Beyond Basics - Introduction to Plasma p-tau217 and AB1-42

Which of the following best describes the role of plasma p-tau217 in clinical practice?

• It confirms diagnosis of frontotemporal dementia

• It is a non-invasive marker that reflects brain tau pathology triggered by amyloid

• It indicates the severity of cardiac amyloidosis

• It directly measures brain volume loss

What does a low level of plasma Aβ1-42 typically indicate in the context of Alzheimer's pathology?

• Healthy neuronal turnover

• Reduced amyloid production in the brain

• Early amyloid deposition in brain plaques

• Tauopathy without amyloid involvement

At what stage in Alzheimer’s disease progression do plasma p-tau217 levels begin to rise?

• After onset of dementia symptoms

• During late-stage AD only

• Several years after amyloid plaque formation

• 10–15 years before symptom onset, following amyloid accumulation

Through which mechanism does p-tau217 typically enter the bloodstream from the central nervous system?

• Intestinal absorption

• Direct neuronal release into blood

• Leakage through the blood-brain barrier and glymphatic transport

• Hepatic secretion

In real-world clinical settings, why might the p-tau217/Aβ1-42 ratio be helpful even if p-tau217 alone is statistically comparable?

• It reduces test cost

• It adds interpretive value in borderline cases

• It is easier to perform in labs

• It avoids the need for PET imaging

What is the source of plasma p-tau217 in Alzheimer’s disease?

• Peripheral nerve endings

• Hepatic tau secretion

• Neuronal tau release due to phosphorylation

• Endothelial tau synthesis

What is one major clinical advantage of using plasma p-tau217/Aβ1-42 over p-tau181?

• Lower specificity for Alzheimer’s

• Earlier and stronger association with amyloid PET positivity

• Better detection of Parkinsonian disorders

• Improved sensitivity to vascular changes