Nowadays, in order to diagnose Alzheimer’s disease, doctors often use brain imaging or analyze cerebrospinal fluid (CSF) samples to detect the presence of amyloid plaques, tau protein tangles and neurodegenerative lesions in the brain.
These are the 3 signs specific to Alzheimer’s disease, but these methods have limitations economically and practically.
In addition, existing blood assays can accurately detect β-amyloid and phosphorylated tau proteins in abnormal plasma.
However, since the overall tau protein measured includes brain-derived tau protein (BD-tau) and tau protein produced by non-brain cells.
Therefore it is not possible to distinguish Alzheimer’s disease from other neurodegenerative diseases.
A recent study published in the journal Brain has developed a technique to selectively detect BD-tau in order to accurately diagnose Alzheimer’s disease.
The researchers designed a special antibody that selectively binds to BD-tau, making it readily detectable in the blood.
Subsequently, using this method, they tested samples from more than 600 patients.
These patients include those diagnosed with Alzheimer’s disease after death and those who develop early memory deficits in Alzheimer’s disease.
It shows that this new method detects levels of BD-tau in blood samples that are consistent with tau levels in CSF and therefore can reliably distinguish Alzheimer’s disease from other neurodegenerative diseases.
In addition, autopsy analysis of the brain confirmed that BD-tau levels also correlated with the severity of amyloid plaques and tau protein tangles in the brain tissue.
In the future, researchers will launch a large-scale clinical trial to validate this approach.