Katharina Buczek
These guidelines, known as the AT(N) framework, require three distinct components to be detected either via imaging or the analysis of CSF samples. These components include tau tangles, amyloid plaque presence, and brain neurodegeneration.
Unfortunately, though, both of these detection options pose severe economic limitations– signaling a desperate need for cost-effective and convenient AT(N) biomarker development in blood samples. This is also a minimally invasive procedure that requires much fewer resources.
The blood diagnostic methods currently used are able two check two of the three necessary benchmarks for diagnosing AD– the detection of abnormalities in the phosphorylated tau form and plasma amyloid beta.
The most significant challenge, though, is detecting biomarkers of neurodegeneration that are directly linked to the brain and are not influenced by any other contaminants produced in other parts of the body.
Yet remarkably, Karikari and his research team were able to develop a technique that selectively detects BD-tau while managing to avoid “big tau” proteins which are produced by cells located outside of the brain.
This was possible after the researchers designed a unique antibody that specifically binds to BD-tau, which ultimately makes it easier to detect in blood samples.
Then, this process was tested using over 600 patient samples obtained from five different cohorts.
These samples came from both patients whose AD diagnoses were confirmed post-mortem, as well as patients with memory impairment suggestive of early-stage AD.
The tests revealed that BD-tau levels detected in blood samples of AD patients matched the same detection levels in the cerebral spinal fluid. It also was able to reliably distinguish AD from other neurodegenerative diseases.
Finally, the detection of BD-tau levels correlated with tau tangles in the brain tissue and amyloid plaque severity– a finding which was confirmed using brain autopsy analyses.
So now, the researchers are hopeful that through the monitoring of BD-tau blood levels, clinical trial design could be improved, and screening may be facilitated. Additionally, patients from populations that have not historically been included in research cohorts may be allowed greater enrollment.
