Decreased serum level of lipoxin A4 (LXA4) may contribute to the pathogenesis of allergic rhinitis

Rhinitis is a prevalent chronic inflammatory disease of the nasal mucosa. Arachidonic acid-derived lipoxin A4 (LXA4) has long been recognized to exert crucial anti-inflammatory and pro-resolving effects on inflammatory responses through a specific receptor named formyl peptide receptor-2 (FPR2). This study aimed to determine the serum level of LXA4 as well as the relative mRNA expression level of FPR2 in peripheral blood cells of patients with rhinitis (allergic and non-allergic) compared to healthy individuals.

The study groups consisted of 37 patients with allergic rhinitis (AR), 16 patients with non-allergic 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.

The serum levels of LXA4 were significantly decreased in AR patients relative to healthy controls (P<0.05). However, there was no significant difference in the mRNA expression level of FPR2 in peripheral blood cells of patients with rhinitis compared to healthy controls.

Our results suggest that reduced serum levels of LXA4 in AR patients may contribute to developing persistent and chronic nasal mucosa inflammation. Therefore, LXA4 or its analogs may help the rational development of new therapeutic approaches for allergic rhinitis.