Blood Based Biomarkers of Neurodegeneration Across the Health Spectrum

Blood tests are currently used to diagnose a variety of diseases, this is done by measuring molecules in the blood that have been produced or affected by the disease, causing the levels to vary from healthy people. Despite this being a standard practice for a variety of diseases, we have lacked the ability to perform tests like this for brain diseases. Instead, we have relied on diagnosing conditions like dementia with memory tests, that are not very accurate, and brain imaging, which is expensive and not accessible for everyone. However, we are finally able to measure proteins in blood that have come from the brain using newly available technology. This enables the development of blood tests for brain diseases that affect these proteins. The goal of this study is to understand what these protein measurements look like across the entire spectrum of brain health, a necessary step to bring us closer to establishing these blood tests. We will establish whether these blood tests can tell the difference between people who are healthy and people who have a brain disease by establishing what the normal ranges of these proteins in the Canadian population are. We will also see if these blood tests can differentiate between the different types of dementia, by comparing the protein levels of each type of dementia against our established normal ranges and the ranges from other forms of dementia. If these blood tests prove to be useful for informing us about known brain diseases, we will then investigate whether COVID-19, as a new disease that may have implications for the brain, has biomarker levels similar to the normal population or to those with dementia. This study will ultimately lay the groundwork for establishing blood tests as a way to diagnose dementia and other brain diseases in Canada. Using these blood tests will provide a more accurate and accessible diagnosis, which is important for allowing people to receive drug treatment that targets their specific disease.