Tue 11 Aug 2020
More studies need to confirm value of test
« Back to News
Very recent news reports have had headlines like this one from the ABC; “Breakthrough new blood test could diagnose Alzheimer's decades earlier.” While this is accurate it might be better if the word “could” was emphasized.
We have reported on potential blood tests for Alzheimer’s disease several times in the past e.g. here
in 2019 and here
in 2018. This study reports some further progress in this field but we are still a long way from a test that can confidently diagnose Alzheimer’s disease very early before the symptoms start.
The new test measures a specific form of the tau protein that is associated with Alzheimer’s disease. The test can discriminate quite well between Alzheimer’s disease and some other forms of dementia that look similar clinically. There is also some evidence that the test can pick up some people who are going on to develop Alzheimer’s disease later in life but are currently without symptoms. This was shown most clearly in a group of people who have a rare inherited form of Alzheimer’s disease caused by a mutation in the PSEN1 gene. There was also preliminary evidence that the test may be able to detect very early non-hereditary Alzheimer’s disease but much bigger studies following many people over time will be needed before it is clear if the test is adequate for this purpose.
If it is, then this will be a major breakthrough as identifying a high-risk group will help in recruiting people for clinical trials of potential preventive treatments.
New York Times