Expression of annexin A1 in normal and chronically inflamed nasal mucosa.

Objective: To examine the expression pattern of annexin A1 in normal and chronically inflamed nasal mucosa to investigate its possible role in nasal inflammation.

Design: Immunohistochemical analysis.

Subjects: Samples of middle turbinates from 5 healthy subjects and 5 patients with perennial rhinitis, and samples of nasal polyps from 7 patients.

Interventions: Annexin A1 expression was examined with a standard immunohistochemical protocol on paraffin-embedded sections.

Results: Annexin A1 was highly expressed by ciliated cells, where it was concentrated on the apical surface and within the cilia. Goblet cells and nondifferentiated basal epithelial cells did not stain. In the glands of the lamina propria, intense staining was found in the cytoplasm and in the nuclei of the cells in the duct epithelium, whereas acinar cells did not stain. Intense cytoplasmic staining was observed in infiltrating polymorphonuclear cells and macrophages. No differences in the pattern or the level of expression of annexin A1 were found in the epithelial cells and glands of normal and chronically inflamed (perennial rhinitis or polyps) nasal mucosa.

Conclusion: These results suggest that the expression of annexin A1 in respiratory epithelium of nasal mucosa is related to cell type and differentiation status of the cells and is not significantly altered by inflammatory diseases.