Today the only way to definitively determine Alzheimer's disease in life is through brain scans and tests of cerebrospinal fluid that should be collected through a lumbar puncture. Though cumbersome and expensive, these tests provide the most accurate diagnosis for patients. Researchers at the Brigade and Women's Hospital are working to develop a blood test that can replace these procedures to accurately diagnose or even predict Alzheimer's disease before the onset of symptoms. Tau protein has long been implicated in Alzheimer's disease, however, it occurs as a family of related molecules that have insignificantly different properties. Brigham's team took advantage of Tau's complexity and built tests to measure different forms of tau and identified a subset of tau proteins that were specifically raised in Alzheimer's disease. The new approach of the team is detailed in Alzheimer's and dementia and is included in the December issue of the journal.
"A blood test for Alzheimer's disease can be done easily and repeatedly, as patients go to their primary care instead of having to go to hospital," said author Dr. Walsh, Dr. Anne Romney Center for Neurological Disease Brigham. "Finally, the blood-based test can replace the test for cerebrospinal fluid and / or brain imaging. Our new test has the potential to do just that. Our test will need further validation in many more people, but if performs both in the first two cohorts, this would be a transformative breakthrough. "
Walsh and colleagues developed tests capable of detecting different populations of tau fragments in cerebrospinal fluid and blood. They apply these tests to the participants assigned to Harvard Age Research, as well as to the participants in the research at the Nuremberg Institute in London. Each participant donates both plasma and cerebrospinal fluid. They confirmed the results of a second group of patients appointed by the Shiley-Marcos Disease Research Center at the University of California at San Diego.
The team analyzed five different tau fragments tests by finding that one known as NT1 analysis showed sufficient diagnostic sensitivity (AD predictability) and specificity (the ability to exclude controls) to continue using it as a potential screening an instrument for Alzheimer's disease. This was confirmed in both patient groups.
In performing the experiment twice – in two groups of patients with two different demographic environments – provided important confirmation, the authors noted that both groups of participants were small (65 participants and 86 participants respectively). Larger groups of participants will need to be studied, and authors are also interested in studying patients over time to determine how blood levels can change with the progression of the disease and what these numbers might look like before the onset of symptoms.
"We have made the data and tools needed to carry out our test widely available because we want other research groups to do this," Walsh said. "It is important for others to confirm our findings to make sure that this test will work in different populations."
This article is reissued by materials provided by Brigam and Women's Hospital. Note: The material may have been edited for length and content. For additional information, please contact the specified source.
Chen, Z., Mengel, D., Keshavan, A., Rissman, R. A., Billinton, A., Perkinton, M.,, Walsh, D.M. (2018). Understanding the complexity of developing extracellular aid for blood pressure tau for Alzheimer's disease. Alzheimer's and dementia. Дой: 10.1016 / j.jalz.2018.09.010