Theme 4: Core Immunology Flashcards
What is being described?
Undesirable, damaging, discomfort-producing, and sometimes fatal reaction produced by the normal immune system directed against innocuous antigens in a pre-sensitized host.
Allergy/hypersensitivity
Which type of hypersensitivity reaction is cell mediated?
Type 4 (delayed type)
Hay fever is an example of which type of hypersensitivity reaction?
Type 1
Goodpasture’s is an example of what type of hypersensitivity reaction?
Type 2 (cytotoxic, IgG, IgM reaction to cell surface antigen)
What is the pathogenesis of a type II hypersensitivity reaction?
IgG/IgM response against self/foreign antigen at the cell surface.
Leads to complement activation, phagocytosis and antibody-dependent cellular cytotoxicity (ADCC).
Leads to cell lysis and necrosis.
Penicillin is a common trigger for what type of hypersensitivity reaction?
Type II
Erythroblastosis fetalis is associated with which type of hypersensitivity reaction?
Type II
What condition is being described?
Rh- mother who does not experience Rh+ antigen until childbirth (if child is Rh+).
Subsequent pregnancy with Rh+ baby can result in haemolysis in unborn/neonatal child.
Erythroblastosis fetalis
An example of a Type II hypersensitivity reaction
Which type of hypersensitivity reaction is being described?
IgG/IgM antibody against soluble antigen - immune complex deposition.
Type III
Clinical features:
- Onset 3-8 hours
- Vasculitis
Which of the following is not associated with Type III hypersensitivity?
a) Serum sickness
b) Cell lysis
c) IgG
d) IgM
e) Systemic lupus erythematosus
b) Cell lysis
This is associated with type II reactions
Farmer’s lung is associated with which type of hypersensitivity reaction?
Type III
Occurs as a result of inhaling the agent from mouldy hay.
A lady presents with an area of inflamed and painful skin over her hypogastric region.
She started wearing a new belt a few days ago but other than that there doesn’t seem to be anything significant.
What type of hypersensitivity reaction is this likely to be?
Type IV hypersensitivity
Metals (e.g. nickel) are common antigens. She has most likely had a delayed reaction to the metal in her new belt buckle.
T cells mediate this type of reaction
What mediates type IV hypersensitivity reactions?
Antigen-specific T cell mediated cytotoxicity
Contact dermatitis is associated with which hypersensitivity reaction?
Type IV (delayed-type)
Which antibody increases in response to a parasitic infection?
IgE
The IgE are specific to the pathogen
