A team of international scientists has found a blood test that screens for Alzheimer’s Disease may be effective in detecting changes in amyloid beta and tau protein levels in the brain years before symptoms emerge.
Previously in 2023, a blood test for detecting amyloid beta protein was developed and made available by a company named AD-Detect; it also created the ALZpath pTau217 assay, which is only available to researchers but allows them to detect this form of tau in a blood test.
This was made available, free of charge, to an international group of researchers based across Scandinavia, Europe and the US to determine how this assay compared to using cerebrospinal fluid to biomarkers used to detect Alzheimer’s disease.
For their study, published in JAMA Neurology, the researchers examined data from three sources: a cohort of individuals at risk of Alzheimer’s disease and two other biobanks set up to investigate neurodegenerative conditions or ageing and dementia.
The total of 786 participants (mean age 66) included 504 females and 282 males.
Analysis of the data showed the assay identified individuals with abnormal levels of amyloid beta and tau, but did not look at whether this correlated with the incidence of Alzheimer’s disease.
Researchers tested the assay in conjunction with imaging data and found the assay provided more accurate detection of hippocampal atrophy and was similar in its ability to detect abnormal levels of amyloid beta and tau as cerebrospinal fluid tests. This was the case across the three groups.
The authors said the assay could detect abnormal levels of amyloid beta and tau in 80% of tested participants, while the remaining 20% would need confirmatory imaging or cerebrospinal fluid tests.
They claimed this was more accurate than current diagnostic tools and could be used to identify people for early intervention with emerging pharmaceutical treatments designed to reduce amyloid build-up.
