Immunology Hypersensitivity Flashcards
Which of the following doesn’t describe hypersensitivity?
A) exaggerated immune responses to harmless environmental antigens
B) exaggerated immune responses to infections
C) inappropriate immune response to auto-antigens
D) appropriate response to an antigen
D
What type is cytolytic hypersensitivity?
Type 2
What type is anaphylactic hypersensitivity?
Type 1
What type is immune-complex mediated hypersensitivity?
Type 3
What type is delayed hypersensitivity?
Type 4
What type is cell mediated hypersensitivity?
Type 4
What type is immediate hypersensitivity?
Type 1
Penicillin allergy is what type
1
What antibody mediates type 1?
IgE
Cells of type 1
Mast cells and eosinophils
——————— is when a patient forms large amounts of IgE to certain harmless antigens instead of forming a low amount ?
Sensitisation type 1
What kind of receptor do IgE molecules bind to ?
fC receptors
T/F: 1st exposure to an allergen = sensitization of Mast cells & Basophils
True
What occurs in the re exposure stage of type 1 ?
Antigen binds 2 adjacent IgE molecules on
mast cells (cross-linking)
Degranulation of mast cells
release granules and mediators
Describe Preformed mediators:
Histamine and platelet activating factor (PAF) ◦
Responsible for symptoms seen during the Early phase, (within 15-20 minutes of exposure to the allergen).
Describe Newly formed mediators:
leukotrienes and prostaglandins, take several hours to be synthesized, typically occurs 5-6 hours after allergen contact symptoms seen during the Late phase are the same as those of the early phase, but persist longer.
T/F: late phase can lead to tissue damage due to hydrolytic enzymes
False late phase
Which of the following is a symptom of systemic anaphylaxis
A) urticaria
B)conjunctivitis
C) bronchoconstriction
D) Bronchial asthma
C
T/F: Systemic anaphylaxis occurs on sensitisation to a harmless antigen ie insect venom
False occurs on re exposure
How to diagnose type 1 ?
- skin test
- measurement of serum levels
First line of management of type 1 (excluding anaphylactic shock) ?
Avoidance
Type 2 hypersensitivity antibodies ?
IgG and IgM
Type of Hypersensitivity that reacts to cell bound antigens ?
Type 2
ADCC is a mechanism of which type ?
2
Complement activation is a mechanism of which type ?
2
Opsonisation of target cell is a mechanism of which type ?
2
Altered signalling is a mechanism of which type of hypersensitivity?
Type 2
Transfusion reactions are examples of which type of hypersensitivity
2
Hemolytic disease of the newborn is an example of which type of hypersensitivity?
Type 2
Drug reactions are which type of hypersensitivity
Type 2
Autoimmune hemolytic anemia
Type
2
Graves’ disease is which type
2
T/F: small insoluble immune complexes may escape phagocytosis
Soluble
Escaped immune complexes are usually found in :
Sites of turbulence like joints and kidneys
Post-streptococcal glomerulonephritis is an example of
Type 3
Systemic lupus erythematosis is a what type
3
Which if the following is not a diagnostic mechanism for type 3 hypersensitivity?
A) tissue biopsies for deposits of Ig and complement by immunofluorescence.
B)depleted immune complexes in serum
C) detection of immune complexes in serum
D) depleted serum complement
B
Which type of hypersensitivity is not antibody mediated ?
Type 4
Main cell in type 4 hypersensitivity?
Th1
Which type of hypersensitivity requires previous exposure ?
All
What Th1 sectretion causes the activation of macrophages?
IFN-γ
Tuberculin skin test (TST) is type
4
T/F:A positive reaction to the Tuberculin skin test is erythema of the area
Induration not erythema
Granulation is what type?
4
Contact dermatitis is what type ?
4
Skin patch test is for what disease?
Contact dermatitis
Skin test is for what disease ?
Type one hypersensitivity
Insulin dependent diabetes type
4
