Chapter 2

Select the term that describes cells or tissue from a genetically different individual within the same species. a. Allogeneic b. Autologous c. Xenogeneic d. Autograft

a. Allogeneic Allogeneic cells or tissue come from a genetically different individual within the same species.

Select the portion of the antibody molecule that imparts the antibody's unique class function. a. Constant region of the heavy chain b. Constant region of the light chain c. Variable region of the heavy chain d. Variable region of the light chain

a. Constant region of the heavy chain The heavy-chain constant region has the function of the class.

Select the substance that regulates the activity of other cells by binding to specific receptors. a. Cytokines b. Complement c. Immunoglobulins d. Anaphylatoxin

a. Cytokines Cytokines are proteins secreted by cells that regulate the activity of other cells by binding to specific receptors.

What is the potential effect in a tube agglutination test if a red cell suspension with a concentration greater than 5% is used? a. False negatives b. False positives c. Hemolysis d. No effect

a. False negatives Antigen excess is termed postzone and will lessen the reaction, causing a false-negative.

Found in secretions, such as breast milk: a. IgA b. IgM c. IgG d. IgE

a. IgA

What immunoglobulin class reacts best at room temperature at immediate-spin? a. IgM b. IgA c. IgE d. IgG

a. IgM IgM is a large immunoglobulin with multiple binding sites that is detectable at room temperature and the immediate-spin phase.

One of the two types of light chains: a. Kappa b. Epitope c. Hinge region d. Isotype e. Idiotype

a. Kappa

Select the region of the antibody molecule responsible for imparting unique antibody specificity. a. Variable region b. Constant region c. Hinge region d. Fc fragment

a. Variable region The variable region is the unique antigen binding site that gives each antibody its specificity.

An antigen that originates from the individual is termed: a. autologous. b. allogeneic. c. hapten. d. immunogen.

a. autologous. Autologous is a term that refers to cells or tissue from self.

What process is described by opsonization? a. Lysis of cells b. Binding to cells or antigens c. Ingestion of cells d. Phagocytosis

b. Binding to cells or antigens Opsonization promotes phagocytosis by binding to cells or antigens.

Part of the antigen that the immunoglobulin binds to: a. Kappa b. Epitope c. Hinge region d. Isotype e. Idiotype

b. Epitope

A technologist added 4 drops of a 5% red cell suspension instead of the required 1 drop to a hemagglutination test. What is the potential consequence to the test results? a. False-positive b. False-negative c. Hemolysis due to complement activation d. Test results are not affected

b. False-negative Postzone occurs when the concentration of antigen exceeds the number of antibodies present. The amount of agglutinates formed under these circumstances is also suboptimal and diminished.

What part of the immunoglobulin molecule distinguishes the isotype? a. Light chain b. Heavy chain c. Kappa chain d. Lambda chain

b. Heavy chain The five distinctive heavy-chain molecules distinguish the class or isotype. Each heavy chain imparts characteristic features, which permit them to have unique biological functions.

Which immunoglobulin class is impacted by the zeta potential in a hemagglutination test? a. IgM b. IgG c. IgA d. IgE

b. IgG IgG antibodies are smaller in size versus IgM antibodies. They cannot span the distance between red cells in a saline solution due to the forces of repulsion.

Associated with immediate-spin in vitro reactions: a. IgA b. IgM c. IgG d. IgE

b. IgM

Associated with intravascular cell destruction: a. IgA b. IgM c. IgG d. IgE

b. IgM

Efficient in activation of the complement cascade: a. IgA b. IgM c. IgG d. IgE

b. IgM

Has the highest number of antigen binding sites: a. IgA b. IgM c. IgG d. IgE

b. IgM

After adding antigen and antibody to a test tube, one large agglutinate was observed. How should this reaction be graded? a. 2+ b. 3+ c. 4+ d. 0

c. 4+ One large agglutinate is graded a 4+ reaction.

Select the cell involved in humoral immunity. a. Neutrophils b. T lymphocytes c. B lymphocytes d. Monocytes

c. B lymphocytes B lymphocytes have the ability to transform into plasma cells to produce antibodies, which is considered a humoral response.

In the complement cascade, lysis of the target cell is mediated by which of the following components? a. C1qrs b. C4a, C3a, and C5a c. C5 to C9 d. C3a and C3b

c. C5 to C9 The membrane attack complex includes the C5 to C9 proteins that mediate lysis of the target cell.

Hemolysis was observed at room temperature when testing a patient's serum with reagent red cells used for screening. When this test was repeated using the patient's plasma, no hemolysis was observed. What was the most likely explanation for the different reactions? a. The plasma sample was collected incorrectly. b. The serum sample was contaminated. c. Complement activation was inhibited by calcium in the plasma sample. d. The serum sample was fresher.

c. Complement activation was inhibited by calcium in the plasma sample. Complement can be activated by some red cell antibodies; however, fresh serum samples are necessary to observe this reaction. Plasma samples contain calcium to inhibit the coagulation cascade, which also will inhibit complement activation.

What portion of the antibody molecule binds to receptors on macrophages and assists in the removal of antibody bound to red cells? a. Fab fragment b. Hinge region c. Fc fragment d. J chain

c. Fc fragment The Fc portion of the antibody binds to the macrophage, which then carries the antigen-antibody complex to the spleen for removal.

Imparts flexibility to the immunoglobulin molecule: a. Kappa b. Epitope c. Hinge region d. Isotype e. Idiotype

c. Hinge region

Able to cross the placenta: a. IgA b. IgM c. IgG d. IgE

c. IgG

Has the highest serum concentration: a. IgA b. IgM c. IgG d. IgE

c. IgG

When testing for the A antigen in a patient, what would you use to perform the test? a. Patient's plasma and commercial A red cells b. Commercial A cells and anti-A c. Patient's red cells and anti-A d. None of the above

c. Patient's red cells and anti-A For antigen testing, antigens are on the red cell; antibodies are in the antisera (commercial antibodies).

What biological molecules are considered the most immunogenic? a. Carbohydrates b. Lipids c. Proteins d. Enzymes

c. Proteins Protein molecules are the most immunogenic, followed by carbohydrates and lipids, which tend to be immunologically inert.

Which of the following will cause an antigen to elicit a greater immune response? a. Small antigen size b. Composed largely of carbohydrates c. Size greater than 10,000 daltons d. Similarity to the host

c. Size greater than 10,000 daltons Antigens will elicit a better immune response if they are larger than 10,000 daltons, are foreign to the host, and are made of proteins.

In a serologic test, the term prozone is also known as: a. equivalence. b. antigen excess. c. antibody excess. d. serum-to-cell ratio.

c. antibody excess. Antibody excess is termed prozone, often leading to a false-negative reaction.

Extravascular destruction of blood cells occurs in the: a. blood vessels. b. lymph nodes. c. spleen. d. thymus.

c. spleen. Extravascular destruction of blood cells is initiated by macrophage interaction with IgG molecules attached to red cells that transport the red cells to the spleen for clearance.

An antibody identified in the transfusion service appeared to be reacting stronger following the second exposure to an antigen from a transfusion. The most likely explanation of this observation is: a. affinity maturation of the immunoglobulin molecule. b. anamnestic response. c. isotype switching. d. All of the above

d. All of the above Genetic changes in the variable region, stimulation of memory B cells, and class switching contribute to the increased strength and specificity of an antibody following the second exposure to an antigen.

Which of the following is responsible for the activation of the classic pathway of complement? a. Bacteria b. Foreign proteins c. Virus d. Antibody bound to antigen

d. Antibody bound to antigen An antigen-antibody complex activates the classical complement cascade, whereas bacterial membranes activate the alternative pathway.

Associated with allergic reactions and mast cell activation: a. IgA b. IgM c. IgG d. IgE

d. IgE

What immunoglobulin class is capable of crossing the placenta? a. IgM b. IgA c. IgE d. IgG

d. IgG Only IgG can cross the placenta as a result of IgG receptor binding sites on placental cells.

Select the immunoglobulin class produced first in the primary immune response. a. IgG b. IgE c. IgA d. IgM

d. IgM IgM antibodies are produced first, followed by the production of IgG antibodies.

In order to enhance the reaction of an antibody in vitro, it may be necessary to adjust which of the following? a. Temperature above 37 C b. Speed of the centrifuge above the calibrated settings c. Increase the concentration of red cells in the test system d. Increase the incubation time in the incubator

d. Increase the incubation time in the incubator Increasing incubation time is effective in increasing antibody reactions; however, optimal temperatures, centrifugation, and antigen concentrations are normally not altered when performing routine transfusion service testing. The manufacturer package insert should be followed to stay within the upper incubation time allowed and prevent dissociation of the antigen from the antibody.

The type of immunoglobulins determined by the heavy chain: a. Kappa b. Epitope c. Hinge region d. Isotype e. Idiotype

d. Isotype

Variable region of an immunoglobulin: a. Kappa b. Epitope c. Hinge region d. Isotype e. Idiotype

e. Idiotype