Flashcards in Transplant Deck (28):
1
What is graft rejection?
Graft rejection is an example of where the immune response acts detrimentally to the transplant recipient
2
Xenograft?
Transfer of tissue between species
3
Isograft?
Identical twins
4
Autograft?
One part of the body to another
5
Allograft?
Same species, different person
6
What does syngeneic mean?
Identical twins
7
What happens to a second skin graft on the same individual?
It is rejected faster than the first
8
What are the cells responsible for rejection?
T-cells
9
What are the T cells reacting against?
MHC/HLA molecules
10
Chromasome for HLA?
6 (short arm)
11
Where is class 1 HLA expressed?
– Universally expressed
– Cytoplasm derived proteins
– Presents Ag to CD8+ T cells
12
Where is class II HLA expressed?
– APC, inducible on other cells
– Extracellular derived proteins
– Presents Ag to CD4+ T cells
13
What are other markers we look for in transplantation?
A1
A2
B27
B8
DR3
DR3
14
What determines who gets a kidney?
HLA matching
This does not occur for other organs (eg lung)
15
What are the three types of rejection?
Antibody mediated
Acute
Chronic
16
When can Antibody mediated rejection take place?
Can be any time (even months or years later)
17
What are the types of antibody responses in rejection?
Pre formed antibodies
- Blood group
- MHC
Previous
- Blood transfusion
- Pregnancy
- Transplant
18
What is acute allograft rejection?
Foreign material travels to the lymph nodes where it can activate a T cell mediated response
19
What is chronic allograft rejection?
Can be both immunological and non-immunological
20
What is common to all chronic allograft rejection?
Intimal loss → loss of tubules
21
How do we prevent allograft rejection?
• Matching ABO antigens (not just expressed on erythrocytes)
• Matching MHC alleles
• Immunosuppressive drugs
22
How do we knock out the immune system?
Knock out the T cell
23
What drug is used to knock out the immune system?
Cyclosporin - selectively knocks out recently activated T cells
Also use steriods and azathioprine
24
What is a problem with using cyclosporin?
No longer effective at fighting viruses
25
What is the action of steroids?
anti-inflammatory effects
26
Side effects of steroids?
Fluid retention
Hypertension
Susceptibility to infection
27
What are the steps in the creation of a bioartificial lung?
Take donor lung
↓
Decellularize with detergent
↓
Establish acellular vasculature, airways and alveoli
↓
Seed scaffold with epithelial and endothelial cells
↓
Perfuse and ventilate in bioreactor
28