Researchers from the Keck School of Medicine of the University of Southern California and the David Geffen School of Medicine at UCLA have found that genetic characteristics seen in about half the population leave allergy-sufferers particularly susceptible to the effects of diesel particles. Results appear in the Jan. 10 issue of Lancet.

"We've known that diesel exhaust particles worsen symptoms in individuals who respond to allergens, such as pollen, but this study suggests a direct way that pollution could be triggering allergies and asthma in a large number of susceptible individuals, and perhaps a new route of intervention," says Frank D. Gilliland, M.D., Ph.D., professor of preventive medicine at the Keck School and the study's lead author.

Exposure to air pollution is related to numerous health effects, including respiratory allergies. In this study, researchers sought to understand how pollutants from diesel exhaust might cause inflammation in the lungs.

Diesel exhaust particles are thought to act by causing the production of molecules called reactive oxygen radicals (hydrogen peroxide, for example) in the lungs' airways. In response, the immune system pumps out substances that cause allergy symptoms.

But compounds called antioxidants can detoxify these particles and temper the body's allergic inflammatory response. Researchers suspect that the better the body can use antioxidants to defend itself, the better it can protect itself from airborne pollutants.

With that in mind, researchers investigated a family of antioxidant-related enzymes found in the lungs. Two of these enzymes are called glutathione S-transferase M1, or GSTM1, and glutathione S-transferase P1, or GST
'"/>

Contact: Jon Weiner
jonweine@usc.edu
323-442-2830
University of Southern California
8-Jan-2004