Expression of interleukin-5, interleukin-8, and interleukin-10 mRNA in the osteomeatal complex in nasal polyposis

Background: Several cytokines are expressed in chronic sinusitis with and without underlying allergy. Their local production and regulation in the osteomeatal complex, the key area of paranasal sinuses, still is not filly understood. This study was performed to investigate differences of cytokine messenger RNA (mRNA) expression between the medial and the lateral part of the middle turbinate and anterior ethmoid mucosa of allergic and nonallergic patients. Methods: Using the LightCycler system for real-time reverse-transcription polymerase chain reaction, we investigated the content of interleukin (IL)-5, IL-8, and IL-10 mRNA in tissue samples from middle turbinates and anterior ethmoids of 18 patients with chronic sinusitis and nasal polyps. Inferior turbinate mucosa of six control subjects without sinusitis and allergy served as control. Results: IL-5 mRNA was detectable in 32 (60%) of 54 samples (two of six controls) in significant different amounts between the various locations (p <= 0.001). Anterior ethmoid mucosa (0.96 +/- 0.99) expressed the highest amount of IL-5 mRNA followed by the lateral (0.37 +/- 0.54) and the medial portion of the middle turbinate (0.12 +/- 0.29) with no difference between allergic and nonallergic subgroups. IL-8 was detected in significant higher amounts in all three origins with no significant difference in concentrations between the examined locations as compared with controls. Patients expressed either IL-5 or IL-8 or both cytokine mRNA. IL-10 was expressed in all three specimens from five of eight allergic patients. All five individuals with clinical symptoms of allergy at the time of operation expressed IL-10 in at least one specimen. Conclusion: IL-5 cytokine expression in the osteomeatal complex is linked to the presence of nasal polyps, whereas IL-8 is up-regulated without distinct correlation to nasal polyps. IL-10 expression was detectable in five of eight allergic patients.