Vergleich von zwei Geräten und zwei Atemmustern bei der Gewinnung von exhaliertem Atemwegskondensat

EBC collection (Exhaled breath condensate) is a promising non-invasive methodto obtain samples from the epithelial lining fluid of the lung. Due to problems of standardization concerning methodical aspects EBC analysis is presently not used in clinical practice. For the first time the comparability for the two commercially available devices (RTube™ and ECoScreen Turbo) was assessed in healthy controls by measuring pH, conductivity and total protein. A further aim of the study was to assess the influence of different breathing patterns (tidal breathing and hyperventilation) on total protein amount and specific proteins (Surfactant Protein-A, das Club Cell Protein, Alpha-1-Antitrypsin) in EBC. EBC was collected in different experimental setup (≥ 10 individuals each) using the RTube™ and ECoScreen Turbo in a randomized crossover design, twice with every device - once in tidal breathing and once in hyperventilation. It could be shown that neither the device nor the breathing pattern significantly altered EBC pH or conductivity. Total protein measurements however were altered by breathing patterns. It could be shown that hyperventilation increased total protein concentrations in EBC. To analyse the source of EBC the bronchial Club Cell Protein (CCP) and Surfactant protein A (SP-A) as a marker of the alveolar fraction were measured after tidal and breathing and hyperventilation. However SP-A and CCP were not consistently detectable in EBC. Thus the question concerning the origin of EBC cannot be answered satisfying at the moment. Alpha-1 Antitrypsin (AAT) was consistently detectable in EBC using both the RTube ™ and the ECoScreen Turbo. It was the first time that AAT was measured in EBC collected with den ECoScreen Turbo. It could be shown that AAT concentration was not statistic significantly altered by the device. Instead hyperventilation increased –similar to the measurements of total protein- AAT concentration in EBC. Up to now there is no research work that would have investigated AAT concentration in EBC after hyperventilation. Finally it could be shown that results of protein measurements changed significantly after normalizing the absolute amount or concentrations of total protein and AAT to ventilated air. Therefore standardization to the ventilated air is recommended for future protein analysis in EBC.