Test to spot Alzheimer’s before symptoms occur

Blood analysis could help detect the disease much in advance

Published - May 04, 2019 10:44 pm IST - London

FILE - In this May 19, 2015, file photo, a doctor points to PET scan results that are part of a study on Alzheimer's disease at a hospital in Washington. Scientists know that long before the memory problems of Alzheimer's become obvious, people experience more subtle changes in their thinking and judgment. (AP Photo/Evan Vucci, File)

FILE - In this May 19, 2015, file photo, a doctor points to PET scan results that are part of a study on Alzheimer's disease at a hospital in Washington. Scientists know that long before the memory problems of Alzheimer's become obvious, people experience more subtle changes in their thinking and judgment. (AP Photo/Evan Vucci, File)

Researchers have developed a test that could help doctors detect Alzheimer’s disease eight years before the first symptoms occur.

Using current techniques, Alzheimer’s disease, the most frequent cause of dementia, can only be detected once the typical plaques have formed in the brain.

At this point, therapy seems no longer possible. However, the first changes caused by Alzheimer’s take place on the protein level up to 20 years sooner.

“Once amyloid plaques have formed, it seems that the disease can no longer be treated,” said study co-author Andreas Nabers from Ruhr-University Bochum in Germany.

In Alzheimer’s patients, the amyloid beta protein folds incorrectly due to pathological changes long before the first symptoms occur.

A team of researchers, headed by Klaus Gerwert from Ruhr-University Bochum, successfully diagnosed this misfolding using a simple blood test. As a result, the disease could be detected approximately eight years before the first clinical symptoms occur.

But experiments showed that the test was not suitable for clinical applications as the test provided false positive diagnoses for 9% of the study participants.

In order to increase the number of correctly identified Alzheimer’s cases, the researchers have now introduced the two-tier diagnostic method.

To this end, they use the original blood test to identify high-risk individuals. Subsequently, they add a dementia-specific biomarker, namely tau protein, to run further tests with those test participants whose Alzheimer’s diagnosis was positive in the first step.

If both biomarkers show a positive result, there is a high likelihood of Alzheimer’s disease, said the study published in the journal Alzheimer’s & Dementia: Diagnosis, Assessment & Disease Monitoring.

“Through the combination of both analyses, 87 of 100 Alzheimer’s patients were correctly identified in our study,” Mr. Gerwert said.

0 / 0
Sign in to unlock member-only benefits!
  • Access 10 free stories every month
  • Save stories to read later
  • Access to comment on every story
  • Sign-up/manage your newsletter subscriptions with a single click
  • Get notified by email for early access to discounts & offers on our products
Sign in

Comments

Comments have to be in English, and in full sentences. They cannot be abusive or personal. Please abide by our community guidelines for posting your comments.

We have migrated to a new commenting platform. If you are already a registered user of The Hindu and logged in, you may continue to engage with our articles. If you do not have an account please register and login to post comments. Users can access their older comments by logging into their accounts on Vuukle.