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Flashcards in Allergy Deck (22)
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1
Q

What indicates the presence of an allergy?

A
  1. Allergen-specific IgE presence
  2. Mast cell/eosiniphil recruitment
  3. Th2 resposne with IL-4,5,13
2
Q

What is atopy?

A

Likelihood of developing a hypersensitivity reaction to common allergens

3
Q

What is the chemical structure of most allergens?

A

Protein or glycoproteins

4
Q

How do allergens activate the innate immune system?

A
  1. Enzymatic activity

2. Activating PRR

5
Q

Allergic rhinitis is more commonly found with what?

A

Outdoor allergens

6
Q

The protease activity of allergens lends them what benefit?

A

Ability to cross the skin or mucosal barrier

7
Q

What factor would contribute to the over development of Th2 which would make a person more susceptible to develop allergies?

A
  1. Antibiotic use
  2. Urban life
  3. Diet
  4. Sensitization to house-dust, mites, bugs
8
Q

What gene polymorphism same considered to contribute to the formation of allergic disease?

A
  1. High Fcepsilon beta chain receptor
  2. IL-4 gene (upregulated)
  3. HLA-DR
  4. CD14
9
Q

What can contribute to reducing the development of atopic phenotypes (Type I hypersensitivity reaction)?

A

Increasing development of Th1 cells will help increase the Treg cells produced early in life. Furthermore, reduce the Th2 cells that are produced early in life, reducing ability for Type I reactions

10
Q

What factors help contribute to Th1 stimulation and therefore reducing the overpopulation of Th2 cells?

A
  1. Rural life
  2. Siblings
  3. Helminth infections
  4. LPS exposure
  5. Exposure to multiple antigens
11
Q

Allergens are proteins or glycoproteins meaning they will interact with what cells for presentation?

A
  1. APC for MHCII presentation which causes release of IL-4 from the DC, causing differentiation of T cell into Th2
12
Q

What is the effect of histamine release?

A

Smooth muscle contraction, vascular permeability

13
Q

What is the effect of TNF-alpha and IL-1

A

target to endothelial cells, causing inflammation

14
Q

What is the effect of tryptase?

A

Causes anaphylaxis and urticaria

15
Q

What is the effect of prostaglandin E2 (PGE2)?

A

Cause pain and increase vascular permeability

16
Q

What is the effect of PGD2 and leukotrienes?

A

Smooth muscle contraction and vascular permeability

17
Q

What is the effect of bradykinin?

A

Vasodilation, which can cause hypotension

18
Q

What are the different mechanisms for desensitization?

A
  1. IgG blocking antibodies
  2. Regulation
  3. Immune deviation
19
Q

How does IgG blocking antibodies promote a mechanism of desensitization?

A

IgG4 will continue to develop and compete for allergen binding with IgE. Reducing the ability for IgE to bind with Fc(epsilon)RI and cause de granulation of mast cells.

20
Q

How does regulation of mechanisms of desensitization essentially reduce allergen sensitivity?

A

This will increase the number of T red cells which can more effectively reduce migration/infiltration/inflammation of the other cell types

21
Q

How can immune deviation contribute to the desensitization mechanism for type I hypersensitivity reactions?

A

Reduce Th2 and increase Th1. Th1 are inhibitory to Th2 formation, which will reduce IgE production and therefore the ability for mast cells to bind and become de granulated.

22
Q

What is an allergen?

A

Ag that stimulates allergic reaction with little or no intrinsic activity