"Previously, we thought that air pollution alone was not enough to incite acute asthma attacks, but [that an attack] also required the presence of allergens such as pollen or house dust mites to establish airway inflammation and allergic responses in the airways," said Dr. Andre Nel, the study's principal investigator and a professor of medicine in the division of clinical immunology and allergy at UCLA's David Geffen School of Medicine. "However, this new experimental study shows that we need to pay closer attention to the intrinsic abilities of the air pollutant particles to induce asthma."
The study, which appears in the November 2003 issue of the Journal of Allergy and Clinical Immunology, will enhance research methods and lead to a better epidemiological understanding of how sudden surges in air pollution levels induce acute asthma attacks. Researchers at the Mayo Clinic in Scottsdale, AZ, collaborated with UCLA researchers on the study.
Asthma affects 15 to 20 million people in the United States, with the largest increase in cases seen among school-age children. Asthma is a chronic inflammatory disease of the small airways in the lung and can trigger acute episodes of airway tightening and wheezing.
Researchers first gave mice a surrogate allergen, which would be similar to exposing humans to an allergen such as pollen. After several days, researchers administered aerosolized diesel particles to the mice, simulating the inhalation of air-pollution particles. This quickly resulted in an acute asthma-like condition. From a research standpoint, this is the first time that the asthma attack-prompting effects of diesel particles have been separated f
Contact: Rachel Champeau
University of California - Los Angeles