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Flashcards in Nelson-Immune Diseases Deck (66)
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1

What is an autoimmune disease?

An immune mediated inflammatory disease>
immune reactions to self antigens>
tissue and cell injury

2

What are the mediators of autoimmune disease?

Autoantibodies
Immune complexes
T lymphocytes

3

Autoimmune disease is d/t the loss of....

self tolerance

4

What is self tolerance?

Unresponsiveness when a lymphocyte is exposed to an antigen

5

What is the difference between central tolerance and peripheral tolerance?

Central (BM, thymus)

Peripheral tolerance (in the periphery, associated w/ anergy)

6

What is central tolerance?

killing immature self reactive T and B lymphocyte clones that recognize self antigens in BM/thymus

7

What is peripheral tolerance?

Irreversible inactivation of lymphocytes
suppression by T reg cells
deletion by activation induced cell death

8

What are the two factors that combined together lead to autoimmune disease?

1. Inheritance of susceptibility genes--> breakdown of self tolerance

2. Environmental triggers (infections/tissue damage)--> activation of self reactive lymphocytes

9

What are some of the ways that infections cause autoimmunity?

1. Up-regulate the expression of co-stimulators--> breakdown of anergy--> activation of T cells for specific (self) antigen

2.Molecular mimicry

3. Infection--> tissue injury > release of self antigens > alteration of self antigens so they're able to activate T lymphocytes

10

What is molecular mimicry?

Offending org can express antigens w/ same AA seq as self antigens--> IR so self antigens

11

What are examples of molecular mimicry?

Rheumatic heart disease: Ab against streptococccal proteins react w/ myocardial proteins--> myocarditis

EBV/HIV: polyclonal B cell activation > production of autoantibodies

12

What is clinical course of untreated autoimmune disease?

Directed at specific org/tissue--> specific disease

Directed at widespread antigen--> systemic/generalized disease

13

What are the general features of autoimmune disease?

once initiated is progressive

sporadic relapses/remissions

inexorable tissue damage if untreated

14

What is SLE?

Multisystem autoimmune disorder>
formation of autoantibodies (antinuclear) >
widespread multiorgan tissue injury)

15

What are some key features of SLE?

Acute or insidious
chronic-relapsing and remitting
Febrile illness
Injury to skin, joints, kdiney, serosal membranes

16

What causes SLE?

You can't maintain self tolerance

Susceptibility genes + env triggers >
loss of self tolerance and persistence of nuclear Ag>
formation of Ag-Ab complexes>
deposited in tissues>
injury (type II hypersensitivity)

17

What is the potential complication of the presence of anti-phospholipid Ab in SLE?

False pos syphillis test
prolong partial thromboplastin time
Complications of hypercoaguable state (secondary anti-phospholipid Ab syndrome)

18

What is secondary anti-phospholipid Ab syndrome?

Venous/arterial thrombosis
spontaneous miscarriages
cerebral ischemia

19

What are the key clinicial features seen in SLE?

SOAP BRAIN MD
S-serositis (inflammation of serious tissues of the body)
O- oral ulcers
A- arthritis
P- photosensitivity
B- blood disorders
R-renal disease
A- anti-nuclear ab pos
I- immunologic abnormalities
N- neurologic disease
M- malar rash
D- discoid rash

20

How does SLE cause renal disease?

Immune complex deposition in the glomeruli--> glomerular injury

21

How does SLE effect the skin?

immune complex deposition at the dermoepidermal junction

22

How is joint characterized in SLE (different from RA)?

non erosive
non-deforming small joint involvement

23

What sersitises are seen w/ SLE?

Pericarditis, endocarditits, pleuritits

24

What is a characteristic pathological findings of lupus nephritis?

wire loop lesions representing extensive subendothelial deposits of immune complexes

25

What is RA?

Chronic systemic inflammatory disorder

Primarily attacks joints>
inflammatory synovitis>
destruction of cartilage and ankylosis

26

What is the end result of RA?

stiffening/immobility of joints

27

What are genetic factors that contribute to RA susceptibility?

Specific HLA genes

HLA-DRB1
PTPN22

28

What are environmental arthritogens that contribute to RA susceptibility?

Ag from infectious organisms

Citrullinated proteins formed in the body

29

What is the pathogenesis of RA?

Exposure to arthritogenic antigen>
genetically predisposed individual>
breakdown of self tolerance>
chronic inflammatory reaction

30

How can initial acute arthritis lead to a continuing autoimmune reaction?

Activation of CD4 helper T cells>
release of inflammatory mediators + cytokines>
destruction of joint