It can be challenging for doctors to determine whether a patient’s cognitive impairments stem predominately from Alzheimer’s disease or vascular problems, the two most common causes of dementia. Doctors typically rely on MRIs or CAT scans to detect evidence of brain injury to help make that determination. Now, researchers at UCLA Health report a key blood molecule may help doctors identify how much impaired blood flow to a patient’s brain is contributing to dementia or cognitive problems.
Their findings are published in the journal Alzheimer’s & Dementia: The Journal of the Alzheimer’s Association in a paper titled, “Placental Growth Factor is a Sensitive Biomarker for Vascular Cognitive Impairment.”
The researchers found that patients with higher levels of placental growth factors (PIGF) were more likely to have cognitive impairment or evidence of brain injury.
“Historically, diagnostic studies for cognitive impairment and dementia have been limited to structural brain imaging, but increasingly there’s a recognition that we can use the bloodstream as an available but imperfect tool to understand who maximally benefits from those structural and functional imaging tools,” said UCLA associate professor and vice chair of research in neurology Jason Hinman, MD, PhD, the study’s lead author. “It may also tell us who might be the best candidates for some of the really new emerging drugs that are available on the market to treat cognitive impairment and dementia.”
At UCLA and four other research sites, 335 patients underwent brain imaging, cognitive testing, and blood collection. Researchers found those in the top quartile for PlGF measurement were three times as likely to have cognitive impairment or dementia compared to those in the bottom quartile. Every unit increase in total PlGF in the bloodstream was also associated with a 22% increase in the likelihood of having cognitive impairment and a 16% increase in the likelihood of having imaging evidence of cerebral small vessel disease.
“The addition of a blood-based biomarker that is associated with the traditional measures of vascular injury could allow a provider to be able to distinguish the patient that has Alzheimer’s-predominant dementia versus a significant vascular contribution,” Hinman said. “Right now it’s kind of the clinician’s best guess. This work can directly inform this diagnostic decision.”
The research consortium is still studying whether PlGF and a bundle of other angiogenic markers in the bloodstream could help predict the risk of future cognitive decline.