CS: Immunology

Question 1

HLA-A3

Answer 1

haemochromatosis

Question 2

HLA-B51

Answer 2

Behcet’s disease

Question 3

HLA-B27

Answer 3

ankylosing spondylitis
reactive arthritis
acute anterior uveitis

Question 5

HLA-DQ2/DQ8

Answer 5

coeliac disease

Question 6

HLA-DR2

Answer 6

narcolepsy
Goodpasture’s
2 sleeping in goodpastures

Question 7

HLA-DR3

Answer 7

dermatitis herpetiformis
Sjogren’s syndrome
primary biliary cirrhosis

Question 8

HLA-DR4

Answer 8

DM 1
RA- in particular the DRB1 gene

Question 9

What are Interferons (IFN)

Answer 9

Interferons (IFN) are cytokines released by the body in response to viral infections and neoplasia.

Question 10

DiGeorge syndrome inheritance and SX

Answer 10

AD, deletion of a section of chromosome 22
C - Cardiac abnormalities
A - Abnormal facies
T - Thymic aplasia
C - Cleft palate
H - Hypocalcaemia/ hypoparathyroidism
22 - Caused by chromosome 22 deletion

Question 11

Hypersensitivity where:
Antigen reacts with IgE bound to mast cells
Examples

Answer 11

Type I - Anaphylactic
* Anaphylaxis
* Atopy (e.g. asthma, eczema and hayfever)

Question 12

Hypersensitivity where:
IgG or IgM binds to antigen on cell surface
Examples (7)

Answer 12

Type II - Cell bound
* Autoimmune haemolytic anaemia
* ITP
* Goodpasture’s syndrome
* Pernicious anaemia
* Acute haemolytic transfusion reactions
* Rheumatic fever
* Pemphigus vulgaris / bullous pemphigoid

Question 13

Hypersensitivity where:
Free antigen and antibody (IgG, IgA) combine
(3 examples)

Answer 13

Type III - Immune complex
Serum sickness
* SLE
* Post-streptococcal glomerulonephritis
* Extrinsic allergic alveolitis (especially acute phase)

Question 14

Hypersensitivity where:
T-cell mediated (7)

Answer 14

Type IV - Delayed hypersensitivity
* Tuberculosis / tuberculin skin reaction
* Graft versus host disease
* Allergic contact dermatitis
* Scabies
* Extrinsic allergic alveolitis (especially chronic phase)
* MS
* GBS

Question 15

hypersensitive where:
Antibodies that recognise and bind to the cell surface receptors.

This either stimulating them or blocking ligand binding

Answer 15

Graves’ disease
* Myasthenia gravis

Question 16

Mnemonic for hypersensitivity reactions

Answer 16

Question 17

Overview of hypersensitivity types mediators, onset

Answer 17

Question 18

IgG
what proportion of serum antibodies?
type of molecule?
what is the role?

Answer 18

75%
Monomer
Enhance phaGocytosis of bacteria and viruses.

Question 19

IgA
what proportion of serum antibodies?
type of molecule?
what is the role?

Answer 19

15%
Mono+Dimer
Found in secretions, provide localized protection on mucous membranes

Question 20

IgM
what proportion of serum antibodies?
type of molecule?
what is the role?

Answer 20

10%
Pentamer
first to be secreted, anti-A, B blood antibodies → Blood Transfusion

Question 21

IgD
what proportion of serum antibodies?
type of molecule?
what is the role?

Answer 21

1%
Monomer
Involved in activation of B cells

Question 22

IgE
what proportion of serum antibodies?
type of molecule?
what is the role?

Answer 22

0.1%
Monomer
Involved in allergic reactions

Question 23

Interferon/IFN-alpha
- Receptors
- produced by
- useful in 4

Answer 23

Interferon-alpha
- bind to type 1 receptors
- produced by leucocytes
-useful in:
—hepatitis B & C,
—Kaposi’s sarcoma,
—metastatic renal cell cancer,
—hairy cell leukaemia
flu-like symptoms and depression

Question 24

Interferon/ IFN-beta
bind to
produced by
useful in (1)

Answer 24

bind to type 1 receptors
produced by fiBroblasts
reduces the frequency of exacerbations in patients with relapsing-remitting MS

Question 25

Interferon INF -gamma -bind to - predominately from cells weaker antiviral action, more of a role in immunomodulation particularly macrophage activation

Answer 25

**INF -gamma** -type 2 receptors -predominately NK cells & T helper cells -weaker antiviral action, more of a role in immunomodulation particularly macrophage activation

Question 26

What are Interferons (IFN)

Answer 26

Interferons (IFN) are cytokines released by the body in response to viral infections and neoplasia. They are classified according to cellular origin and the type of receptor they bind to

Question 27

Skin prick test uses

Answer 27

Useful for food allergies and also pollen

Question 28

Radioallergosorbent test (RAST) used for

Answer 28

food allergies, inhaled allergens (e.g. Pollen) and wasp/bee venom - used when skin prick tests are not suitable, e.g. extensive eczema or if the patient is taking antihistamines

Question 29

Patch testing use for

Answer 29

dermatitis. Around 30-40 allergens are placed on the back. Irritants may also be tested for. The patches are removed 48 hours later with the results being read by a dermatologist after a further 48 hours

Question 30

What are T-helper 1 cells involved in and what do they secrete?

Answer 30

Th1 - involved with cell mediated response (type 4 hypersensitivity) secrete IFN-gamma, IL-2, IL-3

Question 31

What are T-helper 2 cells involved in and what do they secrete?

Answer 31

Th2 - involved with humoral (antibody) immunity secrete IL 4/5/6/10/13

Question 32

Complement deficiencies; what is the effect C1 inhibitor deficiency C3 def C5 def C5-9 def

Answer 32

C1 inh deficiency - hereditary angiodema C3 deficiency - recurrent bacterial infections C5 deficiency - Leiner disease (severe seborrheic dermatitis, diarrhoea, infections) C5-9 def - encodes the membrane attack complex (MAC) prone to N.meningitidis infection