Both interleukin-23A polymorphism and serum interlukin-23 expression are associated with Graves' disease risk

Two independent Chinese cohorts were used to study the genetic association between the interleukin-23A (IL-23A) gene polymorphism (rs11171806) and susceptibility to Graves' disease (GD). The initial Shanghai cohort consisted of 712 unrelated patients with GD and 705 healthy control subjects, and the replication cohort from Xiamen Island included 433 patients with GD and 410 healthy control subjects. The serum concentration of IL-23 in GD patients was measured significantly higher than in health controls. Moreover in the subgroup analysis, higher concentrations of IL-23 were identified in patients of older age (⩾40 years) and female gender. We also performed an association study with the IL-23 gene polymorphism rs11171806 in both cohorts, in Shanghai cohorts, the frequencies of rs11171806 alleles were strongly different between Graves' disease patients (G 95.7% and A 4.3%) and healthy controls (G 97.7% and A 2.3%) (P=2.6×10(-3), OR=1.93 (95% CI: 1.25-2.97)), and in Xiamen cohorts, the proportion of individuals carrying the A allele of rs11171806 was the same significantly higher in Graves' disease patients than in controls [Graves' disease vs. control, 4.8% vs. 4.3%, OR=2.15 (95% CI: 1.23-3.79), P(allele)=6.3×10(-3)]. The distribution of rs11171806 genotype was also investigated in subgroups according to the age and gender. All of these findings suggested that IL-23 may play an important role in the development of GD, and the IL-23A gene is a genetic risk marker for GD in Han Chinese population.