When a patient arrives at a doctor’s office with a persistent cough and the sensation of gunk building up in the lungs, the doctor’s thought process is essentially the same as it would have been decades ago. There has been no understanding of the affected biological pathways causing the gunk buildup in the lung, nor has there been a diagnostic test for chronic bronchitis. UNC School of Medicine researchers are trying to change that.
In a study published in The New England Journal of Medicine, UNC researchers describe how the concentration of mucins – the proteins that make mucus thick – is abnormally high in chronic bronchitis and that high mucin concentrations are associated with disease severity in people with chronic bronchitis. This finding could become the first-ever objective marker of chronic bronchitis and lead to the creation of diagnostic and prognostic tools.
This research, led by Mehmet Kesimer, PhD, associate professor of pathology and laboratory medicine at the UNC School of Medicine, also raises the possibility that developing new drugs to reduce mucin concentrations could help relieve bronchitis symptoms and prevent disease progression in chronic bronchitis subjects.
“Until now, we have had little knowledge of what causes the airway mucus accumulation that plagues chronic bronchitis patients, and the only way we have to diagnose chronic bronchitis is based on what the patient tells us,” said Richard Boucher, MD, director of the UNC Marsico Lung Institute at the University of North Carolina at Chapel Hill and paper co-author. “Frankly, it’s a little embarrassing. Chronic bronchitis is a very common reason why people see their doctor, and we have had no real understanding how it develops or how to diagnose it. This study is a breakthrough in our understanding of this serious condition that affects millions of people in the United States.”
Chronic bronchitis is characterized by recurring bouts of airway inflammation accompanied by a persistent cough and phlegm production. It’s different from acute bronchitis, which typically develops after a cold or the flu and only lasts a few weeks. Although chronic bronchitis has a variety of causes, by far the most common is smoking. Smokers with chronic bronchitis are prone to bacterial infections and face a high risk of developing a more debilitating form of airway inflammation known as chronic obstructive pulmonary disease (COPD), which has no cure and is the third leading cause of death in the United States.