Localization of Active Caspase-3 and Caspase-8 in Nasal Polyps and Nasal Hyperplasia in Consideration of Mast Cell Function: A Semiquantitatively Analysis

Introduction: The pathogenesis of nasal polyposis and nasal hyperplasia is still unknown. The localization of caspases in nasal polyps and nasal hyperplasia of patients with and without allergic rhinitis was studied. Methods: Sections of human nasal polyps (n = 5) and hyperplastic nasal turbinates (5 with, 5 without allergy) were stained for active caspase3 and caspase-8. Double immunofluorescence was used to evaluate colocalization of the caspases with Ki-M1P and tryptase. TUNEL was performed. Results: Active caspase-3 and caspase-8 were seen in nearly all nasal polyps and hyperplastic nasal turbinates. Active caspase-3 was predominantly localized in stromal cells, identified as mast cells. Caspase-8 was localized in mast cells with the pattern similar to active caspase-3 and additionally found in epithelial cells at the nasal and polyp surface and in epithelial cells of glands. Conclusion: Our results suggest that mast cell apoptosis may be involved in the pathological mechanisms which characterize and sustain chronic inflammatory disorders of the nasal mucosa with and without allergy.