Lesson 11: HYPERSENSITIVITY AND AUTOIMMUNE REACTIONS

Question 1

Pathologic lesions triggered by immune responses

Answer 1

hypersensitivities

Question 2

They created the foundation for classifying hypersensitivity reactions by dividing them into four distinct groups according to mechanisms of tissue injury

Answer 2

Gell and Coombs

Question 3

Type II hypersensitivity is also known as?

Answer 3

Cytotoxic or Antibody(IgG/IgM)-mediated

Question 4

ENUMERATE:
Hypersensitivity Reactions

Answer 4

1) Type I hypersensitivity: Immediate or IgE-mediated allergic reactions
2) Type II hypersensitivity: Cytotoxic or Antibody(IgG/IgM)-mediated
3) Type III hypersensitivity: Immune complex mediated
4) Type IV hypersensitivity: Delayed-type or T-cell mediated

Question 5

Type I hypersensitivity is also known as?

Answer 5

Immediate or IgE-mediated allergic reactions

Question 6

Type III hypersensitivity is also known as?

Answer 6

Immune complex mediated

Question 7

Type IV hypersensitivity is also known as?

Answer 7

Delayed-type or T-cell mediated

Question 8

Subtypes of Type I hypersensitivity: Immediate or IgE-mediated allergic reactions

Answer 8

a) IgE-dependent reactions (anaphylactic)
b) IgE-independent (nonimmunologic or anaphylactoid)

Question 9

Subtypes of Type II hypersensitivity: Cytotoxic or Antibody(IgG/IgM)-mediated

Answer 9

a) Antibody-mediated cytotoxic reactions; complement often involved
b) Antibody-mediated cell-stimulating reactions

Question 10

Subtypes of Type IV hypersensitivity: Delayed-type or T-cell mediated

Answer 10

a) Th1 cell-mediated macrophage activation

b) Th1 cell-mediated eosinophilic activation

c) Cytotoxic T cell-mediated reactions

d) T cell-mediated neutrophilic inflammation

Question 11

Ag (antigen) induces cross-linking of IgE bound to mast cells and basophils with release of vasoactive mediators.

What type of hypersensitivity reaction is this?

Answer 11

Type I hypersensitivity

Question 12

In type I hypersensitivity, ag (antigen) induces cross-linking of IgE bound to these cells

Answer 12

mast cells and basophils

Question 13

Typical manifestations of type I hypersensitivity

Answer 13

systemic anaphylaxis and localized anaphylaxis such as hay fever, asthma, hives, food allergies, and eczema

Question 14

Type I hypersensitivity is mediated by what antibodies?

Answer 14

IgE

Question 15

Type II hypersensitivity is mediated by what antibodies?

Answer 15

IgG or IgM

Question 16

Ab (antibody) directed against cell surface antigens meditates cell destruction via complement activation or ADCC.

What type of hypersensitivity reaction is this?

Answer 16

Type II Hypersensitivity

Question 17

Typical manifestations of Type II Hypersensitivity reaction

Answer 17

1. blood transfusion reactions
2. erythroblastosis fetalis
3. autoimmune hemolytic anemia