High motility group box 1 (HMGB1) protein and its receptor for advanced glycation end products (RAGE) expression in chronic rhinosinusitis without nasal polyps

Introduction. Chronic rhinosinusitis (CRS) affects 14% of the world population. The high motility group box 1 (HMGB1) protein triggers inflammation, cell proliferation and cell survival through its receptor for advanced glycation end products (RAGE) upon release from stressed or necrotic cells. The aim of the study was to analyze the expression and function of HMGB1 and RAGE in CRS, providing more information about HMGB1 signaling pathway in CRS, to determine its potential clinical significance. Material and methods. Thirty-seven patients with CRS and 26 normal controls (NC) were enrolled in this study. Classification of disease severity using the SNOT-20 questionnaire, nasal endoscopy, CT scan, assessment of allergy status, microbiological and cytological analysis was performed in patients. Fresh sinus mucosa samples were obtained and analyzed by immunohistochemistry for HMGB1 and RAGE expression in epithelial cells. ELISA assay was performed to evaluate the concentration of HMGB1 in the patients' sera. Results. No differences were found in HMGB1 immunoexpression between CRS patients and NC, however there was a highly significant difference in RAGE immunoexpression between both groups. There was a correlation between RAGE expression and number of tissue-infiltrating lymphocytes. Further, RAGE expression positively correlated with disease severity and a positive history for allergies. Conclusions. Interaction of HMGB1 and RAGE might be relevant to CRS pathomechanisms leading to sinus mucosa hyperproliferation. CRS pathogenesis might be especially related to the RAGE overexpression correlated with disease severity and allergy.