Autoimmunity

Question 1

How can autoimmunity arise?

Answer 1

escaped normal clonal deletion and are suppressed in periphery
breakdown of regulation of self=reactive lymphocytes

Question 2

_____ and _____ tolerance mechanisms must be breached

Answer 2

central

peripheral

Question 3

What central mechanism gets breached during autoimmunity

Answer 3

autoreactive lymphocytes not deleted in bone marrow and thymus

Question 4

What peripheral mechanism gets breached during autoimmunity

Answer 4

normal inhibitory mechanisms fail

Question 5

Predisposing factors to autoimmunity

Answer 5

abnormalities of lymphocytes and APCs
genetic predisposition
microbial infection

Question 6

How can tissue injury be brought about in autoimmunity

Answer 6

autoreactive CTLs
circulating autoantibodies
immune complexes

Question 7

Molecular mimicry

Answer 7

resemble self antigens closesly enough to break tolerance

Question 8

Mycoplasma infections

Answer 8

antibodies can cross-react with an antigen on RBCs to cause destruction

Question 9

rheumatic fever

Answer 9

caused by cross-reaction of streptococcal antibodies with heart valve tissue

Question 10

What happens when a cell that doesn’t normally expresses MHC starts to

Answer 10

activates T lymphocytes

may allow positive selection of autoreactive T cells

Question 11

Autoimmune hemolytic anemia

Answer 11

RBC antibodies produced against RBC membrane proteins
causes RBC lysis and anemia
opsoninzation (removal by phagocytic cells in spleen)

Question 12

Goodpasture’s syndrom

Answer 12

autoantibodies to the alpha3 chain of type IV collagen of the lung and kidney
causes complement activation
causes kidney damage, pulmonary hemorrhage, death
has a smooth ribbon like appearance

Question 13

Pernicious anemia

Answer 13

autoantibodies to intrinsic factor and/or gastric parietal cells
decreased absorption of vitamine B12 causes abnormal erythropoiesis/anemia

Question 14

Hasimoto’s thyroiditis

Answer 14

hypothyroid state

autoantibodies and autoreactive T cells to thyroid gland proteins

Question 15

Idiopathic thrombocytopenia purpura (ITP)

Answer 15

platelets destroyed by autoantibodies to platelet membrane proteins
IV immunoglobin can prevent destruction of platelets

Question 16

Purpura

Answer 16

purple skin lesions due to epidermal hemorrhage

Question 17

Vitiligo

Answer 17

depigmentation of skin by destruction of melanocytes

Question 18

Grave’s disease

Answer 18

caused by autoantibodies against TSH receptor
example of type II hypersensitivity
causes hyperthyroidism

Question 19

Myasthenia graves

Answer 19

autoantibodies to alpha chain of nicotinic acetylcholine receptor on skeletal muscle cells at neuromuscular junctions
blockage of neuromuscular transmission causes muscle weakness and paralysis
example of type II hypersenstivity

Question 20

Type 1A diabetes

Answer 20

autoantibodies to beta cells.

damage to beta cells results in decrease of insulin and increase in blood glucose

Question 21

Multiple sclerosis

Answer 21

autoimmune demyelinating disease of CNS
TH1 and TH17 cells specific for myelin antigens become activated, which drives macrophage activation and subsequent damage to myelin-containing nerve cells
treat with interferon-beta1b, interferon-beta1a, and IV steroids

Question 22

Systemic Lupus Erythematosus

Answer 22

multisystem
broad loss of regulatory control that sustains self-tolerance
autoantibodies against numerous antigens including DNA, RNA, proteins, and ribonucleoproteins
more common in women

Question 23

What is the priniciple danger of systemic lupus erythematosus

Answer 23

kidney failure due to the passage of immune complexes through the glomerulus and deposition on the renal podocytes

Question 24

Drug-induced lupus

Answer 24

slow drug metabolizes, drugs complex with nucleoproteins to generate autoimmunity
reverses upon removal of drug

Question 25

Immunologic factors in lupus

Answer 25

B cell hyperactivity, increased Th activity and/or decreased treg activity

Question 26

Rheumatoid arthritis

Answer 26

inflammatory disease of joints, destruction of joint cartilage and inflammation of synovium
TH1, TH17, macrophages, B cells, and plasma cells create an inflammatory environment consisting of secretion of leukocyte-recruiting cytokines

Question 27

Rheumatoid factor

Answer 27

IgM/IgG to Rc portion of IgG

not in all patients

Question 28

Sjogren’s syndrome

Answer 28

dry eyes and mouth due to destruction of lacrimal and salivary glands
B and T cell influx into glands, but not known whether CMI or humoral immunity responsible for damage
occurs alone of in conjuction with RA or SLE
increased risk for developing lymoid malignancies
mostly women

Question 29

Scleroderma

Answer 29

Excessive deposition of collagen
T cells have hypersenstivity to collagen
results in release of IL-1 and TNF-alpha which results in production of collagen and you get a vicious cycle

Question 30

Polymyositis

Answer 30

muscle injury possibly brought about by CD4+ and CD8+T lymphocytes infiltration of muscles

Question 31

Dermatomyositis

Answer 31

skin rash that often accompanies polymyositis

Question 32

Corticosteroid

Answer 32

anti-inflammatory

Question 33

Azathioprine and cyclophosphamide

Answer 33

cytotoxic drugs that interfere with DNA synthesis and eliminate dividing lymphocytes

Question 34

Cyclosporine and tacrolimus

Answer 34

block activity of calcineurin, blocks transcription of IL-2

nephrotoxic

Question 35

Plasmapheresis

Answer 35

removes Ag-Ab complexes

results in short-term alleviation of symptoms

Question 36

Infliximab

Answer 36

humanized anti TNF-alpha monoclonal antibody

Question 37

Etanerccept

Answer 37

soluble TNF-alpha receptor fusion protein that binds TNG-alpha

Question 38

Adalimumab

Answer 38

recombinant human IgG1 monoclonal