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

Background: Knowledge on the effect of analytical variability and storage conditions are essential for the successful implementation of plasma pTau in prospective settings. Aims: To investigate the performance of plasma pTau, measured in consecutive samples with LUMIPULSE, for detecting Alzheimer�...

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Detalles Bibliográficos
Autores: Arranz Martínez, Javier|||0000-0003-0891-1215, Ferrer Pérez, Rosa|||0009-0004-9477-699X, Zhu, Nuole|||0000-0002-0015-9455, Rubio Guerra, Sara|||0000-0001-7652-8029, Rodríguez-Baz, Íñigo|||0000-0003-3039-9115, Arriola-Infante, J.E., Maure Blesa, Lucia|||0000-0001-5643-7971, Garcia Castro, Jesús|||0000-0003-1503-4775, Selma Gonzalez, Judit|||0009-0006-1021-4653, Carmona Iragui, Maria|||0000-0001-6914-2339, Barroeta, Isabel|||0000-0003-2764-7923, Illán-Gala, Ignacio|||0000-0002-5418-2052, Santos Santos, Miguel Ángel|||0000-0003-1567-617X, Fortea, Juan|||0000-0002-1340-638X, Lleó, Alberto|||0000-0002-2568-5478, Tondo Colomer, Mireia|||0000-0002-0301-9984, Alcolea, Daniel|||0000-0002-3819-3245
Tipo de recurso: artículo
Fecha de publicación:2025
País:España
Institución:Universitat Autònoma de Barcelona
Repositorio:Dipòsit Digital de Documents de la UAB
Idioma:inglés
OAI Identifier:oai:ddd.uab.cat:324111
Acceso en línea:https://ddd.uab.cat/record/324111
https://dx.doi.org/urn:doi:10.1186/s13195-025-01779-7
Access Level:acceso abierto
Palabra clave:Stability
Plasma
Biomarkers
Alzheimer
Blood
Amyloid
Tau
Descripción
Sumario:Background: Knowledge on the effect of analytical variability and storage conditions are essential for the successful implementation of plasma pTau in prospective settings. Aims: To investigate the performance of plasma pTau, 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. Methods: We prospectively measured pTau 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 (4ºC vs -20ºC) 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. Results: We 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 pTau fold-change of 4.5 × compared to A-. We found no differences in plasma pTau concentrations between either short-term storage conditions. The overall coefficients of analytical variation ranged from 1.8% to 3.2%. Plasma pTau 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 pTau ranged between 45.9% and 18.3% using our previously reported strict or lenient cutoffs (overall accuracy 96.6% and 92.1%, respectively). Conclusions: The robust stability and low lot-to-lot variability of plasma pTau 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.