Question 1

HLA testing is useful in what other area of study?
A) Paternity testing
B) Disease correlation
C) Anthropology
D) All of the above

Accepted Answer

HLA testing is used in paternity testing to establish biological relationships, in disease correlation to understand genetic predispositions, and in anthropology to study human migration and evolution.

Question 2

How is histocompatibility testing different from RBC testing?
A) Known serum is used to type antigens on test cells.
B) Recipient serum is screened for the presence of antibodies.
C) Crossmatch of donor cells and recipient serum is performed to determine compatibility.
D) None of the above

Accepted Answer

Histocompatibility testing involves matching tissue antigens, primarily for organ transplantation, whereas RBC testing involves blood group antigens. The options provided are more relevant to blood compatibility testing rather than histocompatibility testing.

Question 3

What does "HLA" stand for?
A) Human lymphodenapathy
B) Human lymphocyte antibody
C) Human leukocyte antigen
D) Human liver antigen

Accepted Answer

HLA stands for Human Leukocyte Antigen, which is a group of proteins found on the surface of white blood cells and other tissues in the body, playing a crucial role in the immune system.

Question 4

Which of the following is a phenomenon in which an antiserum directed against one HLA determinant reacts with other HLA antigenic determinants?
A) Cross reactivity
B) Linkage disequilibrium
C) Recombination
D) Conversion

Accepted Answer

Cross reactivity is the phenomenon where an antiserum directed against one HLA determinant reacts with other HLA antigenic determinants due to structural similarities.

Question 5

What is the purpose of washing the cells after the initial cell-serum incubation in the Amos-modified antibody screen procedure?
A) To identify previously undefined alleles
B) To identify antibodies in the serum of the donor
C) To remove aggregated immunoglobulin in the serum
D) None of the above

Accepted Answer

Washing the cells after the initial cell-serum incubation is done to remove any aggregated immunoglobulin in the serum, which could interfere with the accuracy of the antibody screening results.

Question 6

How is induction of tolerance achieved in kidney transplantation?
A) Administration of cytokines prior to transplant
B) Blood transfusions after transplant
C) Blood transfusions before transplant
D) None of the above

Accepted Answer

Blood transfusions before transplant can help induce tolerance by exposing the recipient's immune system to donor antigens, potentially reducing the risk of rejection.

Question 7

All of the following diseases have been associated with a significant HLA correlation except:
A) narcolepsy.
B) ankylosing spondylitis.
C) Fanconi's anemia.
D) Goodpasture's syndrome.

Accepted Answer

Fanconi's anemia is not associated with a significant HLA correlation.

Question 8

Why are monoclonal antibodies able to detect a broad range of epitopes?
A) They are derived through alloimmunization.
B) They are derived through xenoimmunization.
C) They have both IgM and IgG specificity.
D) None of the above

Accepted Answer

The answer of Why are monoclonal antibodies able to detect...

Question 9

What is the definition of total ischemic time in heart transplantation? A) The amount of time there is not blood flow through the organ B) The time it takes to perform the transplant C) The time it takes for PO₂ levels to normalize after transplant D) The time it takes for CO₂ levels to normalize after transplant

Accepted Answer

Total ischemic time refers to the duration during which the donor heart is without blood flow, from the time it is removed from the donor until it is reperfused in the recipient.

Question 10

How are the heavy chains of major histocompatibility complex (MHC) classes I and II molecules transported into the cell membrane?
A) Heavy chains are transported via extracellular fluid.
B) Heavy chains are inserted through the membrane via hydrophobic residues.
C) Heavy chains are inserted through the membrane via hydrophilic residues.
D) Heavy chains are adsorbed onto the membrane via semipermeable methods.

Accepted Answer

Heavy chains of MHC molecules are inserted into the cell membrane through hydrophobic residues that allow them to span the lipid bilayer.

Question 11

HLA-DR typing requires a suspension.
A) T-lymphocyte
B) B-lymphocyte
C) granulocyte
D) platelet

Accepted Answer

HLA-DR typing is typically performed on B-lymphocytes because they express HLA-DR antigens on their surface.

Question 12

What is meant by the term public as applied to HLA antibodies?
A) Antibodies that detect a single HLA gene product
B) Binding to an epitope unique to one HLA gene product
C) Binding to epitopes shared by more than one HLA gene product
D) All of the above

Accepted Answer

Public HLA antibodies bind to epitopes that are shared by multiple HLA gene products, rather than being specific to a single HLA gene product.

Question 13

The MHC class I region encodes for all of the following genes except:
A) HLA-A
B) HLA-B
C) HLA-DR
D) HLA-C

Accepted Answer

HLA-DR is encoded by the MHC class II region, while HLA-A, HLA-B, and HLA-C are encoded by the MHC class I region.

Question 14

Which of the following is an example of linkage disequilibrium?
A) The actual occurrence of haplotype HLA-B7 and HLA-Cw5 is 6%; the expected occurrence based on gene frequencies is 5%.
B) The actual occurrence of haplotype HLA-C4 and HLA-B37 is 3%; the expected occurrence based on gene frequencies is 4%.
C) The actual occurrence of haplotype HLA-A1 and HLA-B8 is 8%; the expected occurrence based on gene frequencies is 2%.
D) The actual occurrence of haplotype HLA-A11 and HLA-DR4 is 8%; the expected occurrence based on gene frequencies is 7%.

Accepted Answer

Linkage disequilibrium occurs when the actual occurrence of a haplotype is significantly different from the expected occurrence based on gene frequencies. In this case, the actual occurrence of haplotype HLA-A1 and HLA-B8 is 8%, while the expected occurrence based on gene frequencies is 2%. This indicates that these two alleles are linked and are more likely to be inherited together than expected by chance.

Question 15

The surface marker, or antigen, detected in histocompatibility testing of a single individual is referred to as HLA:
A) phenotype.
B) genotype.
C) haplotype.
D) karyotype.

Accepted Answer

The HLA phenotype refers to the specific set of HLA antigens expressed on the surface of cells, which are detected during histocompatibility testing.

Question 16

What is the linkage disequilibrium in reference to the HLA antigens?
A) Occurrence of HLA genes more frequently in the same haplotype than would be expected by chance alone
B) Displacement of HLA genes on different chromosomes
C) Occurrence of HLA genes less frequently in the same haplotype than would be expected by chance alone
D) Crossover of HLA genes

Accepted Answer

Linkage disequilibrium refers to the non-random association of alleles at different loci, in this case, HLA genes, occurring together more frequently in the same haplotype than would be expected by chance.

Question 17

Why is histocompatibility testing negated in both lung and heart transplants?
A) The donor must be living to perform HLA testing.
B) The cold ischemic time is too short.
C) The cold ischemic time is too long.
D) None of the above

Accepted Answer

The cold ischemic time for lung and heart transplants is too short to allow for histocompatibility testing, which requires time to perform.

Question 18

What is the most important step for increasing the number of bone marrow transplants performed?
A) Expand the donor pool to include related individuals.
B) Expand the donor pool to include unrelated individuals.
C) Expand the donor pool to include both related and unrelated individuals.
D) None of the above

Accepted Answer

Expanding the donor pool to include both related and unrelated individuals increases the likelihood of finding compatible matches, thereby increasing the number of transplants that can be performed.

Question 19

The majority of HLA alloantibodies are immunoglobulins.
A) IgM
B) IgG
C) IgE
D) IgA

Accepted Answer

The majority of HLA alloantibodies are IgG, which are involved in immune responses and can cross the placenta.

Question 20

How is complement detected in HLA testing?
A) Agglutination
B) Hemolysis
C) Uptake of trypan blue dye
D) Uptake of mitomycin-C

Accepted Answer

The answer of How is complement detected in HLA testing?
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Quiz 23: The Hla System

HLA testing is useful in what other area of study?

How is histocompatibility testing different from RBC testing?

What does "HLA" stand for?

Which of the following is a phenomenon in which an antiserum directed against one HLA determinant reacts with other HLA antigenic determinants?

What is the purpose of washing the cells after the initial cell-serum incubation in the Amos-modified antibody screen procedure?

How is induction of tolerance achieved in kidney transplantation?

All of the following diseases have been associated with a significant HLA correlation except:

Why are monoclonal antibodies able to detect a broad range of epitopes?

What is the definition of total ischemic time in heart transplantation?

How are the heavy chains of major histocompatibility complex (MHC) classes I and II molecules transported into the cell membrane?

HLA-DR typing requires a suspension.

What is meant by the term public as applied to HLA antibodies?

The MHC class I region encodes for all of the following genes except:

Which of the following is an example of linkage disequilibrium?

The surface marker, or antigen, detected in histocompatibility testing of a single individual is referred to as HLA:

What is the linkage disequilibrium in reference to the HLA antigens?

Why is histocompatibility testing negated in both lung and heart transplants?

What is the most important step for increasing the number of bone marrow transplants performed?

The majority of HLA alloantibodies are immunoglobulins.

How is complement detected in HLA testing?