Brainscape's Knowledge GenomeTM

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


See full index

Clinical Pathology > Theme 2 Lecture 7: Autoimmune diseases > Flashcards

Theme 2 Lecture 7: Autoimmune diseases Flashcards

1
Q

What is innate immunity and what cells does it involve?

A
  • inflammation in target tissues
  • pattern recognition against broad classes of antigen
  • fast response but short lasting
  • involves macrophage, dendritic cells, mast cells, neutrophils and complement
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What is adaptive immunity and what cells does it involve?

A
  • learned responses in immune organs
  • highly specific
  • slow response but long lasting
  • T and B cells
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Is there memory, amplification or regulation involved in innate immunity?

A

no memory, no amplification, little regulation

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

Is there any memory, amplification or regulation involved in adaptive immunity?

A

strong memory, amplification component, many regulatory mechanisms

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

How do the innate and adaptive immune systems interact?

A
  1. innate immune cells directly detect and attack antigenic targets - occurs at sites of infection, phagocytosis, cytotoxicity, inflammatory mediators and chemokines to attract other cells
  2. dendritic cells present antigen to T cells
  3. Cross talk between DCs, T cells and B cells
    - immune memory to determine specific learned responses
    - occurs in lymphoid tissues
  4. adaptive immune cells activate innate immune cells, directing tissue inflammation to specific targets
    - T cell cytokines activate monocytes, macrophages
    - B cell antibodies activate complement
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What are 3 types of phagocytic cells and what do they do?

A
  • Neutrophils: eat and destroy pathogens
  • Macrophages: eat and destroy pathogens and also produce chemokines to attract other immune cells
  • Dendritic cells: eat and destroy pathogens and also present antigen to adaptive immune system
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Name the histamine producing cells and their action

A
  • mast cells, basophils and eosinophils:
  • produce histamine, other chemokines and cytokines
  • vasodilatations - attract other immune cells
  • defence against parasites
  • wound healing
  • allergy and anaphylaxis
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What do complement do?

A
  • directly attacks pathogens via alternative and lectin pathways
  • may be activated by adaptive immune system via antibodies
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

What do cytokines do?

A

send signals between different immune cells

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

What do chemokines do?

A

Attract other immune cells to sites of inflammation

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

What are the two main actions of Th cells?

A
  • could turn into a Th1 cell which produces inflammatory cytokines
  • could turn into a Th2 cell which cross-talks with a B cell to produce plasma and memory cells
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What is autoimmunity?

A

the adaptive immune system recognises and targets the body’s own molecules, cells and tissues (instead of infectious agents and malignant cells)

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

Describe the main characteristics of autoimmunity

A
  • T cells that recognise self antigens
  • B cells and plasma cells that make autoantibodies
  • inflammation in target cells, tissues and organs is secondary to action of T cells, B cells and autoantibodies
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

What are the 4 main autoinflammatory conditions?

A

FMF, TRAPS, CAPS and HIDS

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

What are the main characteristics of autoinflammation?

A
  • seemingly spontaneous attacks on systemic inflammation
  • no demonstrable source of infection as precipitating cause
  • absence of high titre autoantibodies and antigen specific autoreactive T cells
  • no evidence of auto-antigenic exposure
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Compare autoinflammation and autoimmunity in terms of the following:

  1. Immune system involved
  2. Main cellular involvement
  3. Antibody involvement
  4. Clinical features
  5. Therapy
A
  1. autoinflammation - innate
    autoimmunity - adaptive
  2. autoinflammation - neutrophils, macrophages
    autoimmunity - B and T cells
  3. autoinflammation - few or no antibodies
    autoimmunity - autoantibodies present
  4. autoinflammation - recurrent, often seemingly unprovoked attacks
    autoimmunity - continuous progression
  5. autoinflammation - anti-cytokine (IL-1, TNF, IL-6)
    autoimmunity - anti-B and T cell
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

What are some examples of autoinflammatory conditions?

A

monogenic hereditary periodic fevers, polygenic chrohn’s disease, spondylarthropathies

18
Q

What is autoimmunity?

A

breakdown of self tolerance

19
Q

What are the 3 mechanisms of autoimmunity?

A
  1. Failure of central tolerance (T cell selection in thymus and B cell selection in bone marrow)
  2. Genetic predisposition
    - central HLA (MHC) types select for certain self-antigens
    - other genes that regulate immune functions
  3. antigenic factors/ environment
20
Q

What are examples of antigenic factors that can cause autoimmunity?

A
  • infections that trigger autoimmune responses
  • environmental triggers: UV light, smoking
  • alterations in self proteins that increase their immunogenicity
21
Q

Explain central tolerance in the thymus

A

as T cells are randomly generated in the thymus they are tested against self antigens

22
Q

What genes are MHC Class I molecules encoded by?

A

HLA-A, HLA-B, HLA-C

23
Q

Where are MHC Class I molecules found and where do they present ?

A
  • on all nucleated cells

- present antigen to CD8+ T cells

24
Q

What genes are MHC Class II encoded by?

A

HLA-DP, HLA-DQ, HLA-DR

25
Q

Where are MHC Class II molecules found and where do they present ?

A
  • found on dedicated APCs

- present antigens to CD4+ T cells

26
Q

What are other causative associations with autoimmunity?

A
  • sex (hormonal influence) - women&raquo_space; men
  • age (autoimmune more common in elderly)
  • sequestered antigens - may be recognised as foreign by the immune system e.g cell nucleus
  • environmental triggers - infection, trauma-tissue damage, smoking
27
Q

How can changes in the amount or nature of autoantigens cause immunity?

A
  • citrullination (made from amino acids - citrullinate switches places with alanine and antigen can look more foreign e.g RA)
  • tissue transglutamase alters gluten to help it bind to HLA-DQ (–> coeliac disease)
  • failure to clear apoptotic debris increases availability of sequestered antigens inside the cell e.g SLE
28
Q

Explain the features of organ-specific autoimmunity

A
  • affect a single organ
  • autoimmunity restricted to autoantigens of that organ
  • overlap with other organ specific diseases
  • autoimmune thyroid disease is typical
29
Q

Explain the features of systemic autoimmunity

A
  • affect several organs simultaneously
  • autoimmunity associated with autoantigens found in most cells of body
  • overlap with other non-organ specific diseases
  • connective tissue diseases are typical
30
Q

What is the pathogenesis of hashimotos thyroiditis?

A
  • destruction of thyroid follicles by autoimmune process
  • associated with autoantibodies to thyroglobuin and thyroid peroxidase
  • leads to hypothyroidism
31
Q

What is the pathogenesis of graves disease?

A
  • inappropriate stimulation of thyroid gland by anti-TSH autoantibody
  • leads to hyperthyroidism
32
Q

What is the pathogenesis of myasthenia gravis?

A

autoantibodies block the ACh receptor on the post synaptic receptor so nerve impulses can’t travel

33
Q

What are the symptoms of myasthenia gravis?

A
  • weakness of the eye muscles (ocular myasthenia)
  • drooping of eyelids (ptosis)
  • blurred or double vision (diplopia)
  • a change in facial expression
  • difficulty swallowing
  • shortness of breath
  • impaired speech (dysarthria)
  • weakness in arms, hands, fingers, legs and neck
34
Q

What is pernicious anaemia?

A

a condition where the body can’t make enough healthy red blood cells because it dosen’t have enough vitamin B12
It is easily treated- you can just inject B12

35
Q

What are 5 charachteristic symptoms of systemic lupus erythematosus?

A
  1. photosensitive malar rash
  2. multiple mouth ulcers
  3. arthralgia
  4. alopecia
  5. left pleural effusion
36
Q

What are sequestered antigens?

A

antigens that are shielded from the immune system

37
Q

Why might there be failure of clearance of nuclear antigens?

A
  • UV light causes DNA damage and cell death
  • in cell death by necrosis, nuclear antigens may not be cleared and may then act as antigens to the immune system
  • some people have genetic defects in mechanisms to clear cell debris
38
Q

How are immune complexes formed in the circulation?

A
  • antibodies against antigens in the nucleus combine with their target to form immune complexes
  • immune complexes deposit in any organ - activate complement and cause inflammation
39
Q

How does lupus nephritis develop?

A
  1. immune complex deposition
  2. inflammation
  3. leaky glomerulus
  4. loss of renal function
  5. scarring
  6. irreversible renal failure
40
Q

What is a immune complex?

A

antibodies bounded to antigens

41
Q

What are examples of connective tissue diseases?

A
  • SLE
  • Scleroderma
  • Polymyositis - muscle weakness
  • siogrens syndrome - autoimmune disease of exocrine glands
  • ubiquitous antigens
42
Q

Scleroderma is an autoimmune disease where the body makes too much of which protein?

A

collagen

Clinical Pathology (57 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions