Diffuse panbronchiolitis(DPB) is a chronic inflammatory lung disease that presents as coughing, copious sputum, exertional dyspnea, which progresses to bronchiectasis. The pathogenesis of bronchiectasis is controlled by inflammatory mediators, which are closely related to mucus hypersecretion, goblet cell dysplasia. In recent studies, the epidermal growth factor receptor(EGFR) system was reported to be associated with this process. It was hypothesized that a relationship exists between goblet cell dysplasia, EGFR expression, and inflammatory mediators produced by neutrophil.

Alcian blue/periodic acid -Schiff(AB/PAS) stain, MUC5AC, EGFR, CD16 immunohistochemical stain were examined to investigate a role for the EGFR system in a mucus hypersecretion in DPB using the lung biopsy specimens from 13 DPB patients and 6 controls.

In the DPB group, the AB/PAS- and MUC5AC-stained areas were 8.31±3.36%, 11.46±4.68%, respectively. In the control group, the AB/PAS- and MUC5AC-stained areas were 50.5±5.77%, 53.3%±6.67%, which was significantly larger than in the DPB group (each comparison, p<0.05). The percentage of EGFR expression was 9.54±4.95% in the DPB group, but zero in of the control group. The extent of neutrophilic infiltration was 71.92±3.71/5HPF in the DPB group and 45.0±5.73/5HPF in the control group, which was statistically significant(p=0.002).

The EGFR system is highly related to goblet cell dysplasia, mucus hypersecretion and neutrophilic inflammation in DPB.