Myeloperoxidase as a Biomarker in COPD.

Area of Science:

• Pulmonary Medicine
• Biomarker Research
• Inflammation Studies

Background:

• Chronic inflammation and oxidative stress are key in COPD, involving neutrophils.
• Myeloperoxidase (MPO), a neutrophil-derived enzyme, plays a role in these processes and is a potential biomarker.
• Elevated MPO levels are observed in COPD patients and smokers, linked to neutrophilic load and disease severity.

Purpose of the Study:

• To critically review the biological potential, analytical methods, and clinical utility of myeloperoxidase (MPO) as a biomarker in chronic obstructive pulmonary disease (COPD).
• To assess the correlation of MPO levels with neutrophilic inflammation, oxidative injury, and airflow obstruction in COPD.
• To evaluate the challenges and requirements for MPO's clinical translation.

Main Methods:

• Review of existing literature on MPO in COPD.
• Analysis of MPO measurement methodologies in various biological matrices (serum, plasma, sputum, EBC).
• Assessment of preanalytical variability and its impact on MPO measurements.

Main Results:

• MPO can be measured in serum, plasma, sputum, and exhaled breath condensate (EBC).
• Significant preanalytical variability exists, particularly between serum and plasma MPO levels, with plasma potentially being more accurate.
• MPO shows potential in multi-marker panels for COPD inflammatory endotyping and risk stratification.

Conclusions:

• MPO is biologically plausible as a biomarker for neutrophil-mediated inflammation in COPD.
• Clinical application is limited by the lack of standardized assays and harmonized results.
• Further validation of matrices (plasma vs. serum) and integration into compound biomarker approaches are necessary for clinical translation.