p-tau217
Phosphorylated Tau at Threonine 217 (Plasma / CSF p-tau217)
リン酸化タウ217（血漿・髄液 p-tau217 バイオマーカー）
1. Biological & Technical Mechanism
Phosphorylated tau at threonine-217 (p-tau217) is a soluble tau isoform released into cerebrospinal fluid (CSF) and blood plasma in response to cerebral amyloid-beta (Aβ) pathology and early neurofibrillary tangle formation. Compared with earlier markers such as p-tau181, plasma p-tau217 exhibits markedly larger fold-changes between amyloid-positive and amyloid-negative individuals, achieving diagnostic accuracy comparable to amyloid PET and CSF assays.
スレオニン217部位でリン酸化されたタウタンパク質（p-tau217）は、脳内のアミロイドβ（Aβ）プラーク蓄積および初期の神経原線維変化（タウ病理）に応答して脳脊髄液（CSF）や血液（血漿）中へ放出される可溶性バイオマーカーです。従来の p-tau181 と比較して、Aβ陽性例における上昇倍率と疾患特異性が顕著に高く、血液検査でありながらアミロイドPET検査や髄液検査に匹敵する診断精度（AUC > 0.90〜0.95）を示します。
2. Open Science & Clinical Trial Significance
Plasma p-tau217 is transforming clinical trial recruitment (pre-screening prior to PET scans) and longitudinal treatment monitoring in Alzheimer's pipelines tracked on Alzforum and ClinicalTrials.gov.
Alzforum や最新の第3相臨床試験において、高価で侵襲性のあるPET・髄液検査に先立つ被験者スクリーニング指標として、また抗アミロイド療法・抗タウ療法の薬力学的な治療応答性モニタリング指標として標準採用が進んでいます。
Related Neuroscience Terms & Standards
Major lipid carrier in the central nervous system; the APOE ε4 allele is the strongest genetic risk factor for late-onset Alzheimer's disease.
Axonal cytoskeletal protein released into CSF and blood upon neuroaxonal injury; a cross-disease biomarker of neurodegeneration rate in ALS, MS, AD, and FTD.
Molecular neuroimaging technique using radiolabeled tracers to quantify in vivo protein pathology (amyloid plaques, tau tangles), glucose metabolism, or synaptic density.
Primary composite clinical endpoint in early Alzheimer's disease trials, summing 6 cognitive and functional domains (Memory, Orientation, Judgment, Community, Home, Personal Care; range 0–18).
Open Datasets & Research Publications Related to p-tau217
Plasma p-tau217 Demonstrates High Diagnostic Accuracy in Primary Care Setting for Alzheimer’s Disease
Clinical validation indicates that the plasma p-tau217 assay achieves diagnostic accuracy comparable to Amyloid-PET and CSF analysis in primary care settings, providing an accessible biomarker for early Alzheimer’s disease detection.
Development and External Validation of a Plasma p-tau217-Based Model for MCI-to-Dementia Progression
--Clinical trajectories after a diagnosis of mild cognitive impairment (MCI) vary widely, so prognostic models must account for both the timing of subsequent diagnoses and unequal follow-up. Using the Alzheimers Disease Neuroimaging Initiative (ADNI), we developed a Cox proportional-hazards model fo...
Tau-PET subtype modifies the association between plasma p-tau217 and memory in Alzheimer's disease
INTRODUCTIONPlasma p-tau217 is associated with Alzheimers disease pathology and memory performance, but its implications for memory may depend on fibrillar tau topography. We examined whether tau-PET subtype modified the association between plasma p-tau217 and memory. METHODSWe analyzed 396 amyloid...
Analytical validation and amyloid-status discrimination of a high-throughput, research-use-only plasma p-Tau217 immunoassay
BackgroundPlasma phosphorylated tau at threonine 217 (p-Tau217) is a leading blood-based biomarker for Alzheimers disease (AD). Robust analytical characterization on high-throughput platforms is essential for research use and clinical translation. ObjectiveTo evaluate the analytical performance of ...
Plasma p-tau217 Demonstrates High Diagnostic Accuracy in Primary Care Setting for Alzheimer’s Disease
Clinical validation study confirms that blood-based p-tau217 assay matches CSF and Amyloid-PET diagnostic precision in identifying early Alzheimer’s pathology.
Elevation in Plasma p-tau217 Concentrations Among Blood Donors: An Exploratory Cross-Sectional Study
ImportancePhosphorylated tau at threonine 217 (p-tau217) and brain-derived tau (BD-tau) are increasingly used as blood biomarkers of Alzheimers disease (AD) and related neurological disorders. However, the distributions and biological correlates of elevated plasma p-tau217 and BD-tau in plasma from ...
Disclaimer: This encyclopedia entry is intended for academic neuroscience research and data science reference only, and does not constitute medical advice.