Introduction: Early and often subclinical pulmonary infection and pronounced neutrophilic inflammation are major contributors to CF-related morbidity. There is a causal relationship between high airway neutrophil elastase activity and the development of bronchiectasis. Early detection of disease and disease-associated complications is crucial for implementing timely therapeutic measures to reduce disease burden and improve prognosis. Secondary Electrospray Ionization Mass Spectrometry (SESI-MS) is an extremely efficient sensing method for ionizing compounds in exhaled breath allowing extending number of breath compounds resulting in increased specificity.
Method: We developed a sampling device for the use in non-cooperative children with tidal breathing and facemask. The device was optimized for real-time, sensitive analysis by introducing a temperature, humidity and flow controlled air supply. A feasibility study was done with 20 children (age range 3-12y), 9 stable CF and 11 healthy. All children performed 6 measurements with tidal breathing and facemask (TBFM) and single breath maneuver via mouthpiece (SBMP).
Results: The success rate was 100% for TBFM but SBMP analysis was not feasible for 3 children of age 3y, 4y and 6y. The average features per measurement in positive mode were 713 for SBMP and 702 (-2%, SD11%) for TBFM. Molecules were detected in the range of m/z ¼ 50 - 320 with intensities up to 5E+4cps for SBMP and 7E+4cps for TBFM. Data analysis is on-going with a set of 28 breath biomarkers (amino acids, fatty acids and aldehydes) which were detected and identified during previous exhalomics studies. Our preliminary results reveal comparable number of features and intensities between TBFM and SBMP.
Conclusions: Breath exhalomics studies with SESI-MS are feasible in children from 3 years of age. Measurements by TBFM and SBMP resulted in similar number of features and intensities. Therefore, SESI-MS with adapted sampling device can be applied in young non-cooperative children.