Transplantation

Question 1

What is it called when a transplanted kidney is attacked by the recipient’s T cells?

Answer 1

Transplant rejection

Question 2

What is it called when transplanted bone marrow attacks the recipient’s tissues?

Answer 2

Graft-versus-host disease

Question 3

What are the most critical antigens to match when looking for potential organ donors?

Answer 3

ABO blood group antigens

Question 4

A person with Type B blood will have what antigens and what antibodies?

Answer 4

B antigens (and maybe O antigens), Anti-A antibodies

Question 5

A person with Type O blood will have what antigens and what antibodies?

Answer 5

O antigens, Anti-A and Anti-B antibodies

Question 6

What type of transplant rejection is caused by preformed antibodies in the recipient? What 2 types of antigens in the transplanted organ could be the cause?

Answer 6

Hyperacute rejection against blood group antigens (more common) or against HLA antigens (less common)

Question 7

What type of test is done prior to organ transplantation to check for the presence of HLA antibodies in a recipient? The reactivity is often given as a percentage.

Answer 7

Panel Reactive Antibody test

Question 8

What type of transplant rejection occurs when the recipient’s T cells become reactive to the transplanted organ? How can this rejection be treated?

Answer 8

Acute rejection; can treat with immune suppression therapies

Question 9

Describe 2 ways that T-cell mediated acute rejection can occur.

Answer 9

1) T cells respond directly to the MHC II on transplant Antigen Presenting Cells
2) T cells are activated by host APCs, which present transplant antigens. The activated T cells then attack the transplant cells expressing those antigens.

Question 10

What type of transplant rejection results from indirect recognition of the transplant and takes months to years to manifest?

Answer 10

Chronic rejection

Question 11

Chronic rejection of transplanted organs often results from the formation of host antibodies against the graft’s HLA class 1 antigens. What part of the graft do these antibodies target?

Answer 11

The vasculature / blood vessel walls

Question 12

What does HLA stand for, and how is it related to the MHCs?

Answer 12

Human Leukocyte Antigen; HLA refers to the human MHC (major histocompatibility complex), as opposed to say, a rabbit or other vertebrate’s MHC

Question 13

How many HLA loci does a person have, and about how many phenotypes exist for those loci?

Answer 13

6 loci (inherit 3 from each parent); hundreds of phenotypes. 
...so I don't really understand what this means, but it gets said a lot. If anyone would care to explain, please let me know!

Question 14

Very generally, anti-rejection therapy involves giving immunosuppressive drugs to target what kind of white blood cells?

Answer 14

T cells

Question 15

Which of the following would NOT be given for anti-rejection therapy: corticosteroids, purine analogs, FK506, cyclosporine, antilymphocyte globulin, IL-2, or CD3 monoclonal antibodies.

Answer 15

IL-2 is not immunosuppressive - it promotes T cell growth and differentiation. In fact, some of the immunosuppressive drugs listed specifically inhibit IL-2.

Question 16

What happens if MHC presents a signal to a T cell without a co-stimulator?

Answer 16

Anergy - the T cell is inactivated

Question 17

What happens if a co-stimulator interacts with a T cell without a specific accompanying signal?

Answer 17

Nothing

Question 18

Graft-versus-host (GVH) disease can be reduced by removing T cells from the transplant organ. However, there are at least 2 reasons why eliminating the GVH response might not be desirable. What are they?

Answer 18

1) Having some GVH reaction seems to aid engraftment

2) If the recipient has leukemia, a GVH response helps kill residual tumor