Lecture 2 - Hypersensitivity (Dr. Stiner)

Question 1

What is hypersensitivity?

Answer 1

Exaggerated or aberrant immune response to an antigen

Results in inflammation and tissue damage

Question 2

How many types of hypersensitivity reactions are there?

Answer 2

4

Question 3

What is the immune reactant for Type I hypersensitivity?

Answer 3

IgE

Mast cell activation

Question 4

What are some examples of Type I hypersensitivity (IgE)?

Answer 4

allergic rhinitis
asthma
systemic anaphylaxis

Question 5

What is the effector mechanism for Type I hypersensitivity?

Answer 5

Mast cell activation

Question 6

What is the immune reactant for Type II hypersensitivity?

Answer 6

IgG

Question 7

IgG is involved in ______ hypersensitivity.

Answer 7

Type II

Question 8

Drug allergies are examples of Type ___ hypersensitivity (immune reactant ___)

Answer 8

Type II, IgG

Question 9

What are some IgE mediated allergic reactions?

Answer 9

1. Systemic anaphylaxis
2. Acute Urticaria (wheal and flare)
3. Allergic rhinitis (hay fever)
4. Asthma (most common)
5. Food Allergy

Question 10

Systemic anaphylaxis route of entry.

Answer 10

intravenous (either directly or following oral absorption into the blood)

Question 11

Acute Urticaria (wheal and flare ) route of entry.

Answer 11

Through skin.

Question 12

Allergic rhinitis (hay fever) route of entry.

Answer 12

inhalation

Question 13

Asthma route of entry.

Answer 13

Inhalation

Question 14

Food Allergy route of entry.

Answer 14

oral

Question 15

Systemic anaphylaxis response

Answer 15

edema
vascular permeability
trachea closes
circulatory collapse
death

Question 16

Acute urticaria (wheal and flare; hives) response

Answer 16

local increase in blood flow and vascular permeability

Question 17

hay fever (season allergies; allergic rhinitis) response

Answer 17

edema of nasal mucose

irritation of nasal mucosa

Question 18

Asthma response

Answer 18

bronchial constriction
increased mucous production
airway inflammation

Question 19

food allergy response

Answer 19

vomiting
diarrhea
pruritis (itching)
urticaria (hives)
anaphylaxis (rarely)

Question 20

What is pruritis, and what is it a response to?

Answer 20

itching; food allergy

Question 21

What is urticaria, and what is it a response to?

Answer 21

hives; acute utricaria & food allergy

Question 22

Type I hypersensitivity occurs w/in minutes after _______ to antigen/allergen

Answer 22

REEXPOSURE

Question 23

What is the most common disorder of the immune system?

Answer 23

Type I Hypersensitivity
IgE & mast cell reaction
affects 20% of population

Question 24

What are some examples of Type I hypersensitivity?

Answer 24

hives, hay fever, food allergies, bronchial asthma, anaphylaxis

Question 25

What are the two phases of type 1 hypersensitivity response?

Answer 25

1. SENSITIZATION interaction (develop antibodies) | 2. second interaction = hypersensitivity

Question 26

Release of mediators triggers a biphasic response to the allergen/antigen.

Answer 26

1. Immediate Effects | 2. Late Response

Question 27

What are the Immediate Effects of the biphasic response of Type I hypersensitivity?

Answer 27

Dilation of blood vessels increased vascular permeability smooth muscle contraction (immediate!)

Question 28

What is the late phase (second phase) reaction of Type I hypersensitvity?

Answer 28

inflammation

Question 29

What are some mechanisms of the Immediate Response of Type I hypersensitivity?

Answer 29

1. Vasoactive Amines (histamine and serotonin) and proteases 2. synthesis and secretion of LIPID MEDIATORS - Prostaglandins and Leukotrienes

Question 30

What are the lipid mediators that are synthesized and secreted during the IMMEDIATE RESPONSE of type I hypersensitivity?

Answer 30

Prostaglandins | Leukotrienes

Question 31

What are the effects of prostaglandins (lipid mediator)

Answer 31

VASOCONSTRICTION IN THE LUNGS

Question 32

What are the effects of Leukotrienes (lipid mediator)

Answer 32

BRONCHOCONSTRICTION | INCREASED VASCULAR PERMEABILITY

Question 33

What happens during the LATE RESPONSE of the type I hypersensitivity?

Answer 33

1. Synthesis and secretion of cytokines and chemokines | 2. Infiltration of eosinophils, monocytes, and neutrophils

Question 34

What do eosinophils release?

Answer 34

ROS major basic protein prostaglandins leukotrienes

Question 35

What do ROS and major basic protein do?

Answer 35

tissue damage and inflammation

Question 36

IgE + allergen --> Fc interaction on surface of mast cell =

Answer 36

1. cytokines 2. histamine granules 3. lipid mediators - prostaglandins and leukotrienes

Question 37

What are the most common signs of asthma?

Answer 37

Coughing Wheezing Shortness of Breath

Question 38

What are some asthma triggers?

Answer 38

Airborne allergens pollen, animal dander, mold, cockroaches, and DUST MITES respiratory infections (common cold) Physical activity cold air air pollutants and irritants (smoke)

Question 39

Asthma Tx

Answer 39

1. INHALED CORTICOSTERIODS - relieve airway inflammation 2. beta2 agonists 3. LEUKOTRIENE MODIFIERS - block chain rxn that creates airway inflammation 4. CROMOLYN - prevent mast cell degranulation that leads to bronchial constriction and inflammation

Question 40

What determines the type of IgE-mediated allergic reaction that occurs?

Answer 40

the dose and routes of entry of allergens

Question 41

What are the two factors that drive the anaphylactic response?

Answer 41

1. vasoactive amines | 2. lipid mediators

Question 42

What are the 2 symptoms of anaphylaxis?

Answer 42

1. drop in BP | 2. severe bronchioconstriction

Question 43

How is anaphylaxis treated?

Answer 43

1. epinephrine - vasoconstrictor - bronchiodilator 2. antihistamine

Question 44

What 2 events occur as a result of mast cell activation?

Answer 44

1. mast cell degranulation 2. synthesis and secretion of lipid mediators 3. Cytokine release

Question 45

Let's talk about Type II hypersensitivity.

Answer 45

Okay