What does a myeloperoxidase (MPO) level of 291 indicate?

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From the Guidelines

A myeloperoxidase (MPO) level of 291 is significantly elevated, indicating active inflammation and potential vascular damage, which may be associated with conditions such as vasculitis, cardiovascular disease, or other inflammatory disorders. This elevation suggests that the patient may be at risk for complications related to oxidative stress and vascular inflammation. According to the evidence-based guideline for the diagnosis and management of eosinophilic granulomatosis with polyangiitis 1, MPO-ANCA-positive patients frequently show features of vasculitis, such as glomerulonephritis, neuropathy, and purpura. The normal reference range for MPO levels is typically between 0-146 units, and a level of 291 is substantially higher than this range. The clinical significance of this value should be interpreted in the context of the patient's symptoms, medical history, and other laboratory findings, such as ANCA testing, which is recommended for all patients with suspected EGPA 1.

Key points to consider:

  • Elevated MPO levels are associated with increased risk of cardiovascular disease and vascular inflammation
  • MPO-ANCA-positive patients may exhibit features of vasculitis, such as glomerulonephritis, neuropathy, and purpura 1
  • The patient's symptoms, medical history, and other laboratory findings should be taken into account when interpreting the MPO level
  • Additional testing or treatment may be necessary to manage the underlying condition and prevent complications. It is essential to follow up with a healthcare provider to discuss the implications of this test result and determine the best course of action.

From the Research

Myeloperoxidase Level Interpretation

  • A myeloperoxidase level of 291 is considered elevated, as it is associated with inflammation and increased oxidative stress 2.
  • Elevated myeloperoxidase levels are linked to various health issues, including:
    • Cardiovascular disease, such as coronary artery disease, congestive heart failure, and arterial hypertension 2, 3.
    • Autoimmune diseases, like multiple sclerosis and rheumatoid arthritis 4.
    • Cancer development and progression, with myeloperoxidase-derived oxidants contributing to tissue damage and inflammation 5.
  • The clinical significance of an elevated myeloperoxidase level includes:
    • Increased risk for overall and cardiovascular disease-related mortality 2.
    • Potential therapeutic target for the treatment of inflammatory conditions and cancer 6, 5.

Key Points to Consider

  • Myeloperoxidase is a heme-containing peroxidase mainly expressed in neutrophils and monocytes 3, 6.
  • The enzyme plays a crucial role in host defense, inflammation, and neutrophil function, with both beneficial and harmful effects depending on the context 6.
  • Further research is needed to fully understand the role of myeloperoxidase in various diseases and to explore its potential as a therapeutic target 2, 5.

References

Guideline

Guideline Directed Topic Overview

Dr.Oracle Medical Advisory Board & Editors, 2025

Research

Myeloperoxidase - A bridge linking inflammation and oxidative stress with cardiovascular disease.

Clinica chimica acta; international journal of clinical chemistry, 2019

Research

Myeloperoxidase: A new player in autoimmunity.

Cellular immunology, 2017

Professional Medical Disclaimer

This information is intended for healthcare professionals. Any medical decision-making should rely on clinical judgment and independently verified information. The content provided herein does not replace professional discretion and should be considered supplementary to established clinical guidelines. Healthcare providers should verify all information against primary literature and current practice standards before application in patient care. Dr.Oracle assumes no liability for clinical decisions based on this content.

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