Abstract Body

RACIAL DIFFERENCES IN MOLECULAR BIOMARKERS FOR AD

John C. Morris, MD; Suzanne Schindler, MD; Chengjie Xiong, PhD; on behalf of the Knight ADRC, Washington University School of Medicine, St. Louis, Missouri, USA

Objectives:

The possibility of racial differences in molecular biomarkers for Alzheimer disease (AD) has been minimally explored, in part because few research participants from under-represented groups are included in biomarker studies.

Methods:

Using a cohort of 1255 community living adults (including 173 self-identified Blacks), both those who were cognitively normal and those with symptomatic AD, who had completed at least 1 brain magnetic resonance imaging (MRI) study, and/or amyloid positron emission tomography (PET) scan, and/or 1 lumbar puncture to obtain cerebrospinal fluid (CSF), we compared cross-sectional biomarker modalities in Black versus White participants.

Results:

There were no racial differences in mean cortical standardized uptake value ratios for Pittsburgh Compound B or for CSF Aβ42. However, mean CSF concentrations of tau and p-tau₁₈₁ were lower in Black versus White participants; there was a race by APOE ε4 interaction. Moreover, Black participants had more coding variants for TREM2 that were associated with lower CSF soluble TREM2 concentrations than were found for Whites.

Conclusions:

Identifying racial differences in molecular biomarkers for AD is important for the understanding of AD pathophysiology, diagnosis, and treatment. Interpreting these differences will require the appreciation of the effects of systemic racism and other social determinants of health as they relate to observed biomarker disparities in AD.