Transplant

Question 1

What is an autograft transplant?

Answer 1

Transfer of tissue between different sites within the same organism (e.g. skin graft)

Question 2

What is an allograft?

Answer 2

Transfer between genetically non-identical members of the same species

Question 3

What is an isograft?

Answer 3

Transfer between genetically identical individuals, ie. identical twins, also known as syngeneic

Question 4

What is a xenograft?

Answer 4

Transfer between species (human and pig)

Question 5

What is the most common type of transplantation?

Answer 5

Allografting

Question 6

Which major antigens which donor and recipient must share in order for a graft to survive?

Answer 6

ABO blood group antigens

Major Histocompatibility Antigens (HLA).

Question 7

What is an example of a major histocompatibility antigen?

Answer 7

HLA- Human leukocyte antigen

Question 8

Which Human Leukocyte Antigens (HLA) are important for the donor and recipient to share?

Answer 8

HLA-A
HLA-B
HLA-DR

Question 9

Why might a transplant require no blood group or tissue matching or any immunosuppressive therapy?

Answer 9

Little blood or lymphatic supply to the tissue

Question 10

What is an example of an immune privileged site?

Answer 10

Cornea

Question 11

What is an area that doesn’t require donor and recipient matching called?

Answer 11

Immune privileged site

Question 12

What criteria need to be met before a solid organ transplant?

Answer 12

• There must be good evidence that the damage is irreversible
• There must be no other treatments
• The disease must not be able to recur.

Question 13

Why does a stem cell transplant carry a big risk of rejection?

Answer 13

Graft versus host disease

Question 14

What are possible complications of a transplant?

Answer 14

Graft rejection
Graft versus host disease (GVHD)
Infection 
Neoplasia (lymphoma, skin tumours)
Drug side effects 
Recurrence of original disease
Ethical, surgical problems etc.

Question 15

What are possible causes of infection from a transplant?

Answer 15

As a result of immunosuppressive therapy or of transfer of infectious agent in graft

Question 16

What is the more common cause of graft rejection?

Answer 16

Incomplete HLA matching between donor & recipient.

Question 17

What are the 3 types of graft rejection?

Answer 17

Hyperacute
Acute
Chronic

Question 18

When does hyperacute graft rejection occur?

Answer 18

Immediately- within hours of transplant

Question 19

What is a hyperacute graft rejection due to?

Answer 19

pre formed antigens to either ABO blood group or HLA class 1 antigens on the graft

Question 20

What type of hypersensitivity reaction is a hyperacute transplant rejection?

Answer 20

Type 2 hypersensitivity

Question 21

How is the graft destroyed in a hyperacute transplant rejection?

Answer 21

Vascular thrombosis

Question 22

When does an acute graft rejection occur?

Answer 22

Within the first 6 months

7-12 days

Question 23

What type of reaction is an acute graft rejection?

Answer 23

Type 4 hypersensitivity reaction

Question 24

When does a chronic graft rejection occur?

Answer 24

After the first 6 months

Question 25

What can a chronic graft rejection be caused by?

Answer 25

Recurrence of pre-existing autoimmune disease.

Question 26

How can graft rejection be prevented?

Answer 26

ABO matching
Detection of pre-sensitisation to donor antigens
-Close tissue matching (Class I & II HLA - especially at HLA-A, HLA-B & HLA-DR loci)
Prophylactic immunosuppressive therapy

Question 27

What circumstances need to be present for Graft vs Host reaction to occur?

Answer 27

the presence of functioning immunocompetent donor T cells in the graft
 defective immunity (especially T cell immunity) in graft recipient
HLA differences between donor & recipient