NEW YORK (Reuters Health) – Metabolomic analysis of exhaled breath condensate (EBC) allows characterization of airway biochemical fingerprints that differentiate asthma and normal physiology, according to a report in the May 15th American Journal of Respiratory and Critical Care Medicine.

"We believe that metabolomic analysis has a great potential for respiratory medicine of the next years," Dr. Eugenia Baraldi from University of Padova, Italy told Reuters Health. "’Breathomics’ could improve disease diagnosis, allowing the discrimination between different disease sub-phenotypes, particularly in asthmatic subjects."

Dr. Baraldi and colleagues used information from nuclear magnetic resonance (NMR) spectra of EBC to identify NMR variables that best discriminated between 25 children with controlled allergic asthma and 11 age-matched healthy control children.

Selected NMR signals chosen by statistical analysis discriminated between the asthma and healthy control groups with a success rate of approximately 86%, the authors report. This compares with a success rate of approximately 81% for the combination of exhaled nitric oxide and FEV1.

A different statistical method of selecting NMR variables proved successful in all but one case, where an asthmatic sample was classified as healthy, the report indicates.

The most important signals for classification of patients corresponded to acetylated products and oxygen-containing compounds, the investigators write.

"In our study we demonstrated for the first time that metabolomic analysis can be applied to exhaled breath condensate (‘breathomics’) and that it is effective in the discrimination between asthmatic and healthy children," Dr. Baraldi said.

"These NMR signal patterns in exhaled breath condensate may not only serve as phenotypic discriminators but may also open a window on airway biochemical disturbances underlying airway cellular dysfunction," writes Dr. John Hunt from University of Virginia, Charlottesville, Virginia in a related editorial. "In other words, they may help us find the disease in each patient that leads to his or her asthma symptoms."

–Will Boggs, MD