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Exhaled breath condensate: a promising source for biomarkers of lung disease.

Liang Y, Yeligar SM, Brown LA - ScientificWorldJournal (2012)

Bottom Line: Substances measured in EBC include oxidative stress and inflammatory mediators, such as arachidonic acid derivatives, reactive oxygen/nitrogen species, reduced and oxidized glutathione, and inflammatory cytokines.Although EBC is viewed as a noninvasive method for sampling airway lining fluid (ALF), validation is necessary to confirm that EBC truly represents the ALF.Likewise, a dilution factor for the EBC is needed in order to compare across subjects and determine changes in the ALF.

View Article: PubMed Central - PubMed

Affiliation: Division of Neonatal-Perinatal Medicine, Department of Pediatrics, Emory University and Emory+Children's Healthcare of Atlanta Center for Developmental Lung Biology, Atlanta, GA 30322, USA.

ABSTRACT
Exhaled breath condensate (EBC) has been increasingly studied as a noninvasive research method for sampling the alveolar and airway space and is recognized as a promising source of biomarkers of lung diseases. Substances measured in EBC include oxidative stress and inflammatory mediators, such as arachidonic acid derivatives, reactive oxygen/nitrogen species, reduced and oxidized glutathione, and inflammatory cytokines. Although EBC has great potential as a source of biomarkers in many lung diseases, the low concentrations of compounds within the EBC present challenges in sample collection and analysis. Although EBC is viewed as a noninvasive method for sampling airway lining fluid (ALF), validation is necessary to confirm that EBC truly represents the ALF. Likewise, a dilution factor for the EBC is needed in order to compare across subjects and determine changes in the ALF. The aims of this paper are to address the characteristics of EBC; strategies to standardize EBC sample collection and review available analytical techniques for EBC analysis.

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Related in: MedlinePlus

Nonvolatile and volatile components in EBC. Water vapor is rapidly diffused from the lining fluid on the surface of the airway (bronchi) and airspace (alveolar) into the expiratory flow. Droplets (nonvolatile biomarker) formation in the lung is largely from the lining fluid of the airway where turbulence is encountered. Respiratory gases (volatile biomarkers) are from both airspace and airway, and more soluble vapors are typically greater in the airway [5, 67].
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fig1: Nonvolatile and volatile components in EBC. Water vapor is rapidly diffused from the lining fluid on the surface of the airway (bronchi) and airspace (alveolar) into the expiratory flow. Droplets (nonvolatile biomarker) formation in the lung is largely from the lining fluid of the airway where turbulence is encountered. Respiratory gases (volatile biomarkers) are from both airspace and airway, and more soluble vapors are typically greater in the airway [5, 67].

Mentions: Exhaled breath condensate (EBC) is collected from exhaled breath, usually through a refrigerated device [1–4]. During exhalation, volatile molecules and water evaporation directly diffuse as gases from the lining fluid covering airspaces (e.g., alveoli), airways (e.g., bronchi), and the mouth. These gases are then collected into the expiratory air flow. Laser particle counting revealed that micron- and submicron-sized droplet particles are formed in the exhaled breath. Such particles serve as the only evidence of nonvolatile components in the EBC [4]. Yet, the nature and source of exhaled particles/droplets in the EBC matrix are not fully understood. Droplet formation within the lungs during exhalation is largely in the airways where turbulence is encountered (Figure 1). In addition, energy to overcome surface tension during inspiration may also apply to the airway and alveoli, potentially creating exhalable particles. However, the major source for nonvolatile components in the EBC is believed to be the airway lining fluid (ALF) [5, 6]. The main components of EBC include condensed water vapor, volatile molecules (such as nitric oxide, carbon monoxide, and hydrocarbons), and nonvolatile molecules (such as urea, GSH, leukotrienes, prostanoids, and cytokines) [1, 3].


Exhaled breath condensate: a promising source for biomarkers of lung disease.

Liang Y, Yeligar SM, Brown LA - ScientificWorldJournal (2012)

Nonvolatile and volatile components in EBC. Water vapor is rapidly diffused from the lining fluid on the surface of the airway (bronchi) and airspace (alveolar) into the expiratory flow. Droplets (nonvolatile biomarker) formation in the lung is largely from the lining fluid of the airway where turbulence is encountered. Respiratory gases (volatile biomarkers) are from both airspace and airway, and more soluble vapors are typically greater in the airway [5, 67].
© Copyright Policy - open-access
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC3539342&req=5

fig1: Nonvolatile and volatile components in EBC. Water vapor is rapidly diffused from the lining fluid on the surface of the airway (bronchi) and airspace (alveolar) into the expiratory flow. Droplets (nonvolatile biomarker) formation in the lung is largely from the lining fluid of the airway where turbulence is encountered. Respiratory gases (volatile biomarkers) are from both airspace and airway, and more soluble vapors are typically greater in the airway [5, 67].
Mentions: Exhaled breath condensate (EBC) is collected from exhaled breath, usually through a refrigerated device [1–4]. During exhalation, volatile molecules and water evaporation directly diffuse as gases from the lining fluid covering airspaces (e.g., alveoli), airways (e.g., bronchi), and the mouth. These gases are then collected into the expiratory air flow. Laser particle counting revealed that micron- and submicron-sized droplet particles are formed in the exhaled breath. Such particles serve as the only evidence of nonvolatile components in the EBC [4]. Yet, the nature and source of exhaled particles/droplets in the EBC matrix are not fully understood. Droplet formation within the lungs during exhalation is largely in the airways where turbulence is encountered (Figure 1). In addition, energy to overcome surface tension during inspiration may also apply to the airway and alveoli, potentially creating exhalable particles. However, the major source for nonvolatile components in the EBC is believed to be the airway lining fluid (ALF) [5, 6]. The main components of EBC include condensed water vapor, volatile molecules (such as nitric oxide, carbon monoxide, and hydrocarbons), and nonvolatile molecules (such as urea, GSH, leukotrienes, prostanoids, and cytokines) [1, 3].

Bottom Line: Substances measured in EBC include oxidative stress and inflammatory mediators, such as arachidonic acid derivatives, reactive oxygen/nitrogen species, reduced and oxidized glutathione, and inflammatory cytokines.Although EBC is viewed as a noninvasive method for sampling airway lining fluid (ALF), validation is necessary to confirm that EBC truly represents the ALF.Likewise, a dilution factor for the EBC is needed in order to compare across subjects and determine changes in the ALF.

View Article: PubMed Central - PubMed

Affiliation: Division of Neonatal-Perinatal Medicine, Department of Pediatrics, Emory University and Emory+Children's Healthcare of Atlanta Center for Developmental Lung Biology, Atlanta, GA 30322, USA.

ABSTRACT
Exhaled breath condensate (EBC) has been increasingly studied as a noninvasive research method for sampling the alveolar and airway space and is recognized as a promising source of biomarkers of lung diseases. Substances measured in EBC include oxidative stress and inflammatory mediators, such as arachidonic acid derivatives, reactive oxygen/nitrogen species, reduced and oxidized glutathione, and inflammatory cytokines. Although EBC has great potential as a source of biomarkers in many lung diseases, the low concentrations of compounds within the EBC present challenges in sample collection and analysis. Although EBC is viewed as a noninvasive method for sampling airway lining fluid (ALF), validation is necessary to confirm that EBC truly represents the ALF. Likewise, a dilution factor for the EBC is needed in order to compare across subjects and determine changes in the ALF. The aims of this paper are to address the characteristics of EBC; strategies to standardize EBC sample collection and review available analytical techniques for EBC analysis.

Show MeSH
Related in: MedlinePlus