The HLA-G and IL-17A Expression in Nasal Polyposis

Objective: The HLA-G molecules are nonclassic class I antigens with anti-inflammatory and tolerogenic properties, while interleukin-17A (IL-17A) is a key inflammatory cytokine in many disorders. Considering that, the aims of this study were: 1) to evaluate the HLA-G molecule, and 2) to evaluate IL-17A expression in patients presenting with nasal polyposis.

Method: Samples of patients presenting with nasal polyposis (n = 20) were subjected to immunohistochemistry technique. All patients were grouped into atopic and nonatopic patients according to skin prick test and IgE dosage. All statistical analyses were performed using the GraphPad Prism 5.0. The level of statistical significance was accepted at P < .05.

Results: Our preliminary results showed the HLA-G and IL-17A expression in nasal polyposis. Immunohistochemical staining demonstrated a higher expression of HLA-G molecule in samples of nonatopic patients when compared with atopic patients (P = .04). The IL-17A expression was also observed in both atopic and nonatopic patients; however, the numbers of IL-17A positive cells were greater in nasal polyps of atopic patients than in those of nonatopic patients.

Conclusion: These preliminary results indicated that HLA-G and IL-17A may play an important role in the pathology of nasal polyposis. Considering the anti-inflammatory properties of HLA-G and inflammatory activities of IL-17A, we suggest that HLA-G could decreased the susceptibility to disease, while IL-17 should be associated with more severe atopy.