Hypersensitivty- type II, III, IV

Question 1

What does the term hypersensitivity mean?

Answer 1

The antigen specific immune response that are either inappropriate or excessive and result in harm to host

Question 2

How can you trick the immune system?

Answer 2

Believe that have the disease so causes an immune response

- vaccination

Question 3

What are exogenous substances?

Answer 3

Non infectious substances (allergy)
Infectious microbes
Drugs e.g. Penicillin

Question 4

What are intrinsic antigens?

Answer 4

Infectious microbes (mimicry- autoimmune- has parts that are like hosts microbes) 
Self antigens

Question 5

What is type I or immediate

Answer 5

Allergy
Environments non infectious antigen
IGE

Question 6

What is type II hypersensitivity?

Answer 6

AntiBody mediated

IGM

Question 7

What is type III hypersensitivity?

Answer 7

Immune Complexes mediated

IGG

Question 8

What is type IV hypersensitivity?

Answer 8

Cell mediated- Delayed

Environmental infectious agents and self antigens

Question 9

What mechanisms cause hypersensitivity?

Answer 9

The immune repossess that are employed to fight host infection
However too much- overreaction

Question 10

What is the difference between type II and III?

Answer 10

Type III is against soluble

Membrane bound type II

Question 11

What is sensization phase?

Answer 11

First encounter with the antigen

Activation of APC and memory effector cells

Question 12

If an individual has been previously exposed to an antigen what are they said to be?

Answer 12

Sensitised

Question 13

What is the effector phase?

Answer 13

Pathological reaction upon re exposure to the same antigen and activation of the memory cells of the adaptive Immunity

Question 14

When does type II hypersensitivity develop?

Answer 14

5-12 hours after exposure

Question 15

What kind of antibodies does hypersensitivity type II involve?

Answer 15

IGM or IGG

Question 16

What does hypersensitivity type II target?

Answer 16

Cell bound antigens

E.g. Blood group antigens, Rhesus D antigen,self antigens

Question 17

What does type II hypersensitivity cause?

Answer 17

Tissue or cell damage

Change in cell function

Question 18

How can type II sensitive cause cell damage?

Answer 18

by antigen dependant cells when in natural killer cells bind to antibody through FRC receptor and release toxic radicals through to the cell itself
Self antigen- usually present in red blood cells, activate complement and destroyed, also happens in platelets

Question 19

What can complement act on?

Answer 19

Many cells in innate immunity, adaptive immunity and disposal system

Question 20

What is an example of a disease caused by type II hypersensitivity? IGM

Answer 20

Haemolytic transfusion reaction

Question 21

What is haemolytic transfusion reaction?

Answer 21

Life threatening condition
Shock
Kidney failure
Circulatory collapse and death

Question 22

What is the Immune mechanism of haemolytic transfusion reaction?

Answer 22

Incompatible in the ABO of rhesus D antigens
Donor red blood cells destroyed by recipients Immune system
Red blood cell lysis induced by type II hypersensitivity by the naturally occurring antibodies

Question 23

What is an example of type II sensitivity? IGG

Answer 23

Rhesus posture father and Rhesus negative mother
In response the mother will produce anti Rhesus antibodies
If pregnant again her antibodies will cross the placenta and damage fatal red blood cells
Causes haemolytic disease of the newborn- anaemic

Question 24

What is treatment for problems with Rhesus positive father and negative mother?

Answer 24

Give Rhesus d immune globulin human

Prevents mother getting sensitised

Question 25

What is Graves' disease?

Answer 25

Increased thyroid activity | Antigen is TSH receptor

Question 26

What is myasthenia gravis?

Answer 26

Impaired neuromuscular signalling | Antigen=acetylcholine receptor

Question 27

What are the therapeutic approaches for type II hypersensitivity tissue cell damage?

Answer 27

Immune suppression Plasmapheresis Splenectomy Intravenous immunoglobulin

Question 28

What are the therapeutic approaches for type II hypersensitivity physiological damage?

Answer 28

Correct metabolism | Replacement therapy

Question 29

What is plasmapheresis therapy?

Answer 29

Plasma is filtered and discarded and serum is given | Short term relief and allows healing of damaged tissue

Question 30

When is plasmapheresis therapy used?

Answer 30

Myasthenia gravis Goodpastures syndrome Graves' disease

Question 31

When does type III hypersensitivity develop?

Answer 31

Within 3-8 hours

Question 32

What does type III hypersensitivity target?

Answer 32

Soluble antigens e.g. Foreign infection or endogenous (self antigens)

Question 33

What does type iii hypersensitivity cause?

Answer 33

Tissue damage

Question 34

What are the key factors affecting IC pathogenesis ?

Answer 34

Complex size Host response- low affinity antibody or complement deficiency Local tissue factors

Question 35

What is type iii hypersensitivity efffect?

Answer 35

Multiststem disease

Question 36

What are the two main diseases that type III hypersensitivity cause?

Answer 36

Rheumatoid arthritis | Glomerulonephritis

Question 37

What are the features of rheumatoid arthritis?

Answer 37

Rheumatoid factor antigen IGG | Episodes of inflammtion and remission

Question 38

What is glomerulonephritis?

Answer 38

Infectious Bacterial endocarditis Hepatitis b infection

Question 39

What is systemic lupus erthematosus?

Answer 39

Every patient unique Do-DNA antigen Mainly women Repeated miscarriage

Question 40

What are the features of type IV hypersensitivity?

Answer 40

Develops within 24-72 hours | Involves lymphocytes and macrophages

Question 41

What are the subtypes of type IV hypersensitivity?

Answer 41

contact hypersensitivity- eczematous rash Tuberculin hypersensitivity- induration and swelling Granulomatous- tissue damage, granuloma- walls off infected cells

Question 42

What diseases are caused by type IV hypersensitivity exogenously?

Answer 42

Granulomatous hypersensitivity- tuberculosis, leprosy, schistosomiasis, sarcoidosis Contact hyoersensitiy- nickel, poison ivy, organic chemicals

Question 43

If someone has beeen infected with tuberculosis how would you find out if they are sensitised?

Answer 43

Antigen injected and processed by antigen presenting cells T cells recognise antigen and release cytokines which react on endothelium Pathogocytes and plasma to site and causes visible lesion

Question 44

What diseases are caused by type IV hypersensitivity endogenously?

Answer 44

Autoimmune disease e.g. Pancreatic islet cells- insulin dependant diabetes mellitus Thyroid gland- Hashimoto's thyroiditis (cd8+ T cells and antibodies) IGG- rheumatoid arthritis

Question 45

What are the therapies for type iii and IV hypersensitivity?

Answer 45

Anti inflammatory drugs e.g. Non steroid, corticosteroids, second drugs of steroid sparing agents Monoclonal antibodies B cells and T cells Will have more as time goes on