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Also known as: LpPLA2; Lp-PLA2 Activity Test; Platelet-activating Factor Acetylhydrolase; PAF-AH; PLAC
Formal name: Lipoprotein-associated Phospholipase A2

The Test Sample

What is being tested?

Lipoprotein-associated phospholipase A2 (Lp-PLA2) is an enzyme that appears to play a role in the inflammation of blood vessels and is thought to help promote atherosclerosis. This test measures the amount and activity of Lp-PLA2 in the blood.

Some recent studies have shown that Lp-PLA2 is an independent risk marker for cardiovascular disease (CVD), including coronary heart disease (CHD), and ischemic stroke. In these studies, increased concentrations of Lp-PLA2 were seen in many people who were diagnosed with CHD and ischemic stroke, regardless of other risk factors. These findings make this relatively new test potentially useful as one of a growing number of cardiac risk markers that are used to help determine a person's risk of developing CVD.

CVD causes more deaths in the U.S. each year than any other cause, according to the Centers for Disease Control and Prevention. CHD and ischemic stroke are both associated with the buildup of unstable fatty plaque deposits in the arteries that can lead to blockages in blood vessels and to heart attacks or brain damage. There are a variety of risk factors that have been identified as being associated with both conditions, including high blood pressure, diabetes, metabolic syndrome, smoking, obesity, high cholesterol levels, increased LDL (low-density lipoprotein, the "bad cholesterol"), and decreased HDL (high-density lipoprotein, the "good cholesterol").

Many people who have one or more of the commonly recognized risk factors will eventually develop CVD, but a significant number of people who have few or none of these risk factors will also develop CVD. This has lead researchers to look for additional markers that might identify those at increased risk of CVD.

In addition to the traditional risk factors listed above, a low level of chronic, systemic inflammation and blood vessel (vascular) inflammation are thought to contribute to overall risk for developing CVD. The hs-CRP test is associated with systemic inflammation; high levels are associated with increased CVD risk. The Lp-PLA2 test is associated with vascular inflammation, and high levels are thought to increase the chance of cardiovascular events, including heart attack or stroke.

How is the sample collected for testing?

A blood sample is obtained by inserting a needle into a vein in the arm.

NOTE: If undergoing medical tests makes you or someone you care for anxious, embarrassed, or even difficult to manage, you might consider reading one or more of the following articles: Coping with Test Pain, Discomfort, and Anxiety, Tips on Blood Testing, Tips to Help Children through Their Medical Tests, and Tips to Help the Elderly through Their Medical Tests.

Another article, Follow That Sample, provides a glimpse at the collection and processing of a blood sample and throat culture.

Is any test preparation needed to ensure the quality of the sample?

No test preparation is needed.