lecture 30 Flashcards
check on learning
what is hypersensitivity?
an abnormal immune response not necessarily pathogenic, but also not hyper
Type I-IV hypersensitivity involves what?
the first three involve antibodies and the last one is cell mediated
what is Type I hypersensitivity known for?
its known as classical allergy
this is a disorder of the immune system caused by harmless environmental substance known as an allergen
classical allergy
what is atopy?
when a person displays eczema, allergic rhinitis(hay fever), and allergic asthma(lower lung allergy) or all of them with genetic predisposition
how is TIH mediated?
IgE mediated, classic allergy
how is TIIH mediated?
IgG/IgM mediated, cell lysis
how is TIIIH mediated?
IgG mediated, immune complexes
how is TIVH mediated?
T cell, delayed type hypersensitivity`
what are the forms of hypersensitivity reaction?
skin contact, inhalation, ingestion, injection
for allergic symptoms to occur what must be necessary?
environmental variables and genetic susceptibility(polymorphisms in the MHC regions)
what effect on genetics impacts allergic reaction?
gene clusters of alleles, gene mutations, epigenetic modification
common allergens associated with TIH?
plant pollen, food, drugs, animal products
what are the characteristics of allergens?
small MW metabolically active proteins and mucosal exposure
sequence of events in TIH?
TLR, IgE production, mast cells, and repeat exposure (degranulation of mast cells leading to allergic symptoms (coughing, sneezing, SOB, runny eyes and nose)
what are the features of inhaled allergens that drive the IgE response?
molecular type function low dose low molecular mass high solubility high stability peptides bind to MHC II
what two factors lead to a high risk for allergies?
genes and clean environment
what are the products of mast cells?
enzymes toxic mediators cytokines chemokines lipid mediators
name the main products released by mast cells?
histamine, prostaglandins and leukotrienes, and enzymes
effects of histamine?
bronchial SM constriction, constricts intestine, vasodilation
chemotaxis, bronchoconstrict, vasodilate and mucous are the effects of mast cell product?
leukotrienes and prostaglandins
this product of mast cells breaks down connective tissue?
enzymes
main function of eosinophils?
end result?
phagocytosis and release digestive enzymes and ROS
chronic inflammation and tissue damage with persistent attempts to heal via fibrosis
what are the Type I allergy reactions?
contact allergic reactions, respiratory allergies, food allergies
mild and severe reactions of contact allergic reactions?
mild: urticaria, eczema, tenderness and hives
severe: anaphylaxis
mild and severe reactions of respiratory allergies?
mild: rhinoconjunctivitis, itching, runny nose, asthma and sinusitis
severe: anaphylaxis
mild and severe reactions of food allergies?
mild: vomiting, diarrhea
severe: anaphylaxis
4 major changes seen in asthma?
edema
inflammation
mucus production
bronchoconstriction
4 potential ways loss of tolerance can lead to food allergies?
anti CD3 antibodies
alpha beta chains of TCR
cross presentation
cytokines, ICs, immunoregulatory compounds
what are the examples of immunotherapies?
subcutaneous
sublingual
immune tolerance
systemic immunotherapies
this therapy can be administered to the patient at home?
sublingual
patient friendly, safer and effective as allergy shots
this therapy is ineffective when you stop injections and so symptoms reappear?
intravenous immunoglobulins
what happens after receiving allergy shots over a period of time?
iso class type switching from IgE to IgG and allergies disappear
what is the most successful management for unresponsive allergic reactions?
remove the allergen
how can anaphylaxis be treated?
in the early phase
sweating, impending sense of doom and itching are s/s of what?
anaphylaxis
benefits of epi?
increases BP, vasodilate the bronchials, slows degranulation
successful treatment of anaphylaxis includes?
IV, O2, supine, antihistamines, glucagon, and epipen
