Researchers are working on a way to spot Alzheimer’s with a blood test.

An international team, including Australians, has identified biological markers in blood plasma that indicate the extent of buildup of the protein amyloid beta in the brain – the earliest sign of Alzheimer’s disease.

Although the work is at an early stage, it could potentially lead to a blood test for Alzheimer’s, which would be revolutionary.

Currently, diagnosis is costly and inconvenient.

The new technique was tested on two groups of patients - 252 Australian and 121 Japanese.

The scientists say the ratios of the different amyloid-beta-associated protein fragments and a composite score can accurately predict the level of amyloid-beta build-up in the brain.

The study is accessible here.