Expression of cyclooxygenase and lipoxygenase enzymes in sinonasal mucosa of patients with cystic fibrosis

Objective: To evaluate the expression of cyclooxygenase (COX) and lipoxygenase (LO) enzymes in the sinonasal mucosa of patients with cystic fibrosis (CF). Design: Immunohistochemical staining of archived tissue. Participants: Specimens from 9 patients with CF were analyzed; control specimens were obtained from 4 patients without a history of CF or rhinosinusitis. Interventions: Expression of the enzymes COX-1, COX-2, 5-LO, 12-LO, and 15-LO was evaluated with the use of immunohistochemical techniques in archived sinonasal mucosal tissue from patients with CF. These results were compared with those of the control group. Results: We noted the characteristic staining patterns of epithelium and submucosal glands for each enzyme. Statistically significant (P<.05) differences between control and CF specimens were noted in the staining intensity of columnar epithelium for COX-2 (cytoplasm) and 12-LO (cytoplasm and nucleus) and of submucosal glands for COX-2 (cytoplasm) and 12-LO (cytoplasm). No significant differences were noted for the staining intensity of COX-1, 5-LO, or 15-LO between the groups. Conclusions: Significant differences in sinonasal mucosal expression of COX-2 and 12-LO enzymes exist between patients with CF and controls. This suggests a difference in arachidonic acid metabolism between these 2 groups.