Lp-PLA2
Also known as: Lipoprotein-Associated Phospholipase A2, PLAC Test
What Does Lp-PLA2 Measure?
Lp-PLA2 (Lipoprotein-Associated Phospholipase A2), also known as the PLAC Test, measures the activity or mass of an enzyme produced primarily by inflammatory cells in atherosclerotic plaques. This enzyme circulates in the blood attached mainly to LDL (bad) cholesterol particles and plays a direct role in the development of vulnerable, rupture-prone plaques in artery walls. Unlike general inflammation markers, Lp-PLA2 is highly specific to vascular inflammation rather than systemic inflammation elsewhere in the body.
Why Does Lp-PLA2 Matter?
Lp-PLA2 is a clinically significant independent risk marker for coronary heart disease, stroke, and cardiovascular events. Because it reflects inflammation occurring specifically within artery walls, it can identify individuals at elevated cardiovascular risk even when traditional risk factors like cholesterol and blood pressure appear normal. Elevated Lp-PLA2 activity is associated with unstable, lipid-rich plaques that are more likely to rupture and cause heart attacks or strokes. It is particularly valuable for refining risk assessment in patients with intermediate cardiovascular risk and is FDA-cleared for this purpose.
Normal Ranges
Males
Less than 235 nmol/min/mL (activity) or less than 200 ng/mL (mass)
Females
Less than 210 nmol/min/mL (activity) or less than 200 ng/mL (mass)
Children
Not routinely measured in children; reference ranges not well established
Causes of High Levels
- Established coronary artery disease or atherosclerosis
- High LDL cholesterol levels (LDL carries most Lp-PLA2 in the bloodstream)
- Smoking, which promotes vascular inflammation and plaque instability
- Metabolic syndrome or insulin resistance
- Chronic kidney disease
- Elevated lipoprotein(a) or oxidized LDL levels driving plaque formation
Causes of Low Levels
- Statin therapy (statins significantly reduce Lp-PLA2 activity)
- Darapladib or other Lp-PLA2 inhibitor medications
- Low LDL cholesterol levels (less carrier protein available)
- Predominantly HDL-associated Lp-PLA2 phenotype (associated with better outcomes)
How to Improve Your Lp-PLA2
Diet
- Adopt a Mediterranean-style diet rich in olive oil, fish, vegetables, legumes, and whole grains to reduce vascular inflammation
- Increase intake of omega-3 fatty acids from fatty fish (salmon, mackerel, sardines) at least 2-3 times per week to lower inflammatory enzyme activity
- Reduce consumption of trans fats and refined carbohydrates, which promote LDL oxidation and plaque instability
- Include antioxidant-rich foods such as berries, leafy greens, and colorful vegetables to reduce oxidative stress in arterial walls
- Limit processed meats and saturated fat intake to help reduce LDL levels, thereby lowering the carrier for Lp-PLA2
Supplements
- Omega-3 fish oil (EPA + DHA): 2-4 grams per day has been shown to reduce Lp-PLA2 activity and vascular inflammation
- Niacin (vitamin B3): 500-2000 mg per day under physician supervision may reduce Lp-PLA2 and improve lipid profiles
- Curcumin (from turmeric): 500-1000 mg per day of standardized extract may reduce vascular inflammation markers
- Vitamin D3: 1000-2000 IU per day if deficient, as low vitamin D is associated with higher cardiovascular inflammatory markers
Related Biomarkers
Frequently Asked Questions
What is the difference between Lp-PLA2 and CRP for heart disease risk?
Both Lp-PLA2 and high-sensitivity CRP (hs-CRP) measure inflammation, but they reflect different types. CRP is a general marker of systemic inflammation that can be elevated by infections, arthritis, or other conditions unrelated to the heart. Lp-PLA2 is much more specific to vascular inflammation — the kind occurring directly inside artery walls. This makes Lp-PLA2 a more targeted predictor of plaque instability and cardiovascular events, especially in people without obvious systemic inflammation.
Can I have a heart attack risk with normal cholesterol but high Lp-PLA2?
Yes. This is one of the most important reasons Lp-PLA2 testing is valuable. A significant proportion of heart attacks occur in people with seemingly normal or borderline cholesterol levels. Elevated Lp-PLA2 can reveal hidden vascular inflammation and unstable plaque activity that standard lipid panels miss. If your Lp-PLA2 is elevated but cholesterol appears normal, your doctor may recommend further imaging, lifestyle changes, or preventive medication.
Is Lp-PLA2 testing covered by insurance?
Coverage varies by insurance plan and clinical indication. The PLAC Test (Lp-PLA2 activity test) is FDA-cleared for cardiovascular risk assessment, and many insurers cover it when ordered for patients with intermediate cardiovascular risk or as part of an advanced lipid panel. It is best to check with your insurer beforehand. Out-of-pocket costs typically range from $50 to $150 if not covered.