New Blood Tests to detect Alzheimer's Disease

[landover]

In a first-of-its-kind study, researchers have developed a blood test for Alzheimer's disease that predicts with astonishing accuracy whether a healthy person will develop the disease.​

 

[anethum]

In a first-of-its-kind study, researchers have developed a blood test for Alzheimer's disease that predicts with astonishing accuracy whether a healthy person will develop the disease.​

Sort of. From the synopsis of the study:

We discovered and validated a set of ten lipids from peripheral blood that predicted phenoconversion to either amnestic mild cognitive impairment or Alzheimer's disease within a 2–3 year timeframe with over 90% accuracy.

http://www.nature.com/nm/journal/vaop/ncurrent/full/nm.3466.html

 

[braumeister]

If you have blood, you're at risk.

 

[aja8888]

If you have blood, you're at risk.

Especially if it's in your body and being routinely pumped around.

 

[MichaelB]

I split these posts off into a new thread. Currently a diagnosis of Alzheimer's disease is mostly a judgement call and made after years of disease progression. This announcement can be pretty significant. Another link http://www.npr.org/blogs/health/2014/03/09/286881513/alzheimers-blood-test-raises-ethical-questions

The results need to be confirmed, and the approach still needs to be tried in people of different ages and from different racial groups, Federoff says. Even so, he says, it raises the possibility that in the not too distant future, many more people will know their risk of Alzheimer's.

 

[Animorph]

I wasn't exactly astounded by a 90% accuracy, but it's better than nothing.

 

[MichaelB]

I wasn't exactly astounded by a 90% accuracy, but it's better than nothing.

Well, 90% does sound pretty mediocre for a breakthrough in modern medicine. After sitting alongside my mother over the past few years as 4 different specialists administered basically the same test on her my first reaction was to see this as a giant step forward - if it pans out as described in the article. The way they go about it now is stone-age in comparison and the disease is only diagnosed when it is well entrenched and little can be done.

 

[6miths]

Yes 90% is not good. With the incidence of Alzheimer's most of the positives will still be false positives. But it's way worse than that as it says: 'Overall, the blood test predicted who would get Alzheimer's or mild cognitive impairment with over 90% accuracy.' Mild cognitive impairment is now Alzheimer's - I'm sorry but I have mild cognitive impairment at age 52, especially if I don't have any caffeine on board.

A long, long way to go. And I think before we start screening we are supposed to have some form of treatment that works. Do we have that?

 

[Htown Harry]

I think this study is unlikely to change anything in the short term.

One of their cited references articles, from 2011, includes this passage that puts the current announcement in context.

They seem to "hope" that trying some types of AD treatments that don't do lot to modify symptoms in more advanced cases will have a greater effect on pre-symptomatic patients.

Maybe, maybe not.

(AD= Alzheimer's disease, with -P being early, pathophysiological stages without clinical symptoms)
http://www.google.com/url?sa=t&rct=...ai-khNIQ9YUxT8Bq3aULBVQ&bvm=bv.62788935,d.b2I

In particular, the poignant question of “why would anyone
want to know they have AD a decade before they might develop
symptoms, if there is nothing they can do about it?”
should be carefully considered well before any results
from research is translated into clinical practice. First, there
may be important reasons, including social and financial
planning, why some individuals would want to know their
likelihood of developing AD dementia within the next
decade, even in the absence of an available disease modifying
therapy. It is our hope, however, that the advances
in preclinical detection of AD-P will enable earlier, more
effective treatment, just as nearly all of therapeutic gains
in cancer, cardiovascular disease, osteoporosis, and diabetes
involve treatment before significant clinical symptoms are
present. It is entirely possible that promising drugs, particularly
amyloid-modifying agents, will fail to affect the clinical
course of AD at the stage of dementia or even MCI, when
the neurodegenerative process is well entrenched, but may
be efficacious at the earliest stages of the AD-P, before the
onset of symptoms.

The definitive studies to determine whether the majority
of asymptomatic individuals with evidence of AD-P are
indeed destined to develop AD dementia, to elucidate the
biomarker and/or cognitive endophenotype that is most
predictive of cognitive decline, and to determine whether
intervention with potential disease-modifying therapies in
the preclinical stages of AD will prevent dementia are
likely to take more than a decade to fully accomplish.

 

[ERhoosier]

Promising & important report, but agree with 6miths that there's still much more work needed in this area. IMHO- The media seems to have WAY over-hyped this study. It is very preliminary and has some important weaknesses-
1. Only 525 total participants. All 70+yrs old and stated to be "otherwise healthy", but 46 were diagnosed with mild memory impairment or early Alzheimer's on study entry. Only 28 "converted" to "impaired" status during the 5 yr study, and this is a very small # for subgroup where a prospective test could be most useful.
2. Folks with early Alzheimer's Disease and mild memory cognitive impairment were lumped together for analysis, but clearly not all patients with MCI go on to develop AD.
Mild cognitive impairment Treatment at Mayo Clinic - Diseases and Conditions - Mayo Clinic
3. AD/MCI and non-impaired "controls" were only matched for age, sex, and education but not for many other factors associated with AD &/or MCI (e.g. thyroid conditions, sleep disorders, minor strokes, poor diet, etc.).
4. "Accuracy" of 90% for Alzheimer's test in the elderly must be taken in context. Consider that the lifetime risk of a non-impaired 65 yr old getting dementia of ANY cause (not just AD) is 17-20%, so healthy 65yo planning on never getting AD is already 80-83% accurate based on stats alone (pg 19 of link below). I realize this study included folks a bit older (sl higher risk AD), but IMHO any proposed screening test for AD needs to be better than 90% to be both cost-effective & personally useful (e.g. accelerating 'bucket list' planning, budgeting future LTC needs, etc.).

Nice overview of AD can be found here-
http://www.alz.org/downloads/facts_figures_2013.pdf

 

[Htown Harry]

Nice analysis ERH.

Maybe this isn't a "test that predicts with astonishing accuracy", but is instead a report that is astonishing in its accuracy claims ?

 

[Ally]

After watching my mom die of Alzheimer's and all the surrounding effects on family, I'm not sure I would want to take this test anyway. It's bad enough wondering if I might get it, but knowing I probably would get it would be truly depressing.

 

[Walt34]

It's bad enough wondering if I might get it, but knowing I probably would get it would be truly depressing.

I was thinking the same thing. One might expect the rate of suicides by those who got a positive test result to jump. Not a positive outcome.

 

[dontworry]

"A long, long way to go. And I think before we start screening we are supposed to have some form of treatment that works. Do we have that?"

There are medications that can help folks maintain, basically slow the progression of the disease. Aricept, Namenda, Exelon. There may be others that I am not aware of yet. These meds only work for so long, however.

I watched my great-grandparents and my grandparents suffer through dementia. My grandmother had an extended progression and most likely had Alzheimer's. Her sister had early onset Alzheimer's starting in her late 50s. I know my father has huge fears about his future. He is about to turn 65 so hopefully has avoided the early onset type.

At this point I don't think I would want to know if I was doomed or not. How depressing! But the research is definitely needed and let's pray that more treatments and a cure is discovered !