A condition wherein a person has diminished ability to exhibit delayed T-cell hypersensitivity reaction to antigens because of a condition or situation resulting in altered immune function. When referring to inability to react to a skin test, the correct term is cutaneous anergy. Skin tests for anergy (i.e., control antigens) have poor predictive value and are not recommended.
the loss or weakening of immune response to an irritating agent or antigen. Anergy can be thought of as the opposite of allergy, which is an overreaction to a substance. The strength of the immune response is often quantitatively evaluated by standardized skin tests. A small amount of solution containing an antigen known to cause a response, such as tetanus, mumps, or candida, is injected under the skin and the area checked for a localized skin reaction after 48 to 72 hours. Healthy people will develop a measurable area of redness at the injection site; people who are immune suppressed, such as people with AIDS, will have no measurable response to these skin tests.
A state of immune unresponsiveness. Induced when the T cell's antigen receptor is stimulated, effectively freezing T cell responses pending a "second signal" from the antigen-presenting cell. The delivery of the second signal by the antigen-presenting cell rescues the activated T cell from anergy, allowing it to produce the lymphokines necessary for the growth of additional T cells. See the entire definition of Anergy
A state of unresponsiveness, induced when the T cell's antigen receptor is stimulated, that effectively freezes T cell responses pending a "second signal" from the antigen-presenting cell ( co-stimulation).
Anergy is a theory in immunobiology that describes a lack of reaction by the body's defence mechanisms to foreign substances, and consists of a direct induction of peripheral lymphocyte tolerance. A state of anergy often indicates that the immune system is unable to mount a normal immune response against a specific antigen, usually a self-antigen.