7- Hypersensitivity Flashcards
Which hypersensitivity reaction is IgE mediated
Type 1
Describe type 1 hypersensitivity phase 1
sensitisation phase - no clinical signs
allergen exposure via respiratory or skin –> APC capture them which causes naive T cells to differentiate (T helper 2 cells)
Releases cytokines –> B cell proliferation –> IgM to IgE
IgE binds to mast cells
mast cells relocate to near where the allergen was first encountered
Describe type 1 hypersensitivity: phase 2
same allergen encountered
primed IgE coated mast cells bind to antigen –> release of cytoplasmic granules
Pruritis, broncho-constriction, oedema
occurs within 15 mins
Which hypersensitivity type is anaphylaxis an example of
type 1
Which type of sensitivity is atopic dermatitis an example of
type 1
Which hypersensitivity is antibody-mediated ?
type 2
What pathway is activated in hypersensitivty type 2
complement system
In which hypersensitivity type are the antibodies present in circulating blood type 1 or 2
type 2
What type of antibody is present in type 2 hypersensitivity
IgG subtype
Name an example of type 2 hypersensitivity
Myasthenia gravis- deficiency in Ach
Is a neuromuscular disorder
Which type of hypersensitivity reaction involves formulation of immune complexes
type 3 (antigen- antibody)
T/F neutrophils are unable to digest immune complexes
True
Name an example of type 3 hypersensitivity
Equine recurrent airway obstruction
Canine blue eye
Describe type 3 hypersensitivty
-Immune Complex Hypersensitivity
-antigen combines with antibody
- Activates complement system > by-products formed
- Neutrophils
-causes inflammation and tissue destruction
Type 4 hypersensitivity is mediated by
T cell mediated
