Illustration of human blood cells

A new blood test that can spot amyloid and tau in the brain should be on the market soon. The test worked well to accurately and consistently identify accumulations of the proteins implicated in Alzheimer’s disease and related dementias, according to a study published Monday in JAMA Neurology.

The test checks for phosphorylated tau at residue 217 (pTau217), one biomarker that increases when beta amyloid and tau proteins accumulate in the brains of people with the disease. The test is made by ALZpath.

To find out if people have these proteins building up that can cause cognitive diseases, people have to have a brain scan or spinal tap. Both procedures can be hard for all people to access, and can be costly. Collecting cerebrospinal fluid (CSF) can also be painful. That’s why scientists are looking for ways to spot the proteins in blood.

The study looked at three independent clinical studies assessing the test on 786 participants spanning three different groups that included people in Sweden, Spain, Canada and the United States. The mean age of participants was 66.3 years old, and 64.1% were women.The research was led by Nicholas Ashton, PhD, an associate professor of neurochemistry at the University of Gothenburg in Sweden.

The test was 96% accurate in pinpointing elevated levels of beta amyloid and up to 97% accurate in identifying tau, the researchers said. 

In fact, the accuracy was significantly higher than other plasma biomarker combinations and equivalent to CSF biomarkers, the researchers noted.

Last year, the AD-Detect blood test came on the market. It was the first one to evaluate beta amyloid protein. Some researchers have shared concerns about the science behind the Quest Diagnostics test, saying it’s not a detection tool.

In a statement from ALZpath, the company said the test will be available for clinical use as ALZpath Dx later this month. Additionally, the test will be commercially available on other research and diagnostic platforms so it’s accessible worldwide.