Different inflammation types in chronic rhinosinusitis and nasal polyps

Objective and design: Etiology and classification of chronic rhinosinusitis still remain unclear. Chronic rhinosinusitis can be differentiated clinically according to the presence or absence of nasal polyps in the nasal cavity. Knowledge of infiltrating leukocytes in these 2 sinusitis entities is still limited. Therefore, based on quantification of inflammatory cells in biopsies from patients with nasal polyposis and chronic rhinosinusitis without nasal polyps, we tried to answer the question if there is need for further subclassification of chronic rhinosinusitis into different disease entities. Patients and methods: Nasal polyps (n = 37) and tissue from patients suffering from chronic sinusitis without polyps (n = 4 1) were examined by light microscopy after immunostaining with monoclonal antibodies against eosinophilic cationic protein (eosinophilic granulocytes), neutrophilic elastase (neutrophilic granulocytes) and CD38 antigen which is expressed by a variety of cells including plasma cells and activated T lymphocytes. All data were tested using a Mann-Whitney U-test. Results In nasal polyposis, we found a significant increase of eosinophils and neutrophils (p < 0,05) compared to chronic nonpolypous rhinosinusitis. Samples of chronic nonpolypous rhinosinusitis were dominated by neutrophils. In addition, a considerable infiltration of CD38-positive cells around mucosal gland cells was observed in chronic rhinosinusitis but not in nasal polyposis. Conclusions Different types and quantities of inflammatory cells support our hypothesis that there is need for further subclassification of chronic rhinosinusitis according to polypous and nonpolypous.