Purpose: To evaluate whether variations in the IL1B gene could be associated with Graves' ophthalmopathy (GO) in patients with Graves' disease (GD).
Method: This case-control study included 471 Taiwan Chinese patients with GD (200 with GO and 271 without GO) and 160 healthy volunteers. Eight single-nucleotide polymorphisms (SNPs) in IL1B were genotyped with an allele-specific extension and ligation assay.
Results: In the IL1B SNPs examined, the C allele of rs1143634 was associated with GD, whereas the T/T genotype of the SNPs rs1143634 and rs16944 were less associated with the disease. The A/A genotype of the SNPs rs3917368 and rs1143643, which had the strongest interaction, may increase the risk of GO (P = 0.024 and P = 0.017, respectively). Several GD susceptibility and insusceptibility IL1B haplotypes have been identified, and the Ht4-GCGCCTCC haplotype, composed of eight SNPs and associated with low circulating IL1β levels, may be protective against the development of GO (P = 0.025). Moreover, that the GO-susceptible genotype was associated with lower plasma IL1β concentrations implies that the origin of GO may go beyond the IL1B polymorphism-associated elevation of circulating IL1β.
Conclusions: The data for IL1B polymorphisms and the association of GD and GO with plasma IL1β levels show that IL1B polymorphisms may be associated with the development of GD and GO.