For decades, physicians have assessed patients’ heart disease risk by checking their cholesterol levels. They measure low-density lipoproteins, which are bad; high-density lipoproteins, which are good; and triglycerides, which should be low. But the tests are crude enough that at least half of all heart attacks strike people who appear to have normal cholesterol levels. Nutrition sciences professor Ronald Krauss has long maintained that the best way to get the heads up on heart disease is to more precisely measure how many of each size and type of lipoproteins are pulsing through a patient’s arteries.
At the Lawrence Berkeley National Laboratory, Krauss and fellow scientists Henry Benner and Pat Blanche developed ion mobility technology to get an accurate count of all lipoprotein particles in a single analytical step. Their system, known as Ion Mobility Analysis, ranks among R&D Magazine’s 100 most technologically significant new products of 2005.
“There are other methods out there, but our test has a number of advantages,” says Krauss, who is director of atherosclerosis research at the Children’s Hospital Oakland Research Institute. “It’s a relatively accurate and inexpensive way to measure all classes of lipoproteins.”
The test involves first screening a heart patient’s blood specimen to sort cells and other proteins. Next, it is loaded into a tiny tube, where an electrical field turns it into a fine spray, giving the lipoproteins electrical charges. The lipoproteins can then be propelled to the other end of the tube, where a detector registers when different particles hit the finish line. Because lighter ones fly faster than heavier ones, the machine is able to count each one by size. The result: a detailed cholesterol profile in a matter of minutes. The entire procedure takes less than a day.
The technology is similar to the ion mobility spectrometry process used to detect the minutest traces of explosives or narcotics at airport security checkpoints.
Ion Mobility Analysis is not yet ready for routine screening for heart disease, Krauss says. But a year from now, it may well be available to those whose genetic disposition or lifestyle puts them at risk.