Washington University School of Medicine in St. Louis received a $14.6 million grant to support their investigations into whether early markers of Alzheimer’s that have shown promise for predicting the disease in Caucasian populations can also serve as a predictor for the neurodegenerative disease in African Americans. Importantly, the investigation out of St. Louis also probes the important topic of social determinants of health as a potential factor in different markers.
Key reason for the study?
Firstly, Chengjie Xiong, PhD, professor of biostatistics and interim director of the Division of Biostatistics reports “Past studies have produced conflicting data about African Americans and Alzheimer’s disease.” Professor Xiong noted that these past studies were too small, hence the sample size wasn’t sufficient to make any declarations. There may be differences between White and Black populations and the latter has been under studied. A better understanding of this disease in the African American population represents a crucial step to developing better approaches for care, including prospective treatments.
Is Alzheimer’s the same in Black and White populations?
Frankly, scientists are not sure as of yet. Hence this study is set up to help better determine this. They seek to better understand how Blacks are impacted at the “silent stage” of the disease and also at the “Symptomatic stage.”
How will the study team at WUSM accomplish the study?
As reported in the WUSM recent press release, the study team will leverage past study data as well as existing data to obtain a larger sample size of African Americans. Additionally, the team will add prospectively collected data from new studies presently ongoing: inclusive of investigations into Alzheimer’s disease markers in this underrepresented population in addition to how the markers may change over time.
This involves the process of re-analyzing existing samples and brain scans collected from past participants along with prospectively collected samples and scans. Such as cerebrospinal fluid, MRI scans and positron emission tomography (PET) scans. The cerebrospinal fluid samples and imaging scans may reveal the presence of plaques and tangles in the brain—called amyloid plaques and tau tangles—these accumulate silently for a long period of time and eventually interfere with cognition.
What are some of the studies that will contribute to this effort?
Studies involving clinical and biomarker investigations will contribute, such as at the Washington University Knight Alzheimer Disease Research Center, the University of Pennsylvania Alzheimer’s Disease Core Center, the Emory University Alzheimer’s Disease Research Center, the Harvard Aging Brain Study, and the Anti-Amyloid Treatment of Asymptomatic Alzheimer’s trial.
Who will lead the harmonization of clinical and cognitive data across these studies?
John Morris, MD, the Harvey A. & Dorismae Hacker Friedman Distinguished Professor of Neurology and director of the Knight Alzheimer’ Disease Research Center as well as Jason Hassenstab, PhD, associate professor of neurology and the psychometrics leader of the center.
What about central reprocessing of the samples and scans across studies?
This is led by Anne Fagan, PhD, professor of neurology and Tammie Benzinger, MD, PhD, professor of radiology, who takes on the Fluid Biomarker Core and Neuroimaging Core of the Knight Alzheimer Disease Research Center.
Who leads recruitment for this study?
Joyce Balls-Berry, PhD, associate professor of neurology and the leader of the Health Disparities Core.
How many participants will be involved?
Overall, over 1,000 African American participants will be recruited to produce sufficient statistical power required to assess biologically significant differences that may exist between the markers of Alzheimer’s disease in White participants and those in African American populations.
Is there evidence of differences?
Yes. Professor Xiong suggests, “There is some evidence, though it’s not conclusive, that middle-aged and elderly African Americans have lower levels of tau in the cerebrospinal fluid than white people of similar ages.