Breakthrough blood test could detect dementia before symptoms show

Dementia

affects over 55 million people worldwide, with nearly 10 million newly diagnosed cases each year. Dementia can range in severity from mild to severe, where a person may need complete assistance with daily activities. Especially likely in people over the age of 65, dementia is a progressive, neurological disease that may present as forgetting things, feeling anxious, struggling to make decisions and more. The symptoms for dementia are quite subtle and one can only notice them when they occur over a prolonged period of time.

What is dementia?

Dementia is a general term for a group of symptoms that affect a person’s ability to think, remember, and reason. This syndrome causes a decline in cognitive abilities that interferes with daily life. It’s a loss of brain function that can be caused by a number of diseases that damage nerve cells. Dementia is more common as people age, but it’s not a normal part of aging.
Dementia can have a significant impact on people with the disease, their families, carers, and society. There’s often a lack of awareness and understanding of dementia, which can lead to stigma and barriers to diagnosis and care.

However, researchers from the University of California, Los Angeles (UCLA) have identified placental growth factor (PlGF) as a potential blood biomarker for early detection of

cognitive impairment

and dementia.

What is PGIF?

PGIF, or placental growth factor, is a protein that’s released by the placenta and is used to detect pre-eclampsia in pregnant women.
High PlGF levels correlate with increased vascular permeability, suggesting its role in the development of

cerebral small vessel disease

. This finding could enable earlier identification and intervention for at-risk individuals compared to current MRI-based diagnostics.

Growth inhibitory factor (GIF) is a protein that’s related to dementia in the following ways:

Reduced expression in Alzheimer’s disease: GIF levels are reduced in Alzheimer’s disease (AD) brains, especially in reactive astrocytes around senile plaques.
Inhibits neurotrophic activity: GIF inhibits neurotrophic activity in AD brain extracts on neonatal rat cortical neurons in culture.
Different distribution from glial fibrillary acidic protein (GFAP): GIF levels increase more slowly and remain elevated for longer periods than GFAP levels.
Vascular Changes and Dementia: Researchers use MRI scans to track brain blood vessel changes linked to cognitive impairment and dementia. These scans detect ‘downstream’ biological markers, signs that appear later in the disease process. However, a multicenter study led by UCLA researchers suggests that a simple blood test could spot earlier changes, potentially identifying at-risk patients sooner and at a lower cost.
Jason Hinman, MD, PhD, a vascular neurologist at UCLA Health, Interim Co-Director of the Mary S. Easton Center for Alzheimer’s Research and Care at David Geffen School of Medicine at UCLA and senior author of an article in Alzheimer’s & Dementia: The Journal of the Alzheimer’s Association, explained, “We studied a protein in the blood that is critical in the formation of blood vessels but that also appears to play a role in vascular permeability associated with cognitive decline.”
He added, “Evaluating data from a large group of patients with a range of vascular risk profiles and cognition ranging from unimpaired to mild dementia, we found that plasma levels of this protein, placental growth factor (PlGF), could potentially be used as a biomarker to screen for and monitor cognitive impairment and dementia.”

Cerebral Small Vessel Disease and Biomarkers: Dysfunctional cells lining blood vessels in the brain are increasingly recognized as a key driver of processes leading to cerebral small vessel disease (CSVD), a major contributor to cognitive decline and dementia. The leaky vessels are believed to allow fluid and inflammatory molecules to seep into brain tissue. CSVD is typically diagnosed through costly brain MRI, where areas of vascular-mediated brain injury appear as bright spots on clinical MRI sequences – called white matter hyperintensities, or WMH. WMH and other structural changes are late markers of vascular brain injury.
Potential of PlGF as a Biomarker: The researchers studied possible associations involving several factors: plasma levels of PlGF, a highly sensitive research MRI measure of fluid accumulation in the brain called white matter free water (FW), white matter hyperintensities, and patients’ scores on cognitive assessments. Results were consistent with models suggesting that elevated PlGF increases vascular permeability, leading to accumulation of fluid in the brain’s white matter, development of white matter hyperintensities, and subsequent cognitive impairment.
According to first author Kyle Kern, MD, a vascular neurologist at UCLA Health and researcher at David Geffen School of Medicine at UCLA, “As a biomarker for cerebral small vessel disease and the vascular contributions to cognitive impairment and dementia (VCID), PlGF could be used as a cost-effective screening tool for identifying patients at risk for vascular brain injury before the insidious onset of cognitive decline. As a simple blood test, such a tool would be valuable not only for patients and clinicians, but also for researchers identifying patients for clinical trials.”