Increased serum levels of interleukin-17 and transforming growth factor-β in patients with Graves' disease

Graves' disease (GD) is an organ-specific autoimmune disease, characterized by excessive autoantibody levels due to tolerance breakdown of thyroid-specific autoantigens. To determine the role of interleukin-17 (IL-17) and transforming growth factor-ß (TGF-β) in GD, we assessed their serum levels in patients with GD and healthy controls. Thirty patients with hyperthyroidism, goiter, and positive thyroid-stimulating hormone receptor antibody diagnosed as GD, according to the clinical diagnostic criteria for autoimmune thyroid disease. Blood samples were also from 30 healthy individuals matched for age and sex as a control. Serum levels of IL-17 and TGF-ß were by using ELISA. IL-17 and TGF-ß levels (14.43 ± 2.15 pg/mL and 10.44 ± 3.19 pg/mL, respectively) were significantly higher in patients with GD than in controls (7.07 ± 1.45 pg/mL and 4.95 ± 1.35 pg/mL, respectively). However, no correlation between IL-17 and TGF-β level in patients with GD. The elevated serum level of IL-17 and TGF-β in patients with GD reflects Th-2 predominance, which causes increasing of these pro-inflammatory cytokines.