There are significant differences in the cerebrospinal fluid concentrations of tau protein (and its phosphorylated isoform) between African American and white individuals, according to a recent cohort study that sought to ascertain whether there are racial disparities in molecular biomarkers for Alzheimer disease (AD). 1,255 participants were enrolled from January 1, 2004, through December 31, 2015, in longitudinal studies at Washington University and completed an MRI study and/or positron emission tomography of the brain. Researchers found:

• Of total participants, 116 of 173 African American participants (67.1%) and 724 of 1,082 non-Hispanic white participants (66.9%) had normal cognition.
• There were no racial differences in the frequency of cerebral ischemic lesions noted on results of brain MRI, mean cortical standardized uptake value ratios for Pittsburgh compound B, or for amyloid-β42 concentrations in cerebrospinal fluid.
• However, in individuals with a reported family history of dementia, mean total hippocampal volumes were lower for African American participants than for white participants.