Myeloperoxidase (MPO)

Introduction

As a Nurse Practitioner with an autonomous practice in Florida, I often emphasize the importance of understanding biomarkers in assessing and managing health conditions. One such biomarker that plays a significant role in cardiovascular health and inflammation is Myeloperoxidase (MPO). This article aims to provide a comprehensive overview of MPO, including its background, clinical implications, and factors influencing its levels.

What is Myeloperoxidase (MPO)?

Myeloperoxidase (MPO) is an enzyme predominantly produced by white blood cells, specifically neutrophils and monocytes. It is released when the interior walls of arteries are damaged or inflamed. MPO is integral to the body’s immune response, as it has strong antibacterial properties and generates compounds capable of killing pathogens. However, its role in inflammation and cardiovascular disease makes it a critical marker for assessing vascular health.

The Role of MPO in Cardiovascular Health

MPO is involved in various processes that can adversely affect cardiovascular health:

• Vascular Inflammation: MPO perpetuates vascular inflammation by triggering protease cascades that promote atherosclerosis and plaque vulnerability.
  
• Oxidative Stress: MPO generates reactive oxygen species that cause endothelial dysfunction. These reactive species can oxidize the protein, lipid, and antioxidant components of low-density lipoprotein (LDL), converting it into an atherogenic form.
  
• Plaque Destabilization: MPO contributes to the destabilization and rupture of atherosclerotic plaques, leading to increased risk of myocardial infarction and other cardiovascular events.
  
• Endothelial Dysfunction: By promoting vasoconstriction and increasing vascular permeability, MPO exacerbates endothelial dysfunction and cardiovascular risk.

   

Clinical Implications of MPO Levels

Low MPO Levels

• Reduced Cardiovascular Risk: Low or optimal levels of MPO (below 400 pmol/L) suggest a reduced risk of atherosclerosis and cardiovascular disease (CVD).
  
• Decreased Oxidative Stress: Low MPO levels indicate a decreased presence of oxidative stress, reflecting a healthier vascular environment.
  
• MPO Deficiency: A genetic deficiency in MPO can lead to increased susceptibility to infections, including Candida. Interestingly, MPO deficiency may reduce CVD risk, though further research is needed.

   

High MPO Levels

• Increased Cardiovascular Risk: Elevated MPO levels (above 470 pmol/L) are strongly associated with atherosclerosis and predictive of future cardiovascular events. Individuals with high MPO levels are more than twice as likely to experience cardiovascular mortality.
  
• Inflammatory and Autoimmune Conditions: High MPO levels have been observed in various inflammatory and autoimmune diseases.
  
• Oxidative Stress Indicator: Elevated MPO indicates oxidative stress and may suggest suboptimal antioxidant status, which should be addressed through dietary and lifestyle interventions.
  
• Exercise Considerations: Elevated MPO levels can occur in extreme athletes, indicating increased oxidative stress and inflammation.

   

Ranges and Risk Categories for MPO

Understanding MPO levels within specific ranges is crucial for assessing cardiovascular risk:

• Optimal Range: 0.00 – 400.00 pmol/L
  
• Low Risk: 400 – 470 pmol/L
  
• High Risk: ≥ 470 pmol/L

   

These ranges provide a framework for evaluating MPO levels and guiding clinical decision-making.

Factors Influencing MPO Levels

Several factors can influence MPO levels, including lifestyle, diet, and medication use. It is essential to consider these factors when interpreting MPO levels and developing a comprehensive care plan.

Interfering Factors

• Dietary Influences: Antioxidants found in fruits, vegetables, herbs, spices, and other plant-based foods may help prevent MPO-induced oxidation, potentially lowering MPO levels.
  
• Exercise: Intense physical activity can temporarily elevate MPO levels in extreme athletes.

   

Drug Associations

• Increased Levels: Some drugs that impact immune response or inflammation may elevate MPO levels.
  
• Decreased Levels: Anti-inflammatory and antioxidant therapies may reduce MPO levels.

   

Clinical Applications and Future Directions

The measurement of MPO levels is particularly useful in individuals with established heart disease, hypertension, diabetes, or those at risk for CVD and metabolic syndrome. By integrating MPO with other biomarkers—such as N-terminal pro–B-type natriuretic peptide and high-sensitivity C-reactive protein—healthcare providers can improve risk stratification and tailor interventions more effectively.

The Role of Functional Medicine

Functional medicine offers a holistic approach to healthcare, focusing on identifying and addressing the root causes of disease. By integrating MPO assessment into a functional medicine framework, practitioners can develop personalized care plans that address inflammation, oxidative stress, and cardiovascular risk.

Conclusion

Myeloperoxidase (MPO) serves as a valuable biomarker in assessing inflammation and cardiovascular risk. Understanding the implications of MPO levels and the factors influencing them is crucial for optimizing cardiovascular health and preventing disease progression. As healthcare providers, we can leverage this information to deliver targeted, patient-centered care that addresses the underlying drivers of inflammation and vascular dysfunction.

In conclusion, a comprehensive evaluation by a functional medicine practitioner in Florida facilitates identification of cellular-level and molecular imbalances driving cardiovascular dysfunction. By integrating evidence-based therapies with regenerative medicine services—where vascular repair and anti-inflammatory interventions often intersect—we offer patients a preventive framework to rebuild resilience and optimize wellness. Call (904) 799-2531 or schedule online to request your personalized cardiovascular health assessment.

Further Reading

• Feijóo, M., et al. (2009). Infliximab reduces myeloperoxidase concentration in chronic inflammatory joint disease. Clinical and Experimental Rheumatology, 27(1), 167-168. https://pubmed.ncbi.nlm.nih.gov/19204412/

• Stenvinkel, P., et al. (2006). Statin treatment and diabetes affect myeloperoxidase activity in hemodialysis patients. Kidney International, 69(6), 1123-1130.  https://pubmed.ncbi.nlm.nih.gov/17699218/

• Geissen, S., et al. (2024). Inhibition of myeloperoxidase to treat left ventricular dysfunction in non-ischaemic cardiomyopathy. European Heart Journal, ehad545. https://pubmed.ncbi.nlm.nih.gov/39212229/

• Chen, J., et al. (2012). Myeloperoxidase as an imaging biomarker and therapeutic target. Radiology, 262(2), 448-456. This research demonstrates that MPO inhibition reduces oxidative stress and inflammation in a murine model of multiple sclerosis, supporting MPO as a therapeutic target and imaging biomarker. https://pmc.ncbi.nlm.nih.gov/articles/PMC3329272/