Introduction of Interleukin-18 genotype as a risk factor for allergic rhinitis in Chaharmahal va Bakhtiari province

The Interleukin-18 (IL-18) is a member of the IL-1 family. It was originally described as IFN-γ –inducing factor (IGIF), and is known to influence the balance of Th1/Th2 immune response and could induce the allergic rhinitis (AR) expression. The aim of this study was to investigate whether the IL-18 promoter polymorphism (-133 G/C) were associated with AR in Chaharmahal va Bakhtiari province. In this descriptive analytical study, genomic DNA was obtained from the blood samples of 293 AR patients and 218 healthy control volunteers extracted by standard phenol chloroform method. The IL-18 polymorphism was analyzed by polymerase chain reaction and restriction fragment length polymorphism (PCR-RFLP) analysis. The frequency of the GC genotype of the IL-18 gene polymorphism (-133) was greater in allergic rhinitis patients than in control (P<0.05). The rate of increaser distribution was calculated 3.69 by comparing the frequency of the G allele genotype to the genotype a carrier no allele G (CC) in both groups. This study suggests that IL-18 promoter polymorphism (-133 G/C) may be participated as a risk factor in the pathogenesis of AR.