pTau217/Aβ42 ratio

1. pTau217/Aβ42 ratio improves AUC to detect PET-Aβ positivity in humans.

   “Using the pTau217/Aβ42 ratio significantly improved the area under the curve (AUC) over pTau217 alone to detect PET‐Aβ positivity in both the ADCC and ITTC”

   Humansin AD continuum cohort (ADCC) and intention to treat cohort (ITTC)

   Combining Lumipulse pTau217 and Aβ42 as confirmatory tests for Aβ pathology prior to DMT

   AAIC 2025 abstract·7 Jan 2026

More on AUC to detect PET-Aβ positivity

1. pTau217/Aβ42 ratio predicts PET-Aβ in humans (95-97% accuracy in ITTC, 93-95% in ADCC).

   “The highest accuracy observed for either single BBMs, the ratio of BBMs, or the linear combination of BBMs that included age, gender, and APOE ε4 was 93‐95% in the ADCC”

   Humanslinear combination of pTau217, Aβ42/40, age, gender, and APOE ε4, or pTau217/Aβ42 ratio

   Combining Lumipulse pTau217 and Aβ42 as confirmatory tests for Aβ pathology prior to DMT

   AAIC 2025 abstract·7 Jan 2026

More on PET-Aβ

1. pTau217/Aβ42 ratio predicts amyloid pathology in humans (AUC 0.861–0.969).

   “Across the five cohorts ( N =2,481), AUC values ranged from 0.883–0.956 for plasma pTau217 alone and 0.861–0.969 for the plasma pTau217/Aβ42 ratio”

   Humansn = 2,481

   Clinical performance and effect of pre‐analytical variation of plasma pTau217 alone versus the plasma pTau217/Aβ42 ratio for the identification of amyloid pathology

   AAIC 2025 abstract·23 Dec 2025