Immunology of Autoimmune disease Flashcards Preview

The Musculoskeletal System > Immunology of Autoimmune disease > Flashcards

Flashcards in Immunology of Autoimmune disease Deck (35):
1

Everone has low levels of autoantibodies or autoreactive T cells.

True or false?

True

2

In order for autoimmunity to occur, there must be a _________ susceptibility followed by an ___________ ________ or ___________

Genetic

Initiating event or trigger

3

What is IPEX syndrome?

Immunodysregulation polyendocrinopathy enteropathy X-linked syndrome

An inherited condition which involves a mutation in the FOXP3 gene 

This gene is responsible for regulatory T cells which means autoimmunity is abundant in IPEX syndrome

4

How can IPEX syndrome treated?

Haematopoeitic stem cell transplant

Use of immunosuppressive drugs

5

How are hugely diverse B and T cell populations obtained?

T cell receptor alpha and beta chain gene segments are randomly re-arranged creating a huge variety of B and T cells

However, this also means the likelyhood of autoreactivity increases

6

What are the two tolerance mechanisms which try to counteract autoreactivity?

  1. Central tolerance - the removal of self-reactive lymphocytes in primary lymphoid tissues
  2. Peripheral tolerance - inactivation of self-reactive lymphocytes that escape central tolerance (mediated by regulatory T cells)

7

How do regulatory T cells cause suppression?

Secretion of IL-10 and TGF beta

8

Which HLA gene is associated with ankylosing spondylitis?

HLA B27

9

Which HLA gene is associated with rheumatoid arthritis?

HLA DR4

10

Which HLA gene is associated with SLE?

HLA-DR3

11

Which HLA gene is associated with multiple sclerosis?

HLA-DR2

12

Which HLA gene is associated with idiopathic diabetes mellitus?

  • HLA-DR3
  • HLA-DR4

13

Which HLA gene is associated with myasthenia gravis?

HLA-DR3

14

What are the three forms of HLA class I?

  1. HLA - A
  2. HLA - B
  3. HLA - C

15

What are the three forms of HLA class II?

  1. HLA - DR
  2. HLA - DQ
  3. HLA - DP

16

Genes for HLA are encoded on which chromosome?

6

17

What is the significance of having such variety in a population in terms of HLA alleles?

Different alleles can bind different peptides

Hence, some alleles will be more protective or susceptible to certain genetic conditions

18

What is molecular mimicry?

This is when antibody produced to a foreign antigen can cross-react with self antigen.

This is due to the similar peptide structure of the foreign and self antigen

19

What are superantigens?

Antigens which can activate lymphocytes outwith the binding sites

20

What is antigen sequestration?

Release of antigen not normally available for recognition

21

SLE involves which type of hypersensitivity reaction?

III

22

Rheumatoid arthritis involves which type of hypersensitivity reaction?

IV

23

When immune complexes form in the body, why is complement binding useful?

It aids removal

24

In SLE, why is the clearance of apoptotic bodies and immune complexes delayed?

A C1Q mutation creating abnormal C2 and C4 which cannot aid in the removal process

A Mac1 mutation which hinders many processes including apoptosis

25

Anti-dsDNA is associated with which condition?

SLE

26

Anti-Sm is associated with which condition?

SLE

27

Anti-Ro (SSA) and Anti-La (SSB) are associated with which conditions?

Sjogren's syndrome

(also subacute cutaneous SLE and neonatal lupus syndrome)

28

Anti-U3-RNP is associated with which condition?

Systemic sclerosis

29

Anti-centromere antibody is associated with which condition?

Systemic sclerosis

30

Anti Scl-70 antibody is associated with which condition?

Systemic sclerosis

31

Anti-Jo-1 antibody is associated with which condition?

Polymyositis

32

Why does rheumatoid arthritis occur?

Infiltration of the synovium by self reactive CD4+ T cells

Then

Secondary involvement of activated B cells and autoantibodies

33

What is the role of TNF alpha and IL-1 in the disease process of rheumatoid arthritis?

  • Stimulates fibroblasts, osteoclasts and chrondrocytes
  • Stimulates release of matrix metalloproteinases

34

What is a rheumatoid factor?

An autoantibody directed against the common (Fc) region of human IgG

35

Which antibodies are highly apecific for rheumatoid arthritis?

Anti-citrullinated peptide antibodies (ANPA)

These are highly specific to RA, but only postive in around 70% of cases

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