Healthcare (Commonwealth Union) – In a groundbreaking study involving Hispanic and Latino adults, scientists at the University of California San Diego School of Medicine have uncovered a connection between self-reported memory and thinking problems and certain blood-based biomarkers. The discovery could lead to the development of a simple blood test for diagnosing Alzheimer’s disease and related dementias—an option that may prove quicker, less invasive, and more affordable than current diagnostic tools. The findings were published in JAMA Network Open.
The lead author Freddie Márquez, Ph.D., a postdoctoral researcher in the Department of Neurosciences at UC San Diego School of Medicine pointed out that they need better ways to detect underlying neurodegenerative disorders earlier in patients showing signs of cognitive issues. He further stated that their work demonstrates the potential of blood biomarkers as a more practical and widely available method for assessing cognitive decline, especially among communities that traditional approaches have often overlooked.
Researchers of the study pointed out that presently, the Food and Drug Administration has authorized only one blood test to aid in diagnosing Alzheimer’s disease. This test, known as the Lumipulse G pTau217/Aβ42 plasma ratio, measures blood proteins linked to Alzheimer’s. However, it is costly and restricted to specialized medical centers. It remains uncertain whether blood-based screening can be reliably scaled up for early Alzheimer’s detection.
To explore this issue, scientists analyzed information from the Study of Latinos–Investigation of Neurocognitive Aging. This research evaluated brain health in a group of participants drawn from the Hispanic Community Health Study/Study of Latinos—the most extensive and detailed long-term investigation of Hispanic and Latino health in the U.S.
“Hispanic and Latino adults are thought to be more likely to get Alzheimer’s and related dementias, and this group is projected to have the largest increases in disease prevalence over the coming decades,” explained senior author Hector M. González, Ph.D., who is a professor at the Department of Neurosciences, UC San Diego School of Medicine. “Despite this, they’re still significantly underrepresented in Alzheimer’s and dementia research, which is something our study aimed to address.”
The study analyzed blood samples from 5,712 Hispanic and Latino adults aged 50 to 86, searching for brain-related proteins linked to Alzheimer’s disease, including amyloid beta and tau. Participants were also evaluated for subjective cognitive decline, which describes a reduction in cognitive abilities as noticed by the individuals themselves.
Researchers have found that higher blood levels of NfL, a marker of nerve cell injury, and GFAP, an indicator of brain inflammation, were linked to greater self-reported declines in thinking, planning, and overall cognitive performance. Elevated levels of NfL and tau protein (ptau-181) were also associated with more reported memory decline. Interestingly, blood levels of amyloid-beta protein (Aβ42/40), a protein commonly linked to Alzheimer’s disease in the brain, showed no connection with subjective cognitive decline. The study also revealed that even among cognitively healthy individuals, higher NfL levels corresponded with self-reported declines in cognitive performance, suggesting that NfL may detect early changes in cognition. Beyond supporting the potential of blood-based biomarkers for early detection of Alzheimer’s and related dementias, the researchers highlighted the strength of their study in including a diverse population.
Márquez indicated that by involving participants from communities that are often underrepresented in research, they can gain a clearer picture of how factors like social conditions and coexisting health issues affect cognitive changes and the risk of dementia. He further indicated that this gives their results particular significance for everyday clinical settings.
The researchers also emphasized that more studies are needed before this method can be broadly implemented in medical practice, and even then, the test would serve as just one component among many in a clinician’s diagnostic toolkit.
