A team of scientists, led by Western University of Health Sciences Professor Doug Ethell, PhD, has developed a blood test for Alzheimer’s disease risk that may lead to earlier detection and the development of Alzheimer’s disease interventions, according to an article published July 29, 2014.
“Alzheimer’s disease is a puzzle, and this study represents one of several pieces that have locked into place for us over the past couple of years,” Ethell said.
The study, “Women with the Alzheimer’s risk marker ApoE4 lose Aβ-specific CD4+ T cells 10-20 years before men,” describes how the new test gauges the immune responses to a component of brain plaques associated with the disease. Carriers of the Alzheimer’s risk factor ApoE4 showed an earlier decline in this response than non-carriers, by about a decade.
Women showed an earlier decline than men, which is consistent with a 2.5-fold higher risk of Alzheimer’s disease. Women who carried ApoE4 showed the earliest decline of any group, with a precipitous drop found between the ages of 45 and 52, when menopause typically begins.
Aβ-specific CD4+ T cells have a central role in regulating adaptive immune responses to antigens, and have been shown to reduce AD pathology in mouse models. As these cells may facilitate endogenous mechanisms that counter AD, an evaluation of their abundance before and during AD provides important insights, according to the study.
“It’s very exciting because it changes the way we think about this disease, and opens the door to some interesting possibilities,” Ethell said.
The assay may provide an early indicator of changes that precede Alzheimer’s disease by a decade or more by quantifying Aβ-specific CD4+ T cells in human blood. This assay, called CD4see, could accelerate clinical testing of new Alzheimer’s disease interventions that require an early biomarker.
“Our team is very close to figuring out the cause of Alzheimer’s disease,” Ethell said. “We are working on the next piece and if that falls into place, we could be treating early- and middle-stage Alzheimer’s disease patients within three to five years.”
The article was published in Translational Psychiatry, from Nature Publishing Group. Click here to view the article: http://www.nature.com/tp/journal/v4/n7/full/tp201451a.html.