The researches find that the a patient’s response to treatment by doing a simple blood test. This is make possible using the APEX (Amplify Plasmonic EXosome); system invent by researchers from the National University of Singapore (NUS). Designed to pick up an early-stage molecular marker of AD; the aggregated amyloid beta (Aβ), the APEX system could potentially diagnose AD even before clinical symptoms appear.

A simple blood test

This novel technology is highly sensitive and provides an accurate diagnosis  comparable to brain PET imaging; the current gold standard for AD diagnosis  at about S$30 per test; which is less than one per cent of the cost of PET imaging. The current design could test 60 samples simultaneously and results are available in less than one hour.

As the APEX system uses native blood plasma without additional sample processing; it conducts direct measurement and is very simple to use in clinical settings. Led by Assistant Professor Shao Huilin from the NUS Institute for Health Innovation & Technology (NUS iHealthtech); the 12-member research team spent two years developing APEX. The team recently published its research findings in prestigious scientific journal Nature Communications. The study is feature as an Editors’ Choice by the journal.

Additional sample processing

Dementia is the public health crisis of the 21st century. In 2018, dementia has affected 50 million people worldwide; and the number is expect to rise to 82 million by 2030 and 152 million by 2050. Every year, over 9.9 million new cases of dementia are diagnose worldwide. AD is the most common cause of dementia. Due to the complex and progressive nature of AD, early detection and intervention can improve the success of disease modifying therapies.

Unfortunately; current AD diagnosis and monitoring using clinical evaluation and neuropsychological assessments  are subjective and the disease tends to be detected only at a late stage. Other alternatives such as PET imaging and cerebrospinal fluid test are either too expensive for wide clinical adoption or require invasive lumbar punctures.

Neuropsychological assessments

Blood-based tests, on the other hand, have the advantage of being safe, affordable and easy to administer. However, one key challenge for scientists is that blood has very low concentrations of AD molecules, and not all of these molecules are disease-reflective, making detection and diagnosis very difficult.

The invention by the NUS team is therefore a big step forward by providing a solution to effectively ‘capture’ and measure the most meaningful AD molecules in blood samples and amplify them for analysis.”As blood tests are relatively easy to administer, APEX can be also used to monitor a patient’s response to treatment. Furthermore, this technology can be easily scaled up for large cohort clinical validations and drug evaluation,” she added.