11:9: Autoimmunity Flashcards Preview

MHD V: Renal > 11:9: Autoimmunity > Flashcards

Flashcards in 11:9: Autoimmunity Deck (44):
1

What is autoimmunity?

- Immune rxn against self antigen
- Can be directed against single tissue/organ or against many

2

What is self tolerance?

- Lack of responsiveness to self antigens

3

What is immunologic tolerance?

- Making lymphocytes unresponsive to self antigen
- "Self tolerance"
- Result of central tolerance

4

What is central tolerance?

- Clonal deletion of self reactive T and B cells
- Occurs in thymus for T cells
- Occurs in marrow for B cells

5

What is peripheral tolerance?

- Removal of self reactive T cells that escape intrathymic negative selection

6

What happens to T cells that to not recognize self antigen?

Allowed to undergo clonal proliferation

7

What is AIRE?

"Autoimmune regulator"
- Transcription factor promoting expression of self antigen by thymic epithelial cells
- Allows for elimination of self directed T cells

8

What is APECED?

- Occurs when you lack AIRE
- Develop organ specific autoimmune disease
- Often shows problems with eyes, teeth and fingers

9

What is receptor editing?

- Rearrangements altering specificity of B cell receptor to avoid autoreactivity
- Occurs in bone marrow

10

4 mechanisms of peripheral tolerance?

1. Anergy
2. Suppression by Tregs
3. Clonal deletion by induced cell death
4. Antigen sequestration

11

What is anergy?

- A reaction between self reactive T cell and its antigen that leads to expression of proapoptotic proteins and silencing of those T cells
- Most self antigens do not possess stimulatory molecules necessary to mount T cells response

12

How to Tregs impact T cells?

- Release cytokines to suppress function of autoreactive T cells

13

What is Fas-FasL ligand?

Leads to apoptosis of self reactive T cells in periphery

14

What is antigen sequestration?

- Certain areas such as brain eyes and testis have limited exposure to T cells so the celf antigens here are protected
- Can lead to prolonged inflammation / infection because of this as well

15

What is molecular mimicry?

- Virus or bacteria shares epitopes with self proteins expressed on human
- Leads to immune response against human as well
- Rheumatic fever is example of this

16

What is exposure of cryptic self?

- Infection in area usually not exposed to immune system allows self antigen to spread to areas it is not normally present
- Can lead to autoimmune rxn

17

What is SLE?

"Systemic lupus erythematosus"
- Multisystem autoimmune disease caused by variety of antibodies

18

What is necessary for SLE?

1. Ptn. must have multiple susceptibility genes
2. Triggering factor
3. Abnormal immune response: hyperactive B/T cells with inadequate regulation

19

What are some triggering factors for lupus?

1. UVB light
2. Sex hormones
3. Dietary factors
4. Infections agents
5. Drugs
6. Smoking

20

Why does UVB exposure exacerbate SLE?

- Sun kills skin cells releasing self antigen leading to development of autoantibodies

21

Who is more at risk for LUPUS?

Females: due to sex hormones
African Americans

22

What drugs can trigger lupus?

"For example (IE), private message (PM) the PHD
Isoniazid
Ethosuximide
Phenytoin
Minocycline
Procainamide
Hydralazine
D-penicillamine

23

How can you identify drug induced lupus?

Presence of antihistone antibodies

24

What is necessary to diagnose lupus?

4 of 11 symptoms

25

What are the symptoms of lupus

1. Butterfly rash: face
2. Discoid rash: anywhere on body
3. Photosensitivity
4. Oral or nasal ulcers
5. Arthritis: non deforming
6. Serositis: fluid around lungs or heart
7. Kidney disease
8. Brain disease: seizures or psych
9. Low RBC, WBC, or Platelet count
10. Antinuclear antibodies
11. Specific autoantibodies

26

What is SSA associated with?

Neonatal SLE

27

Role of IC in SLE?

- Low levels can be seen
- C1/2/4 deficiencies can be associated with SLE
- Immuno fluorescence can show deposition of IC

28

What are antiphospholipid antibodies?

- Found to be circulating in SLE
- Lead to prolonged PTT and false pos VDRL
- Lead to thrombocytopenia
- Ptn with these is more prone to thrombotic episodes than bleeding and spontaneous abortion

29

What can antiphospholipid antibodies lead to?

Anemia
Neutropenia
Thrombocytopenia

30

What is neutropenia?

Low WBCs

31

What is thrombocytopenia?

Low platelets

32

What is systemic sclerosis?

- Multisystem disorder
- Characterized by inflammatory, vascular and fibrotic changes of skin and organ systems
- Pathogenesis is not known

33

Two type of scleroderma?

1. Diffuse cutaneous
2. Limited cutaneous: CREST syndrome

34

What does presence of anticentromere antibody indicated?

CREST syndrome

35

What does CREST stand for?

Calcinosis- Ca deposits on skin
Raynaud’s - Low blood flow to hands
Esophageal dysmotility - problems w/ contraction
Sclerodactyly - thickness of skin on fingers / toes
Telangiectasias - spider veins / small dilated vessels

36

What is calcinosis?

Ca deposits on skin
- Seen in CREST

37

What is Raynaud's syndrome?

- Low blood flow to hands
- Seen in CREST

38

What is Esophageal dysmotility?

- Problems w/ contraction of esophagus
- Seen in CREST

39

What is Sclerodactyly?

- Thickness of skin on fingers / toes
- Seen in CREST

40

What is Telangiectasias?

- Spider veins / small dilated vessels
- Seen in CREST

41

What is anticentromere antibody associated with?

Systemic sclerosis

42

Clinical presentation of systemic sclerosis?

• Raynaud’s phenomenon
• fibrosis of the skin (scleroderma)
• telangiectasia, calcinosis
• esophageal hypomotility
• arthralgias and /or arthritis
• intestinal hypofunction
• pulmonary fibrosis - from fibrosis
• hypertension - from fibrosis
• renal failure (leading cause of death) - from fibrosis

43

What is skin fibrosis indicative of in sclerosis?

- The more skin fibrosis the more underlying organ fibrosis

44

How to test Scleroderma?

1. CXR
2. ESR
3. Antibody testing
4. Urinalysis for renal involvement