Abstrakt

Biomarkers are substances used as indicators of a biologic status and may be used to identify disease states. To assess them in exhaled breath, exhaled breath condensate (EBC) is the diagnostic sample of interest because its collection is non-invasive, effortindependent and repeatable during spontaneous breathing. Overviewing more than a decade of EBC research, the first enthusiasm was followed by pitfalls and experiences that have thought EBC researchers how extremely important methodological standardisation is before data are interpretable in a biological sense. Methodological standardisation includes (1) standardisation of the EBC collection process, (2) standardisation of the materials used for EBC collection and processing, (3) standardised processing, storage, and analyses of EBC samples. It is unlikely, that “one standardisation” will fulfil the requirements of different substances measurable as a potential biomarker in EBC. It is more likely that different steps of standardisation need to be adjusted for EBC components of interest. Beside these methodological requirements, multiple effects of biological variability have to be taken into account. Sources of intrasubject variability (influence of food intake, medication, circadian changes, variables of ventilation, etc.) should be carefully discovered and minimised or eliminated as much as possible. Nevertheless, a considerable inter- subject variability can hardly be avoided due to significant influences of individual breathing characteristics and the physiology of respiration. Because physiological intersubject variability may overlap disease-related changes in EBC, within-subject comparisons (for example, pre-post comparisons or individual follow-up studies) are more suitable than between-subject comparisons. Calculating how much of an EBC component of interest is exhaled per time or in a defined volume of exhaled breath (instead of comparing concentrations of this component analysed in liquid EBC) is another important step towards a better standardisation of EBC results. Before it will be possible to use EBC analysis in clinical practice, many open questions regarding physiological and disease-related processes in the lung have to be addressed. Future work is very promising with respect to markers lacking in healthy conditions but being present due to defined expositions or diseases (for example workrelated expositions or cancerogenic markers). By applying modern methodological approaches (i.e. genomics, proteomics, metabolomics) to EBC, the vision of the future is to identify fingerprints of exhaled breath (i.e. “breathprints”) that are specific for different diseases.

Autoreninformation

Autoren

• P. Reinhold

Abteilungen

• Institut für molekulare Pathogenese, Friedrich-Loeffler-Institut, Jena

Adresse

PD Dr. Dr. Petra Reinhold
Institut für Molekulare Pathogenese
Friedrich-Loeffler-Institut
Naumburger Straße 96a
D-07743 Jena
Email: [email protected]

Citation