Blood p-tau181 could be used as a simple, accessible, and scalable test for screening and diagnosis of Alzheimer's disea

[cdamaden]

From The Lancent, VOLUME 19, ISSUE 5, P422-433, MAY 01, 2020
Blood phosphorylated tau 181 as a biomarker for Alzheimer's disease: a diagnostic performance and prediction modelling study using data from four prospective cohorts

There's a link to the article below and a link to a medpagetoday article on it. A quote from the article:
"P-tau181 levels in blood samples are increased in individuals who have a positive amyloid scan but not yet a positive tau PET scan, suggesting that plasma P-tau181 becomes positive before tau PET," Blennow said.

"These findings show p-tau181 in blood samples works very well to identify Alzheimer's pathology," and could serve as an easily accessible, cheap test for Alzheimer's disease in primary care, he told MedPage Today.

My comments - I would love to test and get my baseline levels. How about you?

https://www.thelancet.com/journals/lane ... 5/fulltext
https://www.medpagetoday.com/neurology/ ... ate_Active

[NF52]

From The Lancent, VOLUME 19, ISSUE 5, P422-433, MAY 01, 2020... A quote from the article:
"P-tau181 levels in blood samples are increased in individuals who have a positive amyloid scan but not yet a positive tau PET scan, suggesting that plasma P-tau181 becomes positive before tau PET," Blennow said.

"These findings show p-tau181 in blood samples works very well to identify Alzheimer's pathology," and could serve as an easily accessible, cheap test for Alzheimer's disease in primary care, he told MedPage Today.

My comments - I would love to test and get my baseline levels. How about you?

Hi Chris,

I think using a blood test in a primary care setting to identify people with tau, and telling them that also creates a high likelihood that they have "elevated amyloid", which is used as a biomarker for "preclinical Alzheimer's disease pathology" even in people who have normal cognition and no subjective cognitive decline--is very risky right now. My guess is that this blood test will not be approved anytime soon by the FDA for a "cheap test for Alzheimer's disease in primary care". It could save time and money (and aggravation of volunteers) if it becomes used in screening for clinical trials to reduce tau and/or amyloid. , or to people who are at higher risk of subtle but meaningful changes on neuro-psychological tests within the time frame of a 3-5 year study of a non-drug intervention.

We don't know what the missing variable between the observed association of amyloid beta and p-tau with later increased risk of MCI or AD for some (but not all) people, Getting the test would be worth the uncertain prognosis if you hope to sign up for a clinical trial or observational study of people with elevated amyloid or tau. If not, maybe it's worth waiting for more data on this preclinical period to come in?