Introduction
This topic covers autoimmunity and autoimmune diseases: the terms, immune tolerance (central and peripheral, regulatory T cells and other regulatory mechanisms), the causes and mechanisms by which autoimmunity develops, the organ-specific and systemic forms, and the part played by hypersensitivity reactions.
Terms: immunopathology, autoimmunity and autoimmune disease
- Immunopathology involves pathological immune responses that lead to disease. It occurs when the immune system is inadequate, inappropriate or misdirected, often resulting in tissue damage. It includes hypersensitivity disorders, immune deficiency diseases and autoimmune diseases.
- Clinical symptoms of infections can arise from excessive host immune responses; immune reactions can both protect and potentially damage host health. Cellular immunopathology results from excessive T-cell responses against low-cytopathogenicity infections or allogenic organ transplants.
- Autoimmunity is the immune system's ability to identify its own healthy cells.
- Autoimmune diseases are caused by the immune system's inability to differentiate between self- and non-self antigens; the immune system destroys healthy cells. They stem from a failure of tolerance.