Original Title: Efectividad diagnóstica de la determinación de las isoformas fosforiladas de la proteína tau (p-tau) en muestras de sangre (plasma y/o suero) en la enfermedad de Alzheimer

Authors' objectives: This report aims to assess diagnostic effectiveness of the determination of phosphorylated isoforms of the tau protein (p-tau) in blood samples (plasma and/or serum) in relation to AD or MCI due to AD, compared to diagnosis by clinical criteria, CSF biomarkers or PET or post-mortem pathology imaging, from the per spective of the Spanish NHS. The secondary objectives are: • To determine the diagnostic performance of the determination of phosphorylated isoforms of tau protein (p-tau) in blood (plasma and/or serum) samples in relation to AD or mild cognitive impairment (MCI) due to AD compared to diagnosis by clinical criteria, CSF biomarkers or PET imaging. • Determine the diagnostic performance of the determination of phosphorylated isoforms of tau protein (p-tau) in blood samples (plasma and/or serum) in comparison with the definitive post-mortem diagnosis of AD.

Authors' results and conclusions: CONCLUSIONS: The low methodological quality of the available evidence substantially hinders the validity of the studies identified. The main limitations are the risk of selection bias and information bias, the heterogeneity of the criteria (clinical and biomarker) applied to diagnose participants and classify them into subgroups, the variations in the analytical techniques used and their difficult reproducibility, and the lack of transparency in the presentation of results which prevents sensitivity, specificity, and predictive values from being obtained. With the information obtained it is not possible to determine the diagnostic effectiveness of phosphorylated isoforms of tau protein (p-tau) in blood samples (plasma and/or serum) in relation to AD or MCI due to AD. No evidence has been identified on the cost-effectiveness of this diagnostic intervention or on the impact that its generalised implementation would have on the organisation and operations of the units responsible for the diagnosis and treatment of AD. Evidence from studies of adequate methodological quality is required to estimate the diagnostic effectiveness, through studies comparing p-tau in blood samples versus a confirmed diagnosis in a consecutive series of patients from the clinical setting of potential use of the diagnostic test.

Authors' methods: A systematic review (SR) of the available scientific literature on the diagnostic effectiveness of the determination of phosphorylated isoforms of the tau protein (p-tau) in blood samples (plasma and/or serum) in relation to Alzheimer’s dis ease (AD) or mild cognitive impairment (MCI) due to AD was conducted for the period from 1 January 2000 to 1 September 2022.

Project Status: Completed

Year Published: 2023

URL for published report: https://repisalud.isciii.es/rest/api/core/bitstreams/78473a47-9497-405c-b357-bc0bc6f60847/content

URL for additional information: https://redets.sanidad.gob.es/productos/buscarProductos.do?metodo=detalle&id=1246

English language abstract: An English language summary is available

Publication Type: Full HTA

Country: Spain

Organisation Name: Agencia de Evaluacion de Tecnologias Sanitarias

Contact Address: Instituto de Salud "Carlos III", Calle Sinesio Delgado 6, Pabellon 4, 28029 Madrid, Spain. Tel: +34 9 1 822 2005; Fax: +34 9 1 387 7841;

Contact Name: Esther E. García Carpintero

Contact Email: eegarcia@isciii.es

Copyright: Agencia de Evaluacion de Tecnologias Sanitarias