Researchers from Ruhr University Bochum in Germany have developed a new blood test that can identify indicators of Alzheimer’s disease much earlier than the appearance of initial symptoms.

Published in EMBO Molecular Medicine, the results of the research indicated a potential to detect at-risk individuals and allow new drug discovery opportunities.

The test is designed to relatively analyse the levels of pathological and healthy forms of amyloid-β in the blood. Amyloid-β plaque accumulation in the brain is considered as an indicator of the disease and begins 15-20 years before its onset.

“The assay was able to correctly identify nearly 70% of the disease cases, with an overall diagnostic accuracy of 86%.”

It employs the immuno-infrared sensor technology to measure the distribution of the amyloid-β structures, which absorb infrared light at different frequencies. This enables the assay to determine the ratio of healthy to pathological form in the sample.

Led by Klaus Gerwert, the team studied the capability of the test to detect manifestation of pathological amyloid-β in very early (prodromal) phases of Alzheimer’s in the Swedish BioFINDER cohort.

It was observed that the assay can reliably find amyloid-β alterations in the blood of individuals who had a mild cognitive impairment that revealed abnormal deposits in brain scans.

The researchers further compared 809 controls with blood samples from 65 subjects in the ESTHER cohort study who later went to develop the disease.

They found that the test demonstrated an ability to identify disease indications on average eight years prior to the diagnosis in people who did not display any clinical symptoms.

The assay was able to correctly identify nearly 70% of the disease cases, with an overall diagnostic accuracy of 86%.

The researchers hope that the blood test will provide a cheap and simple option to pre-select individuals from the general population.

These people can be further tested using the existing more invasive and costly approaches such as brain scans and cerebrospinal fluid samples in order to eliminate false positives.

The team intends to extend the application of the test to Parkinson’s disease by measuring the associated disease biomarker, α-synuclein.