Hypersensitivity Flashcards

1
Q

What are hypersensitivity reactions?

A

Excessive immune responses that cause damage

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What antigens can cause hypersensitivity reactions?

A

Infectious agents
Environmental substances
Self antigens

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

What is a common causative organism of hypersensitivity?

A

Influenza virus

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

What environmental substances can cause hypersensitivity?

A

Dust - mimics parasites

Nickel

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

What is type I hypersensitivity?

A

Mediated through degranulation of mast cells and eosinophils
Effects are felt within minutes of exposure
Essentially allergy

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What is atopy?

A

Allergy

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What are clinical features of atopy?

A
Anaphylaxis
Angioedema
Urticaria
Rhinitis
Asthma
Dermatitis, eczema
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What is an allergen?

A

An antigen that triggers an allergic reaction

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

What is the hygiene hypothesis?

A

Increase in allergies in developed world is caused by reduced exposure to microorganisms in early life

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What is type II hypersensitivity?

A

Antibody mediated hypersensitivity
IgM or IgG reacting with antigen present on surface of cell
Bound Ig interacts with complement or with Fc receptor on macrophages
Opsonisation of target cells
Immune mediated haemolysis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

How long does type II hypersensitivity take to happen?

A

Several hours

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What are examples of antibodies affecting cell function?

A

Grave’s disease
Pernicious anaemia
Myasthenia gravis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What is type III hypersensitivity?

A

Immune complex disease
Immune complexes of antigen and antibody form and cause damage at site of production or circulate and cause damage elsewhere
Failure of phagocytes to clear immune complexes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

What are examples of human immune complex-mediated diseases?

A

Systemic lupus erythematosus
Polyarteritis nodosa
Poststreptococcal glomerulonephritis
Serum sickness

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

What is type IV hypersensitivity?

A

Slowest form of hypersensitivity
Mediated by T cells
2-3 days to develop
Delayed hypersensitivity

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

What conditions are caused by type IV hypersensitivity?

A
Rheumatoid arthritis
Multiple sclerosis
Type I DM
IBD
Psoriasis
17
Q

What is the main component causing damage in type IV hypersensitivity?

A

Tumour necrosis factor

18
Q

How is type IV hypersensitivity treated?

A

Prevention through avoiding antigens
Anti-inflammatories - NSAIDs, corticosteroids, Drugs that block TNF and IL-6, antibodies against B cells
Immunosuppressive drugs