Transplant

Question 1

What is graft rejection?

Answer 1

Graft rejection is an example of where the immune response acts detrimentally to the transplant recipient

Question 2

Xenograft?

Answer 2

Transfer of tissue between species

Question 3

Isograft?

Answer 3

Identical twins

Question 4

Autograft?

Answer 4

One part of the body to another

Question 5

Allograft?

Answer 5

Same species, different person

Question 6

What does syngeneic mean?

Answer 6

Identical twins

Question 7

What happens to a second skin graft on the same individual?

Answer 7

It is rejected faster than the first

Question 8

What are the cells responsible for rejection?

Answer 8

T-cells

Question 9

What are the T cells reacting against?

Answer 9

MHC/HLA molecules

Question 10

Chromasome for HLA?

Answer 10

6 (short arm)

Question 11

Where is class 1 HLA expressed?

Answer 11

– Universally expressed
– Cytoplasm derived proteins
– Presents Ag to CD8+ T cells

Question 12

Where is class II HLA expressed?

Answer 12

– APC, inducible on other cells
– Extracellular derived proteins
– Presents Ag to CD4+ T cells

Question 13

What are other markers we look for in transplantation?

Answer 13

A1 
A2 
B27 
B8 
DR3 
DR3

Question 14

What determines who gets a kidney?

Answer 14

HLA matching

This does not occur for other organs (eg lung)

Question 15

What are the three types of rejection?

Answer 15

Antibody mediated
Acute
Chronic

Question 16

When can Antibody mediated rejection take place?

Answer 16

Can be any time (even months or years later)

Question 17

What are the types of antibody responses in rejection?

Answer 17

Pre formed antibodies 
- Blood group
- MHC
Previous
- Blood transfusion
- Pregnancy 
- Transplant

Question 18

What is acute allograft rejection?

Answer 18

Foreign material travels to the lymph nodes where it can activate a T cell mediated response

Question 19

What is chronic allograft rejection?

Answer 19

Can be both immunological and non-immunological

Question 20

What is common to all chronic allograft rejection?

Answer 20

Intimal loss → loss of tubules

Question 21

How do we prevent allograft rejection?

Answer 21

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

Question 22

How do we knock out the immune system?

Answer 22

Knock out the T cell

Question 23

What drug is used to knock out the immune system?

Answer 23

Cyclosporin - selectively knocks out recently activated T cells

Also use steriods and azathioprine

Question 24

What is a problem with using cyclosporin?

Answer 24

No longer effective at fighting viruses

Question 25

What is the action of steroids?

Answer 25

anti-inflammatory effects

Question 26

Side effects of steroids?

Answer 26

Fluid retention
Hypertension
Susceptibility to infection

Question 27

What are the steps in the creation of a bioartificial lung?

Answer 27

Take donor lung 
↓ 
Decellularize with detergent 
↓ 
Establish acellular vasculature, airways and alveoli 
↓ 
Seed scaffold with epithelial and endothelial cells 
↓ 
Perfuse and ventilate in bioreactor

Question 28

Future clinical applications of bioartificial transplants?

Answer 28

Standard organ donor 
↓ 
Decellularize 
↓ 
Reconstitute with the recipient’s own (damaged) lung endothelial and epithelial cells 
↓ 
Transplant