Organ Graft Rejection - TOKA

Question 1

What graft will cause the strongest immune rxn to reject the graft?

Answer 1

Xenograft

Question 2

What is the most frequent type of graft?

Answer 2

Allograft

Question 3

Which organ grafts do not trigger an IR?

Answer 3

Autograft and Isograft

Question 4

What is an allograft?

Answer 4

Transplant between different members of the same species

Ex: Pug graft to a golden retriever

** can cause IR and rejection of graft

Question 5

What is an autograft?

Answer 5

When tissue is moved to a dif part of the animals own body

Ex: skin to cover a burn

Question 6

What is an isograft?

Answer 6

Tranplant between 2 genetically identical individuals

Question 7

A pig heart was put into a human. What type of graft is this?

Answer 7

Xenograft

Question 8

What is the organ graft that is transplanted between animals of different species?

Answer 8

Xenograft

Ex: baboon heart to human infant

Question 9

________ rejection occurs within 48 hours after grafting

Answer 9

Hyperacute

Question 10

________ rejection occurs UP TO 7 days after grafting

Answer 10

Accelerated rejection

Question 11

________ rejection occurs after 7 days after grafting

Answer 11

Acute

Question 12

________ rejection develops months after grafting

Answer 12

Chronic

Question 13

If a graft is repeated from the same donor _______________ + __________ will become involved to rapidly reject the graft

Answer 13

Ab + Complement

Question 14

Acute rejection of a graft becomes infiltrated by __________

Answer 14

Cytotoxic T cells

Question 15

Allografted organs are a major source of foreign molecules which include __________

Answer 15

Blood group antigens + MHC molecules (I + II)

Question 16

Which grafts are never rejected?

Answer 16

Between genetically identical individuals/ same individual

Isograft or Autograft

Question 17

How can you prevent an allograft rejection?

Answer 17

Minimally suppress the immune system

1. Inhibit T cell signalling pathways (Cyclosporine/ Tacrolimus)
2. Antimetabolites
3. Block Co stim (CTLA4-Ig)
4. Corticosteroids (anti-inflamm)
5. Target alloantibodies + alloreactive Ab

Question 18

What are metabolic toxins that kill proliferating T cells?

Answer 18

Antimetabolites

*** used to suppress IR + prevent graft rejection

Question 19

What type of graft rejection causes arterial occlusion due to proliferation of smooth muscle cells?

Answer 19

Chronic rejection

** SM thickens and makes lumen smaller = occlusion

Question 20

What are signs of chronic rejection?

Answer 20

GRADUAL rise in creatine and urea

Proteinuria

Hematuria

Question 21

A rapid rise in creatinine would indicate a _________ graft rejection

Answer 21

Acute

Question 22

What is the direct pathway of graft rejection?

Answer 22

T cells recognize unprocessed peptides of allogenic MHC molecules on APC and trigger response

Question 23

What is the indirect pathway of graft rejection?

Answer 23

Presentation of processed peptides of allogenic MHC molecules on self MHC molecule

** Cytotoxic CD8+ T cells and Ab enter graft and destroy it

Question 24

What can bone marrow allografts be used for?

Answer 24

Helps treat some tumors