Blood tests needed for widespread Alzheimer’s diagnosis on the way

Blood tests for Alzheimer’s are needed to more widely diagnose the brain-wasting disease and understand its prevalence, but it will be another couple of years before they become an everyday tool, medical experts and company executives say.
Blood testing is initially likely to be used to rule out Alzheimer’s, with positive results signaling the need for more advanced diagnostics.
Several Alzheimer’s blood tests are in the works – and one is already being sold to consumers – but none have been established as accurate, formally approved by regulators or reimbursed by insurers. Some are being used to help screen participants enrolling in clinical trials of Alzheimer’s treatments.
Alzheimer’s, which gradually destroys memory and thinking skills, is characterized by changes in the brain including buildup of amyloid beta plaques and tau tangles that result in loss of neurons responsible for transmitting information.
Currently, people who might benefit from Leqembi, the new Alzheimer’s drug from Eisai and Biogen, need those changes diagnosed through cognitive assessment and a cerebrospinal fluid (CSF) test, which requires an invasive lumbar puncture, or an expensive PET brain scan that may not be reimbursed by health insurers.