Interleukin-4 gene polymorphisms confer Behcet's disease in Turkish population

Several cytokine genes may play crucial roles in host susceptibility to Behcet's Disease (BD), because the cytokine production capacity varies among individuals and depends on the cytokine gene polymorphisms. The association of the IL-4 and IL-4R alpha gene polymorphisms with the susceptibility to BD was investigated in this study. DNA samples were obtained from a Turkish population of 97 patients with BD and 76 healthy control subjects. All genotyping (IL-4 and IL-4R alpha) experiments were performed using PCR sequence-specific primers. When compared with the healthy controls, the frequency of IL-4 -1098 TG and -590 CT genotypes was higher in the patients with BD. Analysis of allele frequencies showed that IL-4 -1098 G and IL-4 -590 T alleles were more common in the patients with BD when compared with healthy controls. Also, IL-4 TTC and haplotypes were found to confer BD. Interestingly, we demonstrated that IL-4R alpha gene polymorphism seems to be associated with the Pathergy test positivity in patients with BD. Our data suggest that IL-4 gene promoter polymorphisms may affect susceptibility to BD and increase risk of developing the disease. However, in order to confirm and assess the association of IL-4 and IL-4R alpha gene polymorphisms with the BD, large cohort studies are needed.