HealthDay News — Certain molecular biomarkers for Alzheimer disease differ with race, according to a study published online Jan. 7 in JAMA Neurology.
John C. Morris, M.D., from the Washington University School of Medicine in St. Louis, and colleagues enrolled 1,255 participants in longitudinal studies. Participants underwent magnetic resonance imaging of the brain and/or positron emission tomography of the brain with Pittsburgh compound B and/or cerebrospinal fluid (CSF) assays.
The researchers found no racial differences in the frequency of cerebral ischemic lesions noted on results of brain magnetic resonance imaging, in mean cortical standardized uptake value ratios for Pittsburgh compound B, or for amyloid-β42 concentrations in the CSF.
Mean total hippocampal volumes were lower for African-American versus white participants among individuals with a reported family history of dementia (6,418.26 versus 6,990.50 mm³). Compared with whites, African-Americans had lower mean CSF concentrations of total tau (293.65 versus 443.28 pg/mL) and lower mean concentrations of phosphorylated tau181 (53.18 versus 70.73 pg/mL). A significant interaction between race and APOE ε4 was seen for CSF total tau and phosphorylated tau181; racial differences were only seen for APOE ε4-positive participants.
“Racial differences in Alzheimer biomarkers suggest possible race-dependent biological mechanisms that contribute to expression of disease,” the authors write.