To date, few studies have been conducted that examine racial differences in Alzheimer’s disease biomarkers despite the fact that African Americans may have more than 2-fold increased risk for Alzheimer’s dementia than their white counterparts. A study published on this week in JAMA Neurology by Dr. John Morris, Dr. Krista Moulder, Dr. David Holtzman, and colleagues makes history by providing one of the first studies to examine racial differences in molecular biomarkers of Alzheimer’s disease. Dr. Moulder is a recent recipient of a Cure Alzheimer’s Fund grant to study racial disparities in Alzheimer’s disease. Dr. Morris is a member of the Research Strategy Council of Cure Alzheimer’s Fund and Dr. Holtzman is a member of the research leadership group.

Participants in the study had their cerebrospinal fluid (CSF) evaluated for concentrations of toxic indicators of Alzheimer’s disease including Ab42, t-tau, and p-tau₁₈₁. In addition, the study measured amyloid plaque concentrations in the brains of the participants by using positron emission tomography (PET) imaging. 1,255 people were recruited to participate in the study.

The study represents the largest sample size of African American participants assessed with PET-imaging and CSF markers for amyloid and tau. The results of this study begin to provide insight into the crucial question as to what underlies racial disparities in Alzheimer’s disease.

The diversity of clinical trial participants rarely reflects the diversity of the population. 46.8 million African Americans reside in the United States according to the U.S. Census Bureau, yet recruitment of African American individuals into Alzheimer’s disease research studies has lagged behind white populations. A growing proportion of the US population is not receiving the full benefit of advances from clinical trial data.

An excerpt from the news release from Washington University School of Medicine,

“Now, a new study from Washington University School of Medicine in St. Louis has identified racial disparities between African-Americans and Caucasians in the level of a key biomarker used to identify Alzheimer’s disease. The findings, published Jan. 7 in JAMA Neurology, suggest that tools to diagnose the illness may not as effectively apply to African-Americans. Specifically, the concern is that Alzheimer’s may be under-recognized in African-Americans because they typically have lower levels of the brain protein tau – meaning that people might not meet the threshold to be diagnosed when the disease already has begun to develop in their brains.”

For further reading, Dr. Lisa Barnes from the Rush Alzheimer’s Disease Center in Chicago wrote an editorial discussing the findings: “Biomarkers for Alzheimer Dementia in Diverse Racial and Ethnic Minorities – a Public Health Priority.”

https://jamanetwork.com/journals/jamaneurology/article-abstract/2719697?utm_campaign=articlePDF&utm_medium=articlePDFlink&utm_source=articlePDF&utm_content=jamaneurol.2018.4249

For a press release describing the study, please visit the website for the Washington University School of Medicine in St. Louis: https://medicine.wustl.edu/news/racial-differences-in-alzheimers-disease-unveiled/

For coverage of this study by NPR, please see follow the following link: https://www.npr.org/sections/health-shots/2019/01/07/682036486/study-suggests-alzheimer-s-disease-may-work-differently-in-african-americans