COPD linked to increased bacterial invasion

Chronic obstructive pulmonary disease (COPD) is a common smoking-related lung illness and the third leading cause of death in the United States. Scientists have long believed that inhaling toxic gases and particles from tobacco smoke causes inflammation of the small airways in the lungs, leading to the development of COPD. However, the theory doesn’t explain why airway inflammation and disease progression continue even after the patient stops smoking. A new study shows that persistent inflammation in COPD may result from a defect in the immune system that allows airway bacteria to invade deeper into the lung.