Figure 2.

Hashimoto’s thyroiditis (HT) is a T-cell-mediated endocrine autoimmune disease. Patients harbor higher thyroid peroxidase antibodies (TPOAb) and TgAb serum levels and thyroid intraglandular infiltration of B and T lymphocytes with CD4+ Th1 subtype predominance. Graves’ disease (GD) is characterized by a prominent Th2-mediated humoral response, which induce the expression of stimulatory antibodies. Vitamin D is able to reduce the proliferation and differentiation of B cells into plasma cells and induce the apoptotic cascade of immunoglobulin. In this context, vitamin D inhibits the Th1 cells proliferation as well as the Th1-mediated cytokines production (IL-2, IFN-γ, and TNFα) and modulates Th2 cells and cytokines production (IL-4, IL-5, and IL-10) inducing Th2 phenotype. Arrows are used to illustrate decreased (↓) or increased (↑) production of specific actions, cells or molecules.