Any experience with the P Tau 217 plasma test for Alzheimer's?

@lulululu
My husband's primary doctor had never heard of the ptau test. I read about it on this site and had to request the test specifically.

Yes, very helpful. Thanks for sharing. Hope things continue to go well. Please keep us updated. Thanks again.

Yes, my husband had the blood work for the test done last Fall. The results showed he has Alzheimer’s. Insurance covered the cost.

Here is my test scores and comment from Quest Diagnostics, from May 2025.
My doctors used the results to confirm my ALZ diagnosis result according to my MRI and Beta Amyloid and ApOE test results. Plus, my MRI in June showed 2 previous strokes that I never knew I had, and some white matter.

QUEST AD DETECT PTAU217, PLASMA
View trends
Normal value: < OR = 0.15 pg/mL
Value
6.05High
Your value is 6.05 pg/mLThis value is HighNormal value: < OR = 0.15 pg/mL
Plasma p-tau217 levels are consistent with current mild
cognitive impairment and symptomatic Alzheimer's disease
when compared to patients with other neurodegenerative
disorders and show strong correlation with amyloid PET and
tau PET.

Lancet Neurol 2021; 20:739-752

This test was developed and its analytical performance
characteristics have been determined by Quest Diagnostics.
It has not been cleared or approved by the FDA. This assay
has been validated pursuant to the CLIA regulations and is
used for clinical purposes.
Here is my ApoE test result:
ApoE Isoform, Plasma Result
View trends
Value
E3/E4
This test also has not been cleared or approved by the FDA.
These test results convinced my neuro MD and NP people that I definitely have ALZ. I'm not sure if these tests have been FDA approved yet.

Yes, my husband recently had the pTau 217 test in December resulting in 0.987 reported as High. My husband’s dementia is moderate to severe with the pTau indicating a component of Alzheimer’s disease. One day at a time….hoping for the best for you both.

We just got results today on my husband. Labcorp .99 .

Now to discuss with specialist. Sad, but knowing which type of dementia is valuable.

My husband used Care Access for a free blood test panel including pTau. His score was 0.41 which is high. 0.00 to 0.18 is normal. Above 0.18 is considered high based on the Care Access report. He's already had the APOE4 gene test which is positive, plus PET scan, MRI and cognitive testing. Everything confirms MCI due to Alzheimers. He is scheduled for his first Kisunla transfusion next week.

Please do all the reading and due diligence about pTau. This is still new science from what I understand and it is only a bio-marker. It does not mean definitively that someone will have Alzheimers, just that the likelihood is much greater. It is another piece in a very big puzzle. God speed to all.

My husband has moderate dementia. He had the blood test for Tau particles and Amyloid plaques. His result was very low indicating that he did not have Alzheimer's. I had the test done to determine if he was a candidate for any of the infusions that might have made a difference in the progression of his dementia. He is not because he likely has vascular dementia not Alzheimer's. The infusions do not help with vascular dementia which is what he likely has as well as brain damage from two traumatic head injuries. His internist ordered the test and Medicare paid for it. I think getting the blood test gives you one more piece of information to personalize the plan of care for each patient with dementia symptoms.

Keep in mind that the biomarker test can give false positives if the person tested has Chronic Kidney Disease….which makes sense. If your kidneys are having trouble clearing proteins like albumin, why should other proteins like ptau be any different? See attached brief overview,

@tak66 my husband’s TAU was 1.6 and the glucose PET scan results were consistent with Alzheimer’s. The neurologist at Mayo diagnosed him as in the moderate stage.
My heart is heavy for you as your husband is so young to be starting his mental decline. The working things is tough, his place of employment will start to notice his new “quirks” and will help with the decision to retire earlier than expected.
Aricept helped my husband keep his focus and last month the neurologist added Namenda to his treatment plan.
Take any caregiver class you can, start introducing helpers to your husband and take care of you. I am having a young woman come to “help me” with spring cleaning and other tasks just so my husband gets used to another person in the home.
Keep posting on these forums.
Hugs to you and all that need them.