Background
Chronic rhinosinusitis with nasal polyps (CRSwNP) is characterized by eosinophil-dominant infiltration in Europe and the United States. However, CRSwNP in Asia has shown different immunopathologic features. High-mobility group protein box 1 (HMGB1) is a DNA-binding protein that has been suggested to be involved in various chronic inflammatory diseases. The
Conclusion
Upregulation of HMGB1 could be a significant marker typically in eosinophilic CRSwNP and it may also contribute to the pathogenesis of CRSwNP along with IL-5, IL-8, and TNF-α.
Methods
Nasal polyps specimens were collected from 41 patients with CRSwNP (20 eosinophilic and 21 non-eosinophilic) undergoing functional endoscopic sinus surgery (FESS). Biopsies of uncinate process, and ethmoidal mucosa from 9 non-CRS patients were used as controls by means of immunohistochemistry (IHC) staining, Western blotting, and quantitative reverse-transcription polymerase chain reaction (qRT-PCR).
Results
HMGB1-positive expression was significantly increased in the epithelium and among the large inflammatory cells infiltration in Eos CRSwNP and non-Eos CRSwNP as compared with controls (p < 0.001). The HMGB1 protein and messenger RNA (mRNA) levels of HMGB1, IL-5, IL-8, and TNF-α were significantly higher in eosinophilic CRSwNP than those from controls and non-eosinophilic CRSwNP, but no significant differences in these markers were found between non-eosinophilic CRSwNP and controls. HMGB1 expression levels correlated significantly and positively with IL-5, IL-8, and TNF-α (rs = 0.665, 0.771, and 0.724, respectively; p < 0.001) and slightly with eosinophil infiltration (rs = 0.149; p = 0.012) and the blood eosinophils count (rs = 0.225; p = 0.001) in all samples.