Transplantation

Question 1

autologous transplant

Answer 1

the transplant tissue is from the same individual e.g. skin graft

Question 2

syngeneic transplant

Answer 2

between twins

Question 3

allogenic transplant

Answer 3

between genetically non-identical members of the same species

Question 4

xenogenic transplant

Answer 4

between different species

Question 5

cadaveric transplant

Answer 5

organs from dead donor

Question 6

what is rejection

Answer 6

when the immune system attacks the transplant

Question 7

what can reduce the risk of rejection

Answer 7

donor and recipient must be AOB compatible close as possible HLA match recipient must not have anti-donor HLA antibodies immunosuppression

Question 8

what is hyperacute rejection

Answer 8

immune system rejects organ/translant within hours

Question 9

pathophysiology of hyperacute rejection

Answer 9

antibodies bind to ABO blood group or HLA class I antigens on the graft type II hypersensitivity reaction is triggered IgG and IgM bind and recruit macrophages and complement system causing cell damage

Question 10

acute rejection

Answer 10

delayed type IV hypersensitivity reaction days-weeksusually due to HLA incompatibility

Question 11

pathophysiology of acute rejection

Answer 11

dendritic cells from donor stimulate an allogenic response in lymph node node releases T cells which target donor organ

Question 12

afferent phase of acute rejection

Answer 12

donor MHC molecules on dendritic cells recognised by patients CD4+ T cells

Question 13

efferent phase of acute rejection

Answer 13

T cell recruit macrophages< NK cells, B cellsgraft is targeted

Question 14

what is chronic rejection

Answer 14

takes place over months/years often mediated by T cells can be caused by pre-existing autoimmune disease

Question 15

role of immunosuppresants in transplants

Answer 15

prevent rejection at the time of the transplant if the drugs are stopped rejection will occur

Question 16

role of corticosteroids in transplants

Answer 16

low dose prevent early stages of rejection target antigen presenting cells at a high dose they can treat rejection

Question 17

how does ciclosporin work

Answer 17

immunosuppressant interacts with proteins in T cell signalling cascade

Question 18

examples of monoclonal antibodies

Answer 18

basiliximab daclizumab

Question 19

role of monoclonal antibodies in transplants

Answer 19

used in acute graft rejection

Question 20

rapamycin mechanism of action

Answer 20

inhibits signals from IL-2 receptor

Question 21

role of rapamycin in transplants

Answer 21

prevents acute graft rejection

Question 22

side effects of rapamycin

Answer 22

raises lipid and cholesterol levels anaemia hypertension rash thrombocytopenia

Question 23

what are anti-proliferatives

Answer 23

drugs that inhibit DNA production

Question 24

anti-proliferatives examples

Answer 24

azathioprine mycophenolate mofetil methotrexate

Question 25

stem cell sources for transplant

Answer 25

bone marrow peripheral bloodcord blood

Question 26

when is stem cell transplantation used

Answer 26

last resort for haematological malignancies primary immunodeficiency severe combined immunodeficiency

Question 27

autologus stem cell therapy

Answer 27

marrow is removed frozen and reinfused after chemotherapy has been given

Question 28

allogenic stem cell therapy

Answer 28

higher risk risk of graft vs host disease

Question 29

what is conditioning for SCT

Answer 29

high dose chemo/radiotherapy to destroy stem cells before new ones are given

Question 30

what is graft vs host disease

Answer 30

multi-system complication of allogenic bone marrow transplantationT cells respond to allogenic recipient antigens

Question 31

what is the billingham criteria

Answer 31

criteria used to diagnose graft vs host disease

Question 32

three requirements to meet the billingham criteria

Answer 32

transplanted tissue has immunologically functioning cells recipient and donor are immunologically differenr recipient is immunocompromised

Question 33

when does acute graft vs host disease happen

Answer 33

within 100 days

Question 34

features of acute graft vs host disease

Answer 34

affects skin, liver, GImaculopapular rashjaundicewatery/bloody diarrhoea nausea vomiting fever

Question 35

features of chronic graft vs host disease

Answer 35

any organ system can be involved scleroderma vitiligo corneal ulcers scleriti dysphagia oral ulcers oral lichenous changes obtructive or restrictive lung disease

Question 36

what drugs would you use in graft vs host disease

Answer 36

immunosuppressants

Question 37

how can hyperacute rejection be triggered in xenotransplantation

Answer 37

humans make antibodies against sugar side chains that they are exposed to in the gut the antibodies can target the organ and activate the complement system