Lecture 16 - Autoimmune

Question 1

What is an autoimmune disease?

Answer 1

Disease caused by failure of self-tolerance and subsequent immune responses against self-antigens.

Question 2

The autoimmune system directly attacks what?

Answer 2

Attack self tissues.

Question 3

List organ-specific autoimmune diseases. (6)

Answer 3

Insulin-dependent diabetes mellitus (pancreas), multiple sclerosis, myasthenia gravis (muscles), Grave’s disease, Hashimoto’ disease, and Goodpasture’s syndrome.

Question 4

What is molecular mimicry? Give an example.

Answer 4

Determinants of infectious agent mimic a host antigen and trigger self-reactive T cell clones to attack the host tissues.
Rheumatic fever due to A strepococcus.

Question 5

List causes for reduced autoimmune disease.

Answer 5

Ag release from hidden location (by injury or infection), molecular mimicry, inappropriate expression of class II MHC, epitope spreading, and polyclonal B cell activation by CMV, EBV, and some G-negative bacteria.

Question 6

What is epitope spreading?

Answer 6

The initial response to one self determinant (1 peptide) could expand to involve additional determinants on the same molecule as well as additional self-proteins.

Question 7

List 2 polyclonal B cell activation by CMV, EBV, and some G-negative bacteria.

Answer 7

T-cell independent and large amounts of IgM produced.

Question 8

List some gene factors in autoimmunity.

Answer 8

Multiple sclerosis (alleles of HLA-DR), systemic lupus (lack of C1q and C4), genetically determined low expression of given self-antigen in the thymus, and mutation (usually deletion) of autoimmune regulatory-1 gene(AIRE-1)

Question 8

What is insulin dependent diabetes mellitus (IDDM)?

Answer 8

A T cell disease in which the body does not produce enough insulin. T cells attack and destroy pancreatic beta cells.

Question 9

What is multiple sclerosis?

Answer 9

A disease in which the myelin sheath of nerves cells are targeted and attacked by inflammatory lesions.

Question 10

What is Myasthenia Gravis?

Answer 10

A B cell disease marked by progressive weakness and loss of muscle control. The antibodies bind to the receptors and block the signals of the nerve to the muscle cell.

Question 11

What happens in Hashimoto’s thyroiditis?

Answer 11

Th1 cells and autoantibodies specific for thyroid Ag’s–> infiltrate of thyroid leading to hypothyroidism

Question 12

What happens in Goodpasture’s syndrome?

Answer 12

Antibodies to membrane antigens in kidney and alveoli in lungs.
Specificity is part of type IV collagen.
Includes complement activation, cell damage, and inflammation.

Question 13

Systemic Lupus Erythematosus causes what?

Answer 13

Tissue injury by forming immune complexes, and cause destruction, and the phagocytosis of cells.

Question 14

For immunofluorescence, the mesangial and capillary wall is filled with deposits of ___.

Answer 14

IgG

Question 15

What is rheumatoid arthritis? What cause the damage?

Answer 15

A fairly common autoimmune disease that affects the lining of the joints.
Cytokines, especially TNF cause inflammation and tissue damage.

Question 16

What happens to patients with chronic rheumatoid arthritis?

Answer 16

Progressive joint destruction and disability, lifespan shortened by 10-15 years

Question 17

List some treatments of autoimmune diseases that reduces symptoms.

Answer 17

Immunosuppression, removal of thymus, plasmapheresis (removal of blood plasma of patient and replacement of clean plasma)

Question 18

List some treatments of autoimmune diseases that reduces inflammation.

Answer 18

TNF-alpha blockers, IL-1 receptor antagonist, Ab’s against IL 6 and IL-15 receptors, and statins to lower CRP.

Question 19

List some treatment methods for autoimmune diseases. (3)

Answer 19

T cell vaccines, monoclonal antibodies against a variety of target antigens, and oral induction of tolerance.