Overview
Hypersensitivity reactions are exaggerated or inappropriate immune responses to an antigen that cause tissue damage. Following Gell and Coombs they are divided into four types: type I (immediate, IgE), type II (antibody-mediated cytotoxic), type III (immune complex) and type IV (delayed, T cell-mediated).
- Immunopathology involves pathological immune responses that lead to disease.
- It occurs when the immune system is inadequate, inappropriate, or misdirected.
- This often results in tissue damage.
- Immunopathology 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.
- Hypersensitivity Reactions (Allergies) are exaggerated or inappropriate immune responses against an antigen (allergen). They happen when a person previously exposed to an antigen has a 'hypersensitive' reaction upon subsequent exposure. There are four main types.