Aberrant immune responses

Question 1

What the immune system does

Answer 1

• defends against infecting microbes and identifies and eliminates mutated tissue
  -initiates inflammation- healing and repair
  -vaccination and silver bullet (exploring specificity to target abnormal tissue)

Question 2

Allergy

Answer 2

Trigger: external (non-self) usually harmless
Mechanism- immune system activation (hypersensitivity classes) ( Type 1: antibody IgE. Type 2: antibody IgM IgG cytotoxic. Type 3: immune complex. Type 4: cell mediated (T cell)
Memory- specific

Question 3

Allergy type 1: immediate response

Answer 3

• antibody ( IgE) and effector cells (mast cell)

Question 4

Mast cell mediators: histamine

Answer 4

• vasodilation, bronchoconstriction
• shock (low BP)
• angioedema (swelling- rapid onset)
  -wheeze- airways narrowing (asthma

Question 5

Mast cell mediators: leukotrienes

Answer 5

• bronchoconstriction
• wheeze
• secretion (snot)

Question 6

Mast cell mediators: cytokines

Answer 6

• inflammation- organs
• wheeze
• secretion

Question 7

Triggers of allergy

Answer 7

• house dust mite ( allergic rhinitis, asthma)
• latex ( anaphylaxis)
• pollen (hay fever and allergic conjunctivitis)
• food
  -bee sting

Question 8

Auto immunity

Answer 8

• misdirected immune response that occurs when the immune system attacks the body itself
• usually the immune system is programmed to be tolerant of self antigens
• an error of self tolerance

Question 9

autoimmune disease

Answer 9

organ specific
- immune damage to tissue organs
- damage to structure and function of organs
non-organ specific
- widespread molecules in systemic or common cellular structures
- blood vessels, cell nuclei, connective tissue.

Question 10

origins of auto immune disease

Answer 10

• infection: thyroid, pancreas
  -damage: revealing privileged tissue (eye, testis)
• genetic factors: predisposing to auto immunity

Question 11

auto-immune thyroid disease

Answer 11

• thyroid hormones regulated by thyroid stimulating hormones (TSH)
  -TSH bind to receptor and stimulates synthesis of thyroid hormones
• -ve sense feedback then switches off TSH production

Question 12

Grave’s disease

Answer 12

• results in “activating” auto-antibodies that bind to the TSH receptor, leading to overstimulation and production the thyroid hormone

Question 13

Hashimotos

Answer 13

• thyroiditis antibodies to thyroid peroxidase antibodies and thyroid gland destroy thyroid hormone
• gradually developing hypothyroidism

Question 14

causes of thyroid auto-immune disease

Answer 14

• environment
  -genetic factors
• exposure to privileged proteins (TSH receptor, throglobulin, thyroid peroxidase)

Question 15

immune reactions- inflammatory responses

Answer 15

• immune response kills virally infected cells
  -persistent viral particles
  -intensity of inflammatory reponse
• combined antigens (viral/self)
  -destruction of functional liver

Question 16

immune reactions-inflammatory responses pt2

Answer 16

-crtical inflammatory mediators are released in response to immune response eg IL1 and 6- no regulation
- cells are drawn into virally infected organs eg Lungs
- coagulation cascade activated and thrombotic tissue damage
-anti cytokines effective in controlling disease