Decreased Gene Expression of Lipoxin A4 Receptor May Contribute to Nonallergic Rhinitis Pathogenesis

Abstract

Background: Rhinitis is a prevalent chronic inflammatory illness of the nasal mucosa. Arachidonic acid-derived lipoxin A4 (LXA4) has long been recognized to exert crucial antiinflammatory and pro-resolving effects on inflammatory responses through a specific receptor named LXA4 receptor/formyl peptide receptor-2 (ALX/FPR2). This study aimed to determine the serum level of LXA4 and the relative mRNA expression level of FPR2 in peripheral blood cells of patients with rhinitis (allergic and nonallergic) compared to healthy individuals. Materials And Methods: The study groups consisted of 37 patients with Allergic Rhinitis (AR), 16 patients with Nonallergic Rhinitis (NAR), and 20 sex- and age-matched healthy individuals. The measurement of LXA4 serum level was performed by the Enzyme-Linked Immunosorbent Assay (ELISA) technique, and the analysis of FPR2 mRNA expression level was performed by quantitative real-time PCR method. Results: The serum concentrations of LXA4 decreased in AR and NAR patients compared to healthy controls; however, this difference was not statistically significant (P>0.05). Besides, the mRNA expression level of FPR2 in peripheral blood cells of patients with nonallergic rhinitis was significantly lower than that in allergic rhinitis (P<0.05). Conclusion: Our results suggest that reduced gene expression of FPR2 may contribute to developing persistent and chronic nasal mucosa inflammation seen in NAR patients. Therefore, stable analogs of LXA4 and its receptor agonist may help develop new therapeutic approaches for rhinitis.