Two Alzheimer's biomarker studies spur hope for earlier-stage diagnosis

Two separate research teams say they've made new biomarker discoveries that could help boost early detection and treatment of Alzheimer's disease in different ways.

Harvard University and the University of Texas Medical School at Houston are behind the two projects.

The Harvard University team's work is published in the journal Nature and featured in The New York Times, among other publications. Their work focused on the protein REST, which scientists previously thought was only active in the brains of developing fetuses. It turns out the protein is also turned on in the brains of healthy older folks and protects their neurons from stresses relating to aging. According to the research, REST seems to turn off genes that promote cell death. But REST is highly diminished in the brains of people with Alzheimer's and other forms of dementia, according to the study.

This is early research, and much more work is needed to establish whether the REST/Alzheimer's link is definitive. But if it is, the finding could lead to new Alzheimer's drugs based on the REST biomarker. So far, Alzheimer's drug treatments have failed miserably. Researchers believe that hitting the disease earlier before it causes too much neurodegenerative damage could be the way to go, so the Harvard discovery has potential.

The University of Texas Medical School at Houston researchers and colleagues published their Alzheimer's findings in the Cell Press journal Cell Reports. They determined that it may be possible to detect signs of Alzheimer's by screening for amyloid-beta oligomers, precursors of the amyloid plaque that builds up in the brain and many believe is a sign of Alzheimer's disease. The idea is that they likely circulate in the body for years or decades before cognitive symptoms erupt.

The research team used protein misfolding cyclic amplification technology (PMCA) developed initially to find misfolded proteins responsible for "mad cow disease" and other prion diseases. They found that by applying their test to cerebrospinal fluid samples, they could detect amyloid-beta oligomers at very low concentrations. What's more, they could tell the difference between Alzheimer's patients and those with other neurodegenerative or neurological disorders. Importantly, the test reached 90% sensitivity and 92% specificity.

This finding is also early stage. But additional research could give it some serious legs. Again, a biomarker test that provides reliable early-stage Alzheimer's detection could enable a new class of drugs that actually help hold the disease back. Researchers believe that they could commercialize a PMCA-based Alzheimer's biomarker test within three years if further testing can confirm its utility.

Scientists have had high hopes before in the quest to defeat Alzheimer's, only to be defeated as studies reached their later stages. Both findings, therefore, require cautious optimism for now.

- here's the Harvard/Nature study abstract
- check out the NYT's take on the Harvard study
- here's the University of Texas Medical School at Houston release
- check out the Cell Reports journal article