Following this exposure, participants underwent an "allergen challenge test." This inhalation test identifies the dose that causes their airways to constrict a specified degree. That dose, once determined for each person, is called their provocation dose, said study co-author Dr. Neil Alexis, assistant professor of pediatrics in the division of allergy, immunology and environmental medicine and a UNC center member.
"We found that when allergic individuals breathe endotoxin prior to their allergen challenge, they in fact became more sensitive to the allergen challenge. They were provoked at a lower concentration of allergen compared to previously inhaling air without endotoxin," he said.
The findings have implications for air pollution exposure, "in particular those pollutants that cause airway inflammation, which endotoxin does and which ozone does," Alexis said. "So in folks who are already allergic, if they are inhaling pollutants that can further exacerbate their inflammation, it may aggravate the symptoms they normally would have. In other words, they may experience a worsening of their symptoms."
Further UNC studies will examine if endotoxin, ozone and other airborne agents share common interactive mechanisms that may increase allergen sensitivity and disease severity in people with asthma.
"There is also the possibility of finding drugs to block that interaction and prevent the worsening of asthma," Boehlecke said. Along with Alexis and Boehlecke, UNC co-authors were Drs. Milan Hazucha, Robert Jacobs, Parker Reist, Philip A. Bromberg and David Peden.
'"/>
Contact: Leslie Lang
llang@med.unc.edu
919-843-9687
University of North Carolina School of Medicine
9-Dec-2003