Neurology and Neurosurgery

April 23, 2022

Mayo Clinic researchers have identified novel plasma mRNA measures that can potentially improve the diagnosis of Alzheimer's disease in African Americans.

African Americans' risk of developing the disease is twice as high as the risk for non-Hispanic whites. However, African Americans are underrepresented in Alzheimer's disease research. Mayo Clinic's study, to be published in EBioMedicine, is the first to evaluate plasma transcript levels as potential biomarkers of Alzheimer's disease in African Americans.

The researchers designed a panel to measure the cell-free mRNA levels of genes relevant to Alzheimer's disease. Fifty transcripts were measured in plasma samples from 151 African Americans with Alzheimer's disease and 269 African Americans without cognitive impairment.

Key points

• Incorporating the plasma levels of six mRNA molecules into a statistical model improved by 8% the researchers' ability to accurately identify study participants with Alzheimer's disease.
• That statistical gain is an improvement compared with models that account only for known risk factors, such as age, sex and the presence of the APOE-e4 allele.
• The mRNA molecules in Mayo Clinic's model are encoded by the genes CLU, APP, CD14, ABCA7, AKAP9 and APOE.
• Measuring gene expression in plasma samples avoids more-complex imaging or cerebrospinal fluid tests.
• The study's findings could help improve the predictive value of Alzheimer's disease biomarker panels for all populations.

The study participants were members of the Consortium for African-American Alzheimer's Disease Studies, which was established in 2015 by Nilufer Taner, M.D., Ph.D., a neurologist at Mayo Clinic in Jacksonville, Florida. The consortium focuses on improving health equity in Alzheimer's disease through genomic research.

For more information

Reddy JS, et al. Transcript levels in plasma contribute substantial predictive value as potential Alzheimer's disease biomarkers in African Americans. EBioMedicine. In press.

Refer a patient to Mayo Clinic.