define hypersensitivity

Question 1

Hypersensitivity: Definition

Answer 1

Immunologically driven host tissue-damaging process

• Immunologically driven tissue-irritating process

Question 2

name the components of innate immune system

Answer 2

dendrite macrophage eosinophills, basophil, neutrophil complement mast

Question 3

name adaptive immune system components

Answer 3

b cell, t cell(CD4/CD8) keep in mind fc and fab regions on antibodies

Question 4

name the four types of hypersensitivity

Answer 4

ABCD
Type I: Immediate Hypersensitivity (Allergy-Anaphylaxis and Atopy)
Non-microbial environmental antigens that are innocuous. Response within minutes
Mediated by IgE-mast cells.
• Type II: AntiBody Mediated
IgM, IgG antiBodies against cell surface/extracellular matrix
Complement-mediated
• Type III: Immune Complex Mediated
Soluble immune complexes Antigen-IgM or Antigen-IgG
Complement-mediated
• Type IV: Cell Mediated (Delayed)
CD4 and CD8 cells. Cell killing and cytokine-mediated inflammation. 24-48h

Question 5

what is the hallmark of type one hypersensitivity

Answer 5

ige production and th2 helper cells, mediated by ige mast cells

Question 6

describe ways in which molecules relased from mast cells

Answer 6

degranulation of storage granules containing histamine and tryptase immediate, de novo sythesis prostglandins leukotrienes cytokines slower release

Question 7

what cause wheal and flare

Answer 7

histamine vasodilation and increase vascular permeability,

Question 8

what are the chracteristics of main allergens

Answer 8

Individuals are repeatedly exposed to them
- They do not induce macrophages/dendritic cells typical responses driving Th1/Th17 (like microbes
do)

Question 9

name examples of main allergens

Answer 9

foods, pollen sppores, dander, dust mite, drugs, penicillin, venom bee stings

Question 10

what happens in the later responses of type 1 hypersensitivity

Answer 10

cytokines produced, il5 activates eosinophills which can cause tissue damage and inflammation

Question 11

Type I Hypersensitivity: Examples

Answer 11

Pruritus	(itch)
• Urticaria (hives)
• Allergic	Rhinitis	(hay	fever)
• Asthma- immediate	asthma
• Systemic	anaphylaxis	– whole	body

Question 12

how can you diagnose type 1 hypersensitivity

Answer 12

ige in serum greater than 100 iu per ml

skin prick test depending on the size of wheal greater than 3mm

or radio allergosorbent test
serum exposed to labelled ige on a plate and if present it will bind indicating allergy

Question 13

what is serum sickness

Answer 13

Type III Hypersensitivity: Immune Complex Mediated
• Binding of Ab to Ag (self or foreign): soluble complexes not cleared
• Activation of complement, recruitment of neutrophils and macrophages
• Pathologic features reflect the site of depositionà multiple tissues

Question 14

outline what happens triggers type two hypersensitivity

Answer 14

Binding of Ab to Ag on cells / Ag on tissues activate complement and
recruit immune cells

Question 15

outline what happens in type 3 hypersensitivity

Answer 15

• Binding of Ab to Ag (self or foreign): soluble complexes not cleared
• Activation of complement, recruitment of neutrophils and macrophages
• Pathologic features reflect the site of depositionà multiple tissues

Question 16

why is type 4 hypersensitivity antibody independent

Answer 16

Cytokines and t cells mediate inflammation and cytoxicity

• Delayed inflammation: 24-48h after Ag challenge
• Antibody-independent

Question 17

what types of hypersensitivity affect contribute to asthma

Answer 17

hypersensitivity one which is immediate(allergy anaphylaxis and atopy), and delayed cell mediate type 4

Question 18

define asthma

Answer 18

chronic inflammatory disease, wheeze sob chest tightness vary over time and intensity, with variable expiratory airflow limitation

Question 19

describe asthmatic airway

Answer 19

Variable airways narrowingà airflow obstruction that is reversible

Non-specific airways hyperresponsiveness to innocuous stimuli (cold
air, irritants, pollutants)à bronchoconstriction. Always present.

• Mucosal inflammation and airways remodelling

Question 20

name 5 types of asthma

Answer 20

allergic asthma, obesity asthma, late onset asthma, asthma with fixed airflow limitation, non allergic asthma

Question 21

what asthma does ics work best with

Answer 21

inhaled corticosteroids works best with allergic asthma

Question 22

explain how airway remodels in asthma

Answer 22

epithelial cells are leaky, basment membrane thickens, smooth muscle thickens, mucous glands hypertophy

Question 23

what predisposes you to asthma

Answer 23

genetics and atopy(postive skin prick test) demonstrates type 1 sensitivity hyper