Deck 3: Fundamentals of Immunology

Question 1

Which of the following blood group systems is not likely to cause HDN?

A) Kell
B) ABO
C) MN
D) Rh

Answer 1

C

Question 2

An agglutination inhibition test is performed on a person whose blood type is A+. The person's saliva is mixed with type A antisera. After incubation, the solution is mixed with reagent A cells and no agglutination occurs. What can be deduced from this finding?

A) The person is a nonsecretor of A substance.
B) The person is a nonsecretor of O substance.
C) The person is a secretor of A substance.
D) The person is a secretor of O substance.

Answer 2

C

Question 3

What is a possible explanation for a weak reaction (1+) in a reverse ABO grouping test?

A) Elderly patient
B) Immunocompromised patient
C) IgM deficiency
D) All of the above

Answer 3

D

Question 4

At what temperature do IgM antibodies react?

A) 22°C
B) 37°C
C) 56°C
D) 42°C

Question 5

Which immunoglobulin exists in a pentameric configuration?

A) IgG
B) IgM
C) IgA
D) IgE

Question 6

At what age do infants begin to produce their own antibodies?

A) 1 week
B) 2 months
C) 6 months
D) 1 year

Question 7

What test is used to remove autoantibodies from test serum?

A) Adsorption
B) Direct Coombs'
C) Elution
D) Indirect Coombs'

Question 8

What is responsible for recognition of the antibody-binding site to homologous antigen?

A) Phenotype
B) Solubility of antigen
C) Variable region of light/heavy chain
D) Complementarity

Question 9

Extravascular hemolysis occurs when red blood cells are coated with antibody; what organ sequesters these cells?

A) Thymus
B) Reticuloendothelial system
C) Bone marrow
D) All of the above

Question 10

How can T cells be differentiated from B cells?

A) Secretion of interleukin-2
B) CD2 marker
C) Agglutination of sheep erythrocytes
D) All of the above

Question 11

Which IgG subclass primarily comprises antibodies to the Rh blood group system?

A) IgG₁, IgG₂
B) IgG₂, IgG₄
C) IgG₃, IgG₄
D) IgG₁, IgG₃

Question 12

Only 5% of Kell-negative individuals will develop antibodies to Kell if exposed to the Kell antigen, whereas 50% to 70% of Rh(D)-negative individuals would produce antibodies to D upon exposure. What is the reason for this?

A) Difference in ABO type
B) Difference in immunogenicity
C) Phenotype
D) All of the above

Question 13

What is the purpose of the antihuman globulin (AHG) test in blood banking?

A) It detects red blood cells coated with antibody by bridging the gap between red blood cells.
B) It detects white blood cells coated with antibody by bridging the gap between red blood cells.
C) It detects red blood cells coated with antigen.
D) All of the above

Question 14

Which of the following is not true of monoclonal reagents?

A) Monoclonal reagents are produced for single antigens with more than one epitope.
B) Monoclonal reagents are highly specific.
C) Monoclonal reagents are highly characterized and are uniformly reactive.
D) Monoclonal reagents are produced by hybridoma technology.

Question 15

What class of immunoglobulin is capable of crossing the placenta?

A) IgM
B) IgG
C) IgE
D) IgD

Question 16

What is the definition of an immunoglobulin?

A) A protein molecule produced in response to an antigen
B) A protein molecule produced in response to an antibody
C) A substance that aids in the primary immune response
D) A substance that aids in the growth and proliferation of leukocytes

Question 17

Which of the following statements is true concerning immunoglobulin variations?

A) Allotypic variations occur primarily in the variable region.
B) Isotypic refers to all members of a species.
C) Idiotypic variation occurs in the constant region.
D) Isotypic variation is associated with organ transplantation and paternity testing.

Question 18

IgG-coated RBCs will be phagocytized by what effector cells?

A) Monocytes/macrophages
B) T cells
C) Eosinophils
D) Basophils

Question 19

A person with the genotype MM shows a 3+ reaction when red blood cells are mixed with M antisera, whereas a person with the genotype MN shows a 1+ reaction. What phenomenon is occurring here?

A) Dosage
B) Prozone
C) Zeta potential
D) Hemolysis

Question 20

Name a lymphoid organ in which cells of the immune system can be found.

A) Thymus
B) Bone marrow
C) Spleen
D) All of the above

Question 21

All of the following are characteristics of a secondary immune response except:

A) quickly formed antibodies.
B) higher avidity for antigen.
C) higher dose of antigen required to form antibodies.
D) lower dose of antigen required to form antibodies.

Question 22

When antigen and antibody combine, they are held together by noncovalent forces. With the absence of a visible lattice, this stage is called .

A) adhesion
B) sensitization
C) agglutination
D) inhibition

Question 23

In an immune response, what is the time called during which no antibody is detected in the test serum?

A) Secondary response time
B) Primary response time
C) Latency period
D) Amnestic response time

Question 24

What does hemolysis represent in an antigen-antibody reaction?

A) A negative result
B) A positive result
C) An inconclusive result
D) None of the above

Question 25

What is the equivalent of Factor D (alternative pathway) in the classic complement pathway?

A) C1q
B) C1s
C) C1r
D) C4

Question 26

Which immunoglobulin is found in greatest concentration in serum?

A) IgE
B) IgM
C) IgG
D) IgA

Question 27

What does the term zeta potential mean?

A) The ability of antigen to react with antibody
B) The attraction of positive charges on the red blood cell surface to negative charges in an ionic cloud
C) The attraction of negative charges on the surface of red blood cells to positive charges in an ionic cloud
D) The repulsion between red blood cells caused by noncovalent forces

Question 28

All of the following are true regarding IgM antibodies except:

A) IgM antibodies form against Kell.
B) IgM can bind to up to 10 antigens on a red cell.
C) IgM is 160 Å larger than IgG.
D) IgM is a pentamer.

Question 29

Why are enzymes used in blood banking?

A) Enzymes enhance reactivity of MNS antigens.
B) Sialic acid is released from red blood cells, which helps to reduce the zeta potential.
C) Hydrophobic glycoproteins are removed from the red blood cell membrane, rendering the membrane hydrophilic (water loving), thereby allowing the red blood cells to move closer.
D) All of the above

Question 30

What function does chemically modified IgG serve?

A) It creates a pentameric structure to enhance binding.
B) Disulfide bonds are reduced in the hinge region of IgG, which promotes flexibility of Fab portions.
C) It alters the light chain variability portion of molecule.
D) It dissociates the IgG molecules from surface of sensitized red blood cells.

Question 31

What cells are responsible for mounting a secondary response when exposure to the same antigen occurs?

A) Memory T/B cells
B) Neutrophils
C) Plasma cells
D) Myeloblasts

Question 32

Which of the following antibodies is considered the most significant in blood banking because it reacts at body temperature?

A) IgG
B) IgM
C) IgA
D) IgE

Question 33

When there is an excess of antigen in a serologic test system, what course of action should be followed?

A) Dilute the serum
B) Add complement
C) Decrease the serum-to-cell ratio
D) Increase the serum-to-cell ratio

Question 34

What cells are considered polymorphonuclear granulocytes?

A) Monocytes
B) Eosinophils
C) Lymphocytes
D) None of the above

Question 35

How is the classical pathway of complement activated?

A) By polysaccharides on the surface of bacteria
B) By enzyme catalysis
C) By binding of antigen with antibody
D) By lipopolysaccharides on surface of red blood cells

Question 36

Which is a characteristic of natural killer (NK) cells?

A) They bind to and lyse antibody-coated cells in ADCC.
B) They require the presence of MHC to respond to antigen.
C) They produce antibody to act on foreign antigens.
D) They possess the TCR on their membrane surface.

Question 37

Which antibodies characteristically demonstrate a decreased avidity for antigen?

A) Rh
B) HTLA
C) Lewis
D) ABO

Question 38

At what temperature do IgG antibodies react optimally?

A) 22°C
B) 37°C
C) 56°C
D) 4°C

Question 39

In an immune response, antibodies are formed before .

A) IgG, IgA
B) IgM, IgG
C) IgG, IgM
D) IgM, IgA

Question 40

What Rh type does a mother have to be to produce antibodies to Rh(D) from an Rh-positive infant?

A) O-positive
B) Rh-positive
C) Rh-negative
D) Kell-negative

Question 41

The portion of the immunoglobulin molecule that determines class is the:

A) light chain.
B) kappa chain.
C) lambda chain.
D) heavy chain.

Question 42

Why is EDTA not conducive to complement activation?

A) Antigens are destroyed
B) Antibodies are neutralized
C) Calcium is inactivated
D) It dilutes plasma

Question 43

All of the following are characteristics of antigens that affect the type and extent of immune response except:

A) solubility.
B) charge.
C) molecular weight.
D) genetic locus.

Question 44

Which of the following are produced after exposure to genetically different nonself antigens of the same species?

A) Alloantibodies
B) Autoantibodies
C) Drug-induced antibodies
D) All of the above

Question 45

What are the principle receptors for the FC portion of immunoglobulin and the CR1 complement component, respectively?

A) IgM, C3b
B) IgG, C3b
C) IgG, C3d
D) IgM, C3d

Question 46

What does polyspecific AHG contain?

A) IgG
B) C3b
C) C3d
D) All of the above

Question 47

What happens to the target cell after the cytokine has bound?

A) The contents of the cell are expelled.
B) The target cell is programmed to produce biological responses.
C) The host exhibits a hypersensitivity reaction.
D) ABO antigens are stripped from the membrane.

Question 48

All of the following are functions performed by the complement system except:

A) direct lysis of bacteria.
B) promotion of phagocytosis.
C) decreased vascular permeability.
D) smooth muscle contraction.

Question 49

Which blood group antibodies are known to activate complement, leading to intravascular hemolysis?

A) Lewis
B) Rh
C) Duffy
D) ABO

Question 50

An immunogenic substance that reacts with an antibody is:

A) immunoglobulin.
B) antigen.
C) chromogen.
D) agglutinin.

Question 51

Why is low ionic strength solution (LISS) used in blood banking?

A) It reduces the incubation time.
B) It reduces the net negative surface charge on the RBC.
C) It increases the zeta potential.
D) It enhances aggregation.

Question 52

What MHC Class encodes complement components?

A) Class I
B) Class II
C) Class III
D) All of the above

Question 53

What is the function of mononuclear phagocytes?

A) They present processed antigen to lymphocytes.
B) They present processed antibody to lymphocytes.
C) They release histamine.
D) They produce antibodies.

Question 54

What substances are responsible for the activation of the alternate complement pathway?

A) Enzymes
B) Polysaccharides
C) Proteins
D) All of the above

Question 55

A patient with multiple myeloma exhibits rouleaux formation in an immediate spin crossmatch. What procedure is recommended to distinguish true red blood cell agglutination from nonspecific agglutination?

A) Secretor studies
B) Saline dilution
C) Enzyme treatment
D) Polyethylene glycol enhancement

Question 56

All of the following techniques are used in the laboratory to detect blood group antigens or antibodies except:

A) agglutination.
B) precipitation.
C) ELISA.
D) hemolysis.

Question 57

All of the following are included in the actions of cytokines except:

A) regulation of growth and mobility and differentiation of leukocytes.
B) possible production of a synergistic effect when used together.
C) decrease in the number of cell receptors when going from a resting to a reactive state.
D) binding to target cell receptors.

Question 58

Which of the following corresponds to the basic structure of immunoglobulin?

A) Two light chains held together with an interlink disulfide bond
B) Two heavy chains held together with an interlink disulfide bond
C) One light chain and one heavy chain held together by covalent disulfide bonds
D) Two light chains and two heavy chains held together by covalent disulfide bonds

Question 59

Which of the following statements concerning the structure of immunoglobulins is false?

A) The enzyme papain splits the antibody molecule at the hinge region to give three fragments (2 Fab + 1FC).
B) The FC portion is responsible for complement fixation, monocyte binding, and placental transfer.
C) IgM participates in placental transfer.
D) The Fab portion is the region responsible for antigen binding.

Question 60

The immune response that consists of physical barriers, biochemical effectors, and immune cells is the immune response.

A) auto-
B) innate
C) localized
D) primary

Question 61

The organ in which lymphocytes are formed is the .

A) bone marrow
B) liver
C) thymus
D) spleen

Question 62

Opsonization is:

A) the coating of pathogens with factors that facilitate phagocytosis.
B) a major role of complement in immunity.
C) the binding of an opsonin, such as an antibody, to a receptor on the pathogen's cell membrane.
D) all of the above.

Question 63

Which of the following statements is not true?

A) T-cell receptors do not recognize foreign antigen on their own like B cells do.
B) Major histocompatibility complex (MHC) molecules are cell membrane proteins.
C) MHC molecules are required for T cells to recognize foreign antigens.
D) MHC molecules are required for B cells to recognize foreign antigens.

Question 64

HLA proteins are coded by what complex?

A) Major histocompatibility complex
B) Human leukocyte compatibility complex
C) Complement
D) Innate immune response

Question 65

are produced by monocytes and lymphocytes to help regulate growth, mobility, and differentiation of leukocytes.

A) Monokines
B) Lymphokines
C) Cytokines
D) Optikines

Question 66

HDN is most often associated with what class of antibody?

A) IgG1
B) IgM
C) IgE
D) IgG₄

Question 67

The organs in which lymphocytes differentiate include .

A) bone marrow
B) thymus
C) both
D) neither

Question 68

Anti JK (Kidd) antibodies are of what class of antibody?

A) IgG₁
B) IgG₂
C) IgG₃
D) IgM

Question 69

The four unique serum proteins of the alternate pathway of complement include all but which of the following?

A) Factor B
B) X factor
C) Factor D
D) Initiating factor
E) Factor P