Research from Rutgers Health indicates that blood tests for Alzheimer’s disease need to be interpreted with caution – particularly for Black patients.
“These tests are currently geared towards primary care physicians and directly to older adults concerned about cognitive performance,” said William Hu, senior author of the paper in Alzheimer’s and Dementia, director of the Rutgers Center for Healthy Aging Research, and Chief of Cognitive Neurology & Alzheimer’s Disease Clinic. “They may provide some value to primary care doctors who understand their limitations, but there is no reason for patients who have concerns about their memory to buy these tests, which cost $1,200 to $2,000 and are almost never covered by insurance.”
Concentrations of an Alzheimer’s biomarker are significantly lower in blood than in spinal fluid, where they have been validated as a diagnostic tool in white patients. This difference is particularly large for Black patients, who naturally have lower levels of the biomarker in their spinal fluid. Worse memory function itself also raises blood biomarker levels. “The blood tests have many caveats,” Hu said. “Poor transfer of these proteins from spinal fluid to blood means many patients will go undiagnosed, especially if their disease is mild, while the ability of other ailments to increase these proteins in the blood mean tests produce false positives.” To read the full story.