Hypersensitivity Flashcards
Atopic Allergies are a what to what?
Heritable Predisposition to Environmental Antigens
Name the two phases of hypersensitivity
Sensitisation Phase
Elicitation Phase
What happens in the sensitization phase?
First exposure to antigen = IgE production
Proliferation of T/B cells / memory
IgE sensitize MC
What happens in the elicitation phase?
Memory T/B produce IgE
MC degranulate
Type 1 Hypersensitivity is stimulated by what?
What receptor does IgE bind to on MC after Il-4 stimulation to cause MC degranulation
Haptens / Proteins / Asthma molecules
FCeR1
What else (3) is released from MC? What do these do?
Chymase - Inflammation
Tryptase- Mucous Secretion
N-CFA = chemoattractant (neutrophils)
The skin prick test is used for what hypersensitivity ?
What does it produce within 20 minutes?
Hypersens 1
Zone of Erythema + Localized Wheal
What test is used to detect circulating IgE to known antigen?
RAST
Immunotherapy of type 1 involves an injection of what and how is it done?
What shift is seen?
Intradermal dilute injection of antigen
IgA/IgG production = competition
Th2 –> Th1
What drug is given to decrease circulating IgE + decrease FCeR1 density on MC for type 1
Omalizumab
What is a MC stabalizer>
Cromolyn Sodium
What bacteria causes a releases of IFN-Y which does what which is beneficial for type 1?
Mycobacterium TB
Releases IFN-Y from T cells = Inhibits Class Switching
In type 3 hypersens, what deposits?
What does this activate
Soluble antigen-AB complexes
Classical Complement
What is found on RBC that removes these complexes found in type 3?
CR1
What is attracted to these complexes and what causes it (complement)?
Polymorfs
C5a
