title: Association of susceptibility to brucellosis and interleukin-4 promoter polymorphism.
abstract: A C-T substitution at position 590 in the interleukin-4 (IL-4) gene is associated with increased production of IL-4. We sought to determine the associations between this polymorphism and susceptibility to brucellosis. DNA was extracted from the whole blood of 163 control individuals and 282 patients with brucellosis. A polymorphism in the IL-4 gene at position 590 from the promoter site was determined using an allele-specific PCR method. The prevalence of the T allele of IL-4 polymorphism was significantly higher in the patients group than in controls (28.9% vs 11.4%, p<0.004). Patients with brucellosis had a higher frequency of intermediate producer genotype (CT) (53.5% vs 22.7%, p<0.001) while low producer genotype (CC) was higher in the control group (77.3% vs 44.4%). Multiple logistic regression analysis demonstrated that patients who were heterozygous (CT) for interleukin-4 promoter polymorphism had a significantly higher risk for brucellosis with an odds ratio of 4.2 (95% CI 2.7-6.6, p<0.0001). Our findings demonstrate for the first time an association between IL-4 590 promoter polymorphism and contracting brucellosis in the Iranian population.
authors.affiliation: Department of Internal Medicine, Hamedan University of Medical Sciences, Hamedan, Iran.
authors.forename: Mehdi
authors.initials: M
authors.lastname: Rezazadeh
authors.forename: Mehrdad
authors.initials: M
authors.lastname: Hajilooi
authors.forename: Mehran
authors.initials: M
authors.lastname: Haidari
authors.forename: Alireza
authors.initials: A
authors.lastname: Rafiei
authors.forename: Seyed Ahmad
authors.initials: SA
authors.lastname: Alavi
authors.forename: Fariba
authors.initials: F
authors.lastname: Keramat
mesh_terms: D000328:Adult; D002002:Brucella / Q000472:pathogenicity*; D002006:Brucellosis / Q000235:genetics / Q000276:immunology*; D016022:Case-Control Studies; D005260:Female; D020022:Genetic Predisposition to Disease; D005838:Genotype; D006801:Humans; D015847:Interleukin-4 / Q000235:genetics*; D008297:Male; D008875:Middle Aged; D016017:Odds Ratio; D011110:Polymorphism, Genetic / Q000235:genetics* / Q000276:immunology; D011401:Promoter Regions, Genetic / Q000235:genetics* / Q000276:immunology
chemical_list: C508598:IL4 protein, human; D015847:Interleukin-4