Hypersensitivity, allergy, antihistamines and autoimmunity

Question 1

Anaphylaxis is which type of hypersensitivity?

Answer 1

Type I

Question 2

Which antibodies mediate anaphylaxis?

Answer 2

IgE

Question 3

An allergic reaction is provoked by exposure to the sme antigen. True or false?

Answer 3

True

Question 4

What is the process of coating mast cells with IgE called?

Answer 4

Sensitisation

Question 5

What are the three types of responses that result from activation of mast cells in type I hypersensitivity?

Answer 5

Rapid release of granule content (degranulation)
Synthesis and secretion of lipid mediators
Synthesis and secretion of cytokines

Question 6

Allergic asthma, allergic rhinitis and atopic dermatitis are examples of which type of hypersensitivity?

Answer 6

Type I

Question 7

Which mast cell mediator causes dilation of blood vessels, increases vascular permeability and causes contraction of smooth muscle?

Answer 7

Histamine

Question 8

What are two examples of type II hypersensitivity?

Answer 8

Haemolytic anaemia
Thrombocytopenia
Which are a side effect of certain drugs

Question 9

What happens during type II hypersensitivity?

Answer 9

The antibodies produced during the immune response recognise and bind to the antigen, which are structural components of cell surfaces or other tissue

Question 10

Penicillin, quinidine and methyldopa have been linked to which type of hypersensitivity?

Answer 10

Type II

Question 11

Which antibodies are involved in type II hypersensitivity?

Answer 11

IgG and IgM

Question 12

Epinephrine is used for anaphylaxis. True or false?

Answer 12

True

Question 13

How are the drugs cromlyn and ketotifin used in treatment of type I and II hypersensitivity?

Answer 13

They prevent mast cell degranulation, preventing allergic cascade from happening

Question 14

Which antibodies are involved in type III hypersensitivity?

Answer 14

IgA, IgE, IgG and IgM

Question 15

What is type III hypersensitivity as a result of?

Answer 15

Accumulation of antibody-antigen complexes that have not been cleared well by the innate immune system
The immune complexes insert themselves in joints, blood vessels causing symptoms
When IgG binds antigen, complement is activated and C5a is generated which is a chemoattractant and C3b which is a potent opsonin
Phagocytosis - tissue damage

Question 16

How long does type IV hypersensitivity take to develop?

Answer 16

12 or more hours

Question 17

What is the main difference between type IV hypersensitivity and and the other types?

Answer 17

Not mediated by antibodies, it is cell-mediated (T-cells and macrophages)

Question 18

Mycobacterium Tb can induce which type of hypersensitivity?

Answer 18

Type IV

Question 19

Which type of hypersensitivity does herpes simplex virus cause?

Answer 19

Type iv

Question 20

In auto-immune disease, antibodies are produced in response to own cells and disease associated with these auto-antibodies are referred to as auto-immune disease. True or false?

Answer 20

True

Question 21

In myasthenia gravis, what is the auto-antibody produced against?

Answer 21

The Ach receptor - so there is a reduction in the number and so muscle cannot contract

Question 22

In the form of maturity onset diabetes, what do auto-antibodies cause a reduction in?

Answer 22

The number of insulin receptors

Question 23

How can insulin-resistant form of diabetes be treated?

Answer 23

Insulin at much higher concentrations than normal so that it can compete with auto-antibodies for the receptor sites

Question 24

What happens in insulin dependent diabetes?

Answer 24

IgG auto-antibodies fix complement and mediate lysis of insulin producing B cells in the islets of Langerhans in the pancreas

Question 25

Name three autoimmune diseases

Answer 25

MG
Diabetes
MS