A simple blood test that measures concentrations of inflammatory molecules could allow doctors to determine whether a person is at increased risk of stroke or cognitive decline later in life, a new study shows. have been carried out by researchers at UCLA Health.
Until now, the only way to identify the chances of developing cerebral vascular diseases is based on a combination of imaging techniques such as MRIs, family history, demographic variables and other risk factor assessments, explained the study’s lead author, Dr. Dr. Jason Hinman, of the UCLA Comprehensive Stroke and Center and the Mary S. Easton Center for Alzheimer’s Research and Care at UCLA. In clinical practice, neurologists often only discover that a patient is at risk after he or she has suffered a warning stroke or brain event, Hinman adds.
The study results have been published in the journal Stroke and reveal that measuring concentrations of a network of inflammatory molecules in the blood could help doctors calculate a susceptibility risk score for brain small vessel disease, a common cause. of stroke and a contributing factor to cognitive decline, especially among the elderly.
“In the same way that cholesterol tests are used to assess future risk of a heart attack, we do not yet have something similar to estimate future risk of a stroke,” Hinman points out. “I think we can do this through something as simple as a blood test, which in theory could allow broader access to the best level of care without relying exclusively on advanced imaging and specialized evaluations.”
Molecules associated with the presence of cerebrovascular lesions
The study focused on a network of biologically connected inflammatory molecules known as the interleukin-18 network, or IL-18 network, which includes proteins and signaling molecules used to combat various infections. Previous research has linked single molecules in the IL-18 network to brain small vessel disease and stroke risk. However, concentrations of these individual molecules can vary in response to other diseases, such as influenza or autoimmune disorders, making them unreliable predictors of stroke risk at the individual level, Hinman said.
In 2020, researchers at the University of California, including Hinman, found that six molecules in the IL-18 network were associated with the presence of cerebrovascular lesions during MRI scans. Based on these findings, Hinman sought to determine in this latest publication whether the IL-18 network could be used to assess a person’s susceptibility to the risk of stroke or cognitive decline.
To test this, researchers used health data from a long-term study known as the Framingham Heart Study. This study has followed the medical history of thousands of residents in the city of Framingham, Massachusetts, throughout their lives since its inception in 1948. Blood samples taken from the participants had been analyzed for five of the six molecules subsequently identified. as part of the IL-18 network.
“Estimating future risk of stroke could allow broader access to the best level of care without relying exclusively on advanced imaging studies”
Using the blood samples and medical records of the Framingham participants, Hinman and his co-author were able to create a mathematical model that generates a risk score based on the concentrations of the IL-18 network molecules. Of the more than 2,200 Framingham residents included in Hinman’s study, those whose risk scores were in the top 25% had an 84% chance of suffering a stroke during their lifetime. Overall, elevated risk scores were associated with a 51% increase in stroke risk and resulted in diagnostic prediction compared to existing risk assessment tools.
What is still unclear and requires more study is how, or if it is possible, to modify or reduce a person’s risk score, Hinman said. “The real challenge is in the primary care space. Are you at risk before having an event?” Hinman said. “That’s what we’re all interested in doing, preventing a stroke before it even happens,” he concludes.
