Diesel exhaust as an adjuvant to allergen-mediated oxidative stress and immune response in the asthmatic lung

Asthma patients are at risk of potentially severe and sometimes lethal exacerbations. These exacerbations can be caused by a variety of triggers, such as infections or exposure to allergens. Diesel exhaust and other traffic-related constituents can also be inhaled along with the allergen. This multi-inhalant mixture results in immune reactions that are more complex than exposure to the allergen alone. Although it is well established that multi-inhalant mixtures of allergens and pollution contribute to asthma exacerbations, research in this area typically focuses on exposures to single agents, either diesel exhaust or allergens alone.

Dr. Francesco Sava is investigating the relationship and the synergies that exist between diesel exhaust and allergen-triggered asthma exacerbations using a live-patient model. His aim is to demonstrate that inhalation of diesel exhaust increases allergen-induced inflammation in the lungs of asthmatic patients. Using state-of-the-art equipment, he will expose patients to controlled diesel exhaust concentrations. A very small amount of allergen will be introduced into a segment of the patients’ lungs, and the resulting inflammation will be measured. This multi-inhalant exposure model reflects the real-life conditions that patients are likely to encounter. The experimental model he uses has been widely studied, is very safe, and allows researchers to test allergens on humans without triggering an overt asthma attack.

The research will help define the synergies between the real-world concentrations of inhaled diesel exhaust and allergen exposure in the asthmatic population. This information will likely lead to recommendations for air quality and strategies to protect vulnerable populations.