SELECTED ARTICLES FROM THE RECENT LITERATURE 2004

12/8/04

Responses of asthmatic and normals to diesel exhausts

Summary
Background - Asthmatics are thought to be particularly sensitive to particulate matter (PM) air pollutants, particularly diesel fuel exhaust (DE) materials.

Findings - Standors et al of the Univ. Hospital, Umea, Sweden exposed mild asthmatics and normals for 2 hours to ambient (traffic area) DE levels, averaging 108 mcg/m3 with a 50% cut-off of 10 micron diameter. They found that healthy subjects manifested a neutrophil-rich inflammatory response with an associated increase in IL-8 levels in bronchial lavage fluid and IL-8 mRNA in the bronchial mucosa. In the asthmatics, DE exposure did not induce this neutrophilic inflammatory response nor was the underlying eosinophilic airway inflammation in the asthmatic exacerbated. Epithelial staining for IL-10 was increased in the asthmatic mucosa after DE exposure.

Reference
Eur Respir J 2004;23:82-6

Editor's Comments
These findings are somewhat surprising in the lack of adverse DE effects on airway inflammation considering the findings by Saxon and others that DE exposure enhances IgE-mediated allergic responses in the airways. Perhaps the differences between findings relate to the lower airway studied here vs the nasal challenge in the studies by Saxon and colleagues. Of note, the DE levels to which the subjects described above were exposed were well within current WHO air quality standards.

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