Session 21

Question 1

What is a feature of hypersensitivity reactions?
a. They are elicited in response to harmful pathogens.
b. They consist of a sensitization phase and an effector phase.
c. They can be irritating but are not harmful.
d. There are five different hypersensitivity reactions.

Answer 1

They consist of a sensitization phase and an effector phase.

Question 2

Which type of hypersensitivity is mediated by T-cells?
a. Type I
b. Type II
c. Type III
d. Type IV

Answer 2

Type IV

Question 3

In a type I hypersensitivity reaction, plasma cells produce _______ (antibody), which binds to receptors on _______(cells).
a. IgE, eosinophils
b. IgM, mast cells
c. IgE, mast cells
d. IgG, macrophages

Answer 3

IgE, mast cells

Question 3

What is an example of type II hypersensitivity?
a. Immune-mediated hemolytic anemia
b. Atopy
c. Arthus reaction (localized vasculitis)
d. Contact dermatitis

Answer 3

Immune-mediated hemolytic anemia

Question 4

Which hypersensitivity reactions can directly use complement as an effector mechanism?
a. Type I and Type IV
b. Type II and Type III
c. Type III and Type IV
d. Type I and Type II

Answer 4

Type II and Type III

Question 5

What causes the lesions we see in systemic lupus erythematosus (SLE)?
a. Autoantibody-antigen complexes are formed and deposited in vessels causing inflammation and tissue damage.
b. T- and B-lymphocytes are activated against harmless antigens leading to the production of IgE and mast cell degranulation.
c. Cytotoxic T-cells directly kill host cells and T-helper cells produce cytokines causing macrophage activation and inflammation.
d. Antibodies targeting host cells cause direct cell and tissue damage through cell lysis and phagocytosis.

Answer 5

Autoantibody-antigen complexes are formed and deposited in vessels causing inflammation and tissue damage.

Question 6

What finding on a CBC would you expect to see in a patient with leukocyte adhesion deficiency? Choose the best answer.
a. Neutrophilia
b. Neutropenia
c. Lymphopenia
d. Erythrocytosis

Answer 6

Neutrophilia

Question 7

Which of the following cells are infected with feline immunodeficiency virus?
a. Neutrophils
b. Eosinophils
c. CD4+ T-cells
d. Endothelial cells

Answer 7

CD4+ T-cells

Question 8

Which patients might have a false positive test result when tested for FIV using an ELISA test?
a. A ten-month-old kitten born to a FIV+ queen
b. A cat recently exposed to the feline immunodeficiency virus
c. A four-month-old kitten born to a FIV+ queen
d. A cat with clinical disease and a positive result on Western Blot (confirmatory test)

Answer 8

A four-month-old kitten born to a FIV+ queen