A new study has found a blood plasma linked to inflammation that could be a warning signal for certain dementias. Could it pave the way for low cost screening?
In fact, around 5.8 million people in the U.S. live with the condition, which can impact a person's ability to think, speak, remember, relate to others, and perform everyday tasks.
Dementia is an umbrella term referring to a number of conditions that result from abnormal brain changes that affect the ability to think. It has a number of potential causes.
Alzheimer's is the most common form of dementia, followed by vascular dementia, which stems from microscopic bleeding and blood vessel blockage in the brain. Other causes include vitamin deficiency and thyroid problems.
"Dementia is a complex syndrome often resulting from numerous causes," lead study author Dr. Matthew Pase — of the Florey Institute for Neuroscience and Mental Health in Melbourne, Australia — told Medical News Today.
The study, which appears in the journal Neurology, set out to test the link between an inflammatory marker in blood (sCD14) and incident dementia. The hope is that these biomarkers would ultimately pave the way to predicting dementia.
"In addition to biomarkers of Alzheimer's disease (i.e., amyloid and tau), biomarkers of inflammation and neuronal injury may help improve the prediction of clinical dementia," said Dr. Pase.
What excited the researchers was the potential to assess dementia risk in advance by tapping into cost effective blood-based biomarkers to pave the way for intervention ahead of disease development, possibly changing the course of someone's life.
"The development of cost effective blood biomarkers for dementia could improve clinical research and practice by permitting widespread low cost screening and [assisting] in identifying at risk participants for dementia prevention trials," said Dr. Pase.
"Biomarkers of neural inflammation, such as sCD14, are promising candidates to study since inflammation appears to be a common pathway triggered by a variety of mechanisms leading to dementia."
Inflammation a key predictor of dementia
"Inflammation has been identified as a contributor to many neurological diseases," explained Dr. Pase.
"Injury to the brain that predisposes [it] to dementia, whether due to vascular brain injury, Alzheimer's proteinopathy, or head trauma, is accompanied by a neuroinflammatory response."
However, scientists do not fully understand the role of inflammation in different types of dementia.
Building on prior research in animals that suggested that sCD14 helps regulate the brain's inflammatory response, researchers set out to investigate its use as a biomarker for the risk of cognitive decline and dementia.
The new research, which drew from two community-based studies, looked at more than 4,700 participants. In one study, their average age was 69, and in the other, it was 72. In both studies, the researchers measured the plasma sCD14 in the participants' blood upfront.
In one study, they performed a brain MRI and cognitive tests within the first year and a second round of tests after 7 years. They also surveyed the participants for dementia over an average of 9 years.
In the second study, the team performed the first brain MRI within 3 or 4 years of enrollment and a second MRI around 5 years later.
What the researchers found was that higher levels of sCD14 were associated with brain injury and aging, as well as cognitive decline.
Although there has not been a drug trial looking at the efficacy of lowering sCD14 levels and cognitive ability, there are treatments that use anti-inflammatory medications such as statins to lower sCD14.
"Further research is needed to validate our findings across diverse populations," said Dr. Pase. "As we measured sCD14 in blood, it would be of interest to examine the extent to which blood sCD14 mirrors inflammation in the brain."
"Lastly," he concludes, "since dementia is multifaceted, it will be important to determine which combinations of biomarkers best predict the risk of future dementia."