Immune Disorders

Question 0

How many types of hypersensitivity mechanisms are there?

Answer 0

4

Question 1

What is a hypersensitivity reaction?

Answer 1

An exaggerated or inappropriate adaptive immune response to an antigen/immunogen causing tissue damage

Question 2

What are the 4 types of hypersensitivity reactions?

Answer 2

Immediate (type I)
Cytotoxic (type II)
Complex mediated (type III)
Delayed (type IV)

Question 3

Which antibody mediates Type I hypersensitivity reactions?

Answer 3

Ig E

Question 4

Which antibody mediates Type II hypersensitivity reactions?

Answer 4

IgG

IgM

Question 5

Which antibody mediates Type III hypersensitivity reactions?

Answer 5

IgG

IgM

Question 6

Which antibody mediates Type IV hypersensitivity reactions?

Answer 6

T lymphocytes

Macrophages

Question 7

What is anaphylaxis?

Answer 7

Generalised type I reaction, which leads to vasodilation and constriction of bronchial smooth muscle

Question 8

What type sensitivity is cytotoxic?

Answer 8

Type II

Question 9

What does complement activation lead to?

Answer 9

Cell lysis
Depositation of complement components
Macrophage and neutrophil activation

Question 10

What is haemolytic disease of the newborn?

Answer 10

Rhesus incompatibility

Question 11

What are the effects of rhesus incompatibility?

Answer 11

Spontaneous abortion

Baby born with mild jaundice or HDN

Question 12

What type of hypersensitivity is immune complex hypersensitivity?

Answer 12

III

Question 13

When would type III hypersensitivity occur?

Answer 13

Persistent infection

Autoimmunity

Question 14

What nature can immune complexes be?

Answer 14

Precipitates

Soluble

Question 15

What are intrinsic allergic alveolitis?

Answer 15

An occupational disease due to inhalation of immunogenic proteins or spores

Question 16

What are examples of intrinsic allergic alveolitis?

Answer 16

Farmers lung
Mushroom worker disease
Coffee worker disease

Question 17

What causes farmers lung?

Answer 17

Sensitisation to thermophilic actinomycetes spores from damp hay, years of exposure lead to high circulating levels of IgG and spore antigens. These complexes precipitate in the lung

Question 18

How does the precipitate in farmers lung cause emphysema (irreversible lung damage)?

Answer 18

Complement activates
Initiates inflammation
Destroys alveolar tissue
Fibrosis (tissue repair)

Question 19

What causes serum sickness?

Answer 19

Treatment of an active infection with antibodies

Question 20

How long before serum sickness symptoms develop?

Answer 20

7 days

Question 21

What are the symptoms of serum sickness?

Answer 21

Weakness, fever, skin rash, oedema

Question 22

What type of of hypersensitivity is contact hypersensitivity?

Answer 22

Type IV

Question 23

How long does type IV hypersensitivity take to develop?

Answer 23

72hrs to weeks

Question 24

What is contact hypersensitivity mediated by?

Answer 24

T lymphocytes and macrophages

Question 25

What can cause dermatitis (a type of contact hypersensitivity)?

Answer 25

Biological stains Hair dyes Urushiol (Poison ivy)

Question 26

What is sensitisation?

Answer 26

Initial contact leads to a cell mediated immune response

Question 27

What is autoimmunity?

Answer 27

A breakdown of self tolerance

Question 28

What is self tolerance?

Answer 28

Failure to respond to self antigens

Question 29

What are the two types of self tolerance?

Answer 29

Central tolerance | Peripheral tolerance

Question 30

What characterises central tolerance?

Answer 30

Deletion of self reactive T cells

Question 31

What characterises peripheral tolerance?

Answer 31

Clonal anergy Deletion Active suppression Presence of autoreactive B cells

Question 32

What causes the stimulation of self reactive lymphocytes?

Answer 32

Failure to eliminate self reactive lymphocytes Failure of suppression Occur after microbial infections

Question 33

What are the two types of autoimmunity?

Answer 33

Organ specific | Systemic

Question 34

What characterises organ specific autoimmunity?

Answer 34

Auto antigen localised to one organ

Question 35

What factors influence susceptibility to autoimmunity?

Answer 35

Genetics Environmental Hormonal

Question 36

What are the two types of immunodeficiency?

Answer 36

Primary | Acquired/secondary

Question 37

What characterises primary immunodeficiency?

Answer 37

T cell defect B cell defect Phagocytosis defect Complement defect

Question 38

What causes secondary immunodeficiency?

Answer 38

Malnutrition Treatment eg. X-rays Infection (HIV)