Immunology 1: Hypersensitivity, allergy and inflammation

Question 1

What is the primary mediator in type 1 hypersensitivity reactions?

Answer 1

IgE

Question 2

Give 3 examples of type 1 hypersensitivity reactions

Answer 2

Asthma
Allergic rhinitis
Eczema

Question 3

Recall the pathophysiology of a type 1 hypersensitivity reaction

Answer 3

1. Sensitisation: IgE binds mast cells and basophills

2. 2nd exposure: More IgE , cross-links –> degranulation

Question 4

What is the primary mediator in type 3 hypersensitivity reactions?

Answer 4

Immune complexes

Question 5

Give 2 examples of type 3 hypersensitivity reactions

Answer 5

SLE

Vasculitis

Question 6

Recall the pathophysiology of a type 3 hypersensitivity reaction

Answer 6

Immune complex formed
Cannot traverse vessel walls
Deposition in various tissues

Question 7

What is the primary mediator in type 2 hypersensitivity reactions?

Answer 7

Antibodies

Question 8

Which immunoglobins are associated with type 3 hypersensitivity reactions

Answer 8

IgG

IgM

Question 9

Recall the pathophysiology of a type 2 hypersensitivity reaction

Answer 9

Ab responds to a cell-surface or matrix-bound antigen

Question 10

Give 3 examples of type 2 hypersensitivity reactions and the antigens implicated in each case

Answer 10

1. Glomerular BM = glomerulonephritis
2. AChRs = myasthenia gravis
3. Intrinsic factor = pernicious anaemia

Question 11

Recall 2 tests that can be used to detect type 2 hypersensitivity

Answer 11

Need to look for specific antibody:
Immunofluorescence
ELISA

Question 12

In what disease is the ani-CCP antibody implicated?

Answer 12

Rheumatoid arthritis

Question 13

What is the primary factor involved in type 4 hypersensitivity reactions?

Answer 13

T cells

Question 14

Give 4 examples of type 4 hypersensitivity reactions

Answer 14

Chronic graft reaction
Coeliac
Graft-vs-host disease
Allergy (asthma, eczema etc BECOME type 4 chronically)

Question 15

Recall the pathophysiology of type 4 hypersensitivity reactions

Answer 15

1. T cells stimulated by Ag
2. Macrophages and CD8+ T cells activated
3. Th1 –> IF gamma
4. Th2 –> B cell activation –> IL4,5,13
5. TNF-alpha release causes tissue damage

Question 16

Recall the 6 main mediators involved in inflammation

Answer 16

Histamine
Leukotrienes
Interleukins
Complement
TNF-alpha
Interferons

Question 17

In which type of hypersensitivity reaction is angiodema a key feature?

Answer 17

type 1

Question 18

In which type of hypersensitivity reaction is urticaria a key feature?

Answer 18

type 2

Question 19

What is urticaria and by which Ig is it mediated?

Answer 19

Hives - IgG

Question 20

Define “atopy”

Answer 20

Hereditary tendency to develop hypersensitivity reactions

Question 21

Recall 2 genetic factors that predispose to atopy

Answer 21

1. IL4 gene cluster (lead to raised IgE, asthma)

2. IgE receptor gene on 11q

Question 22

How does gender influence risk of atopy?

Answer 22

In children: more males

In adults: more females

Question 23

What is the main interleukin released by eosinophil degranulation?

Answer 23

Il-5

Question 24

Recall 3 features of the immunopathogenesis of asthma

Answer 24

1. SMC hypertrophy
2. Mucus plugging
3. Subepithelial fibrosis following persistent inflammation

Question 25

What is the proper name for "hay fever"?

Answer 25

Allergic rhinitis

Question 26

Recall 3 clinical features of anaphylaxis

Answer 26

1. Swelling of lips and throat 2. Wheeze and dyspnoea 3. D&V

Question 27

Recall 3 tests that can be used to investigate hypersensitivity

Answer 27

1. Skin-prick testing 2. RAST 3. Total IgE

Question 28

What is RAST?

Answer 28

Rasioallerosorbent test - tests for the amount of a specific IgE in the blood

Question 29

What is the main lung function test used to diagnose asthma?

Answer 29

Peak expiratory flow

Question 30

Recall the immediate treatments used for mild and severe anaphylactic reactions

Answer 30

Mild: anti-histamine Severe: adrenaline

Question 31

Recall the 3 main therapies used in allergic rhinitis

Answer 31

1. Cromoglycate (mast-cell stabiliser) 2. Nasal steroid 3. Anti-histamine

Question 32

Recall the 2 main therapeutic approaches in eczema

Answer 32

1. Emolliants | 2. Topical steroid

Question 33

Summarise the 4 steps of asthma treatment

Answer 33

1. Salbutamol 2. Beclomethasone 3. Longer-acting beta-2 agonist than salbutamol 4. Prednisolone

Question 34

Recall the standard length of a subcutaneous course of immunotherapy

Answer 34

3 years