Novel test allows for rapid diagnosis of Alzheimer’s and Parkinson’s

A more accurate and faster diagnostic technique for neurodegenerative diseases could open the door for earlier treatment and alleviation of the likes of Alzheimer’s and Parkinson’s.

The groundbreaking process developed by University of Minnesota Twin Cities researchers, significantly improves the performance of advanced protein-misfolding detection methods in both humans and animals.

A protein is said to be misfolded when it can’t achieve its normal natural state. Such proteins are a hallmark of ageing and many neurodegenerative disorders like Alzheimer’s, Parkinson’s, mad cow disease (BSE), and chronic wasting disease (widely found in deer), where they build-up in the central nervous system.

Detecting these misfolded proteins is crucial for understanding and diagnosing these devastating diseases. However, existing diagnostic methods, like enzyme-linked immunosorbent assay and immunohistochemistry, can be expensive, time-consuming, and limiting in terms of antibody specificity.

But the University of Minnesota researchers’ method, dubbed Nano-QuIC (Nanoparticle-enhanced Quaking-Induced Conversion), dramatically improves the performance of advanced protein-misfolding detection methods, such as the NIH Rocky Mountain Laboratories’ Real-Time Quaking-Induced Conversion (RT-QuIC) assay.

The researchers have reported their findings in the American Chemical Society’s journal, Nano Letters.

Credit: Sang-Hyun Oh Research Group, University of Minnesota

Sang-Hyun Oh, senior co-author of the paper in the University of Minnesota Department of Electrical and Computer Engineering, said: “This paper mainly focuses on chronic wasting disease in deer, but ultimately our goal is to expand the technology for a broad spectrum of neurodegenerative diseases, Alzheimer’s and Parkinson’s being the two main targets.

“Our vision is to develop ultra-sensitive, powerful diagnostic techniques for a variety of neurodegenerative diseases so that we can detect biomarkers early on, perhaps allowing more time for the deployment of therapeutic agents that can slow down the disease progression. We want to help improve the lives of millions of people affected by neurodegenerative diseases.”

The RT-QuIC method involves shaking a mixture of normal proteins with a small amount of a misfolded one, triggering a chain reaction that causes the compounds to multiply and allowing for the detection of these irregular molecules.

Using tissue samples from deer, the University of Minnesota team demonstrated that adding 50-nanometer silica nanoparticles to RT-QuIC experiments dramatically reduces detection times from about 14 hours to only four hours and increases the sensitivity by a factor of 10.

A typical 14-hour detection cycle means that a lab technician can run only one test per normal working day. However, with a detection time of less than four hours, researchers can now run three or even four tests per day.

Having a quicker and highly accurate detection method is particularly important for understanding and controlling transmission of CWD, a disease that is spreading in deer across North America, Scandinavia, and South Korea.

The researchers believe that Nano-QuIC could eventually prove useful for detecting protein-misfolding diseases in humans, specifically Parkinson’s, Creutzfeldt-Jakob Disease, Alzheimer’s, and ALS.

Peter Larsen, senior co-author of the paper and an assistant professor in the University of Minnesota Department of Veterinary and Biomedical Sciences, explained: “Testing for these neurodegenerative diseases in both animals and humans has been a major challenge to our society. What we’re seeing now is this really exciting time when new, next generation diagnostic tests are emerging for these diseases.

“The impact that our research has is that it’s greatly improving upon those next generation tests, it’s making them more sensitive, and it’s making them more accessible.”