Alzheimer's research in ‘major step’ towards blood test(bbc.com)
bbc.com
Alzheimer's research in ‘major step’ towards blood test
http://www.bbc.com/news/health-28198510
23 comments
I think the most important use of a blood test wouldn't be for patients, but for researchers. If you can predict 90% of a cohort will develop Alzheimer's, you can do much smaller, more powerful trials on interventions.
>there will still be plenty of research to do on how to motivate patient behavior in
a) seeking the test,
b) acting on the results of the test in a rational way, and
c) not piling up other health risks meanwhile.
Given a disease with no cure or treatment, it may actually be rational to NOT seek a diagnosis (or "potential diagnosis") prior to experiencing symptoms. Put another way, what exactly would "acting on the results in a rational way" entail for someone who is currently asymptomatic?
>much work remains to be done to tackle Alzheimer disease and further prolong healthy lifespan for the patients at risk for that disease.
I think the researchers agree with that statement. Another child of your comment mentioned that this is likely more valuable to researchers than tested patients at this point, and I would agree. As the article mentioned, it is believed that treatments started earlier in the disease would be more effective, and the capacity to diagnose earlier in order to test novel agents may well be the most valuable aspect of testing at this point.
a) seeking the test,
b) acting on the results of the test in a rational way, and
c) not piling up other health risks meanwhile.
Given a disease with no cure or treatment, it may actually be rational to NOT seek a diagnosis (or "potential diagnosis") prior to experiencing symptoms. Put another way, what exactly would "acting on the results in a rational way" entail for someone who is currently asymptomatic?
>much work remains to be done to tackle Alzheimer disease and further prolong healthy lifespan for the patients at risk for that disease.
I think the researchers agree with that statement. Another child of your comment mentioned that this is likely more valuable to researchers than tested patients at this point, and I would agree. As the article mentioned, it is believed that treatments started earlier in the disease would be more effective, and the capacity to diagnose earlier in order to test novel agents may well be the most valuable aspect of testing at this point.
It may be worth noting that there are already anti-dementia drugs, but their efficacy is questionable -- especially when administered late in the course of the disease.
Isn't this still too late? On the other hand, there is some early evidence that a blood sugar meter may be able to be used as an early diagnostic, at a time when one can do something about it. Keeping blood sugars relatively low, and, probably more importantly, having relatively long periods of low (but normal) blood sugars through e.g. intermittent fasting or even reducing/removing snacks may be the best preventative measure one can take.
Really wish they broke "86% accuracy" into precision and recall.
Here's the paper: http://www.sciencedirect.com/science/article/pii/S1552526014...
Re your comment: "accuracy 87%, sensitivity 85%, and specificity 88%"
Re your comment: "accuracy 87%, sensitivity 85%, and specificity 88%"
What does that mean for false positive and true negative?
Sensitivity is the true positive rate, specificity is the true negative rate.
From the body of the paper, for their chosen test, their False Positive Rate appears to be 21.2% (100% - 68.8%) and their False Negative Rate appears to be 5.1% (100% - 94.9%). For this type of test, its the false negative rate that we'll really worry about.
From the body of the paper, for their chosen test, their False Positive Rate appears to be 21.2% (100% - 68.8%) and their False Negative Rate appears to be 5.1% (100% - 94.9%). For this type of test, its the false negative rate that we'll really worry about.
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Wow, that's odd. Why does accuracy drop when MRI is included?
Ah, much appreciated.
There really is encouraging progress being made in this area (early prediction of AD) in several different fields. I know of several different groups who are using imaging instead of blood tests to predict conversion of MCI to AD as well. A lot of it is using the data being collected by ADNI:
http://www.adni-info.org
http://www.adni-info.org
I guess the major benefit is for people who do not actually have alzheimers being falsely diagnosed, but early detection doesn't help in any way for people who do have it, right? I'm not sure I'd want to know until it was unavoidable.
I have a hard time understanding why people wouldn't want to know what's in store for the future. Even if it's unavoidable, there's still lots you can do in terms of making best use of the time remaining to you.
The hope is that early detection will allow for prevention. Right now it's difficult to diagnose Alzheimer's until the brain is too damaged to function normally, but some treatments may be able to prevent it from getting worse at an early stage.
There's also a theory (not sure how scientifically valid) that Alzheimer's might be a form of Diabetes (http://opinionator.blogs.nytimes.com/2012/09/25/bittman-is-a...). If that's the case, then it might be possible to prevent the disease by diet alone.
There's also a theory (not sure how scientifically valid) that Alzheimer's might be a form of Diabetes (http://opinionator.blogs.nytimes.com/2012/09/25/bittman-is-a...). If that's the case, then it might be possible to prevent the disease by diet alone.
The need for early diagnosis is important for research purposes - by the time we can see the affects of alzheimers, the damage has already been done. If we can develop an earlier diagnostic test, we can do earlier intervention in clinical trials of treatments.
Yes, there's no treatment now, but progress like this will lead to an actual treatment.
Yes, there's no treatment now, but progress like this will lead to an actual treatment.
At the very least, earlier diagnosis will help the ongoing research into the disease. Even if it doesn't directly benefit this generation of patients, their study may lead to new treatments for the next generation.
"Dr Eric Karran, director of research at Alzheimer's Research UK, described the study as a 'technical tour de force'.
"However, he warned the current accuracy levels risked telling healthy people they were on course to develop Alzheimer's which may lead to anxiety and depression."
I just completed the Coursera online course in human behavior genetics. One of the ways that psychology research can contribute to the hoped-for future of genomic, personalized medicine is by figuring out how patients will react to various kinds of personal medical information about possible future outcomes. Today, there are some genetic tests for Mendelian (single-mutation) diseases that have a very high reliability, but many patients don't seek those tests, even if they have relatives who had the diseases, because there isn't much a patient can do about an incurable disease. People DON'T want to know that they are sure to die with a grave disease in the next twenty years. People would rather imagine that they just might live forever.
So if other studies replicate the result of the study reported here, and perhaps even further refine the accuracy of predicting Alzheimer disease risk from a simple blood test taken earlier in life, there will still be plenty of research to do on how to motivate patient behavior in
a) seeking the test,
b) acting on the results of the test in a rational way,
and
c) not piling up other health risks meanwhile.
And of course if this study finding eventually translates through further research into a deeper understanding of the cause of Alzheimer disease, leading to a prevention strategy or even a cure for that disease, that would be wonderful, but there are plenty of diseases that can be reliably diagnosed without being treatable or even preventable at all. This is a good step forward, but much work remains to be done to tackle Alzheimer disease and further prolong healthy lifespan for the patients at risk for that disease.