Evaluation of a novel immunoassay to detect p-tau Thr217 in the CSF to distinguish Alzheimer disease from other dementias

Jozef Hanes, Andrej Kovac, Hlin Kvartsberg, Eva Kontsekova, Lubica Fialova, Stanislav Katina, Branislav Kovacech, Eva Stevens, Jakub Hort, Martin Vyhnalek, Lynn Boonkamp, Michal Novak, Henrik Zetterberg, Oskar Hansson, Philip Scheltens, Kaj Blennow, Charlotte E. Teunissen, Norbert Zilka

Research output: Contribution to journalArticleAcademicpeer-review

29 Citations (Scopus)


OBJECTIVE: To investigate whether tau phosphorylated at Thr217 (p-tau T217) assay in CSF can distinguish patients with Alzheimer disease (AD) from patients with other dementias and healthy controls. METHODS: We developed and validated a novel Simoa immunoassay to detect p-tau T217 in CSF. There was a total of 190 participants from 3 cohorts with AD (n = 77) and other neurodegenerative diseases (n = 69) as well as healthy participants (n = 44). RESULTS: The p-tau T217 assay (cutoff 242 pg/mL) identified patients with AD with accuracy of 90%, with 78% positive predictive value (PPV), 97% negative predictive value (NPV), 93% sensitivity, and 88% specificity, compared favorably with p-tau T181 ELISA (52 pg/mL), showing 78% accuracy, 58% PPV, 98% NPV, 71% specificity, and 97% sensitivity. The assay distinguished patients with AD from age-matched healthy controls (cutoff 163 pg/mL, 98% sensitivity, 93% specificity), similarly to p-tau T181 ELISA (cutoff 60 pg/mL, 96% sensitivity, 86% specificity). In patients with AD, we found a strong correlation between p-tau T217 and p-tau T181, total tau and β-amyloid 40, but not β-amyloid 42. CONCLUSIONS: This study demonstrates that p-tau T217 displayed better diagnostic accuracy than p-tau T181. The data suggest that the new p-tau T217 assay has potential as an AD diagnostic test in clinical evaluation. CLASSIFICATION OF EVIDENCE: This study provides Class III evidence that a CSF immunoassay for p-tau T217 distinguishes patients with AD from patients with other dementias and healthy controls.
Original languageEnglish
Pages (from-to)e3026-e3035
Issue number22
Publication statusPublished - 1 Dec 2020

Cite this