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.