(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. (Read More)