"While the allergic response may increase during an asthma attack, our research suggests that the anti-viral response also increases," says Michael J. Holtzman, M.D., the Selma and Herman Seldin Professor of Medicine and professor of cell biology and physiology. "We think that a virus in infancy or childhood creates a hit-and-run effect, where a brief infection causes permanent changes in the body's anti-viral system."
Holtzman led the study, which appears in the July 15 issue of the Journal of Clinical Investigation.
The most common cause of lower respiratory illness in children is paramyxoviral infection, which often results in chronic wheezing regardless of whether the child develops allergies. But researchers have yet to figure out how the short-term influence of this viral infection leads to a long-term condition of respiratory inflammation and distress.
Holtzman's team examined mice with bronchiolitis inflamed airways caused by paramyxoviral infection. The mouse disease mimics paramyxoviral infection in humans. These mice responded immediately to the infection immune cells flooded the lining of the respiratory tract, attacking infectious cells and inflaming the tissues. Weeks after infection, the airways of the lung remained extremely sensitive, or hyperreactive, and the airway lining became populated with mucus-producing cells. Each of these changes airway hyperreactivity and cellular remodeling lasted for at least one year and perhaps indefinitely.
"Since each of these changes also is a long-term symptom of asthma, these
Contact: Gila Reckess
Washington University School of Medicine