L15: Hypersensitivity Flashcards
Agent and symptoms of Type I hypersensitivity:
IgE
itching, rash, anaphylactic shock
Agent and symptoms of Type II hypersensitivity:
IgM, IgG
massive hemolysis, anemia, kidney failure
Agent and symptoms of Type III hypersensitivity:
IgG
serum sickness, kidney failure
Agent and symptoms of Type IV hypersensitivity:
TDTH, TH1, TC, macrophages
contact dermatitis
Activation of adenyl cyclase produces:
cAMP
Activation of phospholipase C produces:
DAG and PIP2
The release of Ca2+ from the ER has several effects:
a. synthesis of prostaglandins and leukotrienes
b. assembly of microtubules and microfilaments at the cortex
c. fusion of granule (vesicle) with the plasma membrane.
How do you trigger degranulation?
Cross-linking two high affinity receptors bound to the Fc of the IgE with an allergen activates the tyrosine kinases associated on the cytoplasmic sid
What’s released in degranulation?
- Histamine
- prostaglandins
- luekotrienes
- cytokines
Histamine
- increases smooth muscle contraction of intestine and bronchioles
- increases permeability of venules
- increases mucus secretion by goblet cells
prostaglandins
- synthesized after granule release from arachandoic acid
- bronchoconstrictor
leukotrienes
- synthesized after granule release from arachandoic acid
- does everything histamine does only more strongly and longer
cytokines
- promote inflammatory responses by eosinophils and neutrophils
- TNF-α may also induce shock.
Type I clinical conditions include:
- anaphylactic shock
- Allergic rhinitis
- food allergies
- asthma
How does epinephrine work?
reduces vascular permeability, relaxes smooth muscles, increase cardiac output, and raises cAMP levels, blocks further degranulation.
Type II clinical conditions include:
- Blood transfusion mismatches
- Rh incompatibility
- drug-induced hemolytic anemia
Type III clinical conditions include:
- caused by build up of antigen-antibody complexes
- arthritis
- kidney damage
- clotting
- serum sickness
- autoimmune diseases
Type IV clinical conditions include:
- granulomas (like in TB and leprosy)
- contact dermatitis
- graft rejection