Allergy Flashcards
This is the term for an environmental Ag that elicits allergic responses in susceptible individuals. These Ags have little or no intrinsic toxicity.
Allergen
An ________ is clinically adverse reactions to environmental Ags mediated by acquired immune responses.
Allergy
An allergy is clinically adverse reactions to environmental Ags mediated by acquired immune responses which are marked by:
– The presence of allergen-specific ______
– ______ cells and _______ recruitment and/or activation
– ______-type resonses and IL-4, IL-5, and IL-13 are key elements
IgE
Mast; Eosinophils
Th2
This is the term for the propensity for developing immediate hypersensitivity reactions to common environmental allergens.
Atopy
Allergic diseases have common mechanistic aspects:
– All result from harmful immune responses
– Immune responses are driven by _________ Ags
– Immune response are all associated with the generation of ______
Non-infectious
IgE
In the past, the study of allergic diseases has focused on the ________ immune response, but today the focus has shifted to the role of _______ immune mechanisms.
Adaptive
Innate
Allergens can elicit IgE-specific responses in genetically susceptible individuals. This represents a very small group of Ags to which humans are routinely exposed to. These are a diverse group of _______ and _______.
Proteins
Glycoproteins
Activate an innate immune response by:
- An intrinsic _______ activity
- Activation of _______
*May bias the immune response toward a ____ phenotype.
Enzymatic
PRRs (Pattern-Recognition receptors)
Th2
This the term for airborne proteins or glycoproteins derived from a variety of different sources:
- Pollinating trees and grasses
- Mold spores
- Animal dander (cat, dog, and rodent)
- Particulates secretion by dust mites and cockroaches
Aeroallergens
The indoor allergens are usually associated with…
Asthma
The outdoor allergens are more important in…
Allergic rhinitis
Several allergen have _______ activity. This is an important property which may play an important role for crossing skin or mucosal barriers.
Protease
Allergens tend to be contained within carrier particles. Small particles are _________ which may be important properties in gaining aerial access to nasal and bronchial mucosa.
Aerodynamic
The source may be dominant for a particular country:
– Timothy grass pollen (hay fever) is the most prevalent pollen in the air in the ______
– Birch pollen is in __________
UK
Scandinavia
Factors favoring the ______ phenotype (Protective immunity):
- Presence of older siblings
- Early exposure to day care
- Tuberculosis, measles, or hepatitis A infection
- Rural environment
Th1
Factors favoring the ______ phenotype (Allergic diseases including asthma):
- Widespread use of antibiotics
- Western lifestyle
- Urban environment
- Diet
- Sensitization to house-dust mites and cockroaches
Th2
The tendency to allergic reactions has a strong heritability. The tendency has been termed _______.
Atopy
Atopy is most easily defined as the presence of a type ____ hypersensitivity reaction to an allergen.
I
Atopy is usually demonstrated in the ______ ______ test.
Skin prick
The potentially allergic state (atopy) does not always result in disease. Between 20 and 30 percent of the population is atopic in the ________ world.
Westernized
Parents pass on the atopic trait to their children with a risk of:
- _____ percent (two parent atopic)
- _____ percent (one parent atopic)
- _____ percent (no atopic parent)
75
50
15
The nature of what exactly predisposes to allergy is complex. Polymorphism in genes known to be involved are:
– the Beta chain of the high affinity receptor for IgE (_____)
– the ______ gene
– the ______ alleles
– the CD14
FceRIB
IL-4
HLA-DR
Since ______ constitutes part of the receptor for bacterial cell wall LPS, and infection may have a role in the development of allergy. _____ polymorphisms affecting sensitivity to pathogens could promote hypersensitivity.
CD14
CD14
Studies on HLA associations show that in a North American population ______ and ______ hypersensitivity to the ragweed Ags is associated with HLA-DR2 in patients with ragweed pollen allergy.
IgE
IgG
In monozygotic identical twins (twins with identical genes) concordance for asthma (both twins having the disease) is only ______ percent. The environmental factors have a huge role.
20
The two-fold increase in allergy in Sweden over a 12-year period arose without any fundamental change in the _______ stock of the inhabitants.
Genetic
______ hypersensitivity was much less common in East Germany before reunification with West Germany, but now is rising alarmingly. One possibility is that _______ tendencies arise during fetal or infant life.
IgE
Atopic
It has been demonstrated that high levels of IgE in the _______ blood of infants predicts future development of atopy.
Cord
T/F. The peak allergy incidence caused by birch pollen (common in Scandinavia) is found amongst children born during the months of birch pollen release (February to April).
True
What is the cause of increasing prevalence of allergies? Could by environmental changes in indoor air quality, changes in lifestyle, or the hygiene hypothesis:
- Shift from _____ to _____ type of immunity
- Decreased number/activity of ______ cells
Th1; Th2
Treg
The term “________ hypothesis” was introduced in 1989. The main postulate is: The increased incidence of allergy is associated with the decrease in exposure to common infections during early life.
Hygiene
Neonatal immune system shows a Th2-type bias. The development of atopic (Th2-type) phenotype in a child can be prevented by ______-type responses.
Th1
Infections in the childhood causing Th1-type responses (viruses and intracellular bacteria) can restore the _____/_____ balance.
Th1/Th2
The increased number of _______ cells after infections (all infections including helminthes) can limit the development of unrelated allergies (allergen-mediated disease).
Treg
What are the major sites of maturation for mast cells, basophils, and eosinophils respectively?
Connective tissue
Bone marrow
Bone marrow
What is the major development factor (cytokine) of mast cells?
Stem cell factor
IL-3
What is the major development factor (cytokine) of basophils?
IL-3
What is the major development factor (cytokine) of eosinophils?
IL-5
***Study slides 22-23
Study 5 minutes
Mast cells and basophil mediators include biogenic amines and enzymes stored preformed in ________ as well as cytokines and lipid mediators, which are largely newly synthesized on cell activation. The biogenic amines and lipid mediators induce immediate response which include vascular leakage, bronchoconstriction, and intestinal hypermotility.
Granules
Cytokines and lipid mediators contribute to ________, which is part of the late-phase reaction. Enzymes probably contribute to _______ damage.
Inflammation
Tissue
_____ pick up the allergen and migrate to a regional LN.
DCs
________ are proteins or glycoproteins.
Allergens
Allergens are processed by DCs and presented within ________ for naive T cells. Allergens stimulate DCs to produce ______.
Class II MHC
IL-4
Naive T cell specific for allergen peptide recognizes it in the context of class II MHC. Thereby a _____ cell response is activated. IL-4 bias the development of _____ cells.
Th
Th2
Activated T cell differentiates into Th2-type helper lymphocyte. Clonal expansion occurs. Th2 type cells produce _____ and _____.
IL-4
IL-13
Naive B cell (Ag-presenting) picks up allergen and processes it for presentation to Th cell. Activated Th2 cell recognizes the allergen/MHC II and releases _____ and ______. The B cell is fully activated, switches to ______ production and becomes a plasma cell. Some activated B cells become memory cells.
IL-4
IL-13
IgE
______ cells resign in the tissue, _______ are found in the circulation.
Mast
Basophils
Due to expression of _______, anti-allergen IgE are selectively bound to mast cells and basophils. ______ has very high affinity for Fc of IgE.
FceRI
FceRI
Cross linking of _______ leads to activation of the cells and release of inflammatory mediators.
FceRI
Chronic disease development begins with activation of Th2 lymphocytes and macrophages. There is recruitment and degranulation of ________.
Eosinophils
In _______ disease development, there is obstruction and increased airway responsiveness. Progression inflammation towards airway remodeling.
Chronic
Inflammatory mediators and reactions cause chronic structural changes to the airway. There is activation of tissue ________, which causes increased production of collagen and its deposition. There is also increased production of mucus by _______ cells.
Fibroblasts
Goblet
In tissue remodeling, there is smooth muscle _______ and _______. Increased risk of acute obstruction of airflow in the lung in response to irritants _______ and other irritants.
Hyperplasia
Hypertrophy
Allergens
_________ by allergen immunotherapy has an important place in the management of allergic disease.
Desensitization
Desensitization is indicated for disorders in which _____ hypersensitivity is clearly confirmed. Skin tests and allergen-specific _____ detection must be performed.
IgE
IgE
In desensitization, typical indications include life-threatening allergy to insect stings, drug allergy, and allergic rhinitis. It comprises an induction course of subcutaneous injections of increasing doses of the allergen _______, given once every 1-2 weeks.
Extract
T/F. In desensitization, once the maximum dose is achieved (usually after 6-10 weeks), maintenance injections may be required monthly for 2-3 years but may provide benefit for a further number of years.
True
This mechanism of desensitization occurs during repeated exposure to desensitizing allergen, IgG class Abs develop (especially IgG4); these compete with the pathogenic IgE for allergen binding, and/or prevent IgE-allergen complexes binding to mast cell high affinity IgE receptors.
IgG blocking antibodies
This mechanism of desensitization occurs when exposure to repeated desensitizing allergen induces Treg cells, which recognize allergen but invoke regulatory immune responses, dampening down migration, infiltration and inflammation.
Regulation
This mechanism of desensitization occurs if a shift away from Th2- to Th1-producing CD4 cells results in the generation of cytokines (i.e., IFN-y), which are inhibitory to IgE production.
Immune deviation
