Endocrine Abstracts

Background and aims: Interleukin-12 (IL-12) is a pro inflammatory cytokine, which was suggested to play a key role in the pathogenesis of Th1-cell-mediated autoimmune diseases. The aim of our study was to estimate the association of 1188A/C polymorphism of IL12B gene with the predisposition to Graves’ disease (GD) in Polish population.

Materials and methods: The study was performed in the group consisting of 245 individuals with GD sequentially recruited from the endocrinology outpatient clinic. GD was confirmed on the basis of clinical observation, biochemical criteria of thyrotoxicosis and the presence of TSH receptor antibodies. Two hundred and one healthy volunteers served as the control group. In all subjects A1188C polymorphism in the 3′-UTR region of the IL-12B gene was determined by direct sequencing of the appropriate fragment of IL-12B gene.

Results: In our study the frequencies of 1188C allele and 1188CC genotype were significantly higher in patients with GD in comparison to healthy subject (respectively, 22.1% vs. 16.2%, P=0.027 and 7.7% vs. 1.5%, P=0.003). There were no differences in the distribution of 1188AA and 1188AC genotype IL-12B gene between the studied groups. Furthermore we also observed that frequency of 1188CC genotype was higher in patient with ophtalmopathy in comparison to subject without ophtalmopathy and healthy controls. The frequency of 1188CC IL-12 genotype was also higher among patients, who developed GD before the age of 40 years, when compared to subjects with Graves’ disease onset before age of 40.

Conclusions: We observed that the frequency of 1188CC genotype of IL-12B gene is higher in patients with GD and with ophtalmopathy in comparison to subject without ophtalmopathy and healthy controls. This suggests that 1188A/C polymorphism in IL-12B gene could have a role in predisposition to Graves’ ophthalmopathy.