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Flashcards in tyoe 1 hypersensitivity Deck (32)
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1
Q

Hypersensitivity Reactions

A

Activation of immune system in the absence of a danger

Resulting in tissue damage, discomfort and even death

2
Q

Type 1 Hypersensitivity

A

immediate HSR

3
Q

Type 1 Hypersensitivity Immune Reactant

A

IgE

4
Q

Type 1 Hypersensitivity Antigen

A

Soluble antigen

5
Q

Type 1 Hypersensitivity Effector Mechanism

A

Mast-cell activation

6
Q

Type 1 Hypersensitivity Examples

A

allergic rhinitis, asthma, system anaphylaxis

7
Q

Allergen

A

a stimulus

Harmless environmental substance that induces an allergic response

8
Q

Anaphylaxis

A

A rapidly progressing allergic reaction, could be life-threatening

9
Q

Atopy

A

Familial predisposition

10
Q

Initiating cells

A

APC, Th0, Th2 and B cells

11
Q

Common Allergens

A

Low molecular weight proteins

Must contain peptides that bind to host MHC Class II molecules

Favor activation of IL-4 producing Th2

12
Q

IgE

A

very low serum concentrations

Fc region binds to the FcϵR on the effector cells

13
Q

Sensitization phase

A

IgE antibody bind to mast cells, basophils and eosinophils via FcϵR1

14
Q

Activation phase

A

Re-exposure to an antigen cross links cell bound IgE and activates mast cells to degranulate

15
Q

Effector phase

A

many pharmacologically active agents released by the mast cells and basophils

16
Q

Tho -> Th2

A

IL-4

17
Q

B cell -> Th2

A

IL-4

IL-13

18
Q

Th2 -> Eosinophil

A

IL-5

19
Q

recruit eosinophils to tissue of reaction

A

CCL11

20
Q

Mast cells can be activated by

A

PRR such as Toll like receptors

Fc receptor for IgA and IgG

C5a, C3a, C4a 

Chemicals (drugs) 

Stress

21
Q

inhinbits COX

A

aspirin

22
Q

Systemic anaphylaxis

A

allergens reaching the blood steam

23
Q

Inhaled antigens: Asthma

A

cute response in allergic asthma leads to Th2 mediated chronic/late inflammation of the air way

24
Q

TGF beta promotes

A

class switch to IgG/IgA

25
Q

Diagnosis of Type I HSR

A

Skin test:
Wheal and Flare Reaction

2. RAST: 
RadioAllergoSorbent Test (detects allergen specific IgE)
- no IgE = no allergy
  1. Tryptase and histamine serum level:
    Anaphylaxis
26
Q

(pharmalogical treatment) Prevent IgE mediated mast cell degranulation

A

Sodium cromoglycate

27
Q

(pharmalogical treatment) Block mediators by blocking receptors

A

Anti-histamines

28
Q

(pharmalogical treatment) Reverse the action of mediators

A

Epinephrine

29
Q

(pharmalogical treatment) Anti-inflammatory agents

A

Steroids – nasal spray

30
Q

Immunological treatment

A

Desensitization

Monoclonal antibodies

Correction of Th1/Th2 balance

31
Q

Desensitization

A

Allergy shots

Correct isotype switch from IgE to IgG

32
Q

Monoclonal antibodies

A

Anti IL-4, IL-13, IL-5 and IgE

Omalizumab (IgE specific)

Mepolizumab (IL-5 specific)