Lecture 4 Transplantation

Question 1

Define autologous transplant

Answer 1

Refers to tissue returning to the same individual after a period outside of the body

Question 2

Define Syngeneic transplant

Isograft

Answer 2

Transplant between identical twins

Question 3

Define Allogeneic transplant

Answer 3

takes place between genetically nonidentical members of the same species; there is always a risk of rejection.

Question 4

Define cadaveric transplantation

Answer 4

Uses organ from dead donor

Question 5

Define Xenogeneic transplant

Answer 5

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

Question 6

What is the criteria for solid organ transplant

Answer 6

Evidence that damage is irreversible
Alternative treatments are not applicable
Disease must not recur

Question 7

What precautions are carried out to reduce risk of rejection (4)

Answer 7

Donor and recipient must be ABO compatible
Recipient must have anti-donor HLA antibodies
Donor should be close HLA match
Patient must take immunosuppressive treatment

Question 8

Define hyper-acute rejection

Answer 8

Rejection within hours of transplantation

Antibody binding triggers a type II hypersensitivity reaction

Question 9

Define acute rejection

Answer 9

Type IV

Takes place within days or weeks of transplantation

Question 10

Describe the afferent phase of the immunopathology of graft rejection

Answer 10

Donor MHC molecules on dendritic cells are recognised by recipients CD4+ T cells (allorecognition)

Question 11

Describe the efferent phase of the immunopathology of graft rejection

Answer 11

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

Question 12

Define chronic rejection

Answer 12

Rejection takes place months or years after transplant

Question 13

Name the 2 main tissue typic techniques

Answer 13

HLA typing
HLA cross matching with B cells (express class I and class II HLA)

Question 14

When is allogenic stem cell transplant carried out?

Answer 14

Haem malignancy
Aplastic anaemia
SCID

Question 15

What are the sources of stem cells

Answer 15

Bone marrow
Peripheral blood
Cord blood

Question 16

How is a patient prepared prior to receiving stem cells

Answer 16

High dose chemo and radiotherapy

Destroy recipients stem cells

Question 17

What is Graft versus Host Disease

Answer 17

Occurs when donor T cells respond to allogenic recipient antigens

Question 18

How do corticosteroids work as immunosuppressive drugs

Answer 18

Act on APC at low doses

Direct effect on T cells at higher doses

Question 19

How do T-cell signalling blockades work as immunosuppressives (Cyclosporine and Tacrolimus)

Answer 19

Work by interacting with proteins in the intracellular T-cell signalling cascade

Question 20

Why does IL-2 blockade immunosuppress

Answer 20

Activated T cells secrete IL-2 which binds to receptors on neighbouring T cells and stimulates division

Question 21

How doe antiproliferatives immunosuppress

Answer 21

Inhibit DNA production

Question 22

Name examples of anti-proliferatives

Answer 22

Azathioprine
Mycophenolate
Mofetil
Methotrexate

Question 23

What are the side effects of cyclosporin

Answer 23

Increased infections
Increase risk of getting certain cancers
Nephrotoxic
Diabetes
Hypertension

Question 24

What are the side effects of Rapamycin

Answer 24

Raised lipid and cholesterol level 
Hypertension
Anaemia
Diarrhoea
Rash
Acne
Thrombocytopenia