New Test May Help Those Who Retain Cholesterol

Scientists said Wednesday they have developed a new test that could be used to identify people prone to artery-clogging cholesterol buildups, which set the stage for heart attacks.

The blood test reportedly is quicker and less expensive than existing methods and would help doctors in the early diagnosis and treatment of patients who have an inherited inability to reduce levels of cholesterol in their blood.

“It has the potential to be used widely,” said Dr. Jennifer A. Cuthbert of the University of Texas Health Science Center in Dallas, where the test was developed.

Genetic Defect Cited

In most people, cells use up cholesterol when they divide. But about one in every 500 people is believed to suffer from a genetic defect in which their cells lack necessary “receptors” to use low-density lipoproteins (LDL), a form of cholesterol that instead accumulates and clogs arteries, one of the causes of heart attacks.

People diagnosed early as suffering from the disorder could be placed on special diets to reduce cholesterol intake or could be eligible for treatment with new drugs being developed, Cuthbert said.

To develop the test, researchers took blood samples from 27 subjects and isolated white blood cells. The cells were then stimulated to divide, a process that requires cholesterol. Another substance, mevinolin, was used to prevent the cells from making their own cholesterol.

Cells Failed to Divide

The researchers then added small amounts of LDL, which would allow normal cells to reproduce. Cells from those with the genetic defect failed to divide. The rate of reproduction was measured by the amount of DNA produced.

“The cells that came from patients (with the genetic deficiency) required twice as much cholesterol to be added in order for their cells to grow properly,” said Cuthbert, who reported the findings in the New England Journal of Medicine.

Existing tests detect the genetic defect by growing skin cultures and take up to three months to produce results. This test could be done within one week, she said.

Larger studies are needed to confirm the test’s reliability before it could be used widely, she said.