Explainer: How a blood test can spot early Alzheimer's pathologies in the brain

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By Beth Roberts

A simple blood test could help diagnose Alzheimer’s disease much faster, without invasive tests - but how does it work, and could it be available on the NHS any time soon?

Researchers have found that a blood test that looks for a biomarker of Alzheimer’s disease showed a similar performance to cerebrospinal fluid (CSF) tests - and outperformed MRI scans.

The researchers at the University of Gothenburg, Sweden found that a commercial blood test from diagnostics company ALZpath could accurately identify levels of the protein p-tau217. This is found at elevated levels in people with the disease and considered a leading biomarker candidate for Alzheimer’s.

Blood tests have long promised a way to simplify and speed up the diagnosis of Alzheimer's disease, which currently relies on expensive, invasive procedures like brain MRI and lumbar punctures. Faster and simpler tests could make it easier to screen for Alzheimer’s disease much earlier.