CD79A and chronic obstructive pulmonary disease: In the bronchial mucosa (lamina propria) of our rapid decliners with COPD we observed a significant reduction of plasma cell numbers (Fig. 3) compared to non-decliners, which was also significantly and positively associated with the total IgA score in lamina propria and secretory IgA score in bronchial epithelium, confirming a relationship between the plasma cell numbers populating the bronchial mucosa and secreted IgA (Fig. 4).