Cytokine promoter polymorphisms in Taiwanese patients with Graves' disease

Objectives:This study aimed to examine the association between promoter polymorphisms of Th1 and Th2 cytokine genes [interleukin-4 (IL-4 T-34C, A-81G, C-285T and T-589C), IL-6 (G-174C), IL-10 (A-592C and T-819C) and tumour necrosis factor-alpha (TNF-α G-238A and G-308A)] and Graves' disease (GD) in Taiwanese population.Design and methods:Genomic DNA was extracted from peripheral blood cells of 137 GD patients and 189 control subjects. Cytokine gene polymorphisms were analyzed by polymerase chain reaction and restriction fragment length polymorphism.Results:Genotype frequencies of TNF-α G-238A or G-308A between control and GD subjects were significantly different. Frequencies of the high TNF-α secreting alleles (-238*A and -308*A) and IL-10 -819*C allele were significantly increased in GD patients. No significant differences regarding IL-4 or IL-6 gene polymorphisms between GD patients and control subjects were found.Conclusions:Our data demonstrated that TNF-α G-238A and G-308A genotypes were strongly associated with GD incidence.