SINGAPORE — A team of researchers at the National University of Singapore (NUS) has developed a new blood test to detect Alzheimer’s disease that it says is the fastest and most accurate in the world.

The Amplified Plasmonic Exosome (Apex) system is able to detect mild cognitive impairment and Alzheimer’s disease, which leads to severe dementia, and can provide results within an hour, after analysing certain proteins in blood samples.

Currently, there are three ways to diagnose dementia: A neuropsychological test, spinal fluid sampling and brain Positron Emission Tomography (PET) imaging.

The most common method is the neuropsychological test, while the PET scan is considered the most accurate test on the market now.

The brain PET imaging uses a special dye which contains radioactive tracers, that patients would have to either inhale or receive it through an injection. The patient would then have to wait an hour for the tracer to be absorbed by the body.

The areas of the brain containing disease would then appear as coloured spots on the PET scan.

Assistant professor Shao Huilin from NUS Institute for Health Innovation & Technology (NUS iHealthtech), who led the study, said: “The clinical study shows that the Apex system can accurately identify patients with Alzheimer’s and those with mild cognitive impairment (MCI). It also differentiates them from healthy individuals and patients suffering from other neurodegenerative diseases.”

She added that the blood test shows “comparable results with PET imaging, the current gold standard for Alzheimer’s diagnosis”.

The blood test is expected to be in use in hospitals and general practitioner clinics within the next five years, Prof Shao said, adding that it will priced at around S$30.

The current design can test 60 samples simultaneously, with the results being available in less than one hour.

Last year alone, dementia affected 50 million patients worldwide and the number is expected to increase to 82 million by 2030 and 152 million by 2050.

Every year, there are more than 9.9 million new cases of dementia diagnosed worldwide.

A study conducted by Singapore's Institute of Mental Health in 2015 estimated that one in 10 people in Singapore over the age of 60 had dementia. It also projected that there would be more than 100,000 dementia patients here in a few years’ time.

Prof Shao hopes that this new blood test will be able to help stem the tide.

“With this new blood test to enable early detection for Alzheimer’s disease, we think that it can offer many new opportunities for intervention and management. For example, by encouraging lifestyle changes, more active participation in cognitive as well as physical activities, we can regulate the progression of the disease.”

The early detection of Alzheimer’s can also help facilitate the discovery and development of new drugs, she added.

Out of the 84 patients involved in the clinical study, all 68 who have dementia or neurovascular compromises were diagnosed by the blood test.

Prof Shao noted that for now, there is no good blood-based method to effectively screen and monitor Alzheimer’s, making the NUS test a world’s first.

“New tests that are under investigation have either poor accuracy or low sensitivity. The Apex technology addresses both of these limitations and is therefore a very powerful and objective companion diagnostic system to complement existing clinical and neuropsychological tests for early detection and better management of the disease,” she said.

She added that the convenience of blood tests will also be able to allow doctors to monitor a patient’s response to treatment.

“This technology can be easily scaled up for large-cohort clinical validations and drug evaluation.”