What Is the New Test?
A news item crossed my radar screen a couple weeks ago. This actually goes all the way back to August 2019, and was published in the Neurology, which is an academic journal, and subsequently was picked up by various news outlets.
I saw this through a press release from Washington University School of Medicine which is located in St. Louis, Missouri. The report focused on a new blood test that’s available for Alzheimer’s Disease.
Currently, it’s in testing phases. But, it has been developed, and researchers think that it holds great promise, and let me explain why that is.
So, first of all:
What does the test do?
I have both an ARTICLE and a YouTube VIDEO on some of the possible causes for Alzheimer’s disease. One of the causes that’s often referenced is the accumulation, in the brain, of various protein “gunk.”
There are two different types of protein that are implicated in this. The first is called beta-amyloid and the second is called tau. The two of these, together, account for the various “plaques and tangles” that Alzheimer’s patients’ brains seem to be riddled with.
The 100% definitive test for this is going to be an autopsy. (For these assortment of Alzheimer’s “tests,” see – again – either my other written work, e.g., HERE, or the companion, video presentation, HERE.)
There is very little use, obviously, for an autopsy to play in terms of preventative medicine or even in treatment, while somebody’s alive. It can give you the accurate cause of death only after the fact. But it’s not going to be too good for medicinal purposes.
Now comes a blood test that promises, or at leads holds the promise, of being able to detect levels of beta-amyloid in the blood during a person’s life.
Two kinds of beta-amyloid protein are being focused upon. And those are designated “Number 40” and “Number 42.”
My layman’s “take” on this is that there is an array of these beta-amyloid’s, but that 40 and 42 somehow play particularly important roles in the pathological accumulation of these deposits in an Alzheimer’s-afflicted brain.
I should say the test has actually been going on for couple years.
What researchers have hypothesized, and has since been borne out – at least, in early stages – is that levels of beta-amyloid in the blood suggest an accumulation of the beta-amyloid in the brain.
Why is the test important?
I mentioned that autopsies are the definitive test for Alzheimer’s. But, of course, autopsies are no good for diagnostic purposes so long as the patient is alive.
So, the most accurate test a living person can get right now is a so-called “Pet Scan,” which is shorthand for the more forbidding “positron-emission-tomography scan.”
A pet scan is essentially the best test that’s available.
But… pet scans are both expensive and time-consuming to perform. Therefore, this blood test holds out the hope for being able to be administered on a much wider scale and at far less of a cost.
Those are two points in its favor.
In theory, a blood test of this kind would be able to be given in a doctor’s office – instead of, for example, having to send the patient to an imaging center.
How Accurate Is the Blood Test?
What researchers discovered, when they compared the blood-test results against the pet-scan results, was that the blood test was 88% correlated with the pet scan.
What this seems to suggest is that, if for every 100 pet scans displaying evidence of Alzheimer’s, a blood test would detect Alzheimer’s in 88 of those cases.
At least… that’s the way I’m reading the article. (Disclaimer: I am not a medical professional! This is simply my untutored commentary on the situation. For advice, seek a healthcare expert who is familiar with your personal history.)
So, the test was (provisionally) determined to be 88% effective, in the above respect.
What Other Risk Factors Were Considered?
It’s worth pointing out that when they coupled the blood test with a couple of other risk factors – for example, age – the effectiveness increased.
It’s widely accepted that a person’s Alzheimer’s risk goes up with age. In fact, it’s said that your risk actually doubles every five years after age 65.[1]
Also, they factored in genetic predisposition. So, if you have the APO-E4 variant gene in your genetic makeup – as I myself do (see my video testimony, HERE) – then you have a higher (3 to 5 times higher actually!) chance of developing Alzheimer’s sometime in your life.[2]
Another risk factor – believe it or not – is sex. We talked about this in other places. (My AlzheimersProof.com post is HERE and my video is HERE.) Sex may not be its own risk factor. It may simply be that women live longer and therefore are more likely to manifest symptoms of Alzheimer’s and other dementias because of their longevity. But it is sometimes said that two out of three Alzheimer’s sufferers are female.[3]
When researchers incorporated age and genetic predisposition, they found that the test was 94% effective in terms of matching up to the pet scan.
What’s the Practical Benefit of an Alzheimer’s Blood Test?
But what they found, in addition to that, was that when some of the blood tests came up positive for people who had not yest been pet scanned, those people eventually came up positive on the pet scan as well.
This suggested to researchers that the test might actually be even more accurate than the pet scan, and able to detect Alzheimer’s in its very earliest stages.
Recall, also, that Alzheimer’s disease manifests in symptoms. But researchers believe that the underlying brain changes may take place as far back as a decade or more prior to the onset of symptoms.
One of the benefits obviously of early detection is they want to be able to treat people in presymptomatic stages. They feel like once memory changes, and other changes manifest in the brain, then that brain is already so damaged that it is basically beyond help.
In possibly being able to find people in the earliest stages of Alzheimer’s, another potential benefit of the blood test is that it might help with constructing clinical trials for developing interventions.
An early version of this test goes back to 2017 or even 2016. At that time, some of the articles referenced “autoimmune antibodies,” also called “autoantibodies.” The idea was that the immune system’s response to the accumulation of beta-amyloid protein might be able to be gauged. But, upon closer inspection of these articles now, in retrospect, they also seem to be describing a blood test that focuses on some of these beta-amyloid protein variants.
The fundamental idea is to try to catch Alzheimer’s disease in its very earliest stages.
Sometimes this “preclinical” stage is referred to variously as Very Mild Cognitive Impairment (especially on the so-called 7-Stage-Dementia view – about which, see HERE and HERE) or Mild Cognitive Impairment, often better known simply by the abbreviation “MCI.”
Note, however, that not all cases of MCI develop into Alzheimer’s disease. For one thing, there are other sorts of dementia (e.g., Lewy-Body Dementia, Multi-Infarct Dementia, Parkinson’s Disease, etc.) and there are traumatic brain injuries and other conditions that also might be prefaced by mild cognitive impairment. (For the difference between “Alzheimer’s Disease” and “dementia,” see my video, HERE.)
“Mild Cognitive Impairment” is, in a sense, just a catchall phrase for a certain level of mental diminishment as well as for the impoverishment of other perceptual and reasoning capabilities.
Concluding Reflection
There’s little doubt, though, that this blood test is fascinating. Even though it still has some way to go before you can expect it at a physician’s office near you, it holds promise.
Number one, it’s less expensive than the pet scan. Number two, it is able to be administered more widely, and in more environments – like doctors’ offices, and other places (such as out-patient clinics and “urgent-care” centers) – whereas the pet scan is obviously limited to an imaging center. Number three, it’s possibly more accurate than the pet scan. And, number four, it’s certainly superior to the autopsy in the sense that it holds out promise for being able to help treat and diagnose people while they are still alive – which is, quite obviously, advantageous.
Notes:
(Featured image credit: Billy W., <https://images.freeimages.com/images/large-previews/97a/blood-test-1545982.jpg>.)
[1] See: “Causes and Risk Factors for Alzheimer’s Disease,” Alzheimer’s Association, <https://www.alz.org/alzheimers-dementia/what-is-alzheimers/causes-and-risk-factors>.
[2] Though, the risk really ramps up after age 75. See the video for details.
[3] Again, see the Alzheimer’s Association: “Women and Alzheimer’s,” <https://www.alz.org/alzheimers-dementia/what-is-alzheimers/women-and-alzheimer-s>.