Alzheimer's disease detection in the blood

A team of scientists from Hokkaido University and Toppan, have developed a biosensing technology that can detect Aβ-binding exosomes in the blood of mice, which increase as Aβ accumulates in the brain.

When tested on mice models, the Aβ-binding exosome Digital ICATM (idICA) showed that the concentration of Aβ-binding exosomes increased with the increase in age of the mice.

In addition to the lack of effective treatments of Alzheimer's, there are few methods to diagnose Alzheimer's. Alzheimer's can only be definitively diagnosed by direct examination of the brain-which can only be done after death. Aβ accumulation in the brain can be measured by cerebrospinal fluid testing or by positron emission tomography; however, the former is an extremely invasive test that cannot be repeated, and the latter is quite expensive. Thus, there is a need for a diagnostic test that is economical, accurate and widely available.

The team adapted Toppan's proprietary Digital Invasive Cleavage Assay (Digital ICATM) to quantify the concentration of Aβ-binding exosomes in as little as 100 µL of blood. The device they developed traps molecules and particles in a sample one-by-one in a million micrometer- sized microscopic wells on a measurement chip and detects the presence or absence of fluorescent signals emitted by the cleaving of the Aβ-binding exosomes.

Reference:

Kohei Yuyama et al, Immuno-digital invasive cleavage assay for analyzing Alzheimer's amyloid β-bound extracellular vesicles, Alzheimer s Research and Therapy, DOI: 10.1186/s13195-022- 01073-w