By Briana Lee
Last month, the largest international meeting on Alzheimer’s disease took place in Chicago, Illinois. As my first conference, Alzheimer’s Association International Conference (AAIC) was an intense and inspiring experience for me. I had the opportunity to learn of cutting-edge research by leading scientists in the biomedical and Alzheimer’s disease research field. I presented my own project investigating how brain imaging may be used for early Alzheimer’s disease detection. If you’d like to learn more, check out my blog post here, otherwise stick around for some exciting highlights from AAIC.
Alzheimer’s disease is currently the 6th leading cause of death in America and this number is expected to increase with our aging population. For this reason, research to understand and treat the condition has only increased as well. To support these efforts, the National Institute of Aging (NIA) at the National Institute of Health (NIH) plans to increase funding to Alzheimer’s disease research and related projects three-fold, funding up to 25% of new/early-stage projects for the next fiscal year. According to Dr. Richard Hodes, director of the NIA, the field of Alzheimer’s research is moving toward a more collaborative and “open science” environment. As a major force in promoting this movement, the NIA plans to continue its support of a more open-source/open-data research community so that with the collection and analysis of vast amounts of data, research progress will continue to accelerate.
Early Effects of Amyloid
Amyloid, a hallmark protein of Alzheimer’s disease, can build up in the brain for 10 to 20 years before reaching disease-state levels and a major question in the Alzheimer’s field is how this pathology manifests into clinical symptoms over time. This issue is one of the focuses of the Dallas Lifespan Brain Study, led by Dr. Denise Park at the University of Texas. Started in 2008, this longitudinal study follows 500 healthy and cognitively normal adults ages 20 to 89, showing no significant amyloid build up at the start of the study, indicated by normal PET scan results. This database is one of the only studies following middle-aged healthy adults as they age, and scientists plan to use this resource to track the progression of amyloid deposition before dementia onset.
Presented at AAIC, Dr. Park gave a plenary speech on recent analysis now at 4 years into the study. She and her group found that the amount of amyloid in the brain may be related to the rate of cognitive decline in Alzheimer’s patients. This means that people with higher levels of amyloid correlated with greater declines in cognitive performance over a 4-year time span. Even more striking, this relationship seems to be detectable even in the healthy younger cohort however this relationship was only observed in the vocabulary measures. It’s become increasingly clear, early intervention will be key to treating Alzheimer’s disease and this work suggests subtle differences in amyloid may matter even in healthy middle-aged people, providing a potential window for early detection and intervention. In addition, as of now, PET scans are used in a positive or negative fashion and this recent evidence suggests a new approach to PET scan interpretation may be helpful for predicting the rate of future cognitive decline.
Blood Brain Barrier and the Immune System
As a highly specialized and critical organ in the body, the brain is protected from the blood by a protective structure, called the blood-brain barrier. The blood-brain barrier is highly selective in what it allows to the brain, exchanging mostly small nutrients and gas molecules and excluding large immune cells. Research over the last decade however has demonstrated immune system involvement in many neurological conditions including Alzheimer’s disease.
Dr. Michal Schwartz at the Weizmann Institute of Science, Rehovot, Israel, a world pioneer in neuroimmunology, focused much of her career on this topic; what is the immune system doing in the brain and how is it entering the brain despite blockage by the blood brain barrier. From her work, Dr. Schwartz and her team found that immune cells enter the central nervous system through a structure in the brain called the choroid plexus, an area that functions like a gateway between cerebral spinal fluid and blood. In addition, they discovered that in the healthy brain, an immune signaling factor, IFN-γ, acts on this gateway site to prepare it for important exchanges, but in the Alzheimer’s brain, this activation may be reduced. Finally, Dr. Schwartz was a major player in initially promoting the notion that the immune system may play a protective role in the brain and currently her efforts are focused on ways to harness the immune system to fight against Alzheimer’s disease.
Though I’ve only covered a few talks here, this week-long conference was the largest AAIC in history and it seems the field is both growing and focusing its attention to many emerging topics such as the immune system as well as classic Alzheimer’s research topics like cognition and amyloid pathology. I feel fortunate to be a part of such a diverse and abundant research field and while historically Alzheimer’s research has had many challenges and failures, the collective efforts of all these dedicated researchers makes me optimistic for the future. It’s truly an exciting time to be a part of this effort and with medications currently in Phase II clinical trials and efforts to improve interventions for both patients and caregivers, it seems treatment may soon be within reach.