L15: Hypersensitivity

Question 1

Agent and symptoms of Type I hypersensitivity:

Answer 1

IgE

itching, rash, anaphylactic shock

Question 2

Agent and symptoms of Type II hypersensitivity:

Answer 2

IgM, IgG

massive hemolysis, anemia, kidney failure

Question 3

Agent and symptoms of Type III hypersensitivity:

Answer 3

IgG

serum sickness, kidney failure

Question 4

Agent and symptoms of Type IV hypersensitivity:

Answer 4

TDTH, TH1, TC, macrophages

contact dermatitis

Question 5

Activation of adenyl cyclase produces:

Answer 5

cAMP

Question 6

Activation of phospholipase C produces:

Answer 6

DAG and PIP2

Question 7

The release of Ca2+ from the ER has several effects:

Answer 7

a. synthesis of prostaglandins and leukotrienes
b. assembly of microtubules and microfilaments at the cortex
c. fusion of granule (vesicle) with the plasma membrane.

Question 8

How do you trigger degranulation?

Answer 8

Cross-linking two high affinity receptors bound to the Fc of the IgE with an allergen activates the tyrosine kinases associated on the cytoplasmic sid

Question 9

What’s released in degranulation?

Answer 9

• Histamine
• prostaglandins
• luekotrienes
• cytokines

Question 10

Histamine

Answer 10

• increases smooth muscle contraction of intestine and bronchioles
• increases permeability of venules
• increases mucus secretion by goblet cells

Question 11

prostaglandins

Answer 11

• synthesized after granule release from arachandoic acid

- bronchoconstrictor

Question 12

leukotrienes

Answer 12

• synthesized after granule release from arachandoic acid

- does everything histamine does only more strongly and longer

Question 13

cytokines

Answer 13

• promote inflammatory responses by eosinophils and neutrophils
• TNF-α may also induce shock.

Question 14

Type I clinical conditions include:

Answer 14

• anaphylactic shock
• Allergic rhinitis
• food allergies
• asthma

Question 15

How does epinephrine work?

Answer 15

reduces vascular permeability, relaxes smooth muscles, increase cardiac output, and raises cAMP levels, blocks further degranulation.

Question 16

Type II clinical conditions include:

Answer 16

• Blood transfusion mismatches
• Rh incompatibility
• drug-induced hemolytic anemia

Question 17

Type III clinical conditions include:

Answer 17

• caused by build up of antigen-antibody complexes
• arthritis
• kidney damage
• clotting
• serum sickness
• autoimmune diseases

Question 18

Type IV clinical conditions include:

Answer 18

• granulomas (like in TB and leprosy)
• contact dermatitis
• graft rejection

Question 19

Novotny description of Type I:

Answer 19

classical allergy

Question 20

Novotny description of Type II:

Answer 20

Antibodies target cells for ADCC

Question 21

Novotny description of Type III:

Answer 21

Excess antibody-antigen complexes

Question 22

Novotny description of Type IV:

Answer 22

Immune cells target rogue cells

Question 23

Subsequent response time (once sensitized)-Type I

Answer 23

immediate

Question 24

Subsequent response time (once sensitized)-Type II

Answer 24

immediate

Question 25

Subsequent response time (once sensitized)-Type III

Answer 25

immediate

Question 26

Subsequent response time (once sensitized)-Type IV

Answer 26

1-3 days

Question 27

mechanism-Type I

Answer 27

IgE activates mast cells and basophils

Question 28

mechanism-Type II

Answer 28

IgM and IgG attach to cells, attracting non-specific cytotoxic cells

Question 29

mechanism-Type III

Answer 29

IgG-antibody complexes overwhelm phagocytosis, triggering excess inflammation

Question 30

mechanism-Type IV

Answer 30

TDTH cells (a type of TH1) signal with cytokines to attack self cells with intracellular pathogen

Question 31

Cells involved-Type I

Answer 31

Mast cells, basophils, and then responding eosinophils

Question 32

Cells involved-Type II

Answer 32

NK cells, macrophages, and neutrophils

Question 33

Cells involved-Type III

Answer 33

neutrophils

Question 34

Cells involved-Type IV

Answer 34

macrophages and TC cells (not neutrophils)

Question 35

Pathology results from-Type I

Answer 35

Substances released by degranulation –smooth muscle | contraction

Question 36

Pathology results from-Type II

Answer 36

Attack on the marked cells by the cytotoxic cells and complement. Red blood cells especially sensitive

Question 37

Pathology results from-Type III

Answer 37

Clumps of complexes activating complement, releasing anaphylatoxins; damage by neutrophils

Question 38

Pathology results from-Type IV

Answer 38

Excess damage to healthy tissues by macrophages and TC cells

Question 39

Diseases- Type I

Answer 39

Hay fever, hives, eczema, food allergies, asthma, | shock

Question 40

Diseases- Type II

Answer 40

Transfusion reactions, erythroblastosis fetalis, hemolytic anemia

Question 41

Diseases- Type III

Answer 41

Local – response to insect bites (Arthus), lung irritants. Systemic: serum sickness, kidney damage

Question 42

Diseases- Type IV

Answer 42

Contact dermatitis, formation of granulomas, graft rejection

Question 43

Related factoids- Type I

Answer 43

Less likely to occur in people exposed to | farm animals

Question 44

Related factoids- Type II

Answer 44

Hemolysis leads to kidney damage

Question 45

Related factoids- Type III

Answer 45

autoimmune disorders(SLE) leading to excess of complexes may trigger this

Question 46

Related factoids- Type IV

Answer 46

Basis of skin test for tuberculosis