New Blood Test Improves Diagnosis of Alzheimer’s Disease

Of those living with AD in Ireland, up to half have not received a formal diagnosis, underscoring the need for better diagnostic methods that are both accurate and scalable. To facilitate precise diagnosis, biomarkers are typically measured in cerebrospinal fluid (CSF) obtained via a diagnostic lumbar puncture (LP), a procedure that is invasive and carries associated risks and challenges. Now, a new blood test could revolutionize patient care, offering the potential for improved AD diagnosis, earlier intervention, and more targeted treatment options.

A collaborative study involving researchers from Trinity College (Dublin, Ireland) is investigating the use of a new blood test, plasma p-tau217, to detect AD. The Lumipulse G plasma p-tau217 assay from Fujirebio (Tokyo, Japan) could potentially replace the current diagnostic method for over half of patients with early symptoms, thereby enabling more patients to be diagnosed accurately and efficiently. The study, published in Alzheimer’s & Dementia: Diagnosis, Assessment and Disease Monitoring, is one of the first in Europe to evaluate the real-world effectiveness of plasma p-tau217, one of the leading automated blood tests for AD, in patients with mild symptoms who are undergoing evaluation in a specialist memory service.

In this study, 148 patients provided both blood and cerebrospinal fluid (CSF) samples during their LP procedure, allowing researchers to directly compare the new blood tests to established CSF biomarkers. Importantly, this was done using fully automated technology (Lumipulse), which is already in use in clinical diagnostic laboratories. The adoption of a fully automated system ensures consistent reliability over time in the laboratory, as well as greater consistency between different laboratories. The study revealed that plasma p-tau217 measurements using the automated system were over 90% as accurate as those obtained from LP. Integrating this blood test into clinical pathways could potentially eliminate the need for more than half of the diagnostic LPs currently conducted. This would have significant implications for the diagnosis and management of early AD. Based on their findings, the research team believes that this new blood test could replace over half of the 150-200 diagnostic LP procedures currently performed annually.

"This study brings us one step closer to using diagnostic blood tests, such as plasma p-tau217, to assist in the clinical-biological diagnosis of early Alzheimer’s Disease,” said Dr. Adam Dyer, Specialist Registrar in Geriatric Medicine & Clinical Lecturer in Medical Gerontology, Trinity College Dublin. “Importantly, this research assessed plasma p-tau217 using fully-automated technology already available in clinical laboratories and used samples from a "real-world" clinical cohort."