MIDTERM - HYPERSENSITVITY Flashcards
The immune response has been described as a defense mechanism by which the body rids itself of potentially __.
harmful antigens
The immune response has been described as a defense mechanism by which the body rids itself of potentially harmful antigens
In some cases, however, this process can end up causing DAMAGE to the host
this process is called
hypersensitivity reaction
When it comes to the mechanism of the
hypersensitivity reaction the individual must first
have become __ by previous exposure to
the antigen
sensitized
hypersensitivity it can define as a
___.
heightened state of immune responsiveness
it is an exaggerated response to a harmless
antigen that results in injury to the tissue, disease, or even
death.
hypersensitivity reaction
why is mortality possible in hypersensitivity reaction?
imbalance when it comes
to the homeostasis,
British immunologists __
devised a classification system for such reactions based on
four different categories
type I-IV
hypersensitivity.
P. G. H. Gell and R. R. A. Coombs
4 DIFFERENT CLASSIFICATIONS OF HYPERSENSITIVITY
TYPE I HYPERSENSITIVITY
TYPE II HYPERSENSITIVITY
TYPE III HYPERSENSITIVITY
TYPE IV HYPERSENSITIVITY
a type of hypersensitivity reaction wherein a cell-bound antibody reacts with antigen to release physiologically active substances.
TYPE I HYPERSENSITIVITY
What would be the immune mediator of type I
hypersensitivity?
IgE
How do hypersensitivity 1 works
IgE will bind to mast cells or basophils, once coated of mast or basophil, they will release mediators such as histamine to fight allergens
a type of hypersensitivity reaction in which free
antibody reacts with antigen associated with cell surfaces.
TYPE II HYPERSENSITIVITY
What would be the immune mediator of type II
hypersensitivity?
IgM or IgG
a type of hypersensitivity in which it helps to activate the complement system by allowing the free antibodies to react and fight the allergens
TYPE II HYPERSENSITIVITY
a type of hypersensitivity reaction wherein an antibody reacts with
soluble antigen to form complexes that precipitate in the
tissues
TYPE III HYPERSENSITIVITY
a type of hypersensitivity reaction wherein a sensitized T cells rather than antibody are
responsible for the symptoms that develop.
Type IV hypersensitivity
the immune mediator for type 4 is the
t cells
types of hypersensitivity in which is involves in complement system
type 2 and 3
TYPE I, TYPE II AND TYPE III
HYPERSENSITIVITY REACTION, always remember that it has been previously referred as the ___.
immediate
hypersensitivity
why do type 1 2 and 3 are called as immediate hypersensitivity
short time lag and the reactions are can be seen in few minutes/hrs
TYPE IV HYPERSENSITIVITY is also called as
delayed type of hypersensitivity.
Type 1 hypersensitivity is also called as
anaphylactic hypersensitivity
what are the antibody mediated hyprsensitivity
1, 2,3
what are the cell mediated hyprsensitivity
type 4
a phase of type 1 hypersensitivty in which the reactions appears within minutes
after exposure to the antigen.
Early phase of allergic reaction
a phase of type 1 hypersensitivity in which the reactions appears several hours after
exposure to antigen.
Late phase allergic reactions
The key reactant presents in type I, or immediate
sensitivity reactions, is __
IgE
the “key reactant” is the same with ___
immune mediator
Antigens that trigger formation of IgE are called ___.
atopic antigens or allergens
any altered reaction to external substances.
Allergy
examples of allergy
pollens and dusts
an inherited tendency to respond naturally
occurring inhaled and ingested allergens with continued
production of IgE.
atopy
Atopy derived from the Greek word “__”
meaning “out of place”
Atopos
In severe cases of type 1 hypersensitivty, ____ can occur.
laryngeal edema, vascular collapse and
death
a general anaphylaxis composed of __
itching,
erythema (redness of the localized area), vomiting,
abdominal cramps, diarrhea and respiratory distress.
a little atopic antigens or allergens can immediately activate type 1 hypersensitivity, this is called as
general anaphylaxis
upon injection of
antigen into the skin of a sensitized animal, a local
anaphylactic reaction will occur within a few minutes.
Local or Cutaneous Anaphylaxis
Local or Cutaneous Anaphylaxis is composed of what signs and symptoms
swelling and redness – a wheal and
flare reaction
Local or Cutaneous Anaphylaxis is known for what reaction
wheal and flare reaction
It occurs when serum is transferred from an
allergic individual to a non-allergic individual, and
then the second individual is challenged with
specific antigen
Passive Cutaneous Anaphylaxis
is the reason why scientist were able to find out that the most immediate type of hypersensitivity is the type 1 is because of __
Passive Cutaneous Anaphylaxis
Passive Cutaneous Anaphylaxis is Done by 2 scientists named ___ and ___
Carl Wilhelm
Prausnitz and Heinz Kustner
in Passive Cutaneous Anaphylaxis , which serum or who’s the one being allergic to fish and who’s the one got the injection
Kustner was allergic to fish and was
injected to Prausnitz,
Etiologic Agents of type 1 hypersensitivty
o Venom from bees, wasps, hornets
o Food allergies
o Drugs
o Latex
Clinical States of type 1 hypersensitivity
o Asthma
o Eczema
o Anaphylactic shock
o Helminthic infection
found throughout the body, they
are most prominent in connective tissue, the
skin, the upper and lower respiratory tract, and
the gastrointestinal tract.
mast cells
These cells contain numerous cytoplasmic
granules that are enclosed by a bilayered
membrane.
mast cells
_____, in mast cells, which comprises approximately 10% of the total weight of granular constituents, is found in 10 times greater supply per cell than in
basophils.
Histamine
In the presence of IgE, the number of receptors
has been found to increase, indicating a possible
mechanism of upregulation during an allergic
reaction.
Basophils
MEDIATORS RELEASE FROM GRANULES
Preformed Mediators (Primary)
Newly Synthesized Mediators (Secondary)
Preformed Mediators (Primary)
histamine, heparin, eosinophil chemotactic factor of
anaphylaxis (ECF-A), neutrophil chemotactic factor,
and proteases.
In addition to immediate release of preformed
mediators, mast cells and basophils are triggered to
synthesize certain other reactants from the breakdown
of phospholipids in the cell membrane.
These products are responsible for a ___ seen within 6 to 8 hours after exposure to antigen.
late phase allergic reaction
Newly formed mediators include
platelet activating
factor (PAF); prostaglandin (PG) D2; leukotrienes (LT),
B4, C4, D4, and E4); and cytokines
The platelet activating factor that we have is the ___
thromboxane A2.
__ and ___ are mainly for smooth muscle contraction
Histamine and heparin
in inflammaton, the first thing to happen is the __
vasodilation
TESTING FOR IMMEDIATE HYPERSENSITIVITY
in vivo and in vitro
___ methods involve direct skin testing, which is the
least expensive and most specific type of testing.
In vivo
In ___, or a prick
test, a small drop of material is injected into the skin at
a single point
cutaneous testing
in in vivo methos, __, and ___ are the two skin
tests most often used.
Cutaneous and the intradermal testing
in cutaneous testing, After how many minutes minutes, the spot is examined, and the
reaction is recorded.
15 mns
A positive reaction for cutaneous testing is formation of a wheal that is __- mm greater in diameter than the negative control.
3 mm
Most likely ang ginagamit as negative control is
the ___ and then the positive control would be the ___.
saline; histamine
use a greater amount of antigen
and are more sensitive than cutaneous testing.
Intradermal testing
They are usually performed only if prick tests are
negative and allergy is still suspected.
Intradermal testing
in intradermal testing, A 1 mL tuberculin syringe is used to administer ml of test solution between layers of the skin
0.01 to 0.05 mL
in intradermal testing, The test allergen is diluted __- times more
than the solution used for cutaneous testing.
100 to 1000 times
in intradermal testing, After 15 to 20 minutes, the site is inspected for
__- formation.
erythema and wheal formation
in intradermal testing, A wheal __- mm greater than the negative control is
considered a positive test.
3 mm
We are dealing with the totality of the IgE and specific antigen that could bind to IgE.
IN VITRO METHODS - TOTAL AND SPECIFIC IgE
an invitro method that – measures total IgE
Radio Immunosorbent Test (RIST)
Uses radiolabeled IgE to compete with patient IgE for binding sites on a solid phase coated with anti IgE.
Competitive RIST
an invitro method that measures antigen specific IgE.
Radioallergosorbent assay (RAST)
It measures the antigen specific to the IgE
Radioallergosorbent assay (RAST)
Principles of the test for invitro methods remain the same, but newer
testing methods involve the use of __- or ___ rather than radioactivity.
enzyme or
fluorescent labels
RIST has largely been replaced by noncompetitive
solid-phase immunoassays due to the expense and
difficulty of working with ___.
radioactivity
Antihuman IgE is bound to a solid phase such as
___, ___, ___
cellulose, paper disk, or a microtiter well
is a noncompetitive
solid phase immunoassay in which the solid phase is
coated with specific allergen and reacted with patient
serum.
Allergen – specific IgE testing
The type II
hypersensitivity is also known as the ___
cytotoxic
hypersensitivity.
type 2 hypersensitivity
They are triggered by __
antigens found on cell surfaces.
in type 2 hypersensitvity
Antibody coats cellular surfaces and promotes
phagocytosis by both __ and ___
opsonization and activation of the
complement cascade
type 2 hypersensitivity, Antibodies can induce complement-dependent lysis or
engage macrophages and polymorphonuclear cells which
have Fc and complement receptors.
this process is called
cytolysis
this reaction is the (Incompatibility of blood
transfusion, HDN - problem with the Rh of the mother
and the infant leading to Type II hypersensitivity
transfusion reaction
a type of anemia that is the type 2 hypersensitivity is invoolved
Autoimmune Hemolytic Anemia
type 2 sensitivity
Drug-induced - Medications involved. (___) It is
seen within the skin similar to petechiae but larger.
Purpura
the difference of type 2 and type 3 are, , the antigen is
___.
soluble
When soluble antigen combines with antibody, complexes
are formed that precipitate out of the serum
whcih hypersensitivity is involved?
type 3 hypersensitiivty
Arthus Reaction
Demonstrated by __ in 1903.
Maurice Arthus
A classic example of localized Type III Hypersensitivity,
localized meaning we are dealing with a specific area.
Arthus Reaction
The inflammatory response is caused by antigen–antibody
combination and subsequent formation of immune
complexes that deposit in small dermal blood vessels.
Arthus Reaction
Complement is fixed, attracting neutrophils and causing
aggregation of platelets
Arthus Reaction
Results from passive immunization with animal serum,
usually horse or bovine, used to treat such infections as
diphtheria, tetanus, and gangrene.
Serum Sickness
for serumsickness or passive immunization,
Generalized symptoms appear in __ days after
injection of the animal serum and include headache, fever,
nausea, vomiting, joint pain, rashes, and lymphadenopathy.
7 to 21
serum sickness
Recovery takes between __ and __ days.
7 and 30
High levels of antibody form immune complexes that
deposit in the tissues.
serum sickness
Usually this is a benign and self-limiting disease.
serum sickness
type 4 hypers.
There is an initial sensitization phase of ___weeks that
takes place after the first contact with antigen.
1 to 2
in type 4 hypers
Then, upon subsequent exposure to the antigen, symptoms
typically take several hours to develop and reach a peak ___ hours after exposure to antigen
48
to 72
type 4 hypers, The reaction cannot be transferred from one animal to
another by means of serum, but only through transfer of ___
T lymphocytes
different clinical states of Type IV
hypersensitivity?
Contact dermatitis,
Tuberculin skintest
Pneumonitis.
