Type I Hypersensitivity- lecture 10/26/21

Question 1

Type I hypersensitivity mediated by:

Answer 1

IgE, mast cell degranulation

Question 2

Immediate mast cell mediators

Answer 2

Histamine, IL-8, ECF-A

Question 3

Mast cell mediators after ~30-60 mins

Answer 3

Prostaglandins, leukotrienes

Question 4

Histamine

Answer 4

Itching, edema (opens blood vessels), bronchial constriction

Question 5

ECF-A

Answer 5

Eosinophil chemotactic factor

Question 6

Il-8

Answer 6

Chemokine, neutrophil chemotaxis

Question 7

Leukotrienes and prostaglandins (4 functions)

Answer 7

• Edema
• Bronchial constriction
• Eosinophil activation
• Eosinophil and neutrophil chemotaxis

Question 8

Sensitization

Answer 8

Making antibodies (IgE) for a particular antigen (allergen), could take a number of exposures

Question 9

Factors of why individuals make IgE antibodies

Answer 9

• Genetic component
• Environmental component
• Mode of at administration (skin or mucosal membrane)
• APCs preferentially activating Th2 and Tfh secreting IL-4 and IL-13
• Failure to control Th2

Question 10

Anaphylactic shock

Answer 10

Blood pressure drop caused by systemic vasodilation

Question 11

Examples of IgE mediated allergic reaction

Answer 11

• Allergic rhinitis
• bronchial asthma
• Acute drug reactions
• Food allergies
• Insect stings
• acute urticaria

Question 12

Two phases of allergic response

Answer 12

Acute phase and late phase (chemokine from cells recruited to the area and those cells

Question 13

Treatments of type I hypersensitivity (5)

Answer 13

• Epinephrine
• Removal of antigen
• Treat with antihistamines etc
• Treat chronic inflammation with corticosteroids
• Xolair (inhibits IgE binding to mast cells)