The T helper (Th)1/Th2 balance. Th1 cytokines, characterized by the production of interferon (IFN)-γ and interleukin (IL)-6, are involved in cellular immunity and immunoglobulin class switching to the IgG2a isotype, whereas Th2 cytokines, characterized by IL-4 and IL-10, are mainly associated with humoral immunity and immunoglobulin class switching to IgG1 and IgE. Th1 cells are the primary Th1 cytokine producing cells. Besides, natural killer (NK) cells and macrophage also contribute to the production of Th1 cytokines. Similarly, Th2 cells produce the most Th2 cytokines in addition to mast cells and basophils. TNF-α denotes tumor necrosis factor alpha.
