Blood biomarkers for potential Alzheimer’s diagnostic tool

A research team at the Washington University School of Medicine (MO, USA) has developed a blood test that has proven to be highly accurate in detecting early signs of Alzheimer’s disease when combined with genetic risk factors.

Randall J Bateman, a Charles F and Joanne Knight Distinguished Professor of Neurology, commented:

“Our study shows that the blood test provides a robust measure for detecting amyloid plaques associated with Alzheimer’s disease, even among patients not yet experiencing cognitive declines.”

Bateman continued:

“A blood test for Alzheimer’s provides a huge boost for Alzheimer’s research and diagnosis, drastically cutting the time and cost of identifying patients for clinical trials and spurring the development of new treatment options… As new drugs become available, a blood test could determine who might benefit from treatment, including those at very early stages of the disease.”

The study suggests that the newly developed blood test could detect plasma Aβ42/Aβ40 amyloid beta protein levels in the blood, indicating whether amyloid plaques have started to develop and amass within the brain. High levels of amyloid plaques and evidence of neurofibrillary tangles (NFTs) are biomarkers of Alzheimer’s disease, which accumulate 1–2 decades before most individuals develop dementia symptoms.

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In order to certify the test’s accuracy, researchers at Washington University School of Medicine applied the test to blood samples from individuals involved in ongoing Alzheimer’s disease studies in the United States, Australia and Sweden. Each of these countries utilizes different protocols for the processing of blood samples and related brain imaging. The results confirmed that the Aβ42/Aβ40 blood test provided highly accurate and consistent results for both cognitively impaired and unimpaired individuals across all three studies.

Bateman further stated,

“These results suggest the test can be useful in identifying nonimpaired patients who may be at risk for future dementia, offering them the opportunity to get enrolled in clinical trials when early intervention has the potential to do the most good… A negative test result also could help doctors rule out Alzheimer’s in patients whose impairments may be related to some other health issue, disease or medication.”

Blood tests will also be the cheaper, more accessible alternative to costly brain scans and spinal taps currently being utilized to diagnose the progression of Alzheimer’s within the brain. More accessible diagnostic methods for Alzheimer’s will hopefully lead to quicker and earlier diagnosis for patients.

Source: Li Y, Schindler SE, Bollinger JG, et al. Validation of Plasma Amyloid-β 42/40 for Detecting Alzheimer Disease Amyloid Plaques. Neuro. 98(7) 688-699 (2021)

Washington University School of Medicine press release: www.medicine.wustl.edu/news/blood-test-for-alzheimers-highly-accurate-in-large-international-study/