Page 552 - Review of Medical Microbiology and Immunology ( PDFDrive )

mebooksfree.com
mebooksfree.com
mebooksfree.com

mebooksfree.com
mebooksfree.com
mebooksfree.com
mebooksfree.com
mebooksfree.com
mebooksfree.com mebooksfree.com mebooksfree.com 3. Regarding the graft-versus-host reaction, which one of the follow- mebooksfree.com
541
CHAPTER 62 Major Histocompatibility Complex & Transplantation
which is used to reduce the inflammatory response in rheu-
matoid arthritis (see Chapter 66).
ing is the most accurate?
Unfortunately, immunosuppression greatly enhances
(A) It occurs primarily when a kidney is transplanted.
(B) It is caused primarily by mature T cells in the graft.
the recipient’s susceptibility to opportunistic infections and
(C) It occurs primarily when ABO blood groups are matched.
neoplasms. For example, some patients undergoing treat-
(D) It occurs primarily when the donor is immunocompromised.
ment for multiple sclerosis with the monoclonal antibody
(E) It occurs primarily when the haplotypes of the donor and
natalizumab developed progressive multifocal leukoen-
recipient are matched.
cephalopathy (see Chapter 44 for a description of this viral
disease). The incidence of cancer is increased as much as 4. Listed below are transplants between individuals with various
genotypes and the outcome of these transplants. The genotypes
100-fold in transplant recipients who have been immuno-
mebooksfree.com mebooksfree.com mebooksfree.com BBmebooksfree.com Rejected mebooksfree.com mebooksfree.com
are designated A and B for simplicity. A person who is AA or
suppressed for a long time. Common cancers in these
BB is homozygous, whereas a person who is AB is heterozygous.
patients include squamous cell carcinoma of the skin, ade-
Regarding outcomes X and Y, which one of the following is the
nocarcinoma of the colon and the lung, and lymphoma.
most accurate?
Immunosuppressive drugs (e.g., cyclosporine) also
reduce GVH reactions. Note that although these drugs sup-
Genotype
Outcome of
Genotype
press the allograft reaction, tolerance to the graft tissue
Transplant
of Recipient
of Donor
does not ensue. Therefore, most patients must take these
AA
Accepted
AA
drugs for their entire lives.
BB
BB
Accepted
SELF-ASSESSMENT QUESTIONS
AA
1. Regarding tissue transplantation, which one of the following is the AA BB Rejected
AB
AA
X
most accurate?
mebooksfree.com
mebooksfree.com mebooksfree.com mebooksfree.com ANSWERS mebooksfree.com mebooksfree.com
Y
AB
AA
(A) An allograft is a graft that transfers tissue or an organ from one
member of a species to a member of another species.
(A) X is accepted, and Y is accepted.
(B) The mother or father of the patient is typically the best donor
(B) X is accepted, and Y is rejected.
of a graft because they are two-haplotype matches.
(C) X is rejected, and Y is accepted.
(C) The ABO blood groups of the donor and recipient do not have
(D) X is rejected, and Y is rejected.
to be matched because they do not play a role in allograft
rejection.
(D) Even when a donor and a recipient are matched at both the
class I and class II MHC loci, rejection can occur and the
recipient should be given immunosuppressive drugs.
(E) If the same donor is the source of tissue for two grafts to a
recipient and the second graft is performed 1 month after the
2. (C)
first graft is rejected, then the second graft will not be rejected. 1. (D)
3. (B)
2. Regarding the MHC proteins and the genes that encode them,
4. (C)
mebooksfree.com
mebooksfree.com
mebooksfree.com mebooksfree.com mebooksfree.com PRACTICE QUESTIONS: USMLE & mebooksfree.com
which one of the following is the most accurate?
(A) The genes encoding class II MHC proteins are highly polymor-
phic, whereas the genes encoding class I MHC proteins are not.
(B) The genes encoding class I MHC proteins are located on a dif-
COURSE EXAMINATIONS
ferent chromosome from the genes encoding class II MHC
proteins.
Questions on the topics discussed in this chapter can be found
(C) The genes are codominant, and each person expresses class I
in the Immunology section of Part XIII: USMLE (National
and class II MHC genes inherited from both mother and father.
Board) Practice Questions starting on page 733. Also see Part
(D) Class II MHC proteins are found on the surface of all cells,
XIV: USMLE (National Board) Practice Examination starting
whereas class I MHC proteins are found only on the surface of
on page 751.
phagocytes.
mebooksfree.com mebooksfree.com mebooksfree.com mebooksfree.com mebooksfree.com mebooksfree.com
mebooksfree.com mebooksfree.com mebooksfree.com mebooksfree.com mebooksfree.com mebooksfree.com