Cysteinyl leukotriene receptor expression in aspirin-sensitive nasal polyposis patients

Background: The aim of this study was to detect cysteinyl leukotriene (Cys-LT) receptors in aspirin-sensitive nasal polyposis patients, and compare them with nasal polyposis and chronic rhinosinusitis patients without aspirin sensitivity. Methods: The formalin-fixed, paraffin-embedded tissue blocks of a total of 52 patients undergoing endoscopic sinus surgery were reviewed by an experienced head and neck pathologist. Of these 52 cases, there were 22 nasal polyposis cases with aspirin sensitivity, 15 nasal polyposis cases without aspirin sensitivity and 15 chronic rhinosinusitis cases without aspirin sensitivity. Immunohistochemical analyses for Cys-LT1 receptors were performed with polyclonal rabbit antibody. Results: Eosinophil receptor intensity levels were 27.68, 21.67, and 14.40, respectively. This was statistically insignificant (p < 0.089). Mast cell receptor intensity levels were 8.41, 5.27, and 4.27, respectively. In the aspirin-sensitive group, mast cell receptor intensity was significantly higher when compared to the nasal polyposis and chronic rhinosinusitis group (p < 0.0001 and p < 0.0001, respectively). The difference in Cys-LT1 receptor immunoreactivity in both eosinophils and mast cells among the 3 groups was also found to be statistically significant (p < 0.001). Conclusions: Our study revealed that nasal polyps of aspirin-sensitive patients were infiltrated with eosinophils and mast cells, Cys-LT1 receptor proportions in these inflammatory cells were found to be higher and Cys-LT1 receptor immunoreactivity in eosinophils and mast cells was increased. Copyright (c) 2007 S. Karger AG, Basel.