New Method Identifies Asthma Attack Type

Asthma flare-ups can be triggered by either viruses or allergens such as pollen, dander and other agents. And now a team of Australian researchers say they've developed a method of distinguishing between the two types of attacks.

Their study of 59 Asthma patients found that expression of a specific gene, called interleukin 10 (IL-10), was a major factor in acute Asthma exacerbations in asthma patients with viral respiratory infections.

"IL-10 gene expression was significantly increased in acute Asthma with virus infection when compared with virus infection controls, uninfected controls and subjects with stable Asthma," researcher Peter G. Gibson, of the John Hunter Hospital in New South Wales, said in a prepared statement.

Asthma Asthma is an inflammatory disorder of the airways, characterized by periodic attacks of wheezing, shortness of breath, chest tightness, and coughing.

Causes, incidence, and risk factors

Asthma is a disease in which inflammation of the airways causes airflow into and out of the lungs to be restricted. When an asthma attack occurs, the muscles of the bronchial tree become tight and the lining of the air passages swells, reducing airflow and producing the characteristic wheezing sound. Mucus production is increased.

IL-10 functions as a potent immunoregulator that broadly suppresses the body's immune responses.

When Asthma patients with respiratory infections recovered from acute asthma, their levels of IL-10 gene expression returned to normal, the researchers noted.

"Thus, IL-10 gene expression from airway cells appeared to be a feature of virus-induced acute asthma," Gibson said.

The study appears in the latest issue of the American Journal of Respiratory and Critical Care Medicine.

SOURCE: American Thoracic Society, Aug. 15, 2005