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Chronic obstructive pulmonary disease (COPD) is a complex and heterogeneous disease that affects 200 million patients worldwide.
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Over the past decade or so, there has been a great deal of interest in the identification and validation of biomarkers of potential clinical use in COPD.
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Adequately validated biomarkers can contribute to improved patient care.
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The recognition of the plasma inflammome in COPD is a major conceptual breakthrough, which may enable the discovery of plasma (inflammatory)
Biomarkers in COPD
Section snippets
Key points
Markers and outcomes: general concepts
A marker is “a measurement that is associated with, and believed to be related patho-physiologically to, a relevant clinical outcome”5; clinical outcome is defined as “a consequence of the disease experienced by the patient,”5 such as death, symptoms, exacerbations, weight loss, exercise limitation, and use of health care resources, among others.5 The relationship between markers and outcomes is neither unique nor simple5 because of the following: (1) A given outcome (ie, mortality) may
Biomarkers: definition and requirements
A biomarker is a special type of marker that has been defined as “a measurement of any molecule or material (eg, cells, tissue) that reflects the disease process.”9 This more restrictive definition excludes functional (or imaging) measurements from the more general concept of a marker discussed earlier and is used in the text later.
Adequately validated biomarkers can contribute to improve patient care by (1) allowing early detection of subclinical disease, (2) improving the diagnosis of acute
Biomarkers in COPD: where are we now?
Over the past few years, several biomarkers have been intensively studied in COPD and are relatively close to use in clinical practice. The better-validated ones are discussed below. Of note, however, the authors focus on biomarkers that can be measured in the systemic circulation because of their easy accessibility. Others of potential relevance, such as those in sputum or exhaled air, are not discussed here.
How can we progress in the field?
Biomarker discovery is moving rapidly in COPD; several biomarkers are poised to garner clinical uptake, with fibrinogen being the closest to FDA approval and qualification. Despite the rapid gains in knowledge in the pathogenesis of COPD, there remain substantial gaps. The emergence of nontargeted proteomics is a very attractive platform for interrogating novel biomarkers without the need of any a priori hypothesis. However, the current technology limits the number of proteins and peptides that
Summary
COPD is a complex disease that affects 200 million patients worldwide. The development of novel therapeutics has been slow owing in part to a lack of simple, sensitive, specific, and repeatable biomarker that can predict disease progression and other clinical outcomes. The recognition of the plasma inflammome in COPD is a major conceptual breakthrough, which may enable the discovery plasma (inflammatory) biomarkers for clinical and research use for certain COPD phenotypes. The pace of biomarker
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