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Flashcards in autoimmune diseases Deck (39)
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1
Q

Innate immunity

A
  • Inflammation
  • More WBC’s
  • No memory
  • Fast response short duration
2
Q

Adaptive immunity

A
  • T cells and B cells
  • Highly specific receptors
  • Strong memory
  • Slow response long duration
3
Q

What cells of the innate immune system are required in the adaptive system

A
  • Dendritic cells (APC’S) present antigen to T cells

- T cell cytokines activate innate cells to cause inflammation

4
Q

Phagocytic cells

A

Neutrophils - destroy pathogens
Macrophages - produce chemokines
Dendritic cells - present antigen to T cells

5
Q

Histamine producing cells

A

Mast cells, basophils, eosinophils

- Produce histamine - vasodilation and attract other immune cells

6
Q

Complement

A

Directly attacks pathogens via alternative and lectin pathways
- Activated by antibodies

7
Q

Cytokines

A

Signal between different immune cells

8
Q

Chemokines

A

Attract other immune cells to sites of inflammation

9
Q

What is autoimmunity

A

The adaptive immune system recognizes and targets the body’s own cells

10
Q

Main characteristics of autoimmunity

A
  • T cells that recognise self antigens
  • B cells and plasma cells that make autoantibodies
  • Inflammation in target cells as secondary response
11
Q

What is autoinflammation

A
  • No component of immune system

- Dysregulation of innate system

12
Q

Main characteristics of autoinflammation

A
  • Spontaneous attacks of systemic inflammation
  • No source of infection
  • Absence of high-titre autoantibodies
13
Q

Causes of autoimmune disease

A

Genes - lag in presentation
Immune regulation - checks to control the system
Environment - specific factors for diseases

14
Q

Central tolerance in the thymus

A
  • T cells in the thymus have to develop many receptors so they are auto-immune
  • If receptors in the thymus match the body’s it is an auto-reactive T cell and it gets deleted
  • If it doesn’t match self antigens, T cell released into circulation
15
Q

How are T cells made

A

Develop in bone marrow from haematopoietic stem cells and mature in the thymus

16
Q

What is +/- selection in the thymus

A

T cells with self antigens are deleted as negative selection. vice versa

17
Q

What forms T regulatory cells

A

T cells with intermediate recognition with self-antigens - Regulate the suppression and expression of different T cells

18
Q

Overcoming tolerance =

A

Autoimmune disease

19
Q

What genes cause genetic susceptibility

A

genes in the MHC

- Major histocompatibility complex

20
Q

MHC class 1

A

On all nucleated cells

  • puts antigens inside cell on surface to be read
  • Presents to CD8 cell - T killer
21
Q

MHC class 2

A

Only in immune syst. (APC’s)

- cells find antigen in environment and presents to CD4 T helper cell

22
Q

Mutation of FoxP3

A

Causes failure to develop regulatory T cells - severe autoimmunity from birth

23
Q

Mutation of PTPN22`

A

Causes T cells to be activated more easily - stronger general immune response

24
Q

Other causative autoimmunity associations

A
  • Sex/hormonal influence
  • Age
  • Sequestered antigens
  • Environmental triggers
25
Q

What is molecular mimicry

A

Antigen on surface of pathogen is the same ass antigen in harmless body cell - antibodies will react against both

26
Q

Molecular mimicry and Rheumatic fever

A

Antigen on streptococcus resembles antigen on heart valve - Antibodies attack both so people with Rheumatic fever can get heart disease as well

27
Q

How do changes in nature of autoantigens cause autoimmunity

A
  • Citrullination of proteins makes them more immunogenic
  • Tissue transglutamase alters gluten
  • Failure to clear apoptotic debris increases chances of sequestered antigens
28
Q

Mechanism of inflammatiion

A
  • TH1 cell stimulates macrophages to release cytokines
  • TH2 cells help b cells differentiate into plasma cells and make autoantibodies
  • T cells cause inflammation by inflammatory cytokines
29
Q

How are Autoreactive B cells harmful

A
  • Directly cytotoxic

- Activate complement which kill the cell

30
Q

How are Autoreactive T cells harmful

A
  • Directly cytotoxic

- Inflammatory cytokine production

31
Q

Organ specific disease

A
  • Affects a single organ
  • Autoimmunity restricted to autoantigens of that organ
  • Overlaps with diseases in other tissues
32
Q

Systemic disease

A
  • Affects several organs at the same time

- Autoimmunity associated with autoantigens found in most cells in body

33
Q

2 Autoimmune thyroid diseases

A

Hashimoto’s thyroiditis

Graves’ disease

34
Q

Hashimoto’s thyroiditis

A
  • Destruction of thyroid follicles
  • Autoantibodies of thyroglobulin
  • Leads to HYPOthyroidism
35
Q

Graves’ disease

A
  • Inappropriate stimulation of thyroid gland by anti-TSH autoantibody
  • Leads to HYPERthyroidism
36
Q

Myasthenia gravis

A
  • Autoantibodies block the ACh receptor
  • ACh can’t bind so causes muscle weakness
  • Particularly in the eyes
37
Q

Pernicious anaemia

A
  • Failure of vitamin B12 absorption
  • B12 needs intrinsic factor in gut to be absorbed
  • Autoantibody binds to intrinsic factor and blocks B12
38
Q

SLE

A
  • Apoptotic debris not cleared, immune system recognises nuclei of debris as foreign
  • Antibodies against antigens in the nuclei form immune complexes
  • Complexes circulate and deposit in any organ causing inflammation
39
Q

Connective tissue diseases

(Systemic

A
  • Systemic lupus
  • Scleroderma
    All have antibodies against nuclear antigens that cause inflammation and organ damage

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