Longitudinal plasma p-tau217 is increased in early stages of Alzheimer's disease

Brain. 2020 Dec 5;143(11):3234-3241. doi: 10.1093/brain/awaa286.


Plasma levels of tau phosphorylated at threonine-217 (p-tau217) is a candidate tool to monitor Alzheimer's disease. We studied 150 cognitively unimpaired participants and 100 patients with mild cognitive impairment in the Swedish BioFINDER study. P-tau217 was measured repeatedly for up to 6 years (median three samples per person, median time from first to last sample, 4.3 years). Preclinical (amyloid-β-positive cognitively unimpaired, n = 62) and prodromal (amyloid-β-positive mild cognitive impairment, n = 49) Alzheimer's disease had accelerated p-tau217 compared to amyloid-β-negative cognitively unimpaired (β = 0.56, P < 0.001, using linear mixed effects models) and amyloid-β-negative mild cognitive impairment patients (β = 0.67, P < 0.001), respectively. Mild cognitive impairment patients who later converted to Alzheimer's disease dementia (n = 40) had accelerated p-tau217 compared to other mild cognitive impairment patients (β = 0.79, P < 0.001). P-tau217 did not change in amyloid-β-negative participants, or in patients with mild cognitive impairment who did not convert to Alzheimer's disease dementia. For 80% power, 109 participants per arm were required to observe a slope reduction in amyloid-β-positive cognitively unimpaired (71 participants per arm in amyloid-β-positive mild cognitive impairment). Longitudinal increases in p-tau217 correlated with longitudinal worsening of cognition and brain atrophy. In summary, plasma p-tau217 increases during early Alzheimer's disease and can be used to monitor disease progression.

Keywords: Alzheimer’s disease; biomarker; p-tau; p-tau217; plasma.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Aged
  • Aged, 80 and over
  • Alzheimer Disease / blood*
  • Alzheimer Disease / psychology
  • Amyloid beta-Peptides / blood
  • Biomarkers / blood
  • Cognitive Dysfunction / blood
  • Cognitive Dysfunction / psychology
  • Disease Progression
  • Female
  • Humans
  • Longitudinal Studies
  • Male
  • Mental Status and Dementia Tests
  • Middle Aged
  • Neuropsychological Tests
  • Phosphorylation
  • Prospective Studies
  • Threonine / metabolism
  • tau Proteins / blood*


  • Amyloid beta-Peptides
  • Biomarkers
  • MAPT protein, human
  • tau Proteins
  • Threonine