Immunology

Question 1

what are the cells of the innate immune system

Answer 1

phagocytes

Nk cells

Question 2

what are the cells of the acquitted/adaptive immune system

Answer 2

B cells

T cells

Question 3

what immune cells target bacteria

Answer 3

phagocytes
antibodies and b lymphocytes
complement

Question 4

what immune cells target viruses

Answer 4

t lymphocytes

antibodies and b lymphocytes

Question 5

what immune cells target fungi

Answer 5

phagocytes
t lymphocytes
eosinophils

Question 6

what immune cells target protozoa

Answer 6

eosinophils

t lymphocytes

Question 7

what immune cells target worms

Answer 7

eosinophils

mast cells

Question 8

what are the physical barrier to infection

Answer 8

skin

• antimicrobial secretions from keratinocytes
• sebaceous/sweat glands
• antigen presenting cells in skin

mucosa

• antimicrobial substances. eg. lysozyme
• IgA
• Gastric acid

Question 9

what are some risk factors to impaired barrier function in skin

Answer 9

eczema 
psoriasis 
erythoderma 
tine pedis (athletes foot)/ cracking of skin 
ulcers/pressure sores

Question 10

risk factors to impaired barrier function in the lungs

Answer 10

cystic fibrosis
COPD
poor swallow

Question 11

risk factors to impaired barrier function GI

Answer 11

Impaired bladder function

urinary stasis

Question 12

what do phagocytes do

Answer 12

ingest organisms following opsonisation

kill via oxygen killing or independent mechanisms

control bacteria and fungi

Question 13

what conditions cause phagocytes deficiency

Answer 13

haematological malignancy

cytotoxic chemotherapy

Question 14

hat are the 2 types of helper T cells

Answer 14

helper T cells

cytotoxic T cells

Question 15

what causes T cell deficiencies

Answer 15

HIV pneumonia
Lymphoma
Primary immunodeficiency syndromes

Question 16

what do B cells do

Answer 16

mature into plasma cells and produce immunoglobulins

Question 17

what do immunoglobulins protect against

Answer 17

recognised antigens also

opsonise microbes for ingestion by phagocytes

Question 18

what is the firs immunoglobulin to be produces

Answer 18

IgM- Has a weak affinity so does not bind very strongly to pathogen

Question 19

what is the most abundant immunoglobulin

Answer 19

IgG - produced after IgM - much stronger affinity

Question 20

where are B cell deficiencies seen

Answer 20

myeloma
primary immune deficiency syndromes
certain immune suppressants

Question 21

what cells are infected by HIV

Answer 21

CD4+ T lymphocytes

Question 22

what does HIV cause a high risk of

Answer 22

invasive pneumococcal disease irrespective of CD4 count

Question 23

what is hyposplenism

Answer 23

decreased spleen function

Question 24

what causes hyposplenism

Answer 24

splenectomy 
functional hyposplenism (sickle cell anaemia, cirrhosis, coeliac disease)

Question 25

what does reduced spleen function cause susceptibility to

Answer 25

encapsulated organisms strep pneumoniae haemophilus influenzae neisseria meningitidis

Question 26

what is the aim of immunosuppression

Answer 26

to reduce the damage caused to the body by the immune system

Question 27

when are immunosuppressive drugs used

Answer 27

autoimmune conditions transplants cancers

Question 28

what are the side effects of immune suppression

Answer 28

- blunted response to stimulus - do not have normal symptoms and signs of infection - often lower threshold for treatment

Question 29

what do steroids increase the risk of

Answer 29

a wide range of infections particularly fungal infections

Question 30

what does anti-TNFa therapy increase the risk of

Answer 30

mycobacterium tuberculosis | fungal infections

Question 31

what do purine analogues increase the risks of

Answer 31

viral infections | pneumoncystitis jirovecci

Question 32

when are prophylaxis given in immunosuppression

Answer 32

HIV - cotrimoxazole | Bone marrow transplant

Question 33

describe the immune response in sepsis

Answer 33

disordered immune response to inflammation cause inappropriate immune activation and inflammatory cascade unchecked inflammation leads to organ dysfunction

Question 34

what causes cardiovascular dysfunction in sepsis

Answer 34

hypotension due to wide spread vasodilation leading to fall in peripheral resistance needs fluid resuscitation

Question 35

what causes pulmonary dysfunction in sepsis

Answer 35

endothelial injury with lung tissue/capillar leak diffuse alveolar oedema respiratory failure, needing supplemental oxygen

Question 36

what causes renal dysfunction in sepsis

Answer 36

acute kidney injury, a rise in urea/creatine due to hypoperfusion

Question 37

what causes CNS dysfunction in sepsis

Answer 37

delirium/acute confusion due to cerebral hypoperfusion drowsy, decreased conscious level

Question 38

what causes lactic acidosis in sepsis

Answer 38

diffuse tissue hypoperfusion leads to anaerobic metabolism and lactic acid production causing acidosis