Prospective evaluation of plasma pTau217 stability for the detection of Alzheimer's disease in a tertiary memory clinic

BackgroundKnowledge on the effect of analytical variability and storage conditions are essential for the successful implementation of plasma pTau217 in prospective settings.AimsTo investigate the performance of plasma pTau217, measured in consecutive samples with LUMIPULSE, for detecting Alzheimer&#...

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Detalles Bibliográficos
Autores: Arranz, J, Ferrer, R, Zhu, NL, Rubio-Guerra, S, Rodríguez-Baz, I, Arriola-Infante, JE, Maure-Blesa, L, Garcia-Castro, J, Selma-González, J, Carmona-Iragui, M, Barroeta, I, Illán-Gala, I, Santos-Santos, M, Fortea, J, Lleó, A, Tondo, M, Alcolea, D
Tipo de recurso: artículo
Estado:Versión publicada
Fecha de publicación:2025
País:España
Institución:Institut d’Investigació Biomèdica Sant Pau (IIB Sant Pau)
Repositorio:r-IIB SANT PAU. Repositorio Institucional de Producción Científica del Instituto de Investigación Biomédica Sant Pau
OAI Identifier:oai:iibsantpau.fundanetsuite.com:p19742
Acceso en línea:https://iibsantpau.fundanetsuite.com/Publicaciones/ProdCientif/PublicacionFrw.aspx?id=19742
Access Level:acceso abierto
Palabra clave:Stability
Plasma
Biomarkers
Alzheimer
Blood
Amyloid
Tau
Descripción
Sumario:BackgroundKnowledge on the effect of analytical variability and storage conditions are essential for the successful implementation of plasma pTau217 in prospective settings.AimsTo investigate the performance of plasma pTau217, measured in consecutive samples with LUMIPULSE, for detecting Alzheimer's disease in a prospective memory clinic setting, along with evaluating its pre-analytical and analytical stability.MethodsWe prospectively measured pTau217 using the LUMIPULSE automated platform in consecutive patient plasma samples collected between May and November 2024 at the Sant Pau Memory Unit (Barcelona). A subset of participants also underwent paired lumbar puncture for CSF AD biomarkers. We compared biomarker concentrations under different short-term storage conditions (4 degrees C vs -20 degrees C) and different protocol pipelines, and assessed lot-to-lot variability. In the subset with available CSF biomarkers, logistic regression was used to evaluate the association between plasma pTau217 and the likelihood of a positive (A +) or a negative (A-) CSF amyloid status. Using ROC analysis, in this prospective cohort we evaluated the accuracy of previously established thresholds derived from historical samples.ResultsWe included 280 participants, divided into two groups: those with (n = 109) and without CSF data (n = 171). Among the subset with CSF, 48% were A + , with a plasma pTau217 fold-change of 4.5 x compared to A-. We found no differences in plasma pTau217 concentrations between either short-term storage conditions. The overall coefficients of analytical variation ranged from 1.8% to 3.2%. Plasma pTau217 concentrations were slightly higher in paired samples of the clinical protocol. Following a two-threshold approach, the need of confirmatory tests (grey zones) after measuring plasma pTau217 ranged between 45.9% and 18.3% using our previously reported strict or lenient cutoffs (overall accuracy 96.6% and 92.1%, respectively).ConclusionsThe robust stability and low lot-to-lot variability of plasma pTau217 measurement in an automated platform result in high diagnostic performance of this biomarker in the prospective evaluation of patients in a memory clinic setting. These findings support its implementation into clinical routine, offering clinicians an accessible biomarker for AD diagnosis.