immunology

Question 1

physiological conditions causing a secondary immune deficiency

Answer 1

extremes of life
- ageing
- prematurity

Question 2

infections causing a secondary immune deficiency

Answer 2

HIV
measles

Question 3

treatment interventions causing a secondary immune deficiency

Answer 3

immunosuppressive therapy
anti-cancer agents
corticosteroids

Question 4

malignancy causing a secondary immune deficiency

Answer 4

cancer of the immune system- lymphoma, leukaemia, myeloma
metastatic tumours

Question 5

biochemical and nutritional disorders

Answer 5

malnutrition
renal insufficiency/dialysis
type 1 and type 2 diabetes
specific mineral deficiencies eg iron, zinc

Question 6

what is a granuloma

Answer 6

an organised collection of activated macrophages and lymphocytes

Question 7

what can trigger the formation of a granuloma

Answer 7

non-specific inflammatory response triggered by diverse antigenic agents or by inert foreigh materials

Question 8

how is a granuloma formed

Answer 8

the triggered response results in activation of T lymphocytes and macrophages
failure of removal of the stimulus results in persistent production of activated cytokines
end result is organised collection of persistently activated cells

Question 9

differential diagnosis of lung granuloma

Answer 9

sarcoidosis
mycobacterial disease (TB, leprosy)
berylliosis, silicosis and other dust diseases
chronic stage of hypersensitivity pneumonitis
foreign bodies

Question 10

presentation of antibody deficiencies

Answer 10

recurrent bacterial infection (recurrent respiratory tract infections, GI infections)
antibody mediated autoimmune diseases
- idiopathic thrombocytopaenia
- autoimmune haemolytic anaemia

Question 11

common primary antibody deficiences

Answer 11

Common variable immune deficiency
selective IgA deficiency

Question 12

what is common variable immune deficiency

Answer 12

low IgG, IgA and IgM
recurrent bacterial infections esp respiratory
often associated with autoimmune disease

Question 13

what is selective IgA deficiency

Answer 13

very common
2/3rd individuals are asymptomatic
1/3rd have recurrent respiratory tract infections
genetic component

Question 14

Hypogammaglobulinaemia

Answer 14

reduced serum immunoglobulin levels

Question 15

primary causes of recurrent bacterial infections and hypogammaglobulinaemia

Answer 15

antibody deficiency
- common variable immune deficiency
- specific antibody deficiency
other conditions, rare in adults (bruton’s agammaglobunaemia)

Question 16

secondary differential diagnoses of recurrent bacterial infections and hypogammaglobulinaemia

Answer 16

protein loss
- protein losing enteropathy
- nephrotic syndrome
failure of protein synthesis
- lymphoproliferative disease (chronic lymphocytic leukaemia, myeloma, NHL)

Question 17

function of natural killer cells

Answer 17

kill cells that lack MHC (molecules on surface)
- no need for antigen specifity
no long term memory
part of innate immunity

Question 18

moa of biologic drugs

Answer 18

most are artificial antibodies that block the body’s own proteins
so they act just like passive immunisation and have to be injected every couple of weeks

Question 19

what is adalimub

Answer 19

targets anti-TNF
is an antiinflammatory
used in rheumatic and inflammatory diseases

Question 20

what is pembrolizumab

Answer 20

acts of anti-PD1
activates T cells
used against cancer

Question 21

what is secukinumab

Answer 21

acts on anti-interleukin 17
main action: blocks one inflammation pathway
used in psoriaisis, arthritis, MS

Question 22

types of transplant rejection

Answer 22

hyperacute rejection
acute cellular rejection
acute vascular rejection
chronic allograft failure

Question 23

pathology of hyperacute rejection

Answer 23

takes minutes to hours to show
thrombosis and necrosis
type II hypersensitivity

Question 24

management of hyperacute rejection

Answer 24

none

Question 25

pathology of acute cellular rejections

Answer 25

5-30 days
cellular infiltration
type IV hypersensitivity
CD4 and CD8, T cells

Question 26

treatment of acute cellular rejection

Answer 26

immunosuppression

Question 27

advantages of inactivated vaccines

Answer 27

can be made quickly
elicit good antibody responses
easy to store
usually safe

Question 28

disadvantages of inactivated vaccines

Answer 28

not very potent
- doesnt stimulate clonal expansion of B and T cells > requiring multiple injections

Question 29

how are neutrophils attracted to site

Answer 29

by release of cytokines (TNFa)

Question 30

complement system activation

Answer 30

antigen-antibody binding called C1 complex which in turn activate C3 convertase

Question 31

alternative pathway

Answer 31

C3b production leads to more C3 convertase activation
- C3b binds to pathogen surface and associates with other complement proteins, forming C5 convertase

Question 32

what are C3b and C5b

Answer 32

proinflammatory mediators

Question 33

what can happen with a complement deficiency

Answer 33

predisposes to bacterial infections (esp meningitis)

Question 34

what are TLRs

Answer 34

toll like receptors
- respond to PAMPS
- expressed on phagocytes and dendrites as built-in burglar alarm for microbes

Question 35

outcome of TLR activation

Answer 35

pro-inflammatory cytokines and type 1 interferon secretion

Question 36

TLR dysfunction

Answer 36

can lead to immunodeficiency (too little)
autoimmunity (too much)

Question 36

TLR dysfunction

Answer 36

can lead to immunodeficiency (too little)
autoimmunity (too much)

Question 37

what is TNF alpha

Answer 37

immediate early fire alarm signal response to many stressors

Question 38

how to vaccinations work

Answer 38

produce memory in B cells and T cells
long lived memory B cells are generated during primary immune responses that can survive for many years even after the antigen has been eliminated
memory B cells rapidly re-activate in response to second encounter with that specific antigen
(clonal expansion, differentiated into plasma cells, antibody production)