Appropriate Use of Lipoprotein-Associated Phospholipase A2 Activity Assay [Utilization Spotlight]

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Since 2012, we have been publishing a Utilization Spotlight in every issue of the Communiqué. Each Spotlight offers a quick view of utilization management best practices in action. This Spotlight is from November 2015.


Overview

Lipoprotein-associated phospholipase A2 (Lp-PLA2) is an inflammatory protein that is produced by macrophages in the vascular intima and is present in high concentrations on the plaques that build up in blood vessels. Several studies have shown that patients with high levels of Lp-PLA2 in the blood are at higher risk of a cardiovascular event such as myocardial infarction or stroke. Mayo Medical Laboratories offers the recently Food and Drug Administration (FDA)-cleared test PLACA / Lipoprotein-Associated Phospholipase A2 Activity, Serum, which produces reliable and reproducible results.


Situation

Lipoprotein-associated phospholipase A2 (Lp-PLA2) is an inflammatory protein that is produced by macrophages in the vascular intima and is present in high concentrations on the plaques that build up in blood vessels. It is also found in the circulation bound to low-density lipoprotein and several studies have shown that patients with high levels of Lp-PLA2 in the blood are at higher risk of a cardiovascular event such as myocardial infarction or stroke.

Testing 

Mayo Medical Laboratories (MML) offers the recently Food and Drug Administration (FDA)-cleared test PLACA / Lipoprotein-Associated Phospholipase A2 Activity, Serum. This test is for Lp-PLA2 activity and should not be confused with the Lp-PLA2 concentration assay that has several known limitations including significant reagent lot variation and specimen instability. The results could be up to 50 percent falsely elevated simply because the specimen was not tested immediately. Therefore, MML decided not to perform the concentration assay.

The Lp-PLA2 activity assay is robust and produces reliable and reproducible results. The specimen is stable even if not tested immediately and results are the same from one lot of reagent to another. This is important for physicians who send the test to a reference laboratory because a delay in specimen processing and testing will not affect the Lp-PLA2 activity test results. MML is confident that the Lp-PLA2 activity assay is analytically robust and that results are accurate and appropriate for clinical use and patient care.

Results

Lp-PLA2 activity is increased in patients who are at higher risk for future cardiovascular events and can be used to augment basic lipid panel testing or in conjunction with other cardiac risk markers. The Lp-PLA2 activity is FDA cleared for risk assessment in a primary prevention setting of patients who have no history of disease and no history of a cardiovascular event. Additional studies indicate that Lp-PLA2 activity may also be useful in secondary prevention to assess risk of recurrent cardiovascular events. Clinicians should be aware that there are some instances in which the Lp-PLA2 activity may be low despite considerable atherosclerotic disease risk. This can happen in patients who are receiving statin treatment or who have had a recent cardiovascular event.

When an increased Lp-PLA2 activity result is identified  in a patient, treatment strategies include prescribing  a statin drug or increasing the dose in patients already taking the drug. Modification of lifestyle and dietary restrictions may also help to lower a patient’s risk of  having a cardiovascular event.

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Kelley Schreiber

Kelley Schreiber is a Marketing Channel Manager at Mayo Medical Laboratories. She is the principle editor and writer of Insights and leads social media and direct marketing strategy. Kelley has worked at Mayo Clinic since 2013. Outside of work, you can find Kelley running, traveling, playing with her new kitten, and exploring new foods.