Original title: Diagnostic Accuracy of a Plasma Phosphorylated Tau 217 Immunoassay for Alzheimer Disease Pathology
The study tested a blood assay that measures p-tau217A form of the tau protein measured in blood and associated with Alzheimer disease pathology., a form of the tau protein linked to Alzheimer disease. It compared blood results with brain scans and spinal-fluid tests in three groups of people. The assay detected abnormal amyloid and tau pathology with high accuracy, similar to spinal-fluid biomarkers. Blood p-tau217 rose over time only in people with abnormal amyloid, and the rise was greatest when tau was abnormal too. A three-range reference approach also reduced the need for follow-up tests by about 80%.
Imagine sorting a pile of mail into boxes when some envelopes need a closer look. The hard part is deciding which ones can be sorted confidently and which should be checked again. In this paper, the blood test is the quick sort: it flags signs linked to Alzheimer disease, while a three-range system helps decide when another test is needed.
People being assessed for Alzheimer disease may have a less invasive way to check for disease-related changes: a blood test rather than relying only on tests of spinal fluid or brain scans. Across three cohorts, the assay identified abnormal amyloid and tau pathology with accuracy comparable to cerebrospinal-fluid biomarkers, though the abstract does not establish how it performs in every clinical setting.
The abstract reports results from three single-center observational cohorts, not a trial showing that testing improves patient outcomes. It does not give enough detail to judge performance across all populations or clinical settings, or to determine how the assay should guide care.
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Diagnostic Accuracy of a Plasma Phosphorylated Tau 217 Immunoassay for Alzheimer Disease Pathology — Nicholas James Ashton, Wagner Scheeren Brum, Guglielmo Di Molfetta et al. — JAMA Neurology — doi:10.1001/jamaneurol.2023.5319
Abstract licence: CC BY
Explanation generated by Synthesis from the abstract — it is not the original paper.