Immunology

Question 0

What are some common causes of secondary immunodeficiency?

Answer 0

Age extremes
HIV
Immunosuppression/Chemo/Radiotherapy/Steroids
Malignancy
Malnutrition

Question 1

What kind of infections indicate immune deficiency?

Answer 1

S - serious
P - persistent
U - unusual
R - recurrent

Question 2

What is reticular dysgenesis?

Answer 2

Failure to differentiate along myeloid lineage - failure to produce neutrophils

Question 3

What is Kostmann syndrome?

Answer 3

Severe congenital neutropaenia

Autosomal recessive

Question 4

What brings about leukocyte adhesion deficiency?

Answer 4

Defect in leukocyte integrins (CD18)

Question 5

What are the clinical features of leukocyte adhesion deficiency?

Answer 5

Leukocytosis
Deep tissue infections
No pus

Question 6

What causes a chronic granulomatous disease?

Answer 6

Failure of oxidative killing mechanisms

Question 7

How does a granuloma form?

Answer 7

Organisms are not cleared
Excessive inflammation
Persistent lymphocyte and phagocyte accumulation

Question 8

Clinical features of chronic granulomatous disease?

Answer 8

Recurrent deep infections (staph, aspergillus, pseudomonas, myco)
Failure to thrive
Lymphadenopathy and hepatosplenomegaly

Question 9

What does the Nitroblue Tetrazolium test test for?

Answer 9

Chronic granulomatous disease

Question 10

What organisms hide from immune cells inside normal cells?

Answer 10

Salmonella
Chlamydia
Rickettsia

Question 11

Where does Mycobacteria hide?

Answer 11

Inside immune cells

Question 12

What infection prophylaxis is used in phagocyte deficiencies?

Answer 12

Co-trimoxazole

Itraconazole

Question 13

What is the role of CD4+ cells?

Answer 13

Immunoregulatory
- Activate CD8+ and B cells
- Produce cytokines
HLA Class ii peptide recognition

Question 14

What is the role of CD8+ cells?

Answer 14

HLA Class i recognition (HLA-A/B/C)
Kill cells directly
- Produce perforin
- Trigger apoptosis
- Secrete INFgamma
Important in viral/tumour defence

Question 15

How are B cells activated?

Answer 15

Encounter antigen in lymph node

Question 16

What is SCID?

Answer 16

Failure of lymphocyte production

Question 17

Clinical presentation of SCID

Answer 17

Unwell by 3 months
Persistent diarrhoea
Infections
Graft vs Host disease
FHx of early infant death

Question 18

What is the commonest form of SCID and how does it present?

Answer 18

X-linked
Very low/absent T cells
Normal/Raised B cells
Poorly developed lymphoid tissue and thymus

Question 19

Patient has:

• Low set ears
• High forehead
• Cleft palate
• Small mouth and jaw
• Hypocalcaemia

Answer 19

DiGeorge syndrome

Question 20

What is type i hypersensitivity?

Answer 20

Immediate hypersensitivity (allergy)

Question 21

What is type ii hypersensitivity?

Answer 21

Direct cell killing

Question 22

What is type iii hypersensitivity?

Answer 22

Immune complex mediated

Question 23

What is type iv hypersensitivity?

Answer 23

Delayed type hypersensitivity

Question 24

What is an allergy?

Answer 24

An IgE-mediated response to external antigen

Question 25

What are the clinical features of Type i allergic disease?

Answer 25

Occurs quickly | Influenced by site of contact

Question 26

What is the pathophysiology of allergic disease?

Answer 26

``` B cells recognise antigen and produce specific IgE T cells help in IgE production Mast cells - IgE binds to FcEpsilon receptors - Release histamine/tryptase/heparin ```

Question 27

What occurs in the inflammatory cascade?

Answer 27

Increased blood flow Smooth muscle contraction Increased vascular permeability Increased mucosal secretions

Question 28

Is angioedema pitting or non-pitting?

Answer 28

Non-pitting

Question 29

What happens in Type ii hypersensitivity?

Answer 29

``` Antibody binds to cell surface Complement activated - Cell lysis - Opsonisation Phagocytosis ```

Question 30

What do IgM and IgG act as in Type ii hypersensitivity?

Answer 30

Opsonins

Question 31

What are some clinical examples of Type ii hypersensitivity?

Answer 31

Transfusion reactions Goopastures syndrome Guillan Barre syndrome

Question 32

How can Type ii hypersensitivity reactions be managed?

Answer 32

Plasmapheresis | Immunosuppression

Question 33

What happens in type iii hypersensitivity?

Answer 33

Antigen binds to autoantibodies -> Immune complex Complexes deposit in small vessels Complement activation Macrophage and neutrophil infiltration

Question 34

What are some examples of type iii hypersensitivity/hypersensitivity pneumonitis?

Answer 34

Farmers lung Bird fanciers lung Malt workers lung Etc

Question 35

What are the symptoms of type iii hypersensitivity reactions and when do they occur?

Answer 35

``` Dry cough Pyrexia SoB Wheeze 4-8 hours after exposure ```

Question 36

Which immune cells mediate Type iv hypersensitivity?

Answer 36

T cells

Question 37

What happens in type iv hypersensitivity?

Answer 37

``` Antigen sensitisation T cell priming Subsequent exposure - Activation of primed T cells - Macrophage, neutrophil and lymphocyte recruitment - Inflammation ```

Question 38

What are the two types of vaccination?

Answer 38

Active | Passive

Question 39

What are the two types of active vaccination?

Answer 39

Live attenuated | Inactive

Question 40

What are the three types of inactive vaccination?

Answer 40

Killed Subunit Toxoid

Question 41

What is passive immunity?

Answer 41

Protection transferred from another person/animal