7 - transplantation

Question 1

define rejection?

Answer 1

damage done by the immune system to a transplanted organ

Question 2

define autologous transplant?

Answer 2

tissue returning to the same individual after a period outside the body, usually in a frozen state

Question 3

define syngeneic transplant?

Answer 3

transplant between identical twins; there is

usually no problem with graft rejection i.e. isograft

Question 4

define allogenic transplant?

Answer 4

takes place between genetically nonidentical members of

the same species; there is always a risk of rejection

Question 5

define cadaveric transplant?

Answer 5

uses organs from a dead donor

Question 6

define xenogenic transplant?

Answer 6

takes place between different species and carries the highest risk of rejection

Question 7

3 criteria which must be met for solid organ transplant?

Answer 7

good evidence that damage is irreversible, alternative treatments are not applicable, disease must not recur

Question 8

4 examples of solid organ transplant?

Answer 8

skin, heart, kidney, cornea

Question 9

problem with solid organ transplants?

Answer 9

rejection

Question 10

4 ways in which rejection is minimised in solid organ transplants?

Answer 10

ABO compatible donor, recipient must not have anti-donor HLA antibodies,
donor should have closest possible match for HLA, patient must have immunosuppressive treatment

Question 11

name 5 cadaveric transplants?

Answer 11

cornea, liver, kidney, pancreas, heart

Question 12

name 3 live transplants?

Answer 12

liver, kidney, stem cells

Question 13

2 indications for liver transplant?

Answer 13

alcoholic liver disease, 1y biliary cirrhosis

Question 14

indication for kidney transplant?

Answer 14

renal failure

Question 15

2 indications for stem cells transplant?

Answer 15

malignancy, haematologic conditions

Question 16

when does hyperacute rejection occur?

Answer 16

within hours of transplant

Question 17

what causes the graft to be destroyed by vascular thrombosis in hyperacute rejection?

Answer 17

antibody binding to ABO group/ HLA class I antigens causes type II hypersensitivity reaction

Question 18

how can hyperacute rejection be prevented?

Answer 18

careful ABO/ HLA cross-matching

Question 19

what type of reaction is acute rejection?

Answer 19

type IV delayed hypersensitivity reaction

Question 20

when does acute rejection take place?

Answer 20

within days/ weeks of transplant

Question 21

main cause of acute rejection?

Answer 21

HLA incompatibility

Question 22

what is the survival of the kidney related to?

Answer 22

the degree of mismatching, especially at the HLA-DR loci

Question 23

2 phases of graft rejection?

Answer 23

afferent phase and efferent phase

Question 24

describe the afferent phase of graft rejection?

Answer 24

donor MHC molecules on ‘passenger leucocytes’ within the graft are recognised by the recipient’s CD4+ T cells = allorecognition

Question 25

describe the efferent phase of graft rejection?

Answer 25

CD4+ T cells recruit effector cells responsible for the tissue damage of rejection; macrophages, CD8+ T cells, NK cells and B lymphocytes

Question 26

when does chronic rejection take place?

Answer 26

months/ years after transplant

Question 27

how does chronic rejection occur?

Answer 27

allogenic reaction is mediated by T cells - results in repeated acute rejection

Question 28

what type of disease can cause chronic rejection?

Answer 28

autoimmune disease

Question 29

what drugs prevent rejection?

Answer 29

immunosuppressive drugs

Question 30

-ve aspect of immunosuppressive drugs?

Answer 30

lack the specificity - therefore prevent immune responses to other infectious agents

Question 31

kidney transplant - final checks?

Answer 31

donor's B cells are mixed with patient's serum to cross match the samples

Question 32

3 sources of stem cells?

Answer 32

bone marrow, peripheral blood, cord blood

Question 33

what are haematopoietic stem cells used for?

Answer 33

used to restore myeloid and lymphoid cells

Question 34

what is the risk of autologous stem cell transplants compared with allogenic stem cell transplants and why?

Answer 34

autologous stem cells transplants are less of a risk - due to GVHD.

Question 35

name 3 circumstances where allogenic stem cell transplant is carried out?

Answer 35

hematologic malignancy, myeloid cell production is reduced, SCID

Question 36

what occurs during conditioning?

Answer 36

Destroy the recipient’s stem cells and allows the engraftment of donor cells

Question 37

what is GVHD?

Answer 37

graft versus host disease

Question 38

when does GVHD occur?

Answer 38

when donor T cells respond to allogeneic recipient antigens

Question 39

what prevents GVHD?

Answer 39

immunosuppressants

Question 40

what 2 organs does chronic GVHD affect?

Answer 40

skin, liver

Question 41

name 2 ways in which corticosteroids are used as immunosuppressives in terms of rejection?

Answer 41

at low doses - to prevent early stages of graft rejection, | at high doses - to treat episodes of rejection

Question 42

which 2 drugs are used in T-cell signalling blockade?

Answer 42

cyclosporine and tacrolimus

Question 43

name 2 monoclonal antibodies used for blocking the IL-2 receptor?

Answer 43

basiliximab, daclizumab

Question 44

what is rapamycin used to treat?

Answer 44

used to prevent graft rejection - does so by blocking IL-2 receptor

Question 45

what are antiproliferatives used for?

Answer 45

to stop DNA production and prevent lymphocyte proliferation

Question 46

why do antiproliferatives cause bone marrow suppression - i.e. myelotoxicity?

Answer 46

they are not specific for T cells

Question 47

name 5 possible side effects of cyclosporin?

Answer 47

infections (bac, vir, fun), nephrotoxicity, increased risk of certain cancers, hypertension, diabetes

Question 48

name 5 possible side effects of rapamycin?

Answer 48

raised lipid/ cholesterol levels, hypertension, anaemia, diarrhoea, acne

Question 49

most common transplant?

Answer 49

kidney

Question 50

name 3 antiproliferatives?

Answer 50

Azathioprine, mycophenolate | mofetil, methotrexate