[Expression and role of IL-18 in chronic rhinosinusitis]

Abstract

Objective:To study the expression and role of interleukin-18 (IL-18) in different clinical phenotypes of chronic rhinosinusitis(CRS)and in different subtypes of CRS with nasal polyps (CRSwNP).Method:During nasal endoscopic surgery, inferior turbinates were obtained from 13 patients with nasal septum deviation (control group),uncinate processes were obtained from 10 patients with chronic rhinosinusitis without nasal polyps (CRSsNP) and nasal polyp tissues were obtained from 36 patients with CRSwNP, respectively. IL-5 expression in CRSwNP was detected by ELISA, and the expression of IL-18 mRNA and protein in different subtypes of CRS were assessed by real-time PCR, ELISA and immunohistochemistr.Result:CRSwNP was divided into 12 cases of IL-5 positive nasal polyps (IL-5+NP)group and 24 cases of IL-5 negative nasal polyps (IL-5-NP)group. The expression of IL-18 mRNA and protein in all CRSsNP,IL-5+NP and IL-5-NP groups were higher than that in control group (P<0.01 or P<0.05),but no significant difference existed between IL-5+NP and IL-5-NP (P>0.05) group. IL-18 also expresses in epithelial cells of normal nasal mucosa.Conclusion:CRSwNP can be divided into two main subtypes: IL-5+NP and IL-5-NP. The increasing expression of IL-18 in CRSsNP, IL-5+NP and IL-5-NP compared with control group indicates that IL-18 may play a key role in the pathogenesis of CRS, and IL-18 expression in nasal polyps is not affected by the type of inflammation. The possible presence of balance between IL-18 and IL-18 binding protein in normal nasal mucosa provides a new way for research and treatment of CRS.

Keywords: interleukin-18; nasal polyps; sinusitis.