Hypersensitivity

Question 1

1. sensitisation in early life-exposed to antigen–> Th2 cytokines produced –> B cells produce IgE
2. Provocation= second exposure to antigen –> cell releases inflammatory mediators eg histamine

Atopy/Allergy

Answer 1

Type 1

Question 2

IgG/IgM antibodies against exogenous/external antigens/derived from “self”-sometimes difficult to separate from autoimmunity

Tissue damage through:
compliment activation
FC binding of immunogobulin+stimulation of phagocytes
antibody dependent cellular toxicity
effects on target cell function

Answer 2

Type 2

Question 3

abnormal deposition of formed antigen/antibody complexes (immune complexes) in tissues

complexes precipitate out of bloodstream and into tissues, causing inflammation : systemic illness (serum sickness)/ localised disorder

Answer 3

Type 3

Question 4

delayed type
Th1 cells + their cytokine products (interleukin-2/interferon)
Immune system struggles to destroy-immune response causing tissue damage

Answer 4

Type 4