New blood test that screens for Alzheimer’s may be a step closer to reality, study suggests

By Jacqueline Howard, CNN Health

CNN — Testing a person’s blood for a type of protein called phosphorylated tau, or p-tau, could be used to screen for Alzheimer’s disease with “high accuracy,” even before symptoms begin to show, a new study suggests.

The study involved testing blood for a key biomarker of Alzheimer’s called p-tau217, which increases at the same time as other damaging proteins — beta amyloid and tau — build up in the brains of people with the disease. Currently, to identify the buildup of beta amyloid and tau in the brain, patients undergo a brain scan or spinal tap, which often can be inaccessible and costly.

But this simple blood test was found to be up to 96% accurate in identifying elevated levels of beta amyloid and up to 97% accurate in identifying tau, according to the study published Monday in the journal JAMA Neurology.

“What was impressive with these results is that the blood test was just as accurate as advanced testing like cerebrospinal fluid tests and brain scans at showing Alzheimer’s disease pathology in the brain,” Nicholas Ashton, a professor of neurochemistry at the University of Gothenburg in Sweden and one of the study’s lead authors, said in an email. Read more…