152 - Transplants

Question 1

Autograft

Answer 1

Graft from one body part to another, in one individual

Question 2

Isograft

Answer 2

Between genetically identical individuals (EG monozygotic twins

Question 3

Allograft

Answer 3

Between different members of the same species

Question 4

Xenograft

Answer 4

Between members of different species (EG porcine heart valves)

Question 5

Syngeneic

Answer 5

Identical twins

Question 6

Immunogenicity against sequential grafts

Answer 6

First graft, if not MHC matched, will be rejected.
If there is a second graft from the same donor, the graft will be rejected much more quickly (secondary response of the immune system)

Question 7

What mediates transplant rejection?

Answer 7

T cells

Question 8

Chromosome on which HLA genes are

Answer 8

Chromosome 6

Question 9

Most important HLAs for graft acceptance

Answer 9

A, B and DR are more important than C, DP and DQ

Question 10

Australian renal transplant waiting list

Answer 10

1500 patients

Question 11

Types of rejection
1
2
3

Answer 11

1) Antibody-mediated
2) Acute
3) Chronic

Question 12

Antibody-mediated rejection mediators

Answer 12

Preformed anti-donor antibodies and complement

Question 13

Acute rejection mediators

Answer 13

T-cells (primary activation)

Question 14

Chronic rejection mediators

Answer 14

Unclear. Antibodies, immune complexes, slow cellular reaction, recurrence of disease.

Question 15

Groups who can have anti-HLA antibodies
1
2
3

Answer 15

1) Blood recipients
2) Pregnancy
3) Transplant

Question 16

Immunological and non-immunological causes of chronic rejection

Answer 16

Immunological: Acute rejection Non-immunological: Viruses: Ischaemia-reperfusion injury

Question 17

Ischaemia-reperfusion injury

Answer 17

When an organ is removed, put on ice and then transplanted. This is damaging to organ, and might lead to it being rejected

Question 18

Intimal fibrosis in kidneys, liver and lungs in transplant rejection

Answer 18

Kidney: Chronic allograft nephropathy
Liver: Vanishing bile duct syndrome
Lungs: Bronchiolitis obliterans syndome

Question 19

Ways to prevent allograft rejection
1
2
3

Answer 19

• Matching ABO antigens (not just expressed on erythrocytes)
• Matching MHC alleles
• Immunosuppressive drugs

Question 20

First drug that could immunosuppress in allografts

Answer 20

Azathioprine

Question 21

More modern immunosuppressants in grafts

Answer 21

Cyclosporine.

Prednisolone.

Question 22

Effect of cyclosporine

Answer 22

Kills recently-activated T-cells (calcineurin inhibitor).

Downregulates IL-2 expression.

Question 23

Side effect of cyclosporine

Answer 23

Nephrotoxicity

Question 24

Azathioprine effects
1
2
3

Answer 24

• Antiproliferative (azathioprine, mycophenalate, rapamycin)
• Inhibit DNA and RNA synthesis
• Blocks IL-2 production and lymphocyte expansion

Question 25

Organ regeneration
1
2
3
4
5

Answer 25

1) Take donor lung
2) Decellularise with detergent
3) Establish acellular vasculature, airways and alveoli
4) Seed scaffold with epithelial and endothelial cells
5) Perfuse and ventilate in bioreactor