HAI Book 2025 - Flipbook - Page 713
Hanseeuw, Bernard
VeraBIND Tau test, a novel plasma assay for active tau pathology, identifies
individuals with positive F18MK6240 tau-PET signal regardless of amyloid
status
Bernard Hanseeuw1,5, Jean-Louis Bayart2, Emilien Boyer2, Lise Colmant2, Lisa Quenon2,
Pascal Kienlen-Campard2, Renaud Lhommel1,2, Adrian Ivanoiu1,2, Anindita Bose3, Khairul
Ansari3, Joshua Soldo3, Khalid Iqbal4,6
1
Cliniques Universitaires Saint-Luc, Brussels, BE
UCLouvain, Brussels, BE
3
Veravas, Inc, Oakdale, MN, US
4
Phanes Biotech, Inc, Malvern, PA, US
5
Mass General Brigham, Boston, MA, US
6
The City University of New York, New York, NY, US
2
Background: Plasma assays targeting tau phospho-epitopes (e.g., pTau217) are frequently positive in the context
of isolated amyloid-´ pathology (A+). Developing plasma assays associated with tau aggregation (T+) is an unmet
challenge. Here, we present the first results of the VeraBIND Tau test, a plasma assay measuring how
hyperphosphorylated tau binds to normal tau, i.e., testing whether plasma tau is pathologically active
(aggregating).
Methods: VeraBIND Tau is an in vitro bead-based ELISA that uses chemiluminescence (Fig.1: overview). Ninetyone participants were recruited from an ongoing study at UCLouvain, Belgium, including 58 clinically normal (CN,
22A+) and 33 clinically impaired (MCI/AD, 29A+). A+ status was determined using either CSF (A´42f544pg/mL) or
amyloid-PET (Centiloidg20). F18MK6240 Tau-PET status was determined visually as negative (Braak 0) or positive
(Braak 2-6). Plasma pTau217 was quantified using Lumipulse (Fujirebio).
Results: The VeraBIND Tau plasma assay was weakly correlated with pTau217 concentration (R2=0.065, p=0.02,
Fig.2). Using tau-PET as ground truth for tau, VeraBIND Tau detected 39 of 41A+T+ participants (sensitivity=95%),
and excluded tauopathy in 33 of 35A-T- participants (specificity=94%). With the same specificity
(threshold=0.193pg/mL), pTau217 achieved similar sensitivity in A+T+ (38 of 41, 93%). However, seven of ten A+Tparticipants had positive pTau217 whereas only three had positive VeraBIND test. In contrast, four of five A-T+
participants had negative pTau217, but positive VeraBIND test. Although positive, the A-T+ participants had
relatively low tau-PET signal (Braak 2-3). The overall diagnostic accuracy of pTau217 was 90% for A-/A+ and 82%
for T-/T+ while the accuracy of VeraBIND was 83% for A-/A+ and 91% for T-/T+.
Conclusions: Whereas pTau217 is more closely associated to amyloid than to tau-PET results, VeraBIND Tau is
highly sensitive to (early) tau-PET positivity, indicating active tau aggregation, with or without amyloidosis. The
mismatch between pTau217 and VeraBIND Tau provides a plasma indication of discordant A/T PET status.
HAI2025 - 713
