An immune response directed against the body’s own cells, tissues, or molecules.
An autoimmune reaction occurs when immune cells or antibodies recognize components of the body as targets and respond against them. Under normal circumstances, the immune system develops mechanisms of self-tolerance that prevent most immune responses against the body’s own tissues.
Autoimmune reactions can contribute to autoimmune diseases when they are persistent or cause significant tissue damage. They may involve antibodies, T lymphocytes, or other components of the immune system and can affect one organ or multiple organs.
COMMONLY CONFUSED WITH
- Allergic reaction: an immune response directed against an external substance that is generally harmless to most people.
- Autoimmune disease: a disease resulting from persistent or clinically significant autoimmune responses; an autoimmune reaction does not necessarily mean that a person has an autoimmune disease.
SEE ALSO