Background: Chronic rhinosinusitis (CRS) with nasal polyps is characterized by eosinophilic infiltration. This study hypothesized that the aggregation of the mucosal pathology during remodeling is related to infiltrating eosinophils in patients with such nasal polyps.
Object: To clarify the pathogenetic role of eosinophils in patients with CRS with nasal polyps, this study investigated the relationship between epithelial damage or basement membrane (BM) thickening and the epithelial infiltration of eosinophils in these nasal polyps.
Methods: The number of eosinophils that infiltrated into the epithelial and subepithelial layers of sinonasal tissues was counted. The staging of epithelial damage allowed the quantification of epithelial loss.
Results: Both epithelial damage and BM thickness in CRS, which were correlated with the number of infiltrated eosinophils, were significantly greater than in the control group. Neither parameter showed significant differences between the asthma and non-asthma groups. There was a significantly correlation in the eosinophilic infiltration between the subepithelial and epithelial layers.
Conclusion: It is suggested that eosinophils that infiltrate into both the epithelial and subepithelial layers play a part in the process of mucosal remodeling of CRS with nasal polyps.