Interlukin-25 and Nasal Polyps, a Novel Target to Hit

Abstract

Background: Chronic Rhinosinusitis (CRS) can be subdivided into 2 major categories; CRS with or without nasal polyps (CRSwNP or CRSsNP) . IL-25 has been implicated in promoting Th2 responses in airway inflammation, However the clinical relevance of local IL-25 in CRS patients remains relatively uncharacterized. Objective: The aim of this work is to evaluate the relation between IL-25 and types of CRS. Subjects and Methods: This is a prospective study on 120 patients (60 CRSwNP, 60 CRSsNP) and 20 controls. All underwent clinical and radiological assessment. Biopsies from their nasal mucosa were taken for pathological assessment to detect mucosal changes, tissue eosinophilia and percentage and intensity of immunohistochemical IL-25 staining in tissues, and for correlation with clinical and radiological criteria. Results: CRSwNP patients are more associated with asthma, higher nasal endoscopy score, more severe inflammatory pathology, partial epithelial degeneration and ulceration and IL-25 tissue levels than CRSsNP and control group. 46% of patients with CRSwNP had tissue eosinophilia which is significantly higher than CRSsNP and control groups. We also found that the total nasal symptom score (TNSS), CT score and basement membrane thickness had a statistically significant positive correlation with immunohistochemical score of IL 25. Conclusion:This study shows increase in IL25 expression and tissue eosinophilia in CRSwNP when compared to CRSsNP and control group. Thus, IL-25 may be a promising therapeutic target and an indicator for the management of CRSwNP patients.