Health & Environmental Research Online (HERO)


Print Feedback Export to File
2631278 
Journal Article 
Abstract 
Influence of diesel exhaust particles (DEP) with and without organic compounds on the allergic inflammation in asthmatic subjects 
Schaumann, F; Berger-Preiss, E; Koch, W; Dijkstra, D; Mueller, M; Braun, A; Hohlfeld, J; Krug, N 
2010 
Yes 
American Journal of Respiratory and Critical Care Medicine
ISSN: 1073-449X
EISSN: 1535-4970 
181 
A1033 
English 
WOS:000208771000034 
is part of a larger document 3452678 Proceedings of the American Thoracic Society 2010 International Conference, May 14-19, 2010, New Orleans
Background: Epidemiological studies suggest that exposure to diesel exhaust particles (DEP) is associated with increased morbidity due to allergic airway disease. Controlled exposure studies with asthmatics have demonstrated that an exposure to DEP increased the airway hyperresponsiveness. Furthermore, in vitro studies have suggested that organic extracts of DEP may play a role in the inflammatory response to DEP. However, human exposure studies which have investigated the influence of DEP and their organic compounds on allergic inflammation directly in the lung of allergic asthmatics are not available up to now. Therefore the aim of the study was to test the hypothesis that the allergic airway inflammation in asthmatic patients will be enhanced by DEP and to a lesser degree, when the organic compounds were removed from DEP. In order to test this, we combine the segmental instillation of DEP with the model of a segmental allergen challenge.

Methods: 15 mild asthmatics allergic to grass pollen or house dust mite were enrolled into the study. DEP were generated using a diesel vehicle on an exhaust roller dynamometer test bench. The organic compound was extracted with toluene followed by dichloromethane in a portion of the DEP. The analysis of PAH was done by gas chromatography with (GC-MS). The total soluble organic fraction of DEP was about 16% and the total amount of PAH was about 1500 µg/g DEP. 5 µg complete DEP as well as 5 µg DEP without organic compounds were instilled in combination with allergen (grass mix or house dust mite) into two different lung segments by bronchoscopy. In addition allergen and saline alone were instilled in two further segments as controls. 24 hours later, during a second bronchoscopy, BAL samples were collected in these challenged segments in order to obtain cells and lavage fluid for cell and immunological analysis.

Results: BAL cells (total: 18.4 x 10^6, eosinophils: 8.6x10^6) were significant decreased in the combined segment with DEP and allergen compared to the allergen segment alone (total: 28.7x10^6; eosinophils 15.8x10^6) p=0.001 and p=0.03, respectively. The combined segment with DEP without organic compounds and allergen showed a non significant decrease in BAL cells (total: 22.8 x 10^6, eosinophils: 11.6x10^6) compared to the allergen segment.

Conclusion: Both, DEP as well as DEP without organic compounds did not enhance but decreased the allergic inflammation. A potential explanation might be the absorption of allergen to particles leading to reduced allergen exposure when combined with DEP. 
American Thoracic Society 2010 International Conference 
New Orleans, LA 
May 14-19, 2010