Novel blood test may diagnose Alzheimer’s

Boston: Scientists have developed a blood test that can accurately diagnose or even predict Alzheimer’s disease before symptoms appear. Currently the only way to definitively diagnose Alzheimer’s disease in life is through brain scans and tests of cerebrospinal fluid that must be collected via lumbar puncture. Though cumbersome and expensive, such tests provide the most accurate diagnoses for patients. Researchers at the Brigham and Women’s Hospital in the US are working to develop a blood test that could replace these procedures. The tau protein has long been implicated in Alzheimer’s, however, tau occurs as a family of related molecules which have subtly different properties. The team took advantage of the complexity of tau and built assays to measure different forms of tau and identified a subset of tau proteins which are specifically elevated in Alzheimer’s disease. “A blood test for Alzheimer’s disease could be administered easily and repeatedly, with patients going to their primary care office rather than having to go into a hospital,” said Dominic Walsh, from Brigham. “Our test will need further validation in many more people, but if it performs as in the initial two cohorts, it would be a transformative breakthrough,” said Walsh. Researchers developed tests capable of detecting different populations of tau fragments in cerebrospinal fluid and blood. They applied these tests to participants who had donated both plasma and cerebrospinal fluid. They validated results in a second group of patients. The team analysed five different tests for tau fragments. — PTI