Allergy textbook Flashcards

1
Q

T/F: Staph can reduce the efficacy of glucocorticoids.

A

TRUE – likely through action of superantigens

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What are superoxide dismutase enzymes?

A

neutralize toxic reactive oxygen species generated in mitochondria by the process of oxidative phosphorylation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

What do fungi cell walls contain?

A

chitin and beta-glucans

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

T/F: Der f 1 is the most common aeroallergen in the dog.

A

False – is the major Df allergen in humans and is almost never recognized by dogs sensitized to Df

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

What is the mechanism of action of capsaicin?

A

binds to a receptor on neurons and leads to a neuronal depletion of substance P, which is involved in pain and neurogenic inflammation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

How do dendritic cells contribute to inflammatory processes?

A

activation of antigen-specific T cells

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

How are ceramides released into the extracellular space?

A

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

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

T/F: In acute allergic responses, Th2 predominates, but in the chronic phase, Th1 response predominates

A

TRUE

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

T/F: Staphylococcal enterotoxin B is an inducer of IL-31.

A

TRUE

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

T/F: Staphylococcus can induce atopic dermatitis by itself.

A

TRUE – thought to be through increased proinflammatory cytokine production

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

T/F: Most tricyclic antidepressants can also produce antihistaminic and anticholinergic effects.

A

TRUE

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

A (decrease/increase) in the expression of kallikrein-related peptidase 7 (KLK7) has been reported in humans with AD.

A

increase; increased protein expression –> increased degradation of corneodesmosomal proteins in stratum corneum

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

How is pentoxifylline metabolized?

A

by liver and red blood cells - extensive enterohepatic recirculation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

What are exfoliative toxins? What strains produce them?

A

virulence factors produced by pathogenic staphylococci that can produce blister formation in the skin. S. aureus, S. hyicus, S. pseudintermedius

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

T/F: There is no significant difference in the number of circulating Tregs between dogs with CAD and healthy dogs.

A

TRUE– however dogs undergoing ASIT will have an increase in their Tregs

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

What tricyclic antidepressants have been used in treatment of atopic dermatitis?

A

cyproheptadine (no effect), amitriptyline (some benefit), hydroxyzine (30% effective), doxepin (30% effective)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

What are the intracellular proteins of corneocytes? What are their functions?

A

filaggrin and keratin; provide mechanical strength to cells and may hamper percutaneous entry of foreign bodies

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

What is TSLP?

A

thymic stromal lymphopoietin; modulates the function of dendritic cells – can trigger Th2 inflammatory responses

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

Why would anti-IgE antibodies (e.g. omalizumab) take longer to demonstrate clinical improvement with atopic dermatitis?

A

IgE is more stable on skin mast cells

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

What is the role of filaggrin in the stratum corneum?

A

aggregation of keratin intermediate filaments into tight bundles –> leads to collapse of the cells –> flattened appearance & mechanical strength

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

What is the mechanism of action of leukotriene inhibitors?

A

either block the synthesis or inhibit the action of leukotrienes; leukotrienes are produced from arachidonic acid & involved in mediating inflammation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

IgE binds to the FceRI on what cells?

A

mast cells and basophils –> inflammatory mediator and cytokine release, eosinophils, dendritic cells/langerhans cells

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

Cross-antigenicity can occur between Ctenocephalides felis felis and what other insects?

A

Blatella germanica (cockroach)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

T/F: Allergic skin has increased concentrations of histamine

A

TRUE

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

A single nucleotide polymorphism with the filaggrin gene is associated with atopic dermatitis in what breed?

A

UK Labradors

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

T/F: Langerhans cells express the high-affinity IgE receptor, FceRI.

A

TRUE

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

T/F: IgG antibodies develop higher levels of affinity than IgE.

A

True – through somatic hypermutation of the variable region gene & multiple iteration of clonal selection

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

What are pyrrolidone carboxylic and urocnic acids? What is their role?

A

degraded products of filaggrin monomers, are natural moisturizing factors

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
29
Q

What are the main storage mites involved in allergy?

A

Acarus siro, Glycyphagus destructor, Tyrophagus putrescentiae, and Lepidoglyphus sp.

30
Q

T/F: The presence of a dog greatly increases the number of mites in house dust.

A

FALSE

31
Q

What are proposed mechanisms of action of pentoxifylline?

A

effects on leukocyte deformability and decreases platelet activation, decreases endothelial leukocyte adnesion, neutrophil degranulation, production of cytokines such as TNF, and inhibits T and B-cell activation

32
Q

Atopic dermatitis

A

genetically predisposed inflammatory and pruritic allergic skin disease with characteristic clinical features, associated with IgE antibodies most commonly directed against environmental allergens

33
Q

What is the mechanism of action of misoprostol?

A

synthetic prostagalndin E1 analogue; blocks one of the COX inflammatory pathways

34
Q

What are the three major lipid constituents of the extracellular lipid lamellae in the mammalian stratum corneum?

A

ceramides, cholesterol, free fatty acids

35
Q

What are reported side effects of misoprostol?

A

vomiting and diarrhea

36
Q

What conditions are favored for storage mites?

A

humidity and heat

37
Q

A (decrease/increase) in expression of claudin-1 gene has been reported in humans with AD.

A

decrease – claudin-1 is a major constituent in tight junctions

38
Q

What specific virulence mechanism of staphylococci can cause lesions that mimic pemphigus foliaceus?

A

exfoliative toxins (EXI and ExpB) – cause epidermal splitting mediated through desmoglein-1

39
Q

TEWL may be influenced by what factors?

A

impaired barrier function, edema, excoriation of inflamed skin

40
Q

What is role of TARC?

A

thymus and activation-regulated chemokine; chemoattractant of Th2 cells

41
Q

IFN-gamma is (increased/decreased) in atopic animals compared to healthy animals.

A

decreased

42
Q

What are staphylococcal superantigens? How do they work?

A

exotoxins exhibiting polyclonal T-lymphocyte proliferating activity, enterotoxins and toxic shock syndrome toxin; can recruit T cells to the skin

43
Q

______ are sphingoids consisting of sphongoid bases that are amide-linked to fatty acids.

A

Ceramides

44
Q

T/F: When the amount of disease-related, allergen-specific IgE is small in comparison to total IgE, efficacy of omalizumab is higher.

A

TRUE

45
Q

Atopy

A

Genetically predisposed tendency to develop IgE-mediated allergy to environmental allergens

46
Q

T/F: Transepidermal water loss in non-lesional skin of dogs with AD is equal to that of healthy dog skin.

A

False – TEWL is higher in both lesional & non-lesional skin of dogs with AD (though it is higher in lesional skin)

47
Q

What are the three major aeroallergens defined in the dog?

A

Derived from Dermatophagoides farinae (Der f 15, Der f 18, and Zen 1) & pollen of Japenese cypress trees

48
Q

What is affinity maturation with respect to IgE?

A

increase in binding affinity of antibodies for an allergen epitope that occurs during B cell clonal selection as a function of hypermutation in the immunoglobulin gene variable region

49
Q

What is RANTES?

A

CCL5 – chemokine that induces leukocyte migration, specifically eosinophils; part of Th1 response

50
Q

What cells release TSLP?

A

keratinocytes

51
Q

What do house dust and storage mites eat?

A

protein-rich substrates like dandruff, hair, nail, feathers, and mold

52
Q

T/F: Cross-sensitization can occur between house dust mites and Sarcoptes.

A

True – as well as Cheyletiella and Otodectes

53
Q

What role do superantigens play in atopic disease?

A

able to promote Th2 polarized skin inflammation, IgE production, T-regulatory cell subversion, expansion & migration of skin-homing T cells, and IgE antisuperantigen production

54
Q

T/F: Dogs and humans are both colonized by M. pachydermatis.

A

False - only dogs

55
Q

T/F: Animals sensitized to house dust mites will also have a positive IgE to Sarcpotes scabiei.

A

False – though they can be sensitized to Sarcoptes as well

56
Q

What is the major constituent in keratohyalin granules?

A

profilaggrin (precursor protein of filaggrin)

57
Q

What is the mechanism of action of tacrolimus?

A

calcineurin inhibitor – binds intracellular protein and forms complex with calcium, calmodulin and calinceurin which inhibits phosphatase activity of calcineurin – blocks activation of nuclear factor of activated T cells

58
Q

What is the role of IL-23?

A

development of Th17 lymphocytes, secreted by activated dendritic cells, monocytes, and macrophages

59
Q

What is the proposed mechanism of serotonin uptake inhibitors and pruritus?

A

serotonin is one of the preformed inflammatory mediators released with mast cell degranulation

60
Q

____ activity has recently been identifid as a candidate virulence factor in M. pachydermatis infection in dogs.

A

phospholipase

61
Q

What does S. pseudintermedius bind to in the dog’s skin?

A

corneocytes, fibronectin & fibrinogen

62
Q

Where are antimicrobial peptides stored in the keratinocyte? When are they released?

A

stored in lamellar bodies, released in the upper layers of the epidermis in the course of keratinization

63
Q

Atopic-like dermatitis

A

inflammatory and pruritic skin disease with clinical features identifical to CAD but an IgE response cannot be documented with serology or IDAT

64
Q

How can staphylococcal superantigens promote a hypersensitivty reaction?

A

SAGs can promote IgE production

65
Q

IS the activity of anti-microbial peptides increased or decreased with staphyloccal skin infections?

A

decreased – staph can produce proteases that break down AMPs

66
Q

T/F: Both gamma-IFN and IL-4 inhibit Th17 differentiation.

A

TRUE– but they stimulate Th1 and Th2 differentiation

67
Q

What is the optimal micoclimate for domestic house dust and storage mites?

A

20-30ºC and 80-90% humidity

68
Q

Besides inciting pruritus, what other role can histamine play in allergic disease?

A

recruitment of leukocytes, enhancement of secretion of proinflammatory cytokines (IL-1 and IL-6) and chemokines (RANTES and IL-8), promotes activation of dendritic cells

69
Q

T/F: Canine and human AD have been associated with loss-of-function filaggrin mutations and altered filaggrin expression.

A

TRUE

70
Q

What surface cell markers are displayed on Tregulatory cells involved in the pathogenesis of allergic disease?

A

CD4+, CD25+, Foxp3+: all suppress the Th2 response to allergens

71
Q

What does omalizumab target?

A

the epitope on IgE that is bound by FceRI