Scientists have created a radical blood test to detect Alzheimer’s disease. This blood test reportedly has an edge over other blood tests in the field.
Alzheimer’s is a neurodegenerative disease and is the most common form of dementia, but its diagnosis is a challenge, especially during the early onset of the disease.
For successful diagnosis, the detection of three distinct markers is recommended. These include inordinate accumulation of amyloid and tau proteins, as well as slow and progressive loss of neuronal cells in specified regions of the brain.
Currently, Alzheimer’s disease diagnosis entails expensive brain imaging and painful lumbar puncture, as per The Guardian. Therefore, the need for a simpler blood test diagnosis is obvious.
Brain imaging is not only expensive, but has a long waiting time for scheduling.
“A lot of patients, even in the US, don’t have access to MRI and PET scanners. Accessibility is a major issue,” Prof Thomas Karikari at the University of Pittsburgh, in Pennsylvania, US, co-author of the study published in the journal Brain, said.
Lumbar puncture is a very painful procedure that is used to extract cerebrospinal fluid (CSF) from the spinal cord. One may even exhibit headaches or backache following the procedure.
Besides being painless and readily available, blood tests will also help in the early detection of the disease, which will, in turn, lead to early initiation of treatment.
“A blood test is cheaper, safer, and easier to administer, and it can improve clinical confidence in diagnosing Alzheimer’s and selecting participants for clinical trial and disease monitoring,” Karikari said, the outlet reported.
Though current blood tests can detect abnormal levels of amyloid and tau proteins, spotting markers of nerve cell damage specific to the brain has proved to be difficult. This is where the blood test developed by Karikari and his team differs. The research team has developed an antibody-based blood test that detects a particular form of tau protein called brain-derived tau. This protein is specific to Alzheimer’s disease.
For the study, the researchers tested 600 patients suffering from different stages of Alzheimer’s. They found that levels of brain-derived tau were commensurate with levels of tau in the CSF. Also, the blood test could tell Alzheimer’s apart from other neurodegenerative diseases.
Protein levels also showed a strong association with the severity of amyloid plaques and tau tangles in brain tissue taken from people dead due to Alzheimer’s, the study found.
Monitoring levels of brain-derived tau in the blood could help create efficient clinical trials for Alzheimer’s treatments, Karikari hoped.
A separate study has found rare, damaging genetic variants that increase the risk of Alzheimer’s disease.
“Our results provide additional evidence for a major role for amyloid-β precursor protein processing, amyloid-β aggregation, lipid metabolism, and microglial function in AD,” the authors wrote in their paper.
Using gene-based burden analysis in place of the more common genome-wide association studies (GWAS), the researchers found a strong link between rare, damaging variants in ATP8B4 and ABCA1 with AD risk, and a signal in ADAM10, as well as rare-variant burden in the genes RIN3, CLU, ZCWPW1 and ACE, according to GenEngNews.