Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Pathology > Hypersensitivities > Flashcards

Hypersensitivities Flashcards

1
Q

IgE mediated degranulation of mast cells is a key effector mechanism of which of the following inflammatory events?

A

Type I Hypersensitivity

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

What are 4 features of type I hypersensitivity?

A

Increased vascular permeability
Oedema
Acute inflammation
Infiltrate of eosinophils

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

What do type one hypersensitivies require first?

A

Prior sensitiziation -> TH2 switches on B cells via ILs

B cell produces IgE antibodies that bind to mast cell (now are armed and will degranulate next time)

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

Can type I hypersensitivites be triggered by opioids or drugs?

A

Yes - things we have never been exposed to before can cause this

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

What are preformed mediators in mast cells?

A

Histamine, heparin and tryptase

Serine proteases activate complement (anaphylotoxins)

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

What are rapidly synthesised mediators in type I reactions?

A

Prostaglandins + leukotrienes - bronchospasm + vasodilation

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

What happens in late phase type I?

A

Cellular infiltrate - onset 4-8h lasts 24h

Mast cells release chemokines -> TFN-a, IL1,3,4,5,6

Epithelial cells release eotaxin, IL6 and IL8

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

What are some examples of type I?

A

Allergic rhinitis, acute bronchial asthma, food hypersensitivity, flea bite HS

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

What is a milk allergy?

A

Milking delayed - a-casein into blood treated as foregin causing systemic anapyhylaxis and multifocal cutaneous oedema

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

What is canine and feline atopy?

A

Allergic dermatitis - from ingested or inhaled antigen

Genetic predisposition (increased IL4) to develop Ag-specigic IgE and IgG against environmental antigens and antibodies attach to cutaneous mast cells

Re-exposure to antigens by any route provokes cutaneous type I hypersensitivity

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

How does desensitisation work?

A

High dose of antigen stimulates TH1 response = IgG production

Activates macrophages to produce IL12 and present antigens to CD4

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

How is type II described?

A

IgG and IgM mediated - IgG binds to self or foreign agntigens coated onto cells stimulating phagocytosis

NKC, copmlement mediated lysis of cell = tissue damage against own cells

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

What is antibody dependent cytotoxicity?

A

Involved in type II

IgG binds with complement -> MAC -> opsonins + chemotaxis for neutrophils + eosinophils damaging accidentally targeted cells

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

What is drug induced immune mediated haemolytic anaemia?

A

Type II reaction

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

What is haemolytic anaemia?

A

Type II - maternal IgG attack fetus erythrocytes (by colostrum)

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

What are myasthenia gravis and pemphigus vulagaris part of?

A

Type II hypersensitivity

Myasthenia - response against nicotinic acetylcholine receptor

Pemphigus - keratinocyte antigens

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

What are two types of immune mediated haemolysis?

A

Extravascular - rbc agglutination and rbc phagocytosis by splenic macrophage = jaundice + anaemia

Intravascular - complement binding + activation rbc lysis and red urine

18
Q

what is type III response?

A

Lots of antigen -> excess antigen and IgG and IgM complexes form in blood that precipitate in tissues (glomeruli, vessel walls)

Activates complement

Usually chronic disease

Neutrophils attracted to complex causing inflammation

19
Q

What can stimulate type III?

A 
Large doses of antigen
Pyometra
Persistent infectious agents
Repeatedly inhaled things
Persistently available self antigen (lupis)
20
Q

Examples of Immune complex diseases (Type III)

A 
EIA
Adrican swine fever
Liver fluke in cattle
Pyometra
Infectious canine hepatitis
21
Q

What is immune complex glomerulonephritis?

A

Circulating Ab:Ag complex deposits in glomerulus

Antibodies leave circulation and complex with glomerular self antigens or endo/exogenous antigens in glomerulus

African swine fever

22
Q

Membranoproliferative glomerulonephritis

A

Subendothelial immune complex deposited

Reactive prolferation of mesangial cells

Thickened glomerular capillary BM and amyloid deposits

23
Q

What is type IV?

A

cell mediated/delayed type

No antibody involvement

depends on Ag specific sensitised T cells to be present to react (infiltration of tissue by monocytes + lymphocytes)

Intensity delayed until 48-72h

24
Q

Cell mediated vs delayed type

A

Protective CMI beneficial

Normal immune respone to poorly digestible antigen

Immunopathological DTH deleterious + causing chronic lymphocyte + granulomatous inflammation

25
What is tuberculin reaction?
Type IV
26
What is canine allergic contact dermatitis?
Type IV - intitiated by transdermal absorbed haptens (formaldehyde) IFN-g from CD8+ and CD4+ cells attracts monocytes + lymphocytes
27
Self tolerance
Central clonal deletion of self-reactive T cells and B cells in fetal thymus and bone marrow - t cell receptors on trial in thymus (self react = deleted)
28
What are anatomically sequestered antigens?
Exposed by tissue damage - milk allergy, post traumatic sympathetic uveitis, sperm granulomas
29
What is molecularly sequesered antigen?
exposure of epitopes normally hidden in globular proteins
30
What is bacterial superantigens?
+++ immunostimulatory proteins = bind to MHC and T cell receptor domains, activating large % of bodies APCs and T lymphocytes
31
Which of the following protects spermatozoa from immune attack? a. High background levels of IL-1a, Il-6 and TGF-b and Activin-A in the testis. b. Immune tolerance generated by Hassall's corpuscles during thymus development. c. Low expression of MHC-I by spermatogonia. d. Down-regulation of IL-17 by spermatogonia and spermatocytes.
a. High background levels of IL-1a, IL6 and TGF-b and activin-A in the testis
32
What is canine phemigus?
Bullous vesicular disease - lesions appear at mucocutaneous junctions
33
What are two examples of inherited immunodeficiency?
Chediak-higashi syndrome Severe combined immune deficiency of arabs
34
25. Chédiak-Higashi Syndrome results in: a. Normal CD8+ cytotoxicity & NK functions but impaired B-cells. b. Failure of phagolysosome formation in neutrophils and macrophages. c. Failure of phagocytosis by neutrophils. d. Normal circulating neutrophil numbers but abnormal neutrophil granules. e. A defective adaptive immune system due to a defective immunoglobin gene.
d. Normal circulating neutrophil numbers but abnormal neutrophil granules.
35
Chediak-higashi syndrome
Neutropaenia and partial albinism Neutrophils, macrophages, lymphocytes and melanocytes have defective giant intracellular granules due to microtubule effect Neutrophils and macrophages can phagocytose but phagolysosome fusion is delayed Cd8+ cytotocivity and NK impaired - B cells are fine
36
24. Severe Combined Immune Deficiency (SCID) in Arabian foals has which of the following features? a. There is partial failure of adaptive immune responses. b. Antibody response is retained. c. Defective Ig gene results in loss of B and T cell receptors. d. They can be diagnosed at age 1 week by measuring plasma IgG. e. Haematology at 1 week of age reveals an absence of circulating lymphocytes (absolute lymphocytopaenia).
c. Defective Ig gene results in loss of B and T cell receptors.
37
SIDS
Complete failure of adaptive response - coat linked autosomal recessive Defective B and T cell receptors Normal at birth, fine until 1-3 months surviving on colostrum - rely only on neutrophils Dead by 5 months
38
Acquired immunodeficiency examples
Retrovirus/lentivirus AIDS like - decreased T cell function (FIV, SIV) T-2 toxin, corticosteroids
39
23. In older animals which of the following is a recognised feature of immunosenescence? a. There is a random deletion of CD4 lymphocytes b. Phagocytes increase in number to counteract a decline in lymphocytes. c. Response to vaccination is usually still strong. d. There is an increase in CD4:CD8 lymphocyte ratio e. There is diminished self-renewal capacity of haematopoietic stem cells.
e. There is diminished self-renewal capacity of haematopoietic stem cells.
40
Immunosenescence
Gradual deterioration of immune system with aging Decreased self-renewal of haematopoietic stem cells Less phagocytes NK cells less cytotoxocity function Decline in humoral immunity Reduction in CD4:CD8 ratio

Pathology (6 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2025 Bold Learning Solutions. Terms and Conditions