Hypersensitivity (Ch. 11) Flashcards
Define Type I immediate hypersensitivity
Mechanisms of tissue injury
What Ab involved?
Th 2 cells, IgE, mast cells, eos
Vasoactive amines etc. from mast-cell derived mediators
Cytokine derived mediators and inflammation from eos, nop, lymphocytes
Define Ab mediated Type II hypersensitivity
What Ab involved?
IgM, IgG against cell surfaces
Define Immune Complex mediated Type III hypersensitivity
Immune complexes of circulating Ag and IgM or IgG deposited in vascular membrane
Define T-cell mediated (delayed) Type IV hypersensitivity
T-cells against epithelial cells
Type I hypersensitivity usually involves what Ab
What is another name for this
Aka allergies
Involves IgE
What is the characteristic response of Late Phase Rx
Cytokines from T-cells that recruit Nop and Eos to site of Rx over several hours
What cytokine causes Ig switching
IL-4/IL-13
What are the three responses to Type I hypersensitivity
Rapid release of granules
Synthesis and secretion of lipid mediators
Cytokines
What is the major amine that is released with Type I responses
Histamine - dilation of BV
What do proteases causes and what releases them
Causes damage to local tissue
Released by granules
What do prostaglandins do
Vascular dilation
Released from lipid mediators
What do leukotrienes do and what releases them
Smooth muscles contraction
Released by lipid mediators
What do cytokines do in Type I hypersensitivity
Local inflammation and activation of late-stage response
What happens in hay fever
Mast cells produces histamine and Th2 produces IL-13 which increases Mucus production
What happens in food allergies
Mast cells degranulate which increases histamine and thus peristalsis
