One strategy to help prevent COPD from worsening could be to make dendritic cells less inflammatory, says Curtis, adding that it is a significant challenge to intervene in the immune system without undermining its ability to fight infection.

Key facts about COPD

Chronic obstructive pulmonary disease, or COPD, is a leading cause of disability and killed more than 125,000 Americans over age 25 in 2005. It affects slightly more women than men.

Most people under the umbrella term COPD have emphysema or chronic bronchitis, or both. But asthma, respiratory infections, air pollutants and genetic factors also play a role.

People with emphysema suffer from severe shortness of breath that makes even simple daily tasks like dressing difficult. People with chronic bronchitis experience difficulty breathing, coughing and excessive mucus.

An estimated 40 percent of smokers get COPD. Recent research suggests the disease is more common than previously thought.

Ex-smokers remain at risk. It's common for symptoms to arise in ex-smokers even decades after they have quit smoking.

"Even if everyone in the world stopped smoking today, we would be dealing with the effects of this for 40 years," says Curtis.

Few treatments are very effective. Corticosteroids are of limited use in reducing inflammation.

People with COPD experience higher levels of depression and anxiety that those with other chronic diseases such as cancer and diabetes, studies have shown.

Source: University of Michigan Health System