Flow cytometry platform tracks the effects of lipid-modifying drugs

The platform uses imaging flow cytometry to visualize the morphology of individual plaque particles.

Plaxgen (Fremont, CA), which is developing flow cytometry-based blood diagnostics for plaque-associated diseases such as atherosclerosis and Alzheimer's, has published new research exploring the effect of lipid-lowering drugs, including statins, on the morphology of cholesterol particles in human serum samples.

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In the paper, the researchers observed the effects of several commercially available lipid-lowering drugs on cholesterol particles in blood serum samples of patients with dyslipidemia (abnormal levels of lipids in the blood). They also studied the effect of these drugs on purified very low-density and low-density lipoproteins. Finally, they examined the differences between serum samples from 50 dyslipidemic patients and age-matched normal people. All analysis was performed on Plaxgen's Plaque Array platform, which uses imaging flow cytometry to visualize the morphology of individual plaque particles.

The researchers concluded that lipid-lowering drugs have an affect on the morphology (shape) of individual cholesterol particles, a new measure that may play a role in whether or not these particles move freely in the bloodstream or stick to vessel walls. In serum samples from 50 patients with plaque disease and age-matched normal people, researchers found a higher level of linear-shaped cholesterol particles in the patients with unhealthy cholesterol levels (a mean of 18.3%) than in the normal control group (a mean of 11.1%), which had a higher level of globular-shaped particles in general.

The researchers also observed considerable variation in the lipid-lowering drugs' ability to reduce the formation of linear-shaped cholesterol particles in the blood serum samples. While cholesterol is currently measured by numerical blood serum levels, cholesterol particle shape (linear vs. globular) may play a factor in atherosclerosis and how lipid-lowering drugs work, the researchers observed. Overall, they concluded that the Plaque Array platform, which utilizes imaging flow cytometry, could improve accuracy in atherosclerosis diagnosis and improve the predictability of patient response to lipid-lowering drugs.

"The ability to visualize individual particles in blood serum afforded by the Plaque Array platform gives us new insight into the possible role of plaque particle morphology in atherosclerosis, and could aid in evaluating personalized lipid-lowering drug therapy," says Shanmugavel Madasamy, Ph.D., lead study author and Plaxgen's CEO. "We are extending this approach to studying the morphological features of other plaques, such as amyloid plaque, and their role in the pathology of Alzheimer's disease."

Full details of the work appear in the Journal of Visualized Experiments.

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