Exam 2: Hypersensitivity Flashcards
Asthma or allergies is another name for:
Type 1 Hypersensitivity
Atopic
effected animals with type 1 hypersensitivity
Atopy involves:
excessive amount of IgE and exaggerated Th2 response
Antigens for Type 1 Hypersensitivity include:
disruption of intestinal microflora, parasite worms, food, animals, insect venom, etc.
Type 1 Hypersenstivity involves which antibody?
Ig E
What is IL-4 involvement in Type 1 hypersensitivity?
IL-4 is overproduced, increasing Th2 activation and B cell stimulation
What is Fc(epsilon)R?
is the receptor for IgE that has a high affinity and irreversible binding
Fc(Epsilon)RI is present on which cells?
mast cells, basophils, neutrophils, esoinophls, macrophages and DCs
Fc(epsilon)RII is present on which cells?
B cells, Nk cells, macrophages, DCs, eosinophils and platelets
What is the mechanism for Type 1 hypersensitivity reactions?
- IgE on mast cell binds antigen (requires 2 antibodies)
2. Degranulation of mast cell releases vasoactive molecules, enzymes, cytokines, chemotactic molecules
Degranulation of mast cells causes?
acute inflammation and systemic effects
Antigen binding IgE, with FceRI causes
Mast cell degranulation
Antigenbinding IgE, with FceRII causes
B cell down regulation
Complement Receptor 2 binding to FceR3 causes
B cell stimulation and survival
Mast cells are located
in the intestine, skin, airways and around nerves
Mast cells release?
proinflammatory mediators
Mast cells release what in connective tissue or skin?
Histamine and heparin
Mast cells last in connective tissue/skin for how long?
more than 6 months
Mast cells last in intestines and lungs have a life span of?
less than 40 days
What is required for mast cell reaction?
Antigen binding IgE with two IgE receptors
Within seconds what soluble mediators are released from degranulating mast cells?
via exoctyosis:
histamine, serotonin, tryptase, proteases proteoglycans
Within minutes what soluble mediators are released from degranulating mast cells?
via eicosanoid synthesis and secretion:
Leukotrienes, prostaglandins, platelet activating factor
Within Hours what soluble mediators are released from degranulating mast cells?
via cytokine synthesis and secretion:
Il-4,-4,-4,-13 and TFN alpa, MIP-1alpha
IL-33 stimulates mast cell
degranulation in presence of IgE
IL-33 stimulates Basophil
differentiation in bone marrow
IL-33 stimulates Eosinophils
as terminal effector cells of teh allergic response
Mast cells degranulation in the GI tract causes
Fluid secretion, peristalsis that leads to emptying of the GI tract via diarrhea and vomiting
Mast cells degranulation in the Respiratory Tract causes
mucus secretion, bronchoconstriction leadign to difficulty breathing
Mast cells degranulation in the Blood Vessels causes
increased vascular permeability that leads to the movement of fluids, proteins, and cells out of blood vessels into inflamed tissue
What process enhances mast cell degranulation?
Stimulation of alpha adrenoreceptors and block Beta adrenoreceptors
What chemicals stimulate alpha adrenoreceptors?
Norepinehrine and phenylephrine
What chemicals block beta adrenoreceptors?
propranolol
What processes inhibit mast cell degranulation?
Blocking alpha adrenoreceptors and stimulation of beta adrenoreceptors
what chemicals stimulate beta adrenoreceptors?
Isoproterenol, epinephrine, salbutamol
Examples of Clinical Type 1 hypersensitivity:
allergic anaphylaxis, hygiene hypothesis, milk, food alergy, allergy to vaccines and drugs, parsites, inhalant dermatitis, atopic dermatitis (molds, trees, weeds)
How to diagnose Type 1 Hypersensitivity?
intradermal skin testing, passive cutaneus anaphylaxis (PCA) and Measuring IgE
How to treat Type 1 Hypersensitivity?
avoid exposure to teh allergen, corticosteroids, antihistamines or B stimulants or alpha antagonists
Type 2 Hypersensitivity involves which antigens?
RBC antigens
What initiates RBC destruction during transfusions?
antibodies and complement
First stage clinical signs of nonmatching blood types
Hypotension, brady cardia, apnea
Second Stage clinical signs of nonmatching blood types
Hypertension, cardiac arrhythmia, increased heart rate and increased respiratory rate
Destruction of RBC because of foreign antigen is mediated by:
IgM
What is Hemolytic disease of the new born (HDN)?
appears in foals, whose blood antigens don’t match mares (pos v neg)
What are causes of Type 2 Hypersensitivity?
Drugs, infectious diseases (Equine infectious anemai, anaplasmosis, Trypanosomiasis, babesios- severeanemia)
Antigen and antibody combine with complement to form
The immune complex (IC)
The immune complex initiates what kind of hypersensitivity?
Type 3
Local Type 3 Sensitivity
Immune complexes form within the tissue
Generalized type 3 sensitivity
immune complexes are formed within the blood stream and are deposited in glomeruli in the kidney
Arthus Reaction causes
red edematous, local hemorrhage, thrombosis and tissue destruction
What is the arthus reaction?
it is inflammation of the injection site after injection of antibodies
Examples of Type 3 hypersensitivity
blue eye, hypersensitivity pneumonitis, stahylococcal hypersensitivity
How are immune complexes removed in primates?
via RBCs
How are immune complexes removed in nonprimates?
via platelets
What cells eliminate immune complexes?
Kupffer cells (liver macrophages)
Generalized type 3 hypersensitivity reactions are also referred to as
serum sickness
Type 3 hypersensitivity causes what clinical signs?
arteritis, arthritis and glomerulonephritis
Type 1 glomerulonephritis occurs where?
in mesangial and subendothelial regions
Type 3 glomerulonephritis occurs where?
in the suepithelial region
Type 2 Hypersensitivity occurs where?
glomerular basement membrane
Glomerulonephritis is a causes of
Chronic diseases, such as Equine infectious anemia, infectious canine hepatitis, african swine fever, lympe disease yometra and tumors
Type 4 hypersensitivity is also referred to as:
Delayed Type Hypersensitivity
tuberculin
inflammatory response in teh skin of an animal infected with tuberculosis following intradermal injectino of tuberculin
Type 4 hypersensitivity involves which part of the adaptive immune system?
Cellular Immune response (T cells)
Type 1-3 Hypersensitivity involves which part of teh adaptive immune system?
Humoral immune response (b cells n antibodies)
animal shows what signs of Type 4 hypersensitivity
a reaction at injection site
Tuberculin has false positives because
cross reactions with other bacteria, animals with advanced tuberculosis or tested at early stages of infection
What are examples of tuberculin tests
single intradermal, comparative, short thermal and stormont
allergic contact dermatitis occurs
if reactive chemicals are painted onto skin, bind skin proteins and resulting complex are processed by langerhans cells in the dermis
Examples of Type 4 hypersensitivity/ allergic contact dermatitis reaction
poison ivy, haptens to chrome/nickel or resin/latex
