Immunopathology 2 Flashcards
HYPERSENSITIVITY REACTIONS
Here the organism responds to _____ with an antigen that it ______ and to which it is _____.
renewed contact
already knows
hypersensitive
Adverse reactions caused by immune mechanisms in which there is damage to the tissues/organs in the body.
Gell & Coombs classification
1) _______
2)_________
3)____________
4)__________ H.R
Anaphylactic
Cytotoxic/Cytolytic
Immune complex/Toxic complex rxn
Cell mediated
The first 3 in types of HR reactions requires ______. They are also (delayed or immediate?) H.R, ____hrs after exposure
The last is ____ mediated( ______ and ____)-(delayed or immediate?) H.R., _____hrs after exposure
antibodies(plasma cells); immediate; 2-6
cell ; Tcells & Macrophages; delayed ; 24-36
Hypersensitivity
Excessive pathogenic reaction of a ________ body to _______ contact with the ________
sensitized
renewed; sensitizing antigen.
H.R.- TYPE I
Common allergens in immediate- hypersensitivity reactions causing _____ symptoms include:
____,_____, and _____
Cat antigen and other ______ antigens
____ mite fecal pellet antigens
Mold spores
respiratory
Tree, grass, and weed pollens
animal dander
Dust
HR TYPE 1
Many allergens are environmental substances that are harmless for most individuals. Some individuals apparently inherit genes that make them susceptible to allergies. This susceptibility is manifested by the propensity of these individuals to make strong ____ responses and, subsequently, ____ antibody against the allergens.
TH2
IgE
HR TYPE 1
On first exposure,
____ gets implanted on ____ of ___ cells & ______
This causes ______ of the those cells
2nd exposure causes _________ Fc on surface of the mast cells
Mast cells becomes stimulated to __________
The process is called ______
IgE; FcR
mast; basophils
priming; cross linking of IgE
release all its products.
mast cell degranulation
In HR TYPE 1
Complement is involved
T/F
F
not
HR TYPE 1 PATHOGENESIS
Allergens may be introduced by inhalation, injection or ingestion
*____ cells are often recruited to the site of allergic reactions in response to chemokines that are produced locally; among these chemokines is _____, which also recruits ______ to the same site.
TH2
eotaxin
eosinophils
TYPE 1 PATHOGENESIS
IL-__ stimulates B cells specific for the allergen to undergo ______ to IgE and to secrete this isotype.
IL-___ activates _____ that are recruited to the reaction, and
IL- ___ acts on ____ cells and stimulates ______
4; heavy-chain class switching
5 ; eosinophils
13; epithelial; mucus secretion
Mast cells express a high-affinity receptor for the ___ portion of the __ (light or heavy?) chain of IgE, called _____.
Fc
ε
Heavy
FcεRI
______ are the circulating counterparts of mast cells.
Basophils
role of basophils in most immediate hypersensitivity reactions is not established
T/F
With reason
T
since these reactions occur in tissues and not in the circulation
Mention 3 cells that express the Fc3RI
Mast cell
Basophils
Eosinophils
The third cell type that expresses FcεRI are eosinophils, which are often present in these reactions and also have a role in IgE-mediated host defense against _______ infections
helminth
H.R.-TYPE I
Primary mediators (such as _____,______,____,____,_____,_____ )
cause vaso____, broncho______, etc.
and release of secondary mediators (such as _______,______,_____, and ______)
which lead to inflammatory cell infiltrates.
histamine, serotonin,NCF,ECF,proteases
dilation; constriction
leukotrienes, prostaglandin, PAF, cytokines
HR TYPE 1
CHEMOTAXIS- ____,_____,____
VASOACTIVITY- ______________
SMOOTH MUSCLE SPASMS- ______________
LTB4,ECF,NCF
histamine, PAF, LTC4, D4, E4, neutral protease,PGD2
LTC4,D4,E4,histamine,PG,PAF
HR TYPE 1
Consequences of the mediators
___ease vascular permeability
_____ of lining epithelium
___ease glandular secretion
Smooth muscle (relaxation or contraction?)
Inflammatory cell attraction( _______ and _______)
Incr
Edema
Incr
contraction
eosinophils & neutrophils
HR TYPE 1 Important medical conditions fall into this category
Systemic anaphylaxis: Classic examples are _________ and ______
In some individuals, a severe reaction occurs within minutes, leading to symptomatology such as acute _____, _____ edema, diarrhea, ______, and _____.
penicillin allergy and bee sting allergy.
asthma
laryngeal
urticaria
Shock
HR TYPE 1
Local anaphylaxis (_____)
Classic examples are food allergies and hay fever to ragweed pollen
atopy
About ____% of people have “atopy” and are easily sensitized to allergens that cause a _____ reaction when inhaled or ingested.
This can produce _____,_____,_____ , etc..
10
localized
hay fever, hives, asthma
H.R.-TYPE II
Type II hypersensitivity –cytotoxic
Definition
Ig_ or Ig__ against specific target in the body (cell or receptor)
Pathogenesis: once ____ is attached, the cell would be injured by either _______ or ______
M; G
Antibody; complement or cell mediated cytotoxicity
HR TYPE 2
•Complement-dependent cytotoxicity
-__________ anemia : Body is producing _____ against ______ & attaching to it
•Antibody-dependent cell-mediated cytotoxicity
_______ anemia
•Anti-receptor antibodies
Activate receptors- ______ disease Ab against a specific receptor
Autoimmune hemolytic; auto-ab
its own rbc
Pernicious
Grave’s
Complement dependent reactions:
Antibody is directed against antigen on cells (such as circulating ______) or extracellular materials (________).
The resulting Ag-Ab complexes activate _____ (via the ____ pathway), leading to _____ or extracellular tissue damage.
red blood cells; basement membrane
complement; classic
cell lysis