When doctors need to confirm an Alzheimer's diagnosis, they often turn to a combination of brain imaging and cell analysis. Both have their downsides. The latter involves a lumbar puncture, an invasive and painful procedure that’s more commonly known as a spinal tap. A doctor will insert a needle into the lower back to extract a sample of the patient’s cerebrospinal fluid. A lab technician then tests the sample for signs of progressive nerve cell loss and excessive amyloid and tau protein accumulation. MRI scans are less invasive but they’re often expensive and accessibility is an issue; not every community has access to the technology.
The next best tool for diagnosing Alzheimer’s disease is a blood test. While some can detect abnormal tau protein counts, they’re less effective at spotting the telltale signs of neurodegeneration. But that could soon change. This week, in the journal Brain, a multinational team made up of researchers from Sweden, Italy, the UK and US detailed a new antibody-based blood test they recently developed. The new test can detect brain-derived tau proteins, which are specific to Alzheimer’s disease. Following a study of 600 patients, the team found their test could reliably distinguish the illness from other neurodegenerative diseases.
Dr. Thomas Karikari, a professor of psychiatry at the University of Pittsburgh and one of the co-authors of the study, told The Guardian he hopes the breakthrough could help other researchers design better clinical trials for Alzheimer’s treatments. “A blood test is cheaper, safer and easier to administer, and it can improve clinical confidence in diagnosing Alzheimer’s and selecting participants for clinical trial and disease monitoring,” he said. There’s more work to be done before the test makes its way to your local hospital. To start, the team needs to validate that it works for a wide variety of patients, including those who come from different ethnic backgrounds.