Researchers claim to have developed a brand new “fluid biopsy” technique, offering the potential to detect unique cells that are associated with damage caused during a heart attack. The new technique, which has been developed by a team of U.S. researchers, identifies specific marker cells circulating within the bloodstream. Researchers hope the technique could, in the future, be employed to predict the onset of a heart attack.
CEC Release Triggered During Heart Attacks
The novel blood test was recently described in the Jan. 10 issue of the journal Physical Biology. The technique works by measuring the level of circulating endothelial cells (CECs), in response to a host of pathological conditions. This technique could even help to detect the early onset of a myocardial infarction (a.k.a. a heart attack).
Globally, coronary artery disease is the leading cause of morbidity and mortality. The condition is signaled by the development of atherosclerotic plaques that accumulate within the coronary arteries that deliver oxygenated blood to the heart muscle. Gradually, the plaque hardens and can eventually rupture. The plaque occludes the blood vessel and, in turn, impedes the flow of blood to the heart muscle. However, once a plaque ruptures, a blood clot typically forms over its surface; this event exacerbates the condition and can lead to partial or complete blockage of the affected coronary artery.
Currently, there are no reliable methods available to accurately predict a heart attack, as most techniques (e.g. coronary angiography) measure risk conditions, such as atherosclerotic plaque development and impeded bloodflow; these procedures are unable to predict imminent plaque rupture.
However, prior to a heart attack, the inflammation within the arterial wall triggers some of the endothelial cells to become worn away, thereby increasing the number of circulating endothelial cells in the bloodstream. Elevated CECs are also associated with a number of other diseases, including cancer, cardiovascular pathologies and systemic vasculitis.
HD-CEC to Offer Greater Reliability Over CEC Assay
A number of other researchers have implemented CEC assays to detect the endothelial cells shed from the damaged vessel lining. However, researchers at The Scripps Research Institute in California have produced a highly sensitive platform to “… detect, enumerate and characterize CECs.” It is thought that the new technique, called high-definition CEC (HD-CEC), has the potential to test patients that exhibit the symptoms, but are yet to experience a heart attack. The team consider HD-CEC to be a promising candidate for clinical application in predicting the early onset of heart attacks.
Professor Peter Kuhn indicates that the principal objective behind the investigation was to establish whether CECs could be reliably detected in patients who had experienced a heart attack – something he claims they have achieved. In addition, Kuhn also explains that the results were markedly elevated in heart attack patients, relative to controls:
“Our results were so significant relative to the healthy controls that the obvious next step is to assess the usefulness of the test in identifying patients during the early stages of a heart attack.”
The researchers used HD-CEC to perform assays to characterize CECs from blood samples of 79 patients that had experienced a heart attack. They also used the assay to study the levels of CECs in two other groups, comprising of 25 healthy participants and seven patients undergoing medical treatment for vascular disease.
The assay identified CECs based upon the morphological characteristics of their nuclei and cytoplasm, and reactions with specific antibodies. According to the study, the cells were classified as HD-CECs if they were positive for a specific cell surface protein (CD146), a specialist DNA-staining method, and von Willebrand factor (vWF) – a blood glycoprotein that is involved in platelet adhesion and aggregation.
Ultimately, the CEC levels were significantly elevated in heart attack patients, compared to healthy controls, and were detected with high sensitivity and specificity.
However, according to Kuhn, the next step is to determine how predictive high-definition circulating endothelial cell assays are for detecting patients that are at risk of experiencing heart attacks. He conjectures that CECs are released during the “plaque rupturing” stage – an event that leads up to myocardial infarction. On this basis, the team suggest the technique could prove a much-needed predictive tool.
By James Fenner