Which Assay of Plasma p-Tau217 Is Best for Diagnosing Alzheimer Disease?

An assay that measures the ratio between phosphorylated and nonphosphorylated tau stood out.

Plasma phosphorylated-tau 217 (p-tau217) has quickly become the single most useful blood-based biomarker to reliably detect Alzheimer disease. To determine which assay is the most accurate, investigators compared performance of five plasma p-tau217 tests on measures of amyloid-β (Aβ) on positron emission tomography (PET), tau-PET, and cognition. The cohort comprised 998 people from Sweden (mean age 68; 53% women), of whom 514 were cognitively unimpaired.

Two p-tau217 assays from Washington University used mass spectrometry to assess biomarkers, one of which (%p-tau217) measured the ratio between phosphorylated and nonphosphorylated tau. (A few authors have related patent and technology interests). The other three were immunoassays (one by a …

Reviewing Author

Michael S. Okun, MD

Disclosures

Consultant/Advisory BoardParkinson’s Foundation; Tourette Association of America

Speaker’s BureauMedscape/WebMD CME, Movement Disorders Society CME, American Academy of Neurology CME

RoyaltiesBooks4Patients; Demos; Cambridge; Taylor and Francis; Robert Rose; Public Affairs

Grant/Research SupportNational Institutes of Health; Parkinson’s Foundation; Tourette Association of America; University of Florida Foundation

Editorial BoardsTremor and Other Hyperkinetic Movements; JAMA Neurology

Leadership Positions in Professional SocietiesParkinson’s Foundation (Medical Advisor)