Personalizing Stroke Prevention

The humble C-reactive protein (CRP) test is used for a wide range of assessments, including infections, autoimmune diseases and chronic inflammatory conditions. But it’s possible that the test has just added another function to its arsenal: identifying patients at risk of a second stroke.

“We were actually interested in biomarkers in general that might be useful in prediction of stroke recurrence,” says Stephen Williams, first author on the paper recently published in Neurology. “In this study, we tested six biomarkers loosely classified as ‘pro-inflammatory.’ By taking this unbiased approach, we did not expect any one biomarker to be more useful than any other. It just so happened that CRP came up positive.” Elevated CRP levels are a known risk factor for incident vascular disease – so it makes biological sense that not only high levels of the protein, but also variations in the CRP gene, are linked to an increased risk of recurrent ischemic stroke.

Brad Worrall, associate medical director of the Stroke Service and director of the Acute Stroke Intervention Team at the University of Virginia Health System, says, “Stroke recurrence risk is generally assessed based on the mechanism of the stroke and the associated risk factors. Our current interventions do work, but the CRP tests (both circulating CRP and the genetic test) might allow us to select those individuals that are at especially high risk.” Williams believes that combining the genetic information from his study with circulating CRP levels would be the most powerful approach for the clinic. However, he cautions that, before a broad recommendation can be made, follow-up studies addressing the clinical utility of the tests will be needed.

“Currently, genomic data is not broadly used in day-to-day clinical evaluations, and we hope that this study will aid in shifting that practice toward a more integrated approach,” Williams says. “Genomic testing is coming – and coming fast.  In the very near future, we will need laboratory medicine professionals to be able to execute these genetic tests and clinicians to be knowledgeable as to how to interpret them.” And the researchers haven’t halted their efforts – they’re currently investigating additional biomarkers, assessing the utility of metabolomics data, and trying new methods of using gene expression to explore the underlying biology of atherosclerosis, the biggest risk factor for stroke. If the group’s follow-up studies go as hoped, ischemic stroke patients may one day learn their risk of recurrence from a simple blood test.