Association of Interleukin-18 gene polymorphism -137G/C with Allergic rhinitis

The interleukin-18 (IL-18) gene on chromosome 11 has been suggested as a susceptibility factor for allergies. It is a member of the IL-1 family that was originally described as interferon (IFN-γ)–inducing factor. IL-18 might initiate Th2 responses with production of IgE via the stimulation of IL-4 and IL-13 synthesis in mast cells and in basophil and eosinophil recruitment, such as allergic inflammation. This study was done to assess the association of Interleukin-18 gene polymorphism -137G/C with allergic rhinitis. This case-control study was performed on 293 allergic rhinitis patients and 218 healthy control volunteers. The IL-18 polymorphism was analyzed by polymerase chain reaction and restriction fragment length polymorphism (PCR-RFLP) analysis. The frequency of the GG, GC and CC genotypes were 64.2%, 32.1% and 3.7% in healthy controls and 60.1%, 35.5% and 4.4% in allergic rhinitis patients, respectively. This diference was not significant. This study suggests that IL-18 polymorphism gene -137G/C may not be participated as a risk factor in the pathogenesis of allergic rhinitis.