Blood Test for Alzheimer's Disease?

In this week's issue of ALZForums, there was an article regarding reports of new blood tests that might finally measure amyloid proteins in the blood.  The amyloids would presumably have originated in the brain due to the disease process and might indicate the disease had begun doing damage long before the first cognitive symptoms appear.

Why is this important?  I see two reasons:

• The reports were presented at the 11th Clinical Trials on Alzheimer’s Disease conference, held October 24–27 in Barcelona.  The context was the value of identifying subjects for clinical trials, and there is a search for simple ways of early identification of trial subjects.  A reliable blood test would supersede expensive PET scans (~$5,000/shot) and (as in my experience) an unpleasant lumbar puncture/spinal tap.  This would be a substantial benefit to AD researchers.
• So far, researchers have had little success in improving cognition by removing amyloids from the brain.  There is a belief that if the disease can be detected much earlier, removing amyloids will actually improve cognition.  It will be extremely helpful to identify inception of the disease and begin a treatment long before cognition problems begin.  

Going forward, researchers must standardize conduct of the blood test and begin using it.