Immune system T cell-mediated delayed-type hypersensitivity

Delayed-type hypersensitivity (DTH), also known as Type IV hypersensitivity, is an immune response where sensitized T cells (primarily CD4+ Th1 cells and CD8+ cytotoxic T cells) recognize antigen in the context of MHC molecules on antigen-presenting cells, leading to cytokine release, recruitment of monocytes and macrophages, and subsequent local tissue inflammation and injury. DTH is a key mechanism in a variety of diseases, including contact dermatitis, autoimmune disorders, certain drug eruptions, chronic transplant rejection, and the immune response to some pathogens such as Mycobacterium tuberculosis. Unlike other hypersensitivity reactions, it is not mediated by antibodies but by cell-mediated immune mechanisms and typically develops over 24–72 hours following antigen exposure[1][2][4].

Other names

Delayed-type hypersensitivityType IV hypersensitivityT cell-mediated hypersensitivityCell-mediated hypersensitivity

Inhibition of T-cell activation and cytokine production (for corticosteroids and immunosuppressants) Inhibition of local inflammatory response