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Year 1 - Respiratory (DP) > Immunology > Flashcards

Flashcards in Immunology Deck (42):
0

What kind of infections indicate immune deficiency?

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

1

What are some common causes of secondary immunodeficiency?

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

2

What is reticular dysgenesis?

Failure to differentiate along myeloid lineage - failure to produce neutrophils

3

What is Kostmann syndrome?

Severe congenital neutropaenia
Autosomal recessive

4

What brings about leukocyte adhesion deficiency?

Defect in leukocyte integrins (CD18)

5

What are the clinical features of leukocyte adhesion deficiency?

Leukocytosis
Deep tissue infections
No pus

6

What causes a chronic granulomatous disease?

Failure of oxidative killing mechanisms

7

How does a granuloma form?

Organisms are not cleared
Excessive inflammation
Persistent lymphocyte and phagocyte accumulation

8

Clinical features of chronic granulomatous disease?

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

9

What does the Nitroblue Tetrazolium test test for?

Chronic granulomatous disease

10

What organisms hide from immune cells inside normal cells?

Salmonella
Chlamydia
Rickettsia

11

Where does Mycobacteria hide?

Inside immune cells

12

What infection prophylaxis is used in phagocyte deficiencies?

Co-trimoxazole
Itraconazole

13

What is the role of CD4+ cells?

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

14

What is the role of CD8+ cells?

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

15

How are B cells activated?

Encounter antigen in lymph node

16

What is SCID?

Failure of lymphocyte production

17

Clinical presentation of SCID

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

18

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

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

19

Patient has:
- Low set ears
- High forehead
- Cleft palate
- Small mouth and jaw
- Hypocalcaemia

DiGeorge syndrome

20

What is type i hypersensitivity?

Immediate hypersensitivity (allergy)

21

What is type ii hypersensitivity?

Direct cell killing

22

What is type iii hypersensitivity?

Immune complex mediated

23

What is type iv hypersensitivity?

Delayed type hypersensitivity

24

What is an allergy?

An IgE-mediated response to external antigen

25

What are the clinical features of Type i allergic disease?

Occurs quickly
Influenced by site of contact

26

What is the pathophysiology of allergic disease?

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

27

What occurs in the inflammatory cascade?

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

28

Is angioedema pitting or non-pitting?

Non-pitting

29

What happens in Type ii hypersensitivity?

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

30

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

Opsonins

31

What are some clinical examples of Type ii hypersensitivity?

Transfusion reactions
Goopastures syndrome
Guillan Barre syndrome

32

How can Type ii hypersensitivity reactions be managed?

Plasmapheresis
Immunosuppression

33

What happens in type iii hypersensitivity?

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

34

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

Farmers lung
Bird fanciers lung
Malt workers lung
Etc

35

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

Dry cough
Pyrexia
SoB
Wheeze
4-8 hours after exposure

36

Which immune cells mediate Type iv hypersensitivity?

T cells

37

What happens in type iv hypersensitivity?

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

38

What are the two types of vaccination?

Active
Passive

39

What are the two types of active vaccination?

Live attenuated
Inactive

40

What are the three types of inactive vaccination?

Killed
Subunit
Toxoid

41

What is passive immunity?

Protection transferred from another person/animal