Scientists Spot Treatment Target for Severe Asthma

Curbing immune system compound could ease symptoms, study finds

THURSDAY, Sept. 22, 2005 (HealthDay News) -- Blocking a powerful immune system compound called tumor necrosis factor alpha (TNF alpha) may prove an effective way to treat severe asthma, according to a small study in the current issue of the journal Thorax.

About one in 10 people with asthma has a severe form of the disease, which correlates with relatively large amounts of circulating TNF alpha. TNF alpha is also found in a number of chronic inflammatory conditions such as rheumatoid arthritis, psoriasis and Crohn's disease.

The study, led by researchers at Southampton General Hospital in England, included 26 healthy people, 67 people with mild asthma and 51 people with severe asthma. Bronchial fluid and lung tissue samples showed that TNF alpha levels were much higher in the people with severe asthma and that the TNF was concentrated in mast cells, which are immune cells that play a role in the asthmatic inflammatory reaction.

For 12 weeks, 15 of the people with severe asthma received twice-weekly 25 mg. injections of the drug etanercept (brand name Enbrel), which blocks TNF alpha production. They continued to take their asthma medications. By the end of the study, these patients showed significant improvement in asthma symptoms and lung function, the researchers said.

Treatment with etanercept also curbed inflammatory reaction in the lungs and produced few side effects. While the findings suggest a potentially new method of treatment for severe asthma, further research is needed, the study authors said.

More information

The U.S. National Heart, Lung, and Blood Institute has more about asthma.

SOURCE: BMJ Specialist Journals, news release, Sept. 15, 2005
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