autoimmunity

Question 1

what must happen in the central and peripheral tolerance mechanisms in order for them to be breachedinto autoimmunity

Answer 1

central the autoreactive ly,phocytes must not be deleted in the BM and Thymus and periphery the normal inhibitory mechanisms fail must fail.

Question 2

what are the factors that influence development of an autoimmune disease

Answer 2

abnormalities of lymphocytes and APC’s, genetic predisposition, and microbial infection.

Question 3

what causes the tissue damage in an autoimmune disease

Answer 3

Auto-reactive CTL’s circulating autoantibodies, and immune complexes.

Question 4

what is vertical transmission of an autoimmune disease

Answer 4

if they are IgG antibodies then can cross the placenta and cause symptoms in the child but this is usually reversible once the child is born within a few months can cause organ damage.

Question 5

what is the sequestered antigens theory

Answer 5

where your privileged areas such as eye brain and genitals, if they are damaged and released into the blood they will cause auto immunity because we do not have those proteins available to induce tolerance.

Question 6

what is the microbes theory of autoimmunity

Answer 6

other organisms such as virus have enough similarity to self peptides and then after the virus is gone we still attack self. Known as molecular mimecry.

Question 7

what is the theory of inapproproate expression of MHC

Answer 7

some cells can express class 2 MHC when they are not supposed to and will activate the T cells, also genes near the HLA site could be causing this autoimmune disease as well. Some t cells will bind with positive self but not with high enough affinity for negative selection for destruction.

Question 8

how does hemolytic anemia occur

Answer 8

RBC antibodies produced against RBC membrane proteins, this cause RBC lysis and anemia intrascular hemolysis or can lead to opsiniation and removal of RBC by phagocyte cells in spleen extravascular hemolysis.

Question 9

what is good pasture syndrom

Answer 9

autoantibodies against type 4 collagen most damage in the lung and the kidneys, smooth ribbon like apearance in staining

Question 10

what is pernicios anemia

Answer 10

autoantibodies to intrinisic factor or gastric parietal cells lowers vit B12 absorption and leads to anemia

Question 11

what is hashimotos thyroidits

Answer 11

hypothyroid state agaist thyroid autoreactive against thyroid gland proteins

Question 12

idiopathic throbocyopenia purpura ITP

Treatment?

Answer 12

ITP is caused by anutoantiboides against the platelet membrane protiens causes purple skin lesions due to epidermal hemorrhage IVIG can prevent destruction

IV immunoglobulin administration - prevents destruction by Fc receptor-mediated binding and removal of platelets

Question 13

what is vitiligo

Answer 13

depigmentation of skin by destruction of melanocytes

Question 14

graves disease

Answer 14

autoantibodies agasnt TSH receptor stimulate secretion of thyroid hormones causes hyperthyroidism

Question 15

what is myasthenia gravis

Answer 15

antibodies against the acetocholine receptors leads to lack of nerve impulse reception.

Question 16

type one diabetias

Answer 16

beta islets antibodies causing CTK to kill it

Question 17

multiple sclerosis

Answer 17

causese demyelinatting of CNS, takes 1-2 decades to see it, relapsing remitting or progressive form, therapies include interferion Beta 1B, steroids and beta 1a

Produce IgG specific to myelin, activates complement

Macrophages attract to inflammation, secrete NO –> destroys nerve fibers

Question 18

lupas what is it

Answer 18

Stystemic disease. Broad loss of regulatory control that sustains self toleranc. Antibodies against DNA,RNA proteins and ribonucleoporteins , most common organs skin joints and kidney, more common in women.

Tissue damage via T3HS, RBC/WBC lysis via complement (T2HS)

Principle danger - RBC w/CR1 binding C3b and C4b, forming complexes, passing through kidneys

Question 19

what gives you a predisposition of lupas

Answer 19

gentitcs

some drugs can cause reversible lupas

immunologic factors: loss of B cell self-tolerance due to B cell hyperactivity, excessive T-helper activity and/or lack of appropriate T suppressor activity

Question 20

what is rheumatoid arthritis

Answer 20

destruction of the joints cartilage and inflammation femals more common, closer to type 4 sensitivity, IgM/IgG to Fc protion of IgG makes an immune complex. Cause also effect lungs and heart. Can be treated by etanercpt remose IgG1 antiobdy, Infliximad gets rid of TNF

Question 21

what is sjogrens syndrome

Answer 21

causes dry eyes and mouth desctuciton of lacrimal and salivary glands,

40% chance of lymphoid malignancies

Occurs alone or with RA or SLE

Question 22

what is scleroderma

Answer 22

hypersensitivity to collagen

Pt’s also have antinuclear Ab, though role uncertain

T cells infiltrate dermis –> release IL-1, TNFalpha, lays more collagen down, cycles

Question 23

polymyositis and dermatomoysitis

Answer 23

muscle injury possible by CD4 and CD8 t lymphocites in muscle, causes a skin rash . Could be caused by coxsackie b virus

1/4 have Ab to tRNA synthetase (diagnostic)

Question 24

what are some of the therapies for autoimmune diseaes (5)

Answer 24

Corticosteroids (prednisone) - antiinflammatory, causes bone mineral loss, weight gain, diabetes…

Azathioprine and cyclophosphamide: cytotoxid drugs interfering with DNA synthesis - eliminates diving lymphocytes

Immunosupression - cyclosporine and tacrolimus - blocks transcription of IL-2, but nephrotoxic

Plasmapheresis - remove Ag-Ab complex. Short term

Antagonism of TNF-alpha: Infliximab (humanized anti-THF monoclonal Ab); Etanercept - binds TNF; both good anti-inflammatories

Question 25

what do corticosteroids do during therapey

Answer 25

lower immune response, can cause weight gain diabeties and

Question 26

azathioprine and cyclophophamide

Answer 26

Cytotoxic drugs that interfere with DNA synthesis eliminate dividing lymphocytes. Side effects bone marrow suppression and damage to intestinal epithelium

Question 27

cyclosporin and tacrolimus

Answer 27

blocks transcription of ILA 2 nephrotoxic

Question 28

plasmaphorisis

Answer 28

removes Ag AB comlexes and is a short term relief of symptoms.