Apoptosis in eosinophilic nasal polyps treated in vitro with mitomycin C.

UNLABELLED The etiopathogenesis of eosinophilic nasal polyps is yet to be explained. Eosinophils are key components in the inflammatory infiltrate and are related to the perpetuation of the inflammatory process in chronic rhinosinusitis with nasal polyps. OBJECTIVE This paper aims to evaluate the in vitro action of mitomycin upon the apoptotic index of nasal polyps. MATERIALS AND METHODS This is a self-paired prospective experimental study using biopsy fragments from 15 patients with eosinophilic nasal polyps. Biopsy fragments were divided into two groups. In the case group, the fragments were treated with 400 µg/ml of mitomycin for five minutes. The control group fragments were treated with culture medium. The pair of fragments contained in the two first compartments - control and case - were immediately sent to the histopathologist. The other pair of samples containing control and case fragments was incubated for 12 hours. The fragments were then taken to the histopathologist for testing. The apoptotic index was determined by the morphometry in hematoxylin and eosin staining and DNA fragmentation analysis (TUNEL reaction). RESULTS The comparison between the two groups showed a statistically significant difference (p < 0,001) in the apoptotic index of the 12-hour incubated cultures. CONCLUSION Mitomycin acts in vitro upon the eosinophilic nasal polyps inducing the rise of the eosinophilic apoptotic index.