Immunology Flashcards Preview

Transition block > Immunology > Flashcards

Flashcards in Immunology Deck (41):
1

What are SPUR features?

Serious infections
Persistent infections
Unusual infections
Recurrent infections
(Clinical features suggestive of immunodeficiency)

2

Commonest form of severe combined immunodeficiency

X-linked SCID

3

Underlying immuno-pathophysiology of X-linked SCID

IL-2 receptor mutation; inability to produce T cells and NK cells

4

Clinical presentation of X-linked SCID (4)

Unwell by 3 months old
Persistent diarrhoea
Failure to thrive
Infections of all types

5

Organised collection of activated macrophages and lymphocytes

Granuloma

6

Key mediators in granuloma formation (3)

IL-12 released by macrophages
gIFN produced by T-cells
TNF

7

Granulomatous conditions (3)

Sarcoidosis
Tuberculosis
Silicosis and other dust diseases

8

Manifestations of antibody dysfunction (2)

Recurrent bacterial infections
Antibody-mediated immune diseases

9

Examples of antibody deficiencies (2)

Common variable immune deficiency (CVID)
Selective IgA deficiency

10

What is Bruton's agammaglobulinaemia?

An X-linked primary deficiency of antibody production where patients have no B cells

11

Causes of secondary hypogammaglobulinaemia (2)

Protein loss e.g. nephrotic syndrome
Lymphoproliferative disease e.g. myeloma

12

Type I hypersensitivity

IgE-mediated e.g. anaphylaxis

13

Type II hypersensitivity

Antibody-mediated direct cell-killing, e.g. autoimmune haemolytic anaemia

14

Type III hypersensitivity

Immune complex-mediated e.g. SLE

15

Type IV hypersensitivity

Delayed type, T-cell mediated e.g. graft versus host disease

16

How can antibody lead to direct cell killing? (3)

Activation of complement via the classical pathway leading to:
a) opsonization (optimises phagocytosis)
b) formation of the membrane attack complex, causing lysis
c) recruitment of other immune cells

17

What activates the alternative complement pathway?

LPS on microbial surfaces

18

What does complement deficiency predispose to?

Bacterial infection especially meningitis

19

What types of cell do NK cells target? (2)

Cells which lack MHC molecules on surface; especially viruses and cancer cells

20

What are Toll-like receptors? (2)

Receptors on phagocytes providing innate recognition of pathogens; activation leads to release of pro-inflammatory cytokines

21

What are adalimumab and etanercept? What is their mechanism of action?

TNF-inhibitors used in chronic inflammatory conditions such as rheumatoid arthritis and Crohns disease. Inhibit TNF, thus preventing release of pro-inflammatory cytokines

22

What is the main risk/side effect of adalimumab?

Reactivation of tuberculosis

23

Mechanism of hyperacute graft rejection

Type II hypersensitivity- pre-formed antibody and complement activation

24

Timescale and mechanism of acute graft rejection

5-30 days; Type IV hypersensitivity (T cells)

25

What is the drug target of cyclosporin?

Calcineurin. Inhibition helps prevent lymphocyte activation

26

What is the first antibody to be produced in the immune response?

IgM

27

Vaccination stimulates the production of...

Memory T cells

28

Main types of vaccine

Inactivated vaccines
Live attenuated vaccines

29

Disadvantages of inactivated vaccines (2)

Require multiple/booster injections
Require adjuvants to boost immunogenecity

30

Constituents of the 5-in-1 vaccine

Diphtheria
Tetanus
Pertussis
Polio
HiB

31

What type of vaccine is the 5-in-1? When is this given?

Inactivated vaccines. 8, 12 and 16 weeks
(at 3 years and 4 months, given again minus HiB)
(at 14 years given again minus HiB and pertussis)

32

Advantages of live attenuated vaccines (3)

Elicits antibody and T cell responses
Gives strong response
Usually only one dose required

33

Example of a live attenuated vaccine given at one year

MMR

34

How does the lectin pathway of complement work?

Proteins such as MBL coat sugars on the surface of bacteria, thus activating the complement cascade and helping the bacteria be eliminated

35

Why is the "5-in-1" vaccine given at 3 months, 4 months and 3 years?

In order to boost immunity- 5-in-1 vaccine are inactivated and hence have poor immunogenecity

36

How do live attenuated vaccines work?

pathogen is made virulent, but is still live and replicating, and hence is a good immunogen

37

Which antibody is mostly generated during secondary exposure to a pathogen?

IgG
(there is also smaller levels of IgM)

38

How does IgA selective deficiency usually present?

Most are asymptomatic and will not be detected

39

The main risks of TNF inhbitors is are...

Granulomatous infections, fungal infections

40

Anti-TNFs represent a form of...

Passive immunisation

41

How does imiquimod work?

Activates TLR-8 in macrophages/dendritic cells, leading to activation of these cells. In skin cancer (BCC) it increases infiltration of immune cells into the skin, where they can detect abnormal cancer cells