Decreased Gene Expression of Lipoxin A۴ Receptor May Contribute to Nonallergic Rhinitis Pathogenesis

Background: Rhinitis is a prevalent chronic inflammatory illness of the nasal mucosa. Arachidonic acid-derived lipoxin A۴ (LXA۴) has long been recognized to exert crucial antiinflammatory and pro-resolving effects on inflammatory responses through a specific receptor named LXA۴ receptor/formyl peptide receptor-۲ (ALX/FPR۲). This study aimed to determine the serum level of LXA۴ and the relative mRNA expression level of FPR۲ in peripheral blood cells of patients with rhinitis (allergic and nonallergic) compared to healthy individuals. Materials And Methods: The study groups consisted of ۳۷ patients with Allergic Rhinitis (AR), ۱۶ patients with Nonallergic Rhinitis (NAR), and ۲۰ sex- and age-matched healthy individuals. The measurement of LXA۴ serum level was performed by the Enzyme-Linked Immunosorbent Assay (ELISA) technique, and the analysis of FPR۲ mRNA expression level was performed by quantitative real-time PCR method. Results: The serum concentrations of LXA۴ decreased in AR and NAR patients compared to healthy controls; however, this difference was not statistically significant (P>۰.۰۵). Besides, the mRNA expression level of FPR۲ in peripheral blood cells of patients with nonallergic rhinitis was significantly lower than that in allergic rhinitis (P<۰.۰۵). Conclusion: Our results suggest that reduced gene expression of FPR۲ may contribute to developing persistent and chronic nasal mucosa inflammation seen in NAR patients. Therefore, stable analogs of LXA۴ and its receptor agonist may help develop new therapeutic approaches for rhinitis.

Keywords:

Allergic rhinitis , Inflammation , Omega-۶ fatty acid , Lipoxin A۴ , Formyl peptide receptor-۲