Anergy
Anergy is a hyporeactive type of reactivity usually observed to infectious antigens. It can be specific (immune) and nonspecific – non-immune. With it, there is no hyperreactivity, but there is tolerance to an allergen or immunosuppression after the use of immunosuppressants.
Allergen-specific immuno-mediated anergy is due to hypo- or areactivity to allergens in a patient with allergy and can be immunosuppressive or immunoregulatory. After successful allergen-specific immunotherapy (ASIT), patients remain allergic, but they develop anergy to the allergen. Such anergy differs from pathological anergy, in which there is no response to stimulation with an antigen (infectious or non-infectious) due to a genetically determined lack of response or due to immunosuppression.
Pathological anergy can cause immunodeficiency diseases and infections.
On the other hand, “immunity” which is unsusceptibility to infection, can be also essentially considered anergy. Additional data on the commonality and differences of these concepts is needed.
The anergy of non-immune cells , especially epithelial cells releasing defensins and antibacterial peptides, often leads to immune deficiency and the development of infections.