autoimmune disease

Question 1

What is autoimmune disease?

Answer 1

A failure of self-tolerance and subsequent adaptive immune responses against self-antigens.

Question 2

What are the factors that contribute to autoimmune disease?

Answer 2

Genetic factors(HLA), infection (molecular mimicry), and environmental factors. All lead to breakdown of self-tolerance.

Question 3

What is immune tolerance?

Answer 3

Lack of response to an antigen that is induced by previous exposure of lymphocytes to that Ag.

Question 4

What is central tolerance?

Answer 4

Immunological tolerance to self antigens induced in immature lymphocytes in generative/central lymphoid organs.

Question 5

What are the mechanisms of central tolerance?

Answer 5

Deletion, receptor editing (BCR), regulatory T cell development (CD4+)

Question 6

What is positive T cell selection in the central tolerance?

Answer 6

A low affinity interaction of TCR with self MHC positively selects and rescues thymocytes from program cell death.

Question 7

What is negative T cell selection in central tolerance?

Answer 7

High-avidity recognition of self peptide-MHC complexes and deletes/apoptotic death of cell.

Question 8

What is peripheral immune tolerance?

Answer 8

Immune tolerance in peripheral tissue of mature lymphocytes: Clonal anergy (no B7CD28:), deletion, suppresion via Treg (IL-10, TGF-b).

Question 9

What is mucosal immune tolerance?

Answer 9

Antigens or antibodies administered via oral/nasal can develop a immune tolerance via ignorance (anergy), deletion, Treg (decrease inflammation).

Question 10

What deficiency causes SLE?

Answer 10

Complement proteins C1q, C2, or C4.

Question 11

What is type 2 hypersensitivity?

Answer 11

Antibody dependent cytotoxic. Mediated by IgG and IgM. Cell lysis, cell injury, phagocytosis.

Question 12

What is type 3 hypersensitivity?

Answer 12

Immune complex formation that is deposited in tissue and blood vessel walls. Causes inflammation and tissue damage due to inflammation

Question 13

What is type 4 hypersensitivity (DTH)?

Answer 13

Delayed type hypersensitivity (DTH) is T-helper cell (CD4) mediated inflammatory response. Found in transplant rejection, contact dermatitis, tuberculin-type hypersensitivity.

Question 14

Lupus nephritis

Answer 14

Caused by anti-dna ab

Question 15

autoimmune anemias, thrombocytopenia

Answer 15

Caused by complement fixing abs

Question 16

SLE, RA, Type 1 diabetes

Answer 16

Tissue specific abs

Question 17

Graves disease, myasthenia gravis

Answer 17

autoantibodies to cell surface receptors. Graves disease is hyperthyroidism. Myasthenia gravis is muscle weakness and paralysis.

Question 18

Vasculitis

Answer 18

Inflammation of blood vessels from immune complex deposition

Question 19

Glomerulonephritis

Answer 19

Inflammation of the glomeruli in kidney caused by immune complex deposition.

Question 20

Autoimmune hemolytic anemia

Answer 20

RBC lysis via complement-fixing autoantibodies.

Question 21

Molecular mimicry

Answer 21

Auto-reactive B cells that recognize self-antigen and also cross react with foreign antigen. Rheumatic fever via group A streptococcal.

Question 22

T-cell mediated autoimmune disease

Answer 22

Type 1 diabetes, rheumatoid arthritis, multiple sclerosis, hasimoto’s thyroiditis (hypothyroidism)

Question 23

Rheumatoid arthritis and periodontitis connection

Answer 23

P. gingivalis produces citrullinated peptides and antibodies produced against it. Citrullinated proteins present in gingiva and synovial fluid