Plasma cells and IL-4 in chronic bronchitis and chronic obstructive pulmonary disease.

Rationale: Airway wall inflammation, IL-4, and mucus hypersecretion are thought to be associated.

Objectives: To quantify bronchial inflammatory cells in smokers with chronic bronchitis (CB) with and without airflow obstruction (AO), determining the cells expressing IL-4 and IL-5 and their association with submucosal gland mucin.

Methods: We applied immunohistochemistry to identify, and double-labeling to colocalize, IL-4 and IL-5 to distinct inflammatory cells in resected bronchi from (1) 11 asymptomatic smokers (AS), (2) 11 smokers with CB, and (3) 10 smokers with CB and AO.