SOBA: Potential blood test for Alzheimer's disease(pnas.org)
pnas.org
SOBA: Potential blood test for Alzheimer's disease
https://www.pnas.org/doi/10.1073/pnas.2213157119
40 comments
Does this mean that Alzheimer's is something that floats around your body? Or signs of it floating around? I always assumed it was something that could develop in anyone, like heart disease or some liver problem (except on the brain).
I can’t claim to know much about this, but as someone who recently suffered from possibly temporary amyloidosis-like symptoms, I’ve had to research this a lot recently.
Basically, amyloids have been known for centuries as e.g. white stuff that collects in spleens and recently research on dementia has turned to amyloids as one of the precursors of one of the types of Alzheimer’s. It’s not yet clear if every case has amyloid involvement or if clearing amyloids can resolve the condition without any side effects yet, in particular there’s been reported brain shrinkage.
https://en.m.wikipedia.org/wiki/Amyloid_beta talks about the thing floating around your body in more detail.
I can’t say I’m an expert at any of this though. I’ve mostly looked at this from an AA amyloidosis perspective rather than an Altzheimer’s one.
We actually already have a test for the presence of amyloids - SAA blood tests commonly used to diagnose infection in horses and cats. Other creatures, including humans, can also measure C Reactive Protein, but both CRP and SAA are measures of stress or inflammation associated with bacterial infection. Your body routinely gets rid of amyloids it might produce, which is part of why it’s said people with AA amyloidosis recover when the underlying cause is treated, I think. But it’s unclear how well we can recover long-term and amyloids and biofilms are still active research areas.
All I can say is that for my amyloidosis-like symptoms, taking vitamin C regularly helps my thinking and the occasional high dose of vitamin A appears to temporarily reverse some of the amyloid-induced nerve damage. But I should also clarify I’m still awaiting test results to determine if I have amyloids and also my condition improves with antibiotics which means vitamin A and C might be interfering with bacteria (where biofilm = amyloids) rather than with the amyloid fibrils on their own.
Basically, amyloids have been known for centuries as e.g. white stuff that collects in spleens and recently research on dementia has turned to amyloids as one of the precursors of one of the types of Alzheimer’s. It’s not yet clear if every case has amyloid involvement or if clearing amyloids can resolve the condition without any side effects yet, in particular there’s been reported brain shrinkage.
https://en.m.wikipedia.org/wiki/Amyloid_beta talks about the thing floating around your body in more detail.
I can’t say I’m an expert at any of this though. I’ve mostly looked at this from an AA amyloidosis perspective rather than an Altzheimer’s one.
We actually already have a test for the presence of amyloids - SAA blood tests commonly used to diagnose infection in horses and cats. Other creatures, including humans, can also measure C Reactive Protein, but both CRP and SAA are measures of stress or inflammation associated with bacterial infection. Your body routinely gets rid of amyloids it might produce, which is part of why it’s said people with AA amyloidosis recover when the underlying cause is treated, I think. But it’s unclear how well we can recover long-term and amyloids and biofilms are still active research areas.
All I can say is that for my amyloidosis-like symptoms, taking vitamin C regularly helps my thinking and the occasional high dose of vitamin A appears to temporarily reverse some of the amyloid-induced nerve damage. But I should also clarify I’m still awaiting test results to determine if I have amyloids and also my condition improves with antibiotics which means vitamin A and C might be interfering with bacteria (where biofilm = amyloids) rather than with the amyloid fibrils on their own.
It is clear that clearing the amyloids does not relieve one from the symptoms of dementia, or stop them. See Aducanumab, and the amyloid hypothesis nature article.
Wasnt the base theory, that some viruses damage cells, that then do not become cancerous, but produce useless protein crap, that spills everywhere? Basically slow death, by spam every cellular division?
Are you talking about cellular senescence? Those cells don’t divide. They produce inflammatory proteins, aka senescence-associated secretary phenotype. More senescent cells in ageing, but no direct link AFAIK.
Yes, yes, that was it. Garbage slowly clogging the maintenance functions, building up other toxic substances, like plastic bags clogging a chemical plant over time..
And it does not have to be directly.. it just has to tilt the chemical environment slowly, but steadily towards something bad downstream.
And it does not have to be directly.. it just has to tilt the chemical environment slowly, but steadily towards something bad downstream.
Heart disease risk is strongly influenced by "floating" factors (e.g., apolipoprotein B containing particles).
A risk factor for Alzheimer's disease is your ApoE allele, so it's not particularly odd to me that circulating factors could influence risk. But even if not—even if the test is just picking up on incidentally released factors that are just detectable—it could be sensible.
(I'm saying this completely agnostic to the claims of the article itself, just replying to your comment with general ideas.)
A risk factor for Alzheimer's disease is your ApoE allele, so it's not particularly odd to me that circulating factors could influence risk. But even if not—even if the test is just picking up on incidentally released factors that are just detectable—it could be sensible.
(I'm saying this completely agnostic to the claims of the article itself, just replying to your comment with general ideas.)
Any one else read this as “presidential blood test for alzheimers”?
No need for a test in his case.
The big question is would you want to know of you have Alzheimer’s early at this point? Is there reliable treatment or cure? Those would be easier to develop if a reliable test is invented, but without them, would an adult likely only gain the loss of agency of their life? What would you do to prepare you and loved ones for losing yourself? What would your remaining life change into, by knowing? What would your loved and not so loved ones do if they knew?
I would use the time to get my finances in order - which essentially means moving as many of my assets as possible out of reach of the predatory nursing home and memory care industry.
I would try and find a way transfer all my assets to my children and/or spouse, and ensure they would never list me as a dependent anywhere. I'm not clear if the nursing home can take your spouse's assets or not. If so we would need to file for divorce to protect her assets.
I would essentially go broke and let medicade pay for my care. Sure they don't put you in in the "finest" facility, but pretty soon you'll be far enough gone it won't matter. The expensive places are just widow dressing anyway. You are treated the same everywhere.
I would try and find a way transfer all my assets to my children and/or spouse, and ensure they would never list me as a dependent anywhere. I'm not clear if the nursing home can take your spouse's assets or not. If so we would need to file for divorce to protect her assets.
I would essentially go broke and let medicade pay for my care. Sure they don't put you in in the "finest" facility, but pretty soon you'll be far enough gone it won't matter. The expensive places are just widow dressing anyway. You are treated the same everywhere.
You have a very dark view. As someone who has put a few family members through nursing homes and hospice my experience was very pleasant.
Nobody was after their money. No one was trying to rip them off. The hospice care was kind and supportive.
Why do have some idea that a nursing home is going take you money? I’ve never heard of these situations outside of Reddit.
Nobody was after their money. No one was trying to rip them off. The hospice care was kind and supportive.
Why do have some idea that a nursing home is going take you money? I’ve never heard of these situations outside of Reddit.
Me too. Who paid for that pleasant experience? https://www.npr.org/sections/health-shots/2022/07/28/1113134...
Both of my grandmothers had Alzheimer's, and both clearly in retrospect tried to hide their problems as long as possible. Knowing might have made some difference in type of care, but not much, and at least one of them clearly explicitly hid it because she was as scared of the potential consequences of e.g. ending up in a nursing home as she was of the condition itself. I'm terrified of getting it, given what I've seen of it, and the prevalence of it in my family, but I'm not at all confident I'd want to know because of how it might affect my enjoyment of the time I'd have left.
At the same time, by the time it becomes a question, odds are the patient may be showing symptoms where it isn't a question if anything is wrong, but whether or not what they have is treatable (that we know something was seriously wrong was the case for both my grandmothers). Perhaps being able to rule Alzheimer's out will be helpful in that respect.
At the same time, by the time it becomes a question, odds are the patient may be showing symptoms where it isn't a question if anything is wrong, but whether or not what they have is treatable (that we know something was seriously wrong was the case for both my grandmothers). Perhaps being able to rule Alzheimer's out will be helpful in that respect.
My father told me he loved me and was proud of me and how i turned out and that he had no regrets (He doesn't really know my name anymore). I would do the same for my loved ones and tell them things are ok and to let me go. (I've also told them if i don't remember them, the wolves will take good care of me!) Looking a his lifestyle and considering this as an epidemic, lifestyle & inflammation seems to be big factors. Diabetes and Pre-Diabetes are also risk factors. If i was aware early enough i would start exercising more, adopt an anti-inflammatory diet, meditate and consider psychedelics https://pubmed.ncbi.nlm.nih.gov/32973482 and get my affairs in order as much as i could. So basically the test may help people shift gears harder and consider lifestyle changes and preparation.
Yes, absolutely I'd want to know, the same as I'd prefer to know my date of death if possible, so I can have a clearer understanding of how much time I have left to complete my goals. I operate under the understanding that I might die instantly at any moment and that's fine, but knowing the "hard cap" on my length of life would be nice as well.
I'm sure some would like it so they could plan their assisted suicide, many who have seen someone suffer alzheimer's would prefer not to, based on my conversations.
I'm sure some would like it so they could plan their assisted suicide, many who have seen someone suffer alzheimer's would prefer not to, based on my conversations.
I would want to know as early as possible. Find a cure for it!
If there is no cure in my lifetime, then as an act of final service to humankind - study me. Use my data as progressive snapshots, the more snapshots there are, the sooner we find the cure!
If there is no cure in my lifetime, then as an act of final service to humankind - study me. Use my data as progressive snapshots, the more snapshots there are, the sooner we find the cure!
People who are genetically predisposed to Alzheimer's have had similar experience, by taking genetic tests to check their variants.
https://www.nytimes.com/2012/06/10/magazine/an-alzheimers-ge...
https://www.nytimes.com/2012/06/10/magazine/an-alzheimers-ge...
People choose to be tested for Huntington disease, including many young adults who have recently turned 18 (in the USA). While, like yourself, I don't know what I would personally chose to do if faced with this situation, the availability of a specific test with a high NPV and low FP rate would be beneficial to have.
I would prefer early awareness just so I can be more attentive to potential early warnings signs. Though, this only makes sense if you have some degree of optimism that there will be more effective treatments available by the time genetics catch up with you.
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Sounds amazing, though I don’t know how long it takes for something to go from the “medical research” stage to “a test your doctor can order” stage, and I’m afraid that will be >10 years
The likelihood of hurting the patient weighs in on how hard it is to get something approved, and blood tests are much less likely to hurt somebody than a lot of other things.
Especially with something not quite actionable, like routine PSA testing or back pain, physicians have been historically trained to withhold on testing in the interest of cost-savings and patient anxiety.
However, with medical assistance in dying coming on line, at least in Canada, the “actionable” part may be pre-planning.
However, with medical assistance in dying coming on line, at least in Canada, the “actionable” part may be pre-planning.
I’d love to see a future where we test “excessively”. A CT/Ultrasound when someone walks in to emerg, bloodwork for things that are just possibilities, and so-on.
The value in catching things early and in having a timeline to look back on is probably massive.
The value in catching things early and in having a timeline to look back on is probably massive.
Tests have a false positive rate. Real suffering is caused by increasing the number of false positives (by increasing testing).
I've heard this argument often, and it's never articulated correctly.
(1) False positives if handled poorly cause suffering.
(2) There is problem where we hide the statistics in an attempt to make things more relatable. Tests are often not "positive" or "negative", they just mean something like "given your situation, you have an x% chance of having this issue".
Conveying the information more accurately and responding correctly fix most problems. Cancers and some other diseases are almost entirely preventable if fixed early enough, which require more testing with more false positives and this is absolutely worth the tradeoff for most people. Ultimately, we should give patients the information and choice whether to test or not.
(1) False positives if handled poorly cause suffering.
(2) There is problem where we hide the statistics in an attempt to make things more relatable. Tests are often not "positive" or "negative", they just mean something like "given your situation, you have an x% chance of having this issue".
Conveying the information more accurately and responding correctly fix most problems. Cancers and some other diseases are almost entirely preventable if fixed early enough, which require more testing with more false positives and this is absolutely worth the tradeoff for most people. Ultimately, we should give patients the information and choice whether to test or not.
False positives, or even the screening itself, if at a large enough scale, causes death.
E.g. I had a gastroscopy recently. Endoscopies (e.g. for gastroscopy, colonoscopy) have incidence rates in the 0.1%-1% range. Most incidents are minor. Minor bleeds etc. Some are major. Perforation is a risk. Some performation leads to death. Over-prescribe endoscopies either as a first test or as a followup and you'll be killing more people than you save, even if the risk to any individual patient is tiny.
It might seem worth it. E.g. you might catch a prostate cancer early from a colonoscopy. You might catch a hernia that could become a problem from a gastroscopy. Or any number of other things.
The problem is that broaden screening too much, and your true positive rate becomes too low, and the true positive rate where the problem would otherwise go undetected and cause problems becomes even lower, and so for many conditions routine screening barely budges survival rates for true positives, but creates a mortality rate for false positives.
Sometimes broadening testing is worth it - a serious enough and frequent enough condition can warrant it by saving more than it kills even if you only marginally improve survival rates, or you might have a condition that is rare but where detection can very significantly affect survival rates.
But often it isn't. E.g. too broad screening for prostate cancer and breast cancer are both cases where the benefit in terms of nudging survival rates from broad screening vs. more targeted efforts (e.g. screening people who have felt something) is low enough that the advice most places is to focus on limited age groups or other risk factors. Hernias - I turned out to have one - is another one where the proportion that ever becomes a serious problem is so limited that the (tiny) risk of more broadly using gastroscopy to look specifically for that (rather than to investigate potentially more serious problems) is rarely warranted, and where the risk of a portion of patients pushing and getting (a lot more risky) surgical intervention in cases where it is not medically necessary is another reason to discourage too broad screening.
There's a continuum here from not allowing patients to choose, via allowing it but discouraging it, to actively encouraging it, to broad screening programs. There are a whole lot of things that'd be fine to allow if a patient has specific fears, that still should be broadly discouraged.
E.g. I had a gastroscopy recently. Endoscopies (e.g. for gastroscopy, colonoscopy) have incidence rates in the 0.1%-1% range. Most incidents are minor. Minor bleeds etc. Some are major. Perforation is a risk. Some performation leads to death. Over-prescribe endoscopies either as a first test or as a followup and you'll be killing more people than you save, even if the risk to any individual patient is tiny.
It might seem worth it. E.g. you might catch a prostate cancer early from a colonoscopy. You might catch a hernia that could become a problem from a gastroscopy. Or any number of other things.
The problem is that broaden screening too much, and your true positive rate becomes too low, and the true positive rate where the problem would otherwise go undetected and cause problems becomes even lower, and so for many conditions routine screening barely budges survival rates for true positives, but creates a mortality rate for false positives.
Sometimes broadening testing is worth it - a serious enough and frequent enough condition can warrant it by saving more than it kills even if you only marginally improve survival rates, or you might have a condition that is rare but where detection can very significantly affect survival rates.
But often it isn't. E.g. too broad screening for prostate cancer and breast cancer are both cases where the benefit in terms of nudging survival rates from broad screening vs. more targeted efforts (e.g. screening people who have felt something) is low enough that the advice most places is to focus on limited age groups or other risk factors. Hernias - I turned out to have one - is another one where the proportion that ever becomes a serious problem is so limited that the (tiny) risk of more broadly using gastroscopy to look specifically for that (rather than to investigate potentially more serious problems) is rarely warranted, and where the risk of a portion of patients pushing and getting (a lot more risky) surgical intervention in cases where it is not medically necessary is another reason to discourage too broad screening.
There's a continuum here from not allowing patients to choose, via allowing it but discouraging it, to actively encouraging it, to broad screening programs. There are a whole lot of things that'd be fine to allow if a patient has specific fears, that still should be broadly discouraged.
I don’t know if I would advocate for “excessive” endoscopies. You’re right: there’s a not insignificant chance for injury or death and I can imagine an situation where the risk goes up due to the staff being overworked.
However, a non-invasive scan (ultrasound, CT) still has a decent chance of catching prostate cancer and hernias, and as far as I’m aware they carry zero risk of injury or death.
However, a non-invasive scan (ultrasound, CT) still has a decent chance of catching prostate cancer and hernias, and as far as I’m aware they carry zero risk of injury or death.
CT scans are not risk free. They're x-rays and while again the individual risk is tiny, doing a large number of them over a large population would be expected to increase incidence of cancer [1] (in fact more so than I thought).
External ultrasound (ultrasounds can also be done endoscopically) itself I think is risk free, but inducing anxiety in patients or exposing patients to a healthcare facility is categorically not risk free even though the risk is very small for each individual patient.
The problem is not that the risk is high for individual screening events, but that even a one in a million even will happen regularly once you start regularly screening a multi-million person population.
There is no such thing as a risk free event once the scale is large enough, so the question becomes whether the risk is low enough relative to the potential benefit, and then you need to consider that often a true positive is rare, and making a difference to the outcome of a true positive is even rarer, so depending on what you're looking for even a one in a million adverse outcome might negate the benefit or worse.
EDIT: To add one more point: If you do external ultrasounds and find a potential cancer, you will be prescribing additional tests. Any false positives from the ultrasound will thus end up contributing to excess further testing, and you need to count the harm from that as well. A 1% false positive rate coupled with a 1:10k cancer risk from a follow up CT scan or a (I don't know what the real rate is for perforation) 1:10k risk of perforation with an endoscopy and you have a one in a million severe adverse effect. Do it enough and you'll have deaths even when the starting point is something as innocuous as an external ultrasound. That doesn't mean it can't be worth it. But it does mean you need a risk analysis before any largescale screening effort.
[1] https://www.cancer.gov/about-cancer/diagnosis-staging/ct-sca...
> Individuals who have had multiple CT scans before the age of 15 were found to have an increased risk of developing leukemia, brain tumors (6), and other cancers (7) in the decade following their first scan. However, the lifetime risk of cancer from a single CT scan was small—about one case of cancer for every 10,000 scans performed on children.
External ultrasound (ultrasounds can also be done endoscopically) itself I think is risk free, but inducing anxiety in patients or exposing patients to a healthcare facility is categorically not risk free even though the risk is very small for each individual patient.
The problem is not that the risk is high for individual screening events, but that even a one in a million even will happen regularly once you start regularly screening a multi-million person population.
There is no such thing as a risk free event once the scale is large enough, so the question becomes whether the risk is low enough relative to the potential benefit, and then you need to consider that often a true positive is rare, and making a difference to the outcome of a true positive is even rarer, so depending on what you're looking for even a one in a million adverse outcome might negate the benefit or worse.
EDIT: To add one more point: If you do external ultrasounds and find a potential cancer, you will be prescribing additional tests. Any false positives from the ultrasound will thus end up contributing to excess further testing, and you need to count the harm from that as well. A 1% false positive rate coupled with a 1:10k cancer risk from a follow up CT scan or a (I don't know what the real rate is for perforation) 1:10k risk of perforation with an endoscopy and you have a one in a million severe adverse effect. Do it enough and you'll have deaths even when the starting point is something as innocuous as an external ultrasound. That doesn't mean it can't be worth it. But it does mean you need a risk analysis before any largescale screening effort.
[1] https://www.cancer.gov/about-cancer/diagnosis-staging/ct-sca...
> Individuals who have had multiple CT scans before the age of 15 were found to have an increased risk of developing leukemia, brain tumors (6), and other cancers (7) in the decade following their first scan. However, the lifetime risk of cancer from a single CT scan was small—about one case of cancer for every 10,000 scans performed on children.
Testing everyone might catch some stuff early, at the cost of a boatload of biopsies that turn up nothing. The cost to patients of a false positive and having to wait for a biopsy to clear you is not zero.
Are you just talking about cases of possible cancer?
If anything, it can give a lot more data on how Alzheimers develops over the years.
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IMHO Alzheimer’s disease is not a single disease but rather a collection of diseases that exhibit similar symptoms and pathologies. I based this opinion on years of observations of old people I know.
Dementia is a syndrome. Alzheimer's is just one form of dementia. Unless you knew the specific diagnosis of the old people you've observed you might just have observed people with different forms of dementia. It's possible Alzheimer's itself will turn out to be a syndrome, but if so it still forms a very specific subset of dementia.