16 IMMUNOLOGY AND SEROLOGY

Question 1

Which immunoglobulin is typically found in external secretions such as saliva and tears?
a. IgA
b. IgE
c. IgG
d. IgM

Answer 1

a. IgA

Question 2

Which of the following does not characterize T lymphocyte function?
a. Produce and secrete immunoglobulins
b. Develop killer cells that produce cytokines
c. Suppress the immune response
d. Develop helper cells

Answer 2

a. Produce and secrete immunoglobulins

Question 3

Of the circulating lymphocytes in peripheral blood, which are in the greatest percentages (80%)?
a. B lymphocytes
b. T lymphocytes
c. Plasma cells
d. Macrophages

Answer 3

b. T lymphocytes

Question 4

In certain disease states, what is the process in which antibodies are made to “self” antigens?
a. Autoimmune disease
b. Infection
c. Inflammatory response
d. Phagocytosis

Answer 4

a. Autoimmune disease

Question 5

The primary requirement for a substance to be an antigen in a particular individual is that it must:
a. Have a large molecular weight
b. Be composed of protein and polysaccharide
c. Be different from “self”
d. Have several different combining sites

Answer 5

c. Be different from “self”

Question 6

Which of the following immunoglobulins is found in the greatest amounts in the serum but is the smallest in size?
a. IgA
b. IgD
c. IgG
d. IgM

Answer 6

c. IgG

Question 7

Which of the following immunoglobulins can cross the placenta and therefore provides passive immunity to the infant for the first few months of life?
a. IgA
b. IgD
c. IgG
d. IgM

Answer 7

c. IgG

Question 8

Which of the following is true about immunoglobulins?
a. Produced by T lymphocytes
b. Produced by B lymphocytes
c. Purified (cloned) from a single ancestral cell
d. Derived from the thymus and influenced by thymic hormones

Answer 8

b. Produced by B lymphocytes

Question 9

Which of the following antibodies result from exposure to antigenic material from another species?
a. Heteroantibodies
b. Alloantibodies
c. Isoantibodies
d. More than one of the above

Answer 9

a. Heteroantibodies

Question 10

Which of the following substances gain antigenicity only when coupled to a protein carrier?
a. Agglutinins
b. Agglutinogens
c. Haptens
d. Opsonins

Answer 10

c. Haptens

Question 11

In the first phase of a primary antibody response, the most notable characteristic would be:
a. Higher titer of IgG
b. Higher titer of IgM
c. Long lag time
d. Mostly IgM antibody produced

Answer 11

b. Higher titer of IgM

Question 12

Complement plays an important role in immunology for all the following reasons except:
a. It triggers the ultimate formation of the membrane attack complex.
b. It can result in a hemolytic transfusion reaction in an incompatible ABO transfusion.
c. Some of the components can be assayed for diagnostic purposes.
d. It circulates in the blood in an active form waiting to be called into action.

Answer 12

d. It circulates in the blood in an active form waiting to be called into action.

Question 13

Type II hypersensitivity reactions are related to:
a. Bee venom
b. Antibodies (IgM, IgG)
c. IgE antibodies
d. Nickel allergy

Answer 13

b. Antibodies (IgM, IgG)

Question 14

Type III hypersensitivity reactions associated with immune complexes include:
a. Autoimmune disorder
b. Neoplastic disorder
c. Infectious disease
d. All the above

Answer 14

a. Autoimmune disorder

Question 15

A type IV hypersensitivity reaction can be caused by:
a. Nickel
b. Incompatible blood transfusion
c. Bacterial contamination of water
d. An autoimmune disorder

Answer 15

a. Nickel

Question 16

After latex exposure in a person who is allergic to latex, a reaction typically occurs within:
a. 30 minutes
b. 2 hours
c. 48 hours
d. 1 week

Answer 16

a. 30 minutes

Question 17

Which of the following is the visible result of an antigen-antibody reaction between a soluble antigen and its specific antibody?
a. Sensitization
b. Precipitation
c. Agglutination
d. Complement fixation

Answer 17

b. Precipitation

Question 18

Which of the following is used to confirm a positive screening result in testing a patient for HIV antibody?
a. ELISA
b. Immunofluorescent assay
c. Western blot
d. Northern blot

Answer 18

c. Western blot

Question 19

The heterophil antibody produced in infectious mononucleosis is of which immunoglobulin class?
a. IgA
b. IgD
c. IgG
d. IgM

Answer 19

d. IgM

Question 20

Which of the following is not a characteristic of heterophil antibodies produced in infectious mononucleosis?
a. Absorbed by guinea pig kidney cells
b. Not absorbed by guinea pig kidney cells
c. Absorbed by beef red cells
d. React with horse, ox, and sheep red cells

Answer 20

a. Absorbed by guinea pig kidney cells

Question 21

During the “window phase” of HBV infection, which of the following may be the only detectable marker?
a. Anti-HBc
b. Anti-HBe
c. Anti-HBs
d. HBsAg

Answer 21

a. Anti-HBc

Question 22

When the antigen-antibody complex occurs, agglutination takes place only if the antigen:
a. Is a particle such as a bacterium or blood cell
b. Is soluble
c. Both a and b
d. Neither a nor b

Answer 22

a. Is a particle such as a bacterium or blood cell

Question 23

The rheumatoid factor in rheumatoid arthritis cannot be associated with which immunoglobulin?
a. IgA
b. IgM
c. IgG
d. None of the above

Answer 23

d. None of the above

Question 24

An important screening test for systemic lupus erythematosus is for:
a. Antinuclear antibodies (ANAs)
b. C3 levels
c. C4 levels
d. Cryoglobulins

Answer 24

a. Antinuclear antibodies (ANAs)