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Updated: Nov 4, 2025
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Breath Collection from Children for Disease Biomarker Discovery
Published on: February 14, 2019
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Exhaled breath condensate pH determinants in school-aged children: A population-based study
Tiago Azenha Rama1,2, Inês Paciência2,3, João Cavaleiro Rufo2,3
1Immunoallergology unit, Centro Hospitalar Universitário São João, Porto, Portugal.
Summary
Asthma is linked to lower exhaled breath condensate (EBC) pH in children. Environmental factors like temperature and air quality also influence EBC pH, impacting its use as an airway inflammation biomarker.
Area of Science:
- Pediatric Pulmonology
- Environmental Health
- Biomarker Research
Background:
- Exhaled breath condensate (EBC) pH is a potential biomarker for airway inflammation.
- Clinical application is hindered by lack of standardization and interstudy variability.
- Underlying mechanisms for EBC pH variability, beyond endogenous factors, are largely unknown.
Purpose of the Study:
- To investigate the association between asthma and EBC pH in children.
- To explore environmental factors contributing to interstudy variability in EBC pH measurements.
Main Methods:
- Cross-sectional analysis of EBC from 613 children (7-12 years).
- Evaluated lung function, exhaled nitric oxide, allergic sensitization, BMI, and indoor air quality (IAQ).
- Used regression models to assess asthma and IAQ effects on EBC pH, analyzing acidic and alkaline EBC pH groups.
Main Results:
- Asthma correlated with lower EBC pH in the acidic group, independent of IAQ.
- In the acidic group, EBC pH was affected by temperature and PM2.5.
- In the alkaline group, EBC pH was influenced by relative humidity and endotoxin levels.
Conclusions:
- Environmental factors significantly influence EBC pH in children.
- Asthma and environmental exposures are key determinants of EBC pH.
- Consideration of these factors is crucial for accurate interpretation of EBC pH in pediatric populations.
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