Cytokines play a key
role in the
regulation of immune and inflammatory responses. Therefore,
cytokine genes are potentially related to susceptibility to
Graves' disease (GD). The aim of this study was to investigate the putative functional polymorphisms within
tumor necrosis factor-alpha (
TNF-alpha),
tumor necrosis factor-beta (
TNF-beta),
interferon-gamma (IFN-gamma), and
interleukin-1 receptor antagonist (
IL-1Ra)
genes, in
patients with GD (n = 137) compared to a healthy
Thai control group (n = 137). The results showed no statistically significant difference between the study groups for
TNF-beta (Ncol site in
intron 1), IFN-gamma (+874 in
intron 1), and
IL-1Ra (variable numbers of
tandem repeats in
intron 2)
gene polymorphisms. Only the -863A
allele within the
promoter region of the
TNF-alpha gene, which may
affect the affinity of the promoter nuclear factor (NF)-kappab interaction, was found to be increased in GD
patients compared to the controls (p = 0.009, OR = 1.8, 95% CI = 1.15 to 2.84). The effect of the -863A
allele of the
TNF-alpha gene was
similar to the autosomal dominance mode of inheritance (p = 0.01, OR = 2, 95% CI = 1.16 to 3.44). This polymorphism may be involved in the susceptibility to GD in part through its higher promoter activity of
TNF-alpha production.