Grant: Project Grant

Alzheimer's Disease (AD) is the most common type of dementia and causes symptoms such as memory loss and problems with language and thinking that eventually limit everyday activities of life. In Canada, over 1 in 3 seniors die from AD and over 25,000 new cases are diagnosed each year, 65% of which are women. Although clinical onset and diagnosis of AD typically occurs after age 65 years, we now know that brain changes including build-up of amyloid plaques, spreading of neurofibrillary tangles, and loss of neurons, begin ~20 years before the emergence of memory problems. The challenge is that current methods to detect these early brain changes require very expensive brain scans or very invasive collection of cerebrospinal fluid through a lumbar puncture. Fortunately, new technologies now raise the possibility of using blood tests to measure these brain changes. This project will evaluate 5 candidate proteins that can now be measured in blood as candidate biomarkers that improve our ability to predict a person's risk of AD at least a decade before memory problems start. The candidate proteins we will test are called p-tau-181, NF-L, Ab40, Ab42 and GFAP. First, we will work with a large collection of 5,200 blood samples already collected by Statistics Canada from the Canadian population to define what the normal levels are for these proteins across the life span, from age 3-79 years, as it is important to define what "normal levels" are so that abnormal levels can be recognized. Second, we will measure these proteins in three Canadian cohorts including the Canadian Consortium for Neurodegeneration in Aging (CCNA, 1,400 specimens), the UBC AD clinic (2,000 specimens) and disease-free "Super-Seniors" (500 specimens). As each cohort already has a wealth of clinical, genetic and brain scan data, we will be able to determine whether blood tests improve our ability to predict a person's risk of AD.