Detect Alzheimer's disease in the blood

Researchers from Hokkaido University and Toppan have developed a method to detect the build-up of amyloid β in the brain from biomarkers in blood samples, a feature
of Alzheimer's disease.

Alzheimer's disease is a neurodegenerative disease characterized by the gradual loss
of neurons and synapses in the brain.
One of the main causes of Alzheimer's disease is the accumulation of amyloid (Aβ) in the brain, where plaques
form.
Alzheimer's disease is more common in people over the age of 65 and cannot be prevented or reversed
at present.
Therefore, Alzheimer's disease is a major concern
in countries with aging populations such as Japan.

A team of scientists from Hokkaido University and Toppan, under the leadership of Kohei Yuyama, a specially appointed associate professor at Hokkaido University's School of Advanced Life Sciences, has developed a biosensing technology that can detect Aβ-binding exosomes in the blood of mice, which increase
when Aβ accumulates in the brain.
Their research was published in the journal Alzheimer's Disease Research and Treatment.

When tested on a mouse model, a β binding exosome digital ICA^TM (idICA) showed that the concentration of a β binding exosome increased
with the age of mice.
This is very important because the mice used are Alzheimer's model mice, and as they age, Aβ accumulates
in the brain.

In addition to the lack of effective treatments for Alzheimer's disease, there are few
ways to diagnose Alzheimer's disease.
Alzheimer's disease can only be confirmed by a direct examination of the brain, and this examination can only be done
after death.
Aβ accumulation in the brain can be measured by cerebrospinal fluid detection or positron emission tomography; However, the former is an extremely invasive test that cannot be repeated, while the
latter is quite expensive.
Therefore, an economical, accurate and widely used diagnostic test
is required.

Yuyama's team's previous work has shown that the accumulation of Aβ in the brain is associated with Aβ-binding exosomes secreted by neurons, which degrade and transport Aβ to microglia of the brain
.
Exosomes are membrane envelopes secreted by cells with cell markers on their surfaces
.
The team used Toppan's proprietary Digital Invasive Lysis Analysis (Digital ICA)^TM to quantify the concentration
of a β binding exosomes in the blood of 100 μ L.
The device they developed captured molecules and particles in the sample one by one in a microscopic well of 1 million microns on a measurement chip and detected the presence
of a fluorescence signal emitted when a β bound exosomes split.

Clinical trials of this technology are currently underway in
humans.
This highly sensitive idICA technique is the first application of ICA, which enables high-sensitivity detection of exosomes that retain specific surface molecules from a small amount of blood without the need to learn special techniques; Since it is generally suitable for exosome biomarkers, it can also be used in the diagnosis
of other diseases.
ichi Makino is an employee of Toppan in
Japan.