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Year 2 Clinical Pathology > Autoimmune diseases > Flashcards

Flashcards in Autoimmune diseases Deck (56)
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1
Q

What 3 factors contribute to the development of autoimmune disease?

A

1) Genes
2) Immune regulation
3) Environment

2
Q

What is the most common gene implicated in autoimmune disease?

A

MHC/HLA

3
Q

What role do MHC/HLA genes play in autoimmune disease?

A

MHC/HLA genes have different subtypes DR1, DR2 etc. each of them has a different shape which are better at presenting particular Ags, eg. the Ab found in rheumatoid arthritis directly fits into the type of MHC gene associated with rheumatoid arthritis

4
Q

What are the 2 types of MHC/HLA?

A

Class 1 - all cells have it, important in viral infection and malignancy
Class 2 - found in APCs, pick up Ag from elsewhere in the body and take them to T cells

5
Q

What MHC/HLA gene is found commonly in Type 1 DM? 2

A

DR3,DR4

6
Q

What MHC/HLA gene is found in MS? 1

A

DR2

7
Q

What MHC/HLA gene is found in Graves Disease?

A

DR3

8
Q

What 2 MHC/HLA genes are commonly found in systemic lupus erythematosus?

A

DR2, DR3

9
Q

What 2 MHC/HLA genes are commonly found in rheumatoid arthritis?

A

DR1, DR4

10
Q

How is the FOXP3 gene implicated in autoimmune diseases?

A

Mutation of FOXP3 causes failure to develop regulatory T cells - severe autoimmunity from birth

11
Q

How is the PTPN22 gene implicated in autoimmune diseases?

A

Mutations in PTPN22 cause T cells to be activated more easily - get a stronger immune response in general

12
Q

Where does the process of developing central tolerance take place?

A

1) B cells in bone marrow

2) T cells in the thymus

13
Q

Other than genetics what other factors show a causative association with autoimmune diseases?

A

1) Sex - more common women
2) Age - more common in the elderly
3) Sequestered Ag - may be recognised as foreign by the immune system eg. cell nucleus, eye, testis
4) Environmental triggers

14
Q

Name 3 environmental for autoimmune disease development?

A

1) Infection
2) Trauma-tissue damage
3) Smoking

15
Q

Which environmental trigger is most important in rheumatoid arthritis?

A

smoking

16
Q

In what 3 ways does autoimmunity cause disease? 3

A

1) Autoreactive B cells and auto-Ab - directly cytotoxic, activation of complement, interfere with normal physiological function
2) Autoreactive T cells - directly cytotoxic, inflammatory cytokine production
3) General inflammation and end-organ damage

17
Q

What are the 2 main differences between organ specific and systemic autoimmune diseases?

A

1) Organ specific = 1 organ
Systemic = affects several organs simultaneously
2) Organ specific = autoimmunity restricted to autoantigens of that organ
Systemic = Autoimmunity associated with autoantigens found in most cells of body

18
Q

Organ specific autoimmune diseases often overlap with other organ specific diseases, which is typical?

A

Autoimmune thyroid disease

19
Q

Systemic autoimmune diseases often overlap with other non-organ specific autoimmune diseases, which are typical?

A

Connective tissue disease

20
Q

What is the basic disease process of Hashimotos thyroiditis?

A

1) Destruction of thyroid follicles by autoimmune process

2) Leads to hypothyroidism

21
Q

What are the 2 types of auto-Ab associated with Hashimotos thyroiditis?

A

1) Auto-Ab to thyroglobulin

2) Auto-Ab to thyroid peroxidase

22
Q

What is the disease process of Grave’s disease?

A

1) Inappropriate stimulation of thyroid gland by anti-TSH-autoantibody
2) Leads to hyperthyroidism

23
Q

What is the auto-Ab associated with Grave’s disease?

A

anti-TSH-autoantibody

24
Q

What is the disease process of Myasthenia Gravis?

A

Auto-Ab which bind to the Ach receptor at the neuromuscular junction, they don’t stimulate they just block it - get muscle weakness as reduced signalling

25
Q

What is the classic symptom of myasthenia gravis?

A

Fatigable muscle weakness (gets worse with repeated movement) - eyes commonly affected

26
Q

Why is pernicious anaemia a macrocytic anaemia?

A

Have enough Hb but cant produce enough red blood cells so have reduced number of cells all stuffed full

27
Q

What is the role of auto-Ab in pernicious anaemia?

A

Auto-Ab to intrinsic factor block it preventing it to form a complex with B12 required for B12 to be absorbed

28
Q

Name 4 connective tissue disorders?

A

1) Systemic lupus erythematosus
2) Scleroderma
3) Polymyositis
4) Sjogrens syndrome

29
Q

What are the 6 common symptoms of SLE?

A

1) Photosensitive rash on the face which spares the naso-labial fold (photosensitivity in general)
2) Multiple mouth ulcers
3) Alopecia
4) Arthralgia (painful joints)
5) Arthritis
6) Fatigue

30
Q

What kind of Ab are present in SLE?

A

Anti-nuclear Ab - Ab against proteins and DNA in the nuclei of cells

31
Q

What is meant by the statement ‘nuclei of cells are usually a sequestered antigen?

A

Substances within the nucleus are antigens

B cells and T cells float around the body and don’t normally contact with nuclei and this is a form of protection

32
Q

Why does the formation of anti-nuclear Ab is SLE explain the symptoms?

A

Anti-nuclear Ab bind to antigens from apoptotic cells causing 1) direct attack of tissue (eg. skin rash) or 2) immune complex deposits mediated inflammation (eg. kidney)v

33
Q

Other than the 6 main symptoms of SLE, what other 3 organs can commonly become involved, does this involvement occur in all patients?

A

1) Lungs - pleural effusion
2) Brain - cerebral lupus, seizures, strokes
3) Kidneys - lupus nephritis

34
Q

What is the disease process in lupus nephritis?

A

1) Immune complex deposition
2) Inflammation
3) Leaky glomerulus
4) Loss of renal functioning
5) Scarring
6) Irreversible renal failure

35
Q

How do you test for SLE?

A

Anti-nuclear Ab

36
Q

What is the treatment for SLE? 3

A

Immunosuppression
Glucocorticoids
B cell depletion

37
Q

What is vasculitis?

A

Inflammation of small blood vessels

38
Q

What are the 3 forms of ANCA Vasculitis?

A

1) Microscopic polyangitis (MPA)
2) Granulomatosis with polyangitis (GPA)
3) Eosinophilic granulomatosus with polyangitis (EGPA)

39
Q

What are the 2 components of Granulomatosus with polynangitis?

A

1) Granulomas (mass of inflammed tissue)

2) Polyangitis (inflammation of many vessels)

40
Q

What are the common sights of destructive lesions in granulomatosus and polynangitis? 5

A

1) Nose
2) Sinuses
3) Trachea
4) Lung
5) Orbits

41
Q

Inflammation of small vessels in what 4 organs occurs in granulomaotsus with polyangitis?

A

1) Skin
2) Kidney
3) Lung
4) Gut

42
Q

What was granulomatosus with polyangitis previously known as?

A

Wegener’s Granulomatosus

43
Q

How do you test for ANCA vasculitis?

A

Anti-neutrophil-cytoplasmic-Abs

44
Q

What is the treatment for ANCA vasculitis? 3

A

Immunosuppression
Glucocorticoids
B cell depletion

45
Q

Are patients ANA (anti nuclear Ab) positive or negative in primary raynauds?

A

ANA negative

46
Q

Are patients ANA positive or negative in secondary Raynaud’s?

A

ANA positive

47
Q

What conditions may secondary Raynaud’s be associated with?

A

Scleroderma (also SLE and other diseases)

48
Q

In which group is primary Raynaud’s common?

A

Young women

49
Q

What are the main features of Scleroderma? 3

A

1) Autoimmunity leads to ischaemia and fibrosis
2) Raynaud’s phenomenon
3) Skin thickening and tightening in fingers and face

50
Q

Fibrosis in scleroderma may affect which 3 organs?

A

1) Lungs
2) Gut
3) Kidneys

51
Q

How would you test for scleroderma?

A

Anti nuclear Ab (looking for anti-centromere or anti-Scl-70 Ab)

52
Q

What is the treatment for Scleroderma? 4

A

Immunosuppression - but often poor response
Vasodilating drugs
Cyclophosphamide
Autologous stem cell transplant

53
Q

What is meant by connective tissue diseases?

A

Not really diseases of connective tissue

Immunity against ubiquitous self antigens causes inflammation or fibrosis in any tissue

54
Q

What is the treatment for Hashimoto’s thyroiditis?

A

Replace thyroxine

55
Q

What is the treatment for Grave’s disease?

A

Block thyroid function

56
Q

What is the treatment for myasthenia gravis? 3

A

1) Acetyl cholinesterase inhibitors
2) Plasmapharesis
3) Thymectomy

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