EXPRESSION OF CYCLO-OXYGENASE-1 AND CYCLO-OXYGENASE-2 PROTEINS IN UPPER RESPIRATORY MUCOSA

Background Cyclo-oxygenases 1 (Cox-1) and 2 (Cox-2) catalyse the conve rsion of arachidonic acid to prostaglandin endoperoxides, leading to t he formation of prostaglandin and thromboxane mediators of inflammatio n. The involvement of these enzymes in inflammatory disorders such as sinusitis and nasal polyps is unknown although this may be relevant to their pathophysiology. Methods We studied Cox-1 and Cox-2 immunoreact ivities in nasal polyp, maxillary sinus, and turbinate biopsies obtain ed from eight patients with chronic allergic rhinitis and sinusitis an d/or nasal polyps, 15 patients with chronic non-allergic rhinitis and sinusitis and/or nasal polyps and five control subjects (patients requ iring nose surgery not related to sinusitis or nasal polyps). Results Both Cox-1 and Cox-2 were mainly expressed in the epithelium (basal, c iliated) and were found in 16/28 and 25/28 subjects for Cox-1 and Cox- 2 respectively. We did not find any differences between the patient po pulations. There were no correlations between any of the clinical para meters studied nor the pathological patterns and the presence and char acteristics of the Cox Immunoreactivities. Conclusion Both cyclo-oxyge nase enzymes are expressed in normal human upper respiratory epitheliu m and are not upregulated in chronic sinusitis nor in nasal polyposis, possibly suggesting that Cox products do not have an important role a s mediators of the chronic upper airway inflammation.