Allergy textbook Flashcards
T/F: Staph can reduce the efficacy of glucocorticoids.
TRUE – likely through action of superantigens
What are superoxide dismutase enzymes?
neutralize toxic reactive oxygen species generated in mitochondria by the process of oxidative phosphorylation
What do fungi cell walls contain?
chitin and beta-glucans
T/F: Der f 1 is the most common aeroallergen in the dog.
False – is the major Df allergen in humans and is almost never recognized by dogs sensitized to Df
What is the mechanism of action of capsaicin?
binds to a receptor on neurons and leads to a neuronal depletion of substance P, which is involved in pain and neurogenic inflammation
How do dendritic cells contribute to inflammatory processes?
activation of antigen-specific T cells
How are ceramides released into the extracellular space?
during differentiation of keratinocyes, lamellar granules containing glucosylceramides and sphingomyelins move to the apex of granular cells, fuse with the plasma membrane, and secrete the contents into the extracellular space of the stratum granulosum-stratum corneum boundaries; they are then converted back to ceramides by enzymes
T/F: In acute allergic responses, Th2 predominates, but in the chronic phase, Th1 response predominates
TRUE
T/F: Staphylococcal enterotoxin B is an inducer of IL-31.
TRUE
T/F: Staphylococcus can induce atopic dermatitis by itself.
TRUE – thought to be through increased proinflammatory cytokine production
T/F: Most tricyclic antidepressants can also produce antihistaminic and anticholinergic effects.
TRUE
A (decrease/increase) in the expression of kallikrein-related peptidase 7 (KLK7) has been reported in humans with AD.
increase; increased protein expression –> increased degradation of corneodesmosomal proteins in stratum corneum
How is pentoxifylline metabolized?
by liver and red blood cells - extensive enterohepatic recirculation
What are exfoliative toxins? What strains produce them?
virulence factors produced by pathogenic staphylococci that can produce blister formation in the skin. S. aureus, S. hyicus, S. pseudintermedius
T/F: There is no significant difference in the number of circulating Tregs between dogs with CAD and healthy dogs.
TRUE– however dogs undergoing ASIT will have an increase in their Tregs
What tricyclic antidepressants have been used in treatment of atopic dermatitis?
cyproheptadine (no effect), amitriptyline (some benefit), hydroxyzine (30% effective), doxepin (30% effective)
What are the intracellular proteins of corneocytes? What are their functions?
filaggrin and keratin; provide mechanical strength to cells and may hamper percutaneous entry of foreign bodies
What is TSLP?
thymic stromal lymphopoietin; modulates the function of dendritic cells – can trigger Th2 inflammatory responses
Why would anti-IgE antibodies (e.g. omalizumab) take longer to demonstrate clinical improvement with atopic dermatitis?
IgE is more stable on skin mast cells
What is the role of filaggrin in the stratum corneum?
aggregation of keratin intermediate filaments into tight bundles –> leads to collapse of the cells –> flattened appearance & mechanical strength
What is the mechanism of action of leukotriene inhibitors?
either block the synthesis or inhibit the action of leukotrienes; leukotrienes are produced from arachidonic acid & involved in mediating inflammation
IgE binds to the FceRI on what cells?
mast cells and basophils –> inflammatory mediator and cytokine release, eosinophils, dendritic cells/langerhans cells
Cross-antigenicity can occur between Ctenocephalides felis felis and what other insects?
Blatella germanica (cockroach)
T/F: Allergic skin has increased concentrations of histamine
TRUE
A single nucleotide polymorphism with the filaggrin gene is associated with atopic dermatitis in what breed?
UK Labradors
T/F: Langerhans cells express the high-affinity IgE receptor, FceRI.
TRUE
T/F: IgG antibodies develop higher levels of affinity than IgE.
True – through somatic hypermutation of the variable region gene & multiple iteration of clonal selection
What are pyrrolidone carboxylic and urocnic acids? What is their role?
degraded products of filaggrin monomers, are natural moisturizing factors