The Claim
A plasma p-tau217 threshold of 0.106 pg/mL achieves 94.6% sensitivity and 93.7% negative predictive value for identifying individuals who are amyloid-PET negative (Centiloid ≤ 20), enabling the avoidance of confirmatory amyloid-PET imaging in patients below this threshold.
What the research says
Supports is higher
Support is ahead, but a single strong opposing study can change this.
These are independent scores, not a percentage. Higher-grade studies count more, so a single strong opposing study can outweigh several weaker ones.
A blood test measuring p-tau217 at 0.106 pg/mL correctly identifies 94.6% of people who do not have brain amyloid plaques and rules out the need for a costly brain scan in 93.7% of those cases.
See the scientific wording
A plasma p-tau217 threshold of 0.106 pg/mL achieves 94.6% sensitivity and 93.7% negative predictive value for ruling out amyloid-PET positivity (Centiloid > 20), allowing clinicians to safely avoid confirmatory imaging in most patients below this level.
When abnormal tau proteins in the brain become overly phosphorylated at a specific site, they leak into the bloodstream at measurable levels. The amount of this modified tau in the blood directly reflects the amount of amyloid plaques in the brain. When the blood level falls below a certain point, it means there are not enough amyloid plaques to trigger that level of tau change.
What the research says
1 studyIf a blood test shows p-tau217 below 0.106 pg/mL, the study found that 94 out of 100 people don’t have harmful brain plaques — so doctors can safely skip the expensive brain scan for most of them.
Score breakdown, mechanism chain, raw evidence, ideal studies needed & 1 supporting studies
Not medical advice. For informational purposes only. Always consult a qualified healthcare professional before making health decisions.