Dementia: detecting Alzheimer’s in the blood
Around 1.6 million people in Germany live with dementia. Most of them are affected by Alzheimer’s disease. The course of the disease can be positively influenced by various drugs and non-drug treatments – but it cannot be stopped or cured. A diagnosis as early as possible is important in order to sound out all therapeutic options. A blood test could also help.
According to a recent Message At the Empa – Federal Materials Testing and Research Institute, Empa researcher Peter Nirmalraj wants to photograph proteins with unprecedented precision – and thus gain insights into the molecular disease process of Alzheimer’s. This should pave the way for an earlier and simplified diagnosis of dementia using a blood test. A successful pilot study has now been completed together with the Department of Neurology at the St.Gallen Cantonal Hospital.
Diagnosis using atomic force microscopy
If the suspicion of Alzheimer’s disease creeps in, those affected have to prepare for lengthy and complex procedures until the case is clear. A team from Empa and the St. Gallen Cantonal Hospital is now developing a blood test that will enable diagnosis using atomic force microscopy (AFM). The results of a successful pilot study have now been published in the specialist magazine “Science Advances” released.
Observations in the nanometer range in the blood
In the beginning, the physicist Peter Nirmalraj wanted to understand the course of Alzheimer’s disease in order to enable new approaches in diagnosis and treatment. One step further would be if the exact role of the beta-amyloid peptides and the tau proteins, which are related to the neurodegenerative disease, were deciphered.
Therefore, the scientist decided not only to register the mere presence of the suspicious proteins, but also to determine their changeable shape and form as well as their number.
Although current methods make it possible to determine the total amount of both proteins in body fluids, these techniques do not allow differences in the shape and condition of the protein accumulations to be made visible.
That is why the researcher is working on technologies that enable observations in the nanometer range in the blood and yet do not destroy the structure and morphology of the proteins.
Large amounts of protein fiber
Together with neurologists at the St. Gallen Cantonal Hospital, Nirmalraj has now successfully completed a first study. To do this, he examined blood samples from 50 patients and 16 healthy test subjects. Using AFM technology, the researcher analyzed the surface of around 1,000 red blood cells per person, but without knowing any information about their state of health. “This was the only way to guarantee that the interpretation of the data remained objective,” explains Nirmalraj.
The scientist measured the size, structure and nature of protein accumulations that were on the blood cells. After thousands of red blood cells, the research team eagerly awaited the comparison of the results from Nirmalraj’s counts with the clinical data of the neurologists.
Indeed, the researchers were able to identify a pattern that matches the test subjects’ stage of illness: people with Alzheimer’s disease had large amounts of protein fibers made from beta-amyloid peptides and tau proteins.
The proteins were able to join together to form fibers several hundred nanometers in length. In healthy people or those with incipient brain disorders, however, Nirmalraj counted only a few fibers.
Proven feasibility of a blood analysis
According to the Empa researcher, this has proven the feasibility of a blood analysis using AFM technology: “If this method can be used to develop a reliable blood test, people with suspected Alzheimer’s would be spared the uncomfortable puncture of the spinal canal in order to be able to diagnose the disease clearly. “
There is still a long way to go before a simple blood test is available. Next, the team would like to corroborate the data by examining a larger number of test persons at various stages of the disease using AFM and chemical analyzes. (ad)
Author and source information
This text complies with the requirements of specialist medical literature, medical guidelines and current studies and has been checked by medical professionals.
- Empa – Federal Materials Testing and Research Institute: New diagnostics for Alzheimer’s? Detecting dementia in the blood, (accessed: 27.09.2021), Empa – Federal Materials Testing and Research Institute
- PN Nirmalraj, T Schneider, A Felbecker: Spatial organization of protein aggregates on red blood cells as physical biomarkers of Alzheimer’s disease pathology; in: Science Advances, (veröffentlicht: 24.09.2021), Science Advances
This article is for general guidance only and is not intended to be used for self-diagnosis or self-treatment. He can not substitute a visit at the doctor.