tolerance, autoimmunity, and autoimmune diseases

Question 1

define immunologic tolerance

Answer 1

acquisition of nonreactivity toward particular self-antigens

Question 2

what is the major mechanism of self tolerance

Answer 2

elimination of self-reactive immature lymphocytes

Question 3

failures of tolerance can result in

Answer 3

rxn to self antigen
hypersensitivty rxns to non-self
antiinflammatory w/ no antigen

Question 4

three pathways recognized for T cell tolerance

Answer 4

clonal abortion
funcitonal deletion
t cell suppression

Question 5

what organ is responsible for deleting autoreactive t cells w/ potential to cause disease

Answer 5

thymus

Question 6

what happens to B cells liklihood of tolerance as it matures

Answer 6

less susceptible to tolerization

Question 7

four pathways for b cell tolerance

Answer 7

clonal abortion
clonal exhaustion
functional deletion
antibody-forming cell blockade

Question 8

what is the hallmark of autoimmune disease

Answer 8

tissue injury caused by t lymphs or antibody reactivity to self

Question 9

if autoimmune disorder activates innate immunity what happens

Answer 9

prolonged/excess inflammation from macrophage cytokine release

Question 10

Characteristics of organ-specific autoimmune disorders

Answer 10

produced by t cells or antibodies against antigens restricted to a single organ
- T1D, MS and thyroid

Question 11

characteristics of organ-non-specific autoimmune disorders

Answer 11

systemic autoimmune disease is produced by circulating antibodies or immune complexes that affect multiple organs
- SLE and RA

Question 12

characteristics of mid spectrum disorders

Answer 12

localized lesions in single organ and organ-non-specific autoantibodies

Question 13

all of the following characteristics are common to organ-specific and organ-nonspecific disorders except
a. autoantibody tests are of diagnostic value
b. antibodies may appear in each of the main Ig classes
c. antigens are available to lymphoid system in low concentrations
d. circulatory autoantibodies react with normal body constituents

Answer 13

c. antigens are availble to lymphoid system in low concentrations

Question 14

antibody expression in the development of autoimmunity is regulated by all except
a. genetic predisposition
b. increasing age
c. environmental factors
d. active infectious disease

Answer 14

d. active infectious disease

Question 15

the mechanism responsible for autoimmune disorder is
a. circulating immune complexes
b. antigen excess
c. antibody excess
d. antigen deficiency

Answer 15

a. circulating immune complexes

Question 16

one of the mechanisms believed to induce self-tolerance is
a. induction of responsiveness in immunocompetent cells
b. elimination of clone programmed to react with self antigen
c. decreased suppressor cell activity
d. stimulation of clones of immunocompetent cells

Answer 16

b. elimination of clone programmed to react with self antigen

Question 17

what antibody is useful in monitoring activity and exacerbations of autoimmune disease SLE

Answer 17

anti-DNA antibodies

Question 18

self-tolerance is induced by
a. Burnet clonal selection theory
b. elimination of the smaller clone of immunocompetent cells programmed to react with the antigen
c. induction of unresponsiveness in the immunocompetent cells through excessive antigen binding
d. all of the above

Answer 18

d. all of the above

Question 19

decribe vasculitis

Answer 19

cardiovascular, midspecturm disorder of the blood vessels
- deposition of circulating immune complexes

Question 20

describe carditis

Answer 20

cardiovascular disorder of the heart
- primary idiopathic myocarditis; infiltration of heart by lymphs and macros

Question 21

describe scleroderma

Answer 21

collagen vascular disease, chronic multisystem causing thickening of the skin
- cell hyperactivity correlates ith disease activity

Question 22

describe eosinophilia-myalgia syndrome

Answer 22

caused by exposure to L-tryptophan (1974)
collagen vascular disorder

Question 23

what are the two major forms of autoimmune thyroid disease

Answer 23

chronic autoimmune thyroiditis
graves disease

Question 24

what is the autoimmune process of chronic thyroiditis

Answer 24

development of circulating cytotoxic antibodies eventually destroys the thyroid gland
- hypothyroidism

Question 25

what antibodies are present in chronic thyroiditis

Answer 25

• thyroglobulin
• thyroid microsome: low titers correlate with thyroid involvement
• CA2 antigen: present in 50% of subacute thyroiditis (against colloid protein)
• thyroid membrane receptor: IgG antibodies to produce hyperthyroidism
• T4 and T3: found in hypothyroidism

Question 26

diagnostic eval of chronic thyroiditis

Answer 26

increased TSH, decreased T4/T3 w/ anti-TPO antibodies present

Question 27

diagnostic eval of Graves disease

Answer 27

hyperthyroidism, low TSH, elevated T4 and T3

Question 28

insulin-dependent diabetes mellitus is caused by what

Answer 28

immune destruction (initiated by CD4) by beta cells of pancreatic islets causing low insulin lvls and exogenous insulin dependence

Question 29

describe Sjogren syndrome

Answer 29

a chronic inflammatory disease of endocrine glands that affects lacrimal, salivary, and other excretory glands

Question 30

What are the two most common skeletal muscle disorders

Answer 30

polymyositis and dermatomyositis