The human leukocyte antigen G molecule (HLA-G) expression in patients with nasal polyposis.

INTRODUCTION Sinonasal polyposis (NP) is a chronic inflammatory pathology of the nasal/paranasal cavities which affects from 1%-4% of the population. Although polyps seem to be a manifestation of chronic inflammation in both allergic and non-allergic subjects, the pathogenesis of nasal polyposis remains unknown. HLA-G molecules are a kind of no classic class I antigen with anti-inflammatory and tolerogenic properties. Little attention has been paid to the role of HLA-G chronic inflammatory disorders. OBJECTIVE The aim of this study is to investigate the expression of HLA-G in the NP. MATERIALS AND METHODS Prospective study involving samples of patients presenting with nasal polyposis that were subjected to the immunohistochemistry technique. After a skin prick test, all patients were divided into atopic and nonatopic groups and classified as asthmatic or non-asthmatic. RESULTS Immunohistochemical staining demonstrated a higher expression of the HLA-G molecule in samples from nonatopic than in those from atopic patients, and was significantly lower in the non-asthmatic patients. CONCLUSION These results indicate that HLA-G may play an important role in the pathology of nasal polyposis. Considering the anti-inflammatory properties of HLA-G, this study suggests that it could reduce susceptibility to atopy and asthma.