Brainscape's Knowledge GenomeTM

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


See full index

A Haematology and Immunology > Autoimmunity > Flashcards

Autoimmunity Flashcards

1
Q

Tolerance

A
  • A state of unresponsiveness of the immune system to self

- Central and peripheral

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

What is autoimmunity?

A

Failure of organism in recognising its own constituent parts as self

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

What causes autoimmunity?

A
  • Immune regulation
  • Genetic factors
  • Environment
  • Unknown
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Autoimmunity

A

Physiological autorecognition with secondary epiphenomena

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

Autoimmune disease

A

Immune response contributing directly to tissue/organ damage

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

What is the epidemiology of autoimmune disease?

A
  • F:M 4:1
  • 10-50% of identical twins develop disease so cannot be purely genetic
  • Some HLA alleles occur in certain populations and people more often
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What are the 2 types of autoimmune disease?

A
  • Organ specific

- Non-organ specific

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

Give examples of HLA associated risk factors for autoimmune disease

A
  • Ankylosing spondylitis (B27)
  • Coeliac disease (DQ2, DQ8)
  • Multiple sclerosis (DQ6)
  • Rheumatoid arthritis (DR4)
  • Juvenile rheumatoid arthrtitis (DR8)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Give examples of cell mediated autoimmune reactions

A
  • T1DM
  • Crohn’s disease
  • Psoriasis
  • Coeliac disease
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What is the pathogenesis of T1DM?

A
  • Autoreactive T cells against pancreatic islet cell antigens, leading to destruction and non-production of insulin
  • Anti-glutamic acid decarboxylase
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

What is the pathophysiology of Crohn’s disease?

A
  • Triggered by a foreign pathogen that makes it past the mucosa of the gut leading to APC presentation
  • Autoreactive T cells against intestinal flora antigens leading to lymphocyte infiltration of exocrine glands
  • The cytokine reaction is dysfunctional and exaggerated leading to lots of macrophages creating proteases and platelet activating factors which causes inflammation
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What familial gene is associated with IBD?

A

NOD2

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

What is the pathophysiology of psoriasis?

A

Autoreactive T cells against skin associated antigens

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

What is the pathophysiology of coeliac disease?

A
  • B cells for transglutamine are helped by T cells to -Secretory IgA in mucosal membrane crosses to lamina proprieta
  • Macrophages uptake these TTG antibodies and express MCHII antibodies (HLA-DQ2)
  • CD4 Th cells release IFNy and TNF which destroy the villi, CD8 Tc destroy damaged endomysial cells
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

What is thought to be the cause of coeliac disease?

A

Thought to be caused by breakdown in immune tolerance in which a lack of T regulatory cells or the participation of Th17 cells plays a critical role in the pathogenesis of these disorders

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

What type of hypersensitivity reaction is antibody mediated autoimmunity?

A

Type II

17
Q

What happens in antibody mediated autoimmunty?

A

Antibody binds to targets leading to damage by Fc receptor macrophage with or without complement lysis

  • Can also lead to immune complex formation and deposition, activating phagocytes and causing damage (SLE)
  • Direct effect of the autoantibodies on the autoantigen affecting its function (pemphigus, myasthenia gravis)
18
Q

Give examples of antibody mediated autoimmune disease.

A
  • Goodpasture’s syndrome

- Myasthenia gravis

19
Q

What is the pathogenesis of Goodpasture’s syndrome?

A
  • IgG antibodies react to alpha 3 collagen in the lungs and kidneys (after damage/event)
  • C1 attaches to collagen and activates it by cleaving other elements.
  • This attracts other cells including neutrophils that cause enzyme release and damage
20
Q

What sites are likely to be affected in Goodpasture’s syndrome?

A

Lungs and kidneys

21
Q

What are the risk factors for Goodpasture’s syndrome?

A

Genetic
-HLA-DR15

Environmental
-Infection, smoking, solvents

22
Q

What is the distribution of age or myasthenia gravis?

A

Bimodal distribution of age

  • Young women 20-30
  • Older men 60-70
23
Q

What is the pathogenesis of myasthenia gravis?

A
  • Autoreactive T cells and B cell ACH receptor antibodies block or destroy nicotinic acetylcholine receptors at the NMJ
  • Prevents nerve impulses from triggering muscle contractions
  • Complement activation also causes local inflammation
  • Results in weakness and fatiguability
24
Q

What tumour is myasthenia gravis associated with?

A

Thymoma in 15%

25
Q

What type of hypersensitivity reaction is immune complex autoimmunity?

A

Type III

26
Q

Give an example of an immune complex autoimmune disease?

A

SLE

27
Q

What is immune complex autoimmunity?

A

Antigen-antibody/immune complex formation and deposition, activating phagocytes and causing damage

28
Q

What is the pathogenesis of immune complex autoimmunity?

A
  • A fully differentiated B cell (plasma cell) secretes Abs into serum and has Abs bound to its cell surface to act as receptors
  • Antigen cross links to surface antibodies on plasma cell and gets absorbed. B cell offers a piece of it to Th cells
  • They join via CD4 and CD40 ligands and the B cell releases cytokine which switch its Ig class.
  • This soluble antibody binds to targets leading to damage by FC receptor macrophage and or complement lysis
29
Q

What is the pathogenesis of SLE?

A
  • Failure of tolerance allowing self-reactive B/T cells to circulate
  • Leaked auto-antigen is presented to B cell, passed to Th cells and antibodies to DNA made
  • Secrets anti dsDNA antibodies
  • Complexes form from DNA fragments but are too small for macrophages to sweep up
  • They deposit in tissues (basement membrane), wherein complement is activated and neutrophils are recruited via chemokines who de-granulate and cause inflammation and necrosis
  • More DNA is released making it worse
30
Q

Why are the kidneys and joints affected in SLE?

A

Blood is filtered through the kidneys and synovium hence where the damage occurs

31
Q

Give an example of mixed autoimmunity?

A

Grave’s disease

32
Q

What is the pathophysiology of Grave’s disease?

A
  • Autoantibodies against the TSH receptor.

- Leads to activation of TSH and over-production of T3 and T4

33
Q

What is molecular mimicry?

A
  • Describes a situation in which a foreign antigen can initiate an immune response in which a T or B cell component cross-recognises self.
  • The cross reactive immune response is responsible for the autoimmune disease state
34
Q

How does molecular mimicry occur?

A

An exogenousantigenmay share structural similarities with certain host antigens; thus, any antibody produced against this antigen (which mimics the self-antigens) can also, in theory, bind to the host antigens, and amplify the immune response

35
Q

What is the pathophysiology of MS?

A
  • T cells specific to myelin cross the BBB and release cytokines
  • BBB damage, macrophage and Tc cell migration attacks oligodendrocyte
  • Despite Tr cells allowing healing, eventually the damage becomes worse
36
Q

What can contribute to MS?

A

Association with HLA-DR2 and vitamin D deficiency

37
Q

What is responsible for T cell mediated autoimmune attack in coeliac disease?

A

Gliadin

38
Q

What is component is damaged in Goodpasture’s?

A

Type 4 collagen

A Haematology and Immunology (20 decks)

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