Hypersensitivity Flashcards
Altered immunologic response to an antigen means
damage to the host
An allergy is an ________ ______ ____ against _____ _____
An allergy is an exaggerated immune response against environmental antigens
Autoimmunity is when the immune response is
directed against self (lupus)
Type 1 Hypersensitivity is
IgE mediated
Type 1
Mild β
______ (environmental antigen) is perceived as an ______ and it amounts a ______ immune response π‘ͺ IgE responds and ______ _____ cells π‘ͺ mast cells degranulate and release _______
π‘ͺ histamine binds to ____ receptors (not all) π‘ͺ some _____________, ____________, increased _______ ___________
Mild β
Allergen (environmental antigen) is perceived as an antigen and it amounts a localized immune response π‘ͺ IgE responds and activates mast cells π‘ͺ mast cells degranulate and release histamine π‘ͺ histamine binds to H1 receptors (not all) π‘ͺ some bronchoconstriction, vasodilation, increased capillary permeability
Signs and symptoms of Type 1 Mild response
Ex:
itching,
urticaria (hives),
conjunctivitis,
rhinitis,
GI cramps,
hypotension, bronchospasm
Ex: hay fever, food allergies
Treatment for hypersensitivity type 1
antihistamines (because there are still H1 receptors open) and desensitization
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 ____
rapid
Type 1- severe
Anaphylaxis is _____, ______, and ______
Anaphylaxis is severe, immediate, and systemic
Anaphylaxis begins as ____ then gets into blood and becomes ______
begins as local, becomes systemic
Ex of anaphylaxis reaction (type 1 severe)
Bee sting, penicillin allergy, shellfish allergy
severe type 1 :
Allergen is perceived as an antigen β> ___ responds and
activates ______ cells β> degranulation β> _____ release β> histamine bind to virtually ____ ___ receptors (no room for antihistamine to bind) β> _____/____
_________, ___________, and _____ _____ ______
Allergen is perceived as an antigen β> IgE responds and
activates mast cells β> degranulation β> histamine release β> histamine bind to virtually ALL H1 receptors (no room for antihistamine to bind) β> massive/systemic
vasodilation, bronchoconstriction, and increased
capillary permeability
severe type 1-
S/S = itching, erythema, HA, N/V/D, abdominal cramps,
______, bronchospasm, ______ _______, vascular
______ from severe _______
itching, erythema, HA, N/V/D, abdominal cramps,
dyspnea, bronchospasm, laryngeal edema, vascular
collapse from severe hypotension
Anaphylaxis can result in
anaphylactic shock (respiration becomes
difficult, BP drops, smooth muscles of bladder/GI tract
contract, bronchoconstrictio)
Anaphylactic shock: remember
histamine β> vasodilation β> hypotension
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 ____ ______
must treat with epinephrine as there are no
H1 receptors available for antihistamines to bind to
o Epinephrine will increase cardiac contractility,
βvascular perm, improve cardiac output, and relaxes smooth muscles (bronchodilation)
Type 2 hypersensitivity is _____ mediated (____ or ____)
antibody mediated (IgM or IgG)
Type 2 is
tissue specific and causes complement
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
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
Exs of type 2
autoimmune hemolytic anemia, ABO mismatched blood, Graveβs disease (hyperthyroidism)
Manifestations are tissue dependent
Type 3 is _______ ______ ______
Immune complex mediated
Type 3:
Mediated by ______-____ ______ that form in blood and are deposited in the_____ ______ or_______ β> complexes perceived as an intruder β> _______ _______ where complex is deposited
β> _______ _______ β> opsonization, MAC, chemotaxis, anaphylatoxin β> neutrophils and
lysosomal enzymes β> tissue damage
Mediated by antibody-antigen complexes that form in blood and are deposited in the vessel wall or tissues β> complexes perceived as an intruder β> inflammatory response where complex is deposited
β> complement activation β> opsonization, MAC, chemotaxis, anaphylatoxin β> neutrophils and
lysosomal enzymes β> tissue damage
Type 3: 2 pts
- IgG or IgM
- Dynamic and heterogenous
Type 3:
Complement causes breakdown of cells, which can cause anemia/leukopenia/thrombocytopenia, kidney
damage, etc.
Ex:
Raynaud phenomenon, SLE, glomerulonephritis, arthritis
Type 3: SLE is Systematic Lupus Erythematosus- itβs an _______ _____ ______ disorder- the immune system attacks ___ ___
autoimmune collagen vascular disorder- the immune system attacks native tissue
Type 3: SLE
Antigen-antibody complexes are trapped in tissues β> _____ ______ ______ β>
______,_______,______,_____,____ (just remember all are _____)
o Immune complexes on cell surfaces β> complement activation β> ____ _____ β> anemia,
leukopenia, thrombocytopenia, lymphopenia (all are ____-____)
Antigen-antibody complexes are trapped in tissues β> intense inflammatory response β>
arthritis, dermatitis, pleuritis, pericarditis, glomerulonephritis, ITIS
o Immune complexes on cell surfaces β> complement activation β> cell lysis β> anemia,
leukopenia, thrombocytopenia, lymphopenia PENIA-deficiency
How to differentiate type 2 and 3?
type 2 = only complement activation
type 3= complement activation AND immune complex
Type 4 is _______ mediated
T-cell mediated
Type 4 is NOT
NOT ANTIBODY Mediated
type 4: cytotoxic t cells
direct destruction
type 4: Th1 cells
Th1 cells recruit macrophages β> overproduction of ROS and cell lysis
Ex type 4
Ex: acute graft rejection, TB skin test, poison ivy, metal allergies
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
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
LPS is a common cause of
septic shock
LPS is an _____ released fromβ¦.. that causes a ______ _____ _____
endotoxin released from gram negative bacteria that causes a massive inflammatory response
LPS stimulates ___ -> ____ stimulates degranulation of mast cells -> histamine released -> increased
_______ ________/________-> ________ -> ______
IgE stimulates degranulation of mast cells -> histamine released -> increased
vascular permeability/vaso dilation -> hypotension -> shock
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
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
For viruses- when is the window of opportunity for immune cells to detect the virus?
Right after exocytosis before capsid is put back on
Interferons ..
limit the spread of a virus (they do not cure or kill the virus)
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 β> antiviral proteins _____
viruses from _____ inside the cell
Virus enters a cell ο cell is stimulated to produce
interferons ο interferons leaves cell and binds to
neighboring healthy cells ο interferons stimulate
healthy cells to produce anti-viral proteins +
interferons bind to receptors on cell block some
viruses from binding ο antiviral proteins inhibits
viruses from replicatinginside the cell
