hypersensitivity disorders Flashcards
hypersensitivity (or allergy) is an ____ immune response harmul to the organism itselt
exaggerated
types I, II, and III are ____ - mediated which correspond to defenses against ____ pathogens
type IV are _____ - mediated which correspond to defenses against ____ pathogens
anti-body extracellular
cell intracellular
type I hypersensitivity:
- ____ reactions
- mediated by ____ and ____ Abs that activate ____ cells and ____ to release inflammatory mediators
- also utilize ____ helper cells due to class switching (to IgE)
- triggered by ____ Ags (typically allergens)
- bind with extremely high affinity, even tiny amounts of Ag are able to elicit a massive and ____ rxn
- immediate
- allergens IgE mast eosinophils
- Th2
- environmental
- rapid
type I hypersensitivity:
- mast cells release (IgE binds to ____ on mast cells)
- ____ → vasodilation and inceased vascular permeabiltiy (preformed)
- ____ → protein degradation
- ____ → vasodilation (denovo)
- ____ → bronchospasm (asthma) and other smooth muscle contraction (denovo)
- other cytokines that lead to ____ inflammation
- FceR1
- histamine
- proteases
- prostaglandins
- leukotrienes
- local
type I exposures:
- initial allergen encounter (primary exposure)
- no ____ reaction
- DC captures, processes, and presents Ag to ____ in LN
- ____ are created to recognize specific Ag
- these IgE Abs bind ____ on ____ cells to anticipate future attack
- subsequent allergen encounter (secondary exposure)
- ____ cells are primed and ready to go due to primary exposure
- Ag binds to mast cells → ____ on mast cells
- ____ release of granules containing products of mast cells
- immediate
- CD4 (will differeniate to Th2)
- IgE Abs
- FcRe mast
- immediate
- mast
- crosslink
- immediate
- mast
type I phases:
- immeidate
- ____ after exposure and lasts about an hour
- effects
- ____ from histamine and prostaglandins
- ____ from constricted bronchioles
- ____ from increased vascular permeability of histamine
- late phase
- ____ after exposure
- effects
- infiltrate of ____ , ____ , and ____ cells
- minutes
- effects
- vasodilation
- congestion
- edema
- effects
- minutes
- hours (2-24)
- effects
- eosinophils, neutrophils, T
- effects
- hours (2-24)
examples of type I hypersensitivity:
- systemic anaphylaxis
- allergens:
- route of entry:
- response:
- acute urticaria (wheal-and-flare)
- allergens:
- route of entry:
- response:
- allergic rhinitis (hay fever)
- allergens:
- route of entry:
- response:
- asthma
- allergens:
- route of entry:
- response:
- food allergy
- allergens
- route of entry:
- response:
- systemic anaphylaxis
- drugs, serum, venoms, peanuts
- intravenous (either directly or following oral absorption into the blood)
- circulatory collapse, tracheal occlusion, death
- acute urticaria
- insect bites, allergy testing
- subcutaneous
- local increase in blood flow an vascular permeability
- allergic rhinitis
- pollens (ragweed, birth, etc), dust-mite feces
- inhalation
- edema of nasal mucosa, irritation of nasal mucosa
- asthma
- danders (cat), pollens, dust-mite feces, cold, viral infections, exercise
- inhalation
- bronchial constriction, increased mucus production, airway inflammation
- food allergy
- tree nuts, peanuts, shellfish, milk, eggs, fish
- oral
- vomiting, diarrhea, pruritis (itching) urticaria (hives), and anaphylaxis (rarely)
allergen testing (type I):
based on ____ type I hypersensitivity
positive reaction shows:
____ minutes after exposure
local
redness, swelling, itchiness
20-30
allergen specific immunotherapy (allergen - SIT):
- only ____ for allergic diseases available at this time
- is performed by the administration of ____ doses of the allergen
- mechanism
- induce peripheral ____ cell tolerance to allergens
- increase the ____ for mast cell and basophil activation by allergens
- decrease ____ -mediated histamine release by mast cells and induction of ____ and ____
- the generation of induced regulatory FoxP3+, CD4+, CD25+ ____ cells is the key mechanism in. allergen-SIT increases cytokines ____ and ____
- increases ____/____ cytokine ration
- cure
- increasing
- T
- thresholds
- IgE IgA IgG
- T
- Treg IL-10 TGF-beta
- Th1/Th2
type II hypersensitivity:
- ___ - mediated
- Ab ____ binds to tissue/cellular Ag
- Ab bind to Ag
- activate ____ ____ → recruit leukocytes and release inflammatory cytokines via (C3 and C5)
- ____ binds FcRs on ____ and ____
- typically these Ags are too big to be engulfed by phagocytes so they will release ____ enzymes and ____ → causes bystander damage
- Ab
- directly
- classical compllement
- IgG macrophages neutrophils
- lysosomal ROS
2 types of effector mechanisms of type II hypersensitivity
complement-mediated cytotoxicity
Ab-dependent cellular cytotoxicity (ADCC)
type II reaction to remember:
- graves disease
- Ab targets ____ receptor
- causes stimulation of ____ → resulting in ____
- myasthenia gravis
- Ab targets ____ receptor
- Acetylchoine can’t bind → ____ paralysis
- hemolytic anemia
- hemolytic disease of ____
- ____ induced hemolytic anemia
- rheumatic fever
- targets myocardial Ags (from confusion with ____ Ag)
- inflammation of ____ → myocarditis
- rheumatoid arthritis
- graves disease
- TSH (thryoid stimulating hormone)
- TSH → hyperthyroidism
- myasthenia gravis
- ACh
- flaccid
- hemolytic anemia
- newborn
- drug
- rheumatic fever
- streppococcal
- myocardium
hemolytic disease of newborn (type II):
- occurs when
- mom = Rh ____
- baby = Rh ____
- 1st pregnancy the baby ____
- Rh+ baby causes mother to create Rh ____
- 1st baby is not at ____ but future pregnancies are
- 2nd and future pregnancies the baby does not ____
- Rh+ baby has their blood cells ____ by mothers Abs after crossing the ____
- treatment is ____ ____ (RhoGAM) at ____ weeks
- negative
- positive
- negative
- survives
- Ab
- risk
- survive
- lysed placenta
- anti-anti Rh 28
myasthenia gravis and graves disease (type II):
- both: Abs bind ____
- myasthenia gravis
- Abs bind ____ ____ receptor (NAchR) on ____ ____
- ____ receptor to acetylcholine activation
- symptoms:
- graves disease
- Abs bind ____ ____ ____ receptors (TSHR)
- ____ receptor
- causes ____
- symptoms:
- receptors
- nicotinic acetylcholine skeletal muscles
- blocks
- muscle weakness, drooping of eyelids, impaired speech
- nicotinic acetylcholine skeletal muscles
- thyroid stimulating hormone
- activates
- hyperthyroidism
- anxiety, tremor, heat sensitivity, buldging of eyes (exophthalmos)
- thyroid stimulating hormone
goodpasture’s syndrome (type II)
- Abs bind to college on ____ and ____
- bind to ____ subunit of type ____ collagen and destroys it
- renal glomeruli → ____ ____
- pulmonary alveoli → ____ ____ ____ ____
- activates ____
- lung and kidneys
- A3 IV
- progressive glomerulonephritis
- necrotizing hemorrhagic interstitial pneumonitis
- completment