Hypersensitivity

Question 1

Altered immunologic response to an antigen means

Answer 1

damage to the host

Question 2

An allergy is an ________ ______ ____ against _____ _____

Answer 2

An allergy is an exaggerated immune response against environmental antigens

Question 3

Autoimmunity is when the immune response is

Answer 3

directed against self (lupus)

Question 4

Type 1 Hypersensitivity is

Answer 4

IgE mediated

Question 5

Type 1

Mild –
______ (environmental antigen) is perceived as an ______ and it amounts a ______ immune response 🡪 IgE responds and ______ _____ cells 🡪 mast cells degranulate and release _______

🡪 histamine binds to ____ receptors (not all) 🡪 some _____________, ____________, increased _______ ___________

Answer 5

Mild –
Allergen (environmental antigen) is perceived as an antigen and it amounts a localized immune response 🡪 IgE responds and activates mast cells 🡪 mast cells degranulate and release histamine 🡪 histamine binds to H1 receptors (not all) 🡪 some bronchoconstriction, vasodilation, increased capillary permeability

Question 6

Signs and symptoms of Type 1 Mild response

Ex:

Answer 6

itching,
urticaria (hives),
conjunctivitis,
rhinitis,
GI cramps,
hypotension, bronchospasm
Ex: hay fever, food allergies

Question 7

Treatment for hypersensitivity type 1

Answer 7

antihistamines (because there are still H1 receptors open) and desensitization

Question 8

Mild type 1

Remember: the primary encounter with an allergen is a slow response as the body has to build antibodies against the antigen, but the second encounter will be ____

Answer 8

rapid

Question 9

Type 1- severe

Anaphylaxis is _____, ______, and ______

Answer 9

Anaphylaxis is severe, immediate, and systemic

Question 10

Anaphylaxis begins as ____ then gets into blood and becomes ______

Answer 10

begins as local, becomes systemic

Question 11

Ex of anaphylaxis reaction (type 1 severe)

Answer 11

Bee sting, penicillin allergy, shellfish allergy

Question 12

severe type 1 :
Allergen is perceived as an antigen –> ___ responds and
activates ______ cells –> degranulation –> _____ release –> histamine bind to virtually ____ ___ receptors (no room for antihistamine to bind) –> _____/____
_________, ___________, and _____ _____ ______

Answer 12

Allergen is perceived as an antigen –> IgE responds and
activates mast cells –> degranulation –> histamine release –> histamine bind to virtually ALL H1 receptors (no room for antihistamine to bind) –> massive/systemic
vasodilation, bronchoconstriction, and increased
capillary permeability

Question 13

severe type 1-
S/S = itching, erythema, HA, N/V/D, abdominal cramps,
______, bronchospasm, ______ _______, vascular
______ from severe _______

Answer 13

itching, erythema, HA, N/V/D, abdominal cramps,
dyspnea, bronchospasm, laryngeal edema, vascular
collapse from severe hypotension

Question 14

Anaphylaxis can result in

Answer 14

anaphylactic shock (respiration becomes
difficult, BP drops, smooth muscles of bladder/GI tract
contract, bronchoconstrictio)

Question 15

Anaphylactic shock: remember

Answer 15

histamine –> vasodilation –> hypotension

Question 16

Treatment for anaphylactic shock = must treat with _______ as there are no
H1 receptors available for antihistamines to bind to

o Epinephrine will increase cardiac _______,
______ vascular permeability, improve _____ _____ and relax ____ ______

Answer 16

must treat with epinephrine as there are no
H1 receptors available for antihistamines to bind to
o Epinephrine will increase cardiac contractility,
↓vascular perm, improve cardiac output, and relaxes smooth muscles (bronchodilation)

Question 17

Type 2 hypersensitivity is _____ mediated (____ or ____)

Answer 17

antibody mediated (IgM or IgG)

Question 18

Type 2 is

Answer 18

tissue specific and causes complement

Question 19

Type 2:
______ bind to specific tissue _____ on cell _____ -> activates ________-> cell membrane
damage and lysis via MAC, opsonization, chemotaxis, anaphylatoxin -> ___________ of cell fragments
and flagged cells by macrophages

Answer 19

IgM/IgG bind to specific tissue antigen on cell surface -> activates complement -> cell membrane
damage and lysis via MAC, opsonization, chemotaxis, anaphylatoxin -> phagocytosis of cell fragments
and flagged cells by macrophages

Question 20

Exs of type 2

Answer 20

autoimmune hemolytic anemia, ABO mismatched blood, Grave’s disease (hyperthyroidism)

Manifestations are tissue dependent

Question 21

Type 3 is _______ ______ ______

Answer 21

Immune complex mediated

Question 22

Type 3:
Mediated by ______-____ ______ that form in blood and are deposited in the_____ ______ or_______ –> complexes perceived as an intruder –> _______ _______ where complex is deposited
–> _______ _______ –> opsonization, MAC, chemotaxis, anaphylatoxin –> neutrophils and
lysosomal enzymes –> tissue damage

Answer 22

Mediated by antibody-antigen complexes that form in blood and are deposited in the vessel wall or tissues –> complexes perceived as an intruder –> inflammatory response where complex is deposited
–> complement activation –> opsonization, MAC, chemotaxis, anaphylatoxin –> neutrophils and
lysosomal enzymes –> tissue damage

Question 23

Type 3: 2 pts

Answer 23

• IgG or IgM
• Dynamic and heterogenous

Question 24

Type 3:
Complement causes breakdown of cells, which can cause anemia/leukopenia/thrombocytopenia, kidney
damage, etc.

Ex:

Answer 24

Raynaud phenomenon, SLE, glomerulonephritis, arthritis

Question 25

Type 3: SLE is Systematic Lupus Erythematosus- it’s an _______ _____ ______ disorder- the immune system attacks ___ ___

Answer 25

autoimmune collagen vascular disorder- the immune system attacks native tissue

Question 26

Type 3: SLE
Antigen-antibody complexes are trapped in tissues –> _____ ______ ______ –>
______,_______,______,_____,____ (just remember all are _____)

o Immune complexes on cell surfaces –> complement activation –> ____ _____ –> anemia,
leukopenia, thrombocytopenia, lymphopenia (all are ____-____)

Answer 26

Antigen-antibody complexes are trapped in tissues –> intense inflammatory response –>
arthritis, dermatitis, pleuritis, pericarditis, glomerulonephritis, ITIS

o Immune complexes on cell surfaces –> complement activation –> cell lysis –> anemia,
leukopenia, thrombocytopenia, lymphopenia PENIA-deficiency

Question 27

How to differentiate type 2 and 3?

Answer 27

type 2 = only complement activation

type 3= complement activation AND immune complex

Question 28

Type 4 is _______ mediated

Answer 28

T-cell mediated

Question 29

Type 4 is NOT

Answer 29

NOT ANTIBODY Mediated

Question 30

type 4: cytotoxic t cells

Answer 30

direct destruction

Question 31

type 4: Th1 cells

Answer 31

Th1 cells recruit macrophages –> overproduction of ROS and cell lysis

Question 32

Ex type 4

Answer 32

Ex: acute graft rejection, TB skin test, poison ivy, metal allergies

Question 33

type 4:

TB skin test -> injection of tuberculin into dermis -> if there is TB in the body that the immune
system has encountered, T-cells will _____ tuberculin and form a _____ under at the injection site

Answer 33

TB skin test -> injection of tuberculin into dermis -> if there is TB in the body that the immune
system has encountered, T-cells will attack tuberculin and form a bump under at the injection site

Question 34

LPS is a common cause of

Answer 34

septic shock

Question 35

LPS is an _____ released from….. that causes a ______ _____ _____

Answer 35

endotoxin released from gram negative bacteria that causes a massive inflammatory response

Question 36

LPS stimulates ___ -> ____ stimulates degranulation of mast cells -> histamine released -> increased
_______ ________/________-> ________ -> ______

Answer 36

IgE stimulates degranulation of mast cells -> histamine released -> increased
vascular permeability/vaso dilation -> hypotension -> shock

Question 37

Viruses = intracellular pathogens

Cell-mediated immunity (T-cells) respond
to viral infections

Viruses coated by _____ go _________ by the immune system -> easy for viruses to
reach cells and ________ in -> virus will ____ ____ and go into n______ ->
multiplies, reproduces, and matures ->
________ out of cells -> puts _____ back on to move to another healthy cell

Answer 37

Viruses = intracellular pathogens

Cell-mediated immunity (T-cells) respond
to viral infections

Viruses coated by capsid go undetected by the immune system -> easy for viruses to
reach cells and endocytosis in -> virus will
shed coat and go into nucleus ->
multiplies, reproduces, and matures ->
exocytosis out of cells -> puts capsid
back on to move to another healthy cell

Question 38

For viruses- when is the window of opportunity for immune cells to detect the virus?

Answer 38

Right after exocytosis before capsid is put back on

Question 39

Interferons ..

Answer 39

limit the spread of a virus (they do not cure or kill the virus)

Question 40

Virus enters a cell -> cell is stimulated to produce
________ -> interferons leaves cell and binds to
_________ healthy cells -> interferons stimulate
healthy cells to produce ________ proteins +
interferons bind to receptors on cell _____ some viruses from binding –> antiviral proteins _____
viruses from _____ inside the cell

Answer 40

Virus enters a cell  cell is stimulated to produce
interferons  interferons leaves cell and binds to
neighboring healthy cells  interferons stimulate
healthy cells to produce anti-viral proteins +
interferons bind to receptors on cell block some
viruses from binding  antiviral proteins inhibits
viruses from replicatinginside the cell