Histopathological features of nasal polyps with asthma association: An immunohistochemical study

Background: Myofibroblasts are related to airway remodeling and may play an important role in the pathogenesis of the histological features of nasal polyps associated with asthma. The aim of this study was to analyze and compare the eosinophilic cationic protein, transforming growth factor (TGF) beta, and myofibroblasts in the nasal polyps of patients with chronic sinusitis associated with and without asthma. Methods: Nasal polyp samples were obtained during endoscopic sinus surgery and were classified into asthma and nonasthma groups. Immunohistochemistry was performed using antibodies against activated eosinophils, TGF-beta, and myofibroblasts. Results: The asthma group showed an increased number of activated eosinophils, TGF-beta, and myofibroblasts compared with the nonasthma and control groups. We found no correlation of asthma and aspirin intolerance with the immunohistochemical findings. Conclusion: The increased number of myofibroblasts in the nasal polyps of the asthma group may be responsible for the extracellular matrix accumulation, polyp formation, and polyp recurrence.