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
What happens in bronchial asthma
Mast cells release leukotrienes which increase smooth muscle contraction
What is the treatment for anaphylaxis
Epi 1:1,000 0.3mg
What is the treatment for bronchial asthma
Corticosteroids - reduce inflammation
Leukotriene antagonists - relax bronchial smooth muscles
Phosphodiesterase inhibitors - relax bronchial smooth muscles
What does cromolyn do
Inhibits mast cell degranulation
What does autoimmune hemolytic anemia target and by what mechanism
Erthyrocyte membrane proteins (Rh) by Opsonmization and phagocytosis of erythrocytes
What does Goodpasture syndrome target and by what mechanisms
Targets non collagenous proteins in basement membrane of kidney glomeruli and lung alveoli by complement and Fc receptor mediated inflammation which causes nephritis and lung hemorrhage
What does Graves disease target and by what mechanisms
TSH receptors by Ab-mediated stimulation of TSH receptors which causes hyperthyroidism
What does myasthenia gravis target and by what mechanism
AcH receptor which inhibits AcH binding which causes muscle weakness and paralysis
