Goblet Cell Density Key in Smokers' Prognosis

Researchers have found that current smokers and those with chronic bronchitis are likely to have greater goblet cell density (GCD) than non-smokers or people with chronic obstructive pulmonary disease (COPD). Victor Kim, MD, of the Division of Pulmonary and Critical Care Medicine at Temple University School of Medicine, in Philadelphia, Pennsylvania and colleagues published the results of their study in PLOS ONE.

The study included 12 healthy smokers, 15 patients with moderate to severe COPD, and 11 healthy nonsmokers. The researchers wanted to examine the relationship between goblet cell hyperplasia and smoking to find out if people with chronic bronchitis and current smokers would have more GCD, whether or not they had any airflow obstruction.

Each participant underwent bronchoscopy so that researchers could obtain six endobronchial mucosal biopsies, from the right lower, middle, and upper lobe bronchi. Healthy smokers had a greater GCD than nonsmokers, but also, notably, a greater GCD than the participants with COPD. The researchers also found there was “a significant correlation between pack-year history of smoking with goblet cell density.” Participants with chronic bronchitis also had greater GCD.

The findings of this study suggest that “large airway epithelial mucin stores increase initially before the onset of mild airflow obstruction and then decrease as more severe disease develops.” Another possible conclusion of this study is that “goblet cell hyperplasia does not contribute to airflow obstruction but rather that active smoking is its primary determinant.”

Although the group of participants in this study was small, the researchers contend that excluding people who may have conditions linked to lower airway goblet cell hyperplasia such as upper airway disease or recent exacerbations, adds strength to the findings. However, they also suggest that not systematically collecting exacerbation history before patients were enrolled could be a weakness of the study.

Despite the possible weaknesses, the researchers “were able to demonstrate in this small sample that current smoking and chronic bronchitis, and not airflow obstruction, were independent factors associated with goblet cell hyperplasia.” In addition to adding to the existing literature and knowledge of airway pathology and clinical phenotype, this study highlights the importance of smoking cessation programs.