Transplantation Immunology- Lecture 10/22/21

Question 1

Autograft

Answer 1

Donor and recipient are same person

Question 2

Isograft(syngraft)

Answer 2

Donor and recipient are genetically identical (monozygotic twins)

Question 3

Allograft

Answer 3

Donor and recipient are genetically different

Question 4

Xenograft

Answer 4

Donor and recipient are different species

Question 5

Mechanisms by which grafts are recognized by recipient T-cells (2)

Answer 5

1) Recognize processed donor MHC peptides on APCs
2) Recipient T cells. Directly recognize donor MHC molecules on APCs
Many T cells respond to donor MHC molecules of graft APC

Question 6

Hyperacute rejection

Answer 6

Rejection in minutes to hours

Question 7

Acute rejection

Answer 7

Rejection in 10-14 days

Question 8

Chronic rejection

Answer 8

Months or years after the transplant

Question 9

Hyperacute rejection mechanism

Answer 9

Due to preformed antibodies in the recipient
Can be due to 
-Childbirth
-Previous blood transfusion
-Previous organ transplant recipient

Question 10

Acute rejection mechanism

Answer 10

Due to T-cell response, especially CD8+ T cells

Question 11

Chronic rejection mechanism

Answer 11

Mostly due to CD4+ T cells, chronic inflammation, can also be ADCC and complement activation

Question 12

To prevent hyperacute rejection (2)

Answer 12

• Blood type matching

- Test recipients serum for antibodies to donor (cross-matching)

Question 13

Six point match

Answer 13

Best outcomes, matches at HLA-A, HLA-B, and HLA-DR regions

Question 14

Preventing solid organ rejection (5)

Answer 14

• Match blood group
• Test fr pre formed abs
• Mathc for HLA
• Immunosuppressive drugs
• Live donors better than cadaveric

Question 15

Graft versus host disease

Answer 15

• Contain live T cells
• Recipient is immunosuppressed
• Donor and recipient must have different HLA types