Biol 430
Question Bank
Transplantation
1. For each of the transplants listed below:
a. Indicate in the Transplant type column: “syngenic”, “allogeneic” or “xenogeneic”
b. Indicate in the Response column if the graft will be “accepted” or “rejected”
and if the graft will be rejected:
c. Indicate in the Rejection type column: “Hyperacute” or “Acute”
Donor
Recipient
Transplant type
C57BL/6
Balb/c
C57BL/6
Rat
C57BL/6
C57Bl/6
C57BL/6
C57BL/6 X Balb/c hybrid
Response
Rejection type
C57BL/6 X
Balb/c
Balb/c hybrid
2. Suppose that a child needs a kidney transplant but does not have
an identical twin. The parents, brother and sister all are willing to
donate a kidney, and testing showed that the parents’ genotypes are
HLAD/F and HLAD/H.
A. What do the ‘D/F’ and ‘D/H’ letters mean? Use the diagram
to the right to predict the haplotypes possible among the
children.
B. If your haplotype is HLAF/H, what is the probability that one
of your siblings will have the same HLA alleles?
C. If one of your siblings is an exact HLA match, does this
mean that there will be no rejection? Explain.
3. Match the type of transplant with the appropriate example.
Type of transplant
___ isograft
___ allograft
___ xenograft
___ autograft
Biol 430
Example
A. using a pig heart valve to replace a human one
B. a human heart transplant
C. a skin graft between identical twins
D. using a leg artery during cardiac bypass surgery
Question Bank
Transplantation
Page 1
4. This figure shows the results of HLA-typing
for HLA-DR and HLA-B for a recipient and 5
potential kidney donors. Considering the two
HLA loci examined, which donor would be the
best match?
A. Do the recipient and donor share HLA
alleles where the wells are both blue or
both clear? Explain.
B. Under each HLA type (HLA-DR and
HLA-B), what differs between columns
1 – 5?
C. Theoretically, achieving a perfect tissue match would require comparing all HLA genes for
every possible type of allele, howver, this is not necessary (or practical). Explain.
D. Which donor (A, B, C, D or E) would be the best match with the recipient? Explain.
5. Determine if each of the following statements is True or False, and if it is false, explain why.
a. ___ Direct T-cell allorecognition can occur when graft antigens are presented by recipient
DCs that activate recipient T-cells.
b. ___ A xenograft will most likely trigger a cell-mediated acute rejection.
c. ___ In general, when pairing organ donor and recipient, matching of MHC-II alleles is more
important than matching of MHC-I.
d. ___ Fortunately, rejection of a subsequently transplanted organ is likely to be weaker than
the previous transplant.
e. ___ An identical twin is a better source of organs than a fraternal twin.
f. ___ Acute tissue rejection is a manifestation of a Type III hypersensitivity.
g. ___ There is an inverse linear relationship organ survival time (years) between the number of
HLA mismatches
h. ___ Graft vs Host disease is a common complication of a bone marrow transplant.
i. ___ Indirect T-cell allorecognition occurs when graft antigens are presented by graft DCs to
recipient T-cells.
Biol 430
Question Bank
Transplantation
Page 2
6. Graft rejection is strongest when the donor and recipient have greatest differences in HLA
haplotype.
A. During development in the thymus, T-cells are positively selected for TCRs that can bind to
self-HLAs; thus, theoretically, T-cells of the recipient should not bind to HLA on cells of the
graft. Yet, in ‘direct’ allo-recognition the recipient T-cells are activated by peptides presented on
graft HLAs; explain why this happens.
B. Often, perfusing a transplanted with saline to remove lymphatic cells can reduce
immunological rejection. Why?
C. Explain why HLA differences between the graft and recipient play the major role in graft
rejection during ‘indirect’ allo-recognition, but less so during ‘direct’ allo-recognition.
D. Even if the donor and recipient have the same HLA haplotype, long-term chronic rejection is
likely to occur. Explain why.
7. A variety of tissues can be transplanted with a low risk of rejection. For each of the following
examples explain why allograft rejection is not commonly observed.
A. Heart valve replacement.
B. Bone graft.
C. Cornea transplants.
8. A stem cell transplant would be appropriate under which one of the following circumstances.
Explain your choice.
A. DiGeorges syndrome
C. malignancies of non-immune cell tissues
B. chronic graft rejection
D. SCID.
9. Monoclonal antibodies, such as rituximab, are widely prescribed as anti-rejection therapy and for
a variety of autoimmune disorders.
A. What does it mean that these antibodies have been ‘humanized, and why is this important?
B. How does rituximab function?
C. If you could design an ideal anti-rejection drug, what properties would you design for it?
Biol 430
Question Bank
Transplantation
Page 3
10. Several methodologies can be used to best match donor and recipient prior to transplantation.
A. What is the difference between ‘allo-antibody screening’ and ‘HLA matching’?
C. Which method helps to reduce hyperacute rejection? Which acute rejection?
B. How is HLA match via ‘serological matching’ different from ‘DNA analysis’. Why can these
methodologies not assure that all HLA are matched?
11. Suppose there were an inverse linear
relationship between the number of HLA
mismatches and organ survival time (years).
A. In the diagram to the right, show how the
line might line might appear. (Assume the
lowest survival after 10 years is 40% and the
highest is 80%).
B. But this is not the relationship that is
actually observed. Draw in with a dashed line
a more accurate representation of the
relationship.
C. Identify at least two reasons why the
relationship in non-linear?
Biol 430
Question Bank
Transplantation
Page 4