Blood Test as Accurate as Lumbar Punctures for Detecting Alzheimer’s

By LabMedica International staff writers
Posted on 25 Jan 2024

Image: Detecting Alzheimer’s disease using a blood test could be just as accurate as standard lumbar punctures (Photo courtesy of 123RF)

Individuals with Alzheimer’s disease often exhibit accumulations of amyloid and tau proteins in their brains, key indicators of the condition. Typically, Alzheimer’s diagnosis is based on symptoms like cognitive and memory issues. However, only a small percentage (2%) of those diagnosed with dementia undergo ‘gold standard’ diagnostic methods such as PET scans or lumbar punctures. With the advent of novel Alzheimer’s therapies, enhancing diagnostic accuracy has become increasingly crucial. Now, findings from a study indicate that a commercial blood test might be able to identify Alzheimer’s disease as effectively as standard lumbar punctures. This test specifically detects ‘p-tau217’, a variant of the tau protein, which is a primary marker of Alzheimer’s.

This new study led by researchers at the University of Gothenburg (Mölndal, Sweden) demonstrated that blood levels of p-tau217 correlate with the levels of amyloid and tau proteins identified in brain scans and lumbar punctures. This discovery holds significant promise for transforming the diagnostic process for suspected Alzheimer’s patients. Notably, the study utilized a threshold for categorizing individuals into those likely or unlikely to have Alzheimer’s, and an intermediate group requiring further assessment through conventional methods like lumbar punctures or PET scans. By applying this blood test approach, researchers anticipate a substantial reduction, by approximately 80%, in the need for these more invasive follow-up tests.

However, several questions remain unresolved. There is a need for a more comprehensive understanding of how these blood tests perform in everyday clinical settings, particularly among diverse patient groups. Additionally, like new medical treatments, these blood tests must undergo regulatory approval before they can be integrated into healthcare practice. People need a quick and accurate diagnosis, which will “ultimately bring us closer towards a cure for dementia” said Dr. Sheona Scales, Director of Research at Alzheimer’s Research UK. “In the past year, we have seen incredible progress in the development of blood-based Alzheimer’s tests. And as we see more and more different types of tests becoming available, studies like this are key to understanding which are most accurate.”

Related Links:
University of Gothenburg