second, they found men experience a more rapid accumulation of AD protein biomarkers and a faster rate of cognitive and brain volume decline.

While experts conclude this research is promising, further studies are needed.