A blood test that looks for biomarkers tied to Alzheimer’s disease could be the screening tool needed to identify patients earlier and get them into critical trials.

In a study published Jan. 31 in Nature, Katsuhiko Yanagisawa, director general of Japan’s National Center for Geriatrics and Gerontology, describes a mass spectrometry test that looks for amyloid in the blood.

Amyloid protein deposits in the brain in the brain’s cerebral cortex and along the walls of cerebral blood vessels are clear indicators of Alzheimer’s disease, but they are hard to obtain.

Yanagisawa’s research found the amount of amyloid present in the blood correlated with the degree of a study participant’s cognitive problems and matched PET scans and spinal fluid measurements from the same patients.

He told Scientific American that enough amyloid penetrates the blood–brain barrier to make it a useful measure of cognitive function.

“We think amyloid blood tests could replace costly, invasive amyloid tests, especially when it comes to detecting preclinical Alzheimer’s,” he told the magazine.

Reducing barriers — chief among them cost — to amyloid testing could improve access clinical trials and make those tests  more representative of the population. It could also help researchers distinguish between different types of memory loss.