Alzheimer’s disease is a notoriously difficult condition to diagnose, often only being confirmed at autopsy. The disease affects millions of people, but current tests such as PET scans and CSF samples are expensive, time-consuming, and invasive.

A paradigm-shifting test for Alzheimer’s has been developed by a joint Japanese-Australian team which screens for specific biomarkers in the blood. By simplifying the detection process, routine testing and screening may become commonplace. The newly developed test has been shown to be very accurate, scalable, and much cheaper than the current options to test for the disease. Testing has shown an accuracy of greater than 90 percent as judged against the current standards, with the team hoping to continue improving this figure.

Aβ42 has been recognized as an Alzheimer’s marker for some time, but it has been extremely difficult to detect such minute trace levels of the protein in the blood. This is the breakthrough of this newly developed test. The new technology is based on techniques of co-immunoprecipitation and mass spectroscopy which for the first time allow such small quantities to be measured.

The test specifically compares the ratio of two small amyloid precursor proteins, Aβ40 and Aβ42. Though the pathological process is not fully understood, Aβ42 is known to be neurotoxic and a positive marker for Alzheimer’s. This protein slowly builds up over many years to form aggregations in the brain. As normal brain maintenance mechanisms begin to fail in a patient with early Alzheimer’s, these aggregations grow ever more massive. After years or decades of this slow process, large amounts of Aβ42 may be deposited in the brain which causes degeneration of synapses and symptoms of Alzheimer’s disease.

 

This breakthrough technology can detect changes in blood as much as 15 years before symptoms present. Such a radical shift in detection opens new possibilities for how new drug trials may be performed as well as diagnosis and monitoring in patients. The very idea that the disease can be caught so early may allow new ways of thinking in terms of experimental early interventions. Moreover, patients who have been diagnosed with Alzheimer’s will now be able to easily monitor the progression of their disease. This may provide the ability to plan more clearly for their future, before their memory begins to suffer.

 

Nakamura A, Kaneko N, et at. High performance plasma amyloid-β biomarkers for Alzheimer’s disease. Nature. 2018;554(7691):249-254. doi:10.1038/nature25456.