type IV hypersensitivity
Quick Summary
Type IV hypersensitivity, also known as delayed hypersensitivity, is a cell-mediated immune response that does not involve antibodies. Instead, it is primarily caused by the interaction of T cells with antigens. This process takes longer than antibody-mediated reactions, with symptoms typically appearing 18 to 24 hours after exposure to an antigen.
Two common examples of Type IV hypersensitivity are tuberculin-type hypersensitivity and contact hypersensitivity. Tuberculin-type reactions are the basis for tests like the tuberculin test for tuberculosis. Contact hypersensitivity occurs when a sensitizing chemical, such as those found in poison ivy, interacts with skin proteins, leading to inflammation and contact dermatitis. While often inconvenient, Type IV hypersensitivity is also a crucial part of the immune defense against intracellular parasites and may play a role in controlling some tumors.12
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allergyDelayed, or type IV, allergic reactions are caused by the actions of T cells, which take longer to accumulate at the site where the antigen is present than do B-cell antibodies. The allergic responses appear 12 to 24 hours or more after exposure to an appropriate antigen.…
Read MoreDelayed, or type IV, allergic reactions are caused by the actions of T cells, which take longer to accumulate at the site where the antigen is present than do B-cell antibodies. The allergic responses appear 12 to 24 hours or more after exposure to an appropriate antigen.…
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human diseaseAllergiesType IV hypersensitivity, unlike the other reactions, does not involve antibodies but instead is mediated by T cells. In these reactions, also called delayed-type because they arise in a matter of days rather than minutes or hours, T cells either activate a local inflammatory reaction,…
Read MoreType IV hypersensitivity, unlike the other reactions, does not involve antibodies but instead is mediated by T cells. In these reactions, also called delayed-type because they arise in a matter of days rather than minutes or hours, T cells either activate a local inflammatory reaction,…
Read More