Hypersensitivity

Question 1

What are the 4 types of hypersensitivities

Answer 1

Type 1
type 2
type 3
type 4

Question 2

what is the most common type of hypersensitivity

Answer 2

Type 1

Question 3

the initial exposure of an Antigen and production of antibodies to that Ag is called ?

Answer 3

sensitization

Question 4

T/F All types of hypersensitivity MUST have sensitization of the Ag before a hypersensitive reaction can occur

Answer 4

True

Question 5

Type I hypersensitivity is mediated by what antibody

Answer 5

IgE

Question 6

How fast does the type 1 hypersensitivity occur after reexposures to an antigen/allergen

Answer 6

w/in minutes

FAST*

Question 7

What are the 5 syndromes associated w/ type hypersensitivity

Answer 7

1 - systemic anaphylaxis
2 - hives/ wheel and flare
3 - Hay fever
4 - asthma
5 - food allergy

Question 8

type 1 hypersensitivity is often referred to as an _______ hypersensitivity

Answer 8

allergy or immediate

Question 9

The release of mast cells in type 1 hypersensitivity triggers a biphasic response, what does this mean

Answer 9

1 - Immediate effects : dilation of vessels, vascular permability
2 - late response - inflammation via cytokine prod.

Question 10

During the immediate response of type I hypersensitivity, a mast cell will degranulate causing release of vasoactive amines, and lipid mediators. What are the 2 lipid mediators we are responsible to know

Answer 10

Prostanglandins - vasoconstrict lungs

Leukotrines - bronchoconstriction and increase vascular permeability

Question 11

during the late phase of the type I hypersensitivity, cytokines are secreted, in particular which ones ? What is their main responsibility

Answer 11

IL-4, IL-5, IL-13

Recruit eosinophils, neutrophils, and monocytes

Question 12

lipid mediators prostanglandins and leukotrines are derived from what ?

Answer 12

arachodonic acid

Question 13

What is the role of ITAMS in type I hypersensitivity

Answer 13

start signal cascade leading to degranulation of mast cell

Question 14

once ITAMS is activated, it activates Map Kinase. what does Map kinase activate

Answer 14

1 - PKC

2 - production of cytokines

Question 15

One of the responsibilites of Map kinase in the Type I hypersensitivity pathway is to activate PKC. What are teh two roles of PKC ?

Answer 15

1 - signal for movement of mast cells to surface and release granules
2 - Activate PLA

Question 16

what does PLA activate in the type I hypersensitivity reaction

Answer 16

PLA —-> arachodonic acid —-> lipid mediators

Question 17

what are teh most common signs/symptoms of asthma

Answer 17

cough, wheezing, shortness of breath

Question 18

what is the most common trigger for asthma

Answer 18

dust mites

-there are hundreds of others though

Question 19

dust mites secrete what specific enzyme that can enter through tight junctions and trigger mast cell degranulation

Answer 19

Der p 1

Question 20

What are the 2 treatments strategies for asthma

Answer 20

• inhaled corticosteroids

- leukotriene modifiers

Question 21

what is the functional role of eosinophils

Answer 21

kill parasites

Question 22

the most severe form of type 1 (immediate) hypersensitivity is _____ ? Why ?

Answer 22

anaphylaxis

• severe drop in BP
• severe bronchoconstriction

Question 23

Type II hypersensitivity is involved w/ what antibody

Answer 23

IgG

Question 24

In type I hypersensitivity mast cells are activated, what does the binding of an antigen in type II hypersensitivity activate ?

Answer 24

Complement system proteins

Question 25

What are the 3 types of Type II hypersensitivities we need to know ?

Answer 25

1 - Autoimmune hemolytic anemia 2 - Myasthenia gravis 3 - Graves disease

Question 26

Autoimmune hemolytic anemia targets what cells

Answer 26

fetal RBCs

Question 27

Myasthenia gravis does what to cause type II hypersensitivity

Answer 27

blocks Ach receptor (results in muscle weakness/paralysis)

Question 28

Graves disease does what to cause type II hypersensitivity

Answer 28

stimutates TSH receptor

Question 29

What are the treament strategies for 1) Autoimmune hemolytic anemia 2) Myastenia gravis 3) Graves disease

Answer 29

1 - prednisone, blood transfusion or rhogam 2 - myasthenia gravis - cholinesterase inhibitors and corticosteriods 3 - graves disease - radioactive iodine or anti-thyroid drugs

Question 30

what is unique about type 3 hypersensitivites when an Ag comes into contact with an Ab

Answer 30

form an immune complex and clump together forming deposits in vessels

Question 31

which type of immune-complex clumps would cause a type III hypersensitive reaction, Large aggregates or excess small aggregates

Answer 31

small aggregates b/c can deposit in excess in vessels and tissues = obstruct flow = occluded vessels

Question 32

how long does a type III hypersensitive reaction occur after reexposure

Answer 32

3-10 hours

Question 33

type III hypersensitivy induces inflammation in what 2 mechanisms ?

Answer 33

1 - mast cell activation | 2 - macrophage release of TNF-x and IL-1 (induce inflammatory cascade)

Question 34

The arthus reaction is triggered in the skin by IgG, this is an ex of what type of hypersensitivity

Answer 34

type III

Question 35

what are the 3 examples of type III hypersensitivity we need to know

Answer 35

1 - arthus reaction 2 - serum sickness 3 - SLE (systemic lupus erythmatous)

Question 36

how would one be exposed to arthus reaction (type III hypersensitivity)

Answer 36

- repeated subcutaneous vaccinations | - high levels of IgG immune complexes

Question 37

the classic example for a transient immune-complex mediated syndrome is called

Answer 37

serum sickness

Question 38

what is unique about the duration and treatment of serum sickness (type III hypersensitivity)

Answer 38

self limiting and will resolve itself over time

Question 39

the most severe of the type III hypersensitivities is what ? Why is this ?

Answer 39

SLE (systemic lupus erythmatous) | -b/c its IgG fighting against a SELF-Ag

Question 40

What is unique about type IV hypersensitivities

Answer 40

involve T cells inducing macrophage infiltration

Question 41

when does a type 4 hypersensitivity occur after reexposure to an Ag

Answer 41

2-3 days | *** DTH or delayed type hypersensitivity ****

Question 42

What are the 5 examples of type 4 hypersensitivities that bitch Stiner Jones wants us to know ?

Answer 42

``` 1 - Tuberculin hypersensitivty 2 - contact dermatitis 3 - chronic asthma 4 - Crohns disease 5 - graft rejection ```

Question 43

type 4 hypersensitivities are initiated by _______ with the help of APC's

Answer 43

haptens | **haptens alone to small to elicit immune response ***

Question 44

The tuberculin test is conducted by injecting Ag intradermally and then looking for a response w/in 2-3 days. If there was a response it would be mediated by what kind of t cells

Answer 44

TH1 cells

Question 45

contact dermatitis is a type of type 4 hypersensitivity and occurs in 2 phases, what are they

Answer 45

1 - sensitization - exposure to Ag and formation of CD4 memory T cells 2 - elicitation - reexposure and T cells relaease IFN-gamma to recruit macs

Question 46

chronic asthma is a type 4 hypersensitivity. What t cells mediate this reaction and what do they cause ?

Answer 46

Mast cell degranulation causes TH2 cells to increase eosinophils

Question 47

Initial presentation of what type 4 hypersensitivity may be in the oral cavity

Answer 47

Crohns disease | -type of bowel disease

Question 48

For all types of hypersensitivites, which of them occur b/c of soluble antigens ? Which occur b/c of Ag found on cell surface

Answer 48

Type 1,3,4 find soluble antigens | Type 2 find cell surface Ag