Hyper sensitivity and autoimmunity

Question 1

What cells are involved in innate immunity?

Answer 1

Phagocytes, easoinophils, basophils, mast cells etc.

Question 2

What receptors are involved in innate immunity?

Answer 2

Complement, Cytokines

Question 3

What cells are involved in adaptive immunity?

Answer 3

B cells

T cells

Question 4

What receptors are involved in adaptive immunity?

Answer 4

Ig, Cytokine, Complement

Question 5

What is complement?

Answer 5

Group of proteins present in blood plasma and tissue fluid that combine with antigen - antibody complexes to bring about the lysis of cells.

Question 6

What is hypersensitivity?

Answer 6

Normal, beneficial components of immune system respond in an exaggerated / inappropriate manner to (usually ) environmental organisms that shouldn’t do any harm usuallly .

Question 7

In hypersensitivity, the tissue damage is not caused by the environmental organism, but by the response itself. What is this called?

Answer 7

Bystander response.

Question 8

Which types of hypersensitivity and antibody mediated?

Answer 8

I , II, III

Question 9

Which type of hypersensitivity is due to the inappropriate action of Th1 cells?

Answer 9

IV

Question 10

What is type 1 hypersensitivity ?

Answer 10

Allergy

Question 11

In type 1 hypersensitivity, how can the allergen be exposed?

Answer 11

Airborne, Ingested, Injected, Skin Contact

Question 12

What does IGE do in type 1 inflammatory?

Answer 12

IGE -> binds to mast cells -> releases inflammatory mediators.

Question 13

The inflammatory mediators in type 1 inflammation create an early phase response and a late phase response. What preformed mediators are involved in the early phase response?

Answer 13

Histamine, heparin, easoniphil and neutrophil chemotactic factors.

Question 14

The inflammatory mediators in type 1 inflammation create an early phase response and a late phase response. What newly synthesised meditators are involved?

Answer 14

Prostaglandins.

Question 15

Allergy isn’t just IGE. Its also due to lots of factors, genetic environmental etc. All of this plus symptoms makes an allergy. What is it called when theres IGE but no symptoms (commoner than allergy)

Answer 15

Atopy

Question 16

When may type 2 hypersensitivity occur?

Answer 16

When wrong blood is infused.

Question 17

In type two hypersensitivity, IgG and IgM antibodies are directed on antigens of the surface of the cells / fixed within tissues. Where do these antigens come from?

Answer 17

External (exogenous ) or derived from self

Question 18

The antibody + antigen creates tissue damage. Name 3 ways this could happen. (Type two hypersensitivity)

Answer 18

Complement activation
Antibody dependant cellular cytotoxicity
Effects target cell function ( Inhibition or stimulation)

Question 19

Why do conditions arise in type 3 hypersensitivity?

Answer 19

Abnormal deposition of immune complexes.

Question 20

What are immune complexes? (type 3)

Answer 20

Antigen + Antibody (Ag or Ab)

Question 21

In type three hypersensitivity, where are the antigens from?

Answer 21

Exogenous or self antigen

Question 22

Describe the physiology of immune complexes destruction ( type 3).

Answer 22

Immune complex -> blood stream -> Liver/ spleen -> Destroyed by fixed phagocytes

Question 23

Why may the journey of immune complexes get pathological problems in type three hypersensitivity?

Answer 23

Predisposing factors in antigen / immune response to antigen.

Question 24

What is the pathology of type 3 hypersensitivity?

Answer 24

Abnormal immune complex formation -> Precipitates in tissues -> inflammation.

Question 25

Type three hypersensity - explain serum sickness.

Answer 25

Systemic - deposits of immune complexes in many tissues.

Question 26

Type three hypersensitivity - explain ARTHUS reaction.

Answer 26

Local - deposits form in local tissue.

Question 27

In type 4 hypersensitivity - what does the body struggle to respond too?

Answer 27

Microorganism - may have evolved to evade immune response.

Hapten + Carrier

Question 28

Explain happen + carrier in type 4 hypersensitivity.

Answer 28

Hapten is exogenous low molecular antigen that is too small to produce an immune response, so it binds to an endogenous host protein (which provides bulk)

Question 29

During type four hypersensitivity, what does the body do?

Answer 29

1) produces Th1.
2) this produces cytokines ( interleukin - 2 & beta - inferon)
3) these activate macrophages and are responsible for cell mediated immunity.
4) inflammation

Question 30

What is cell mediated immunity?

Answer 30

Immunity that does not involved antibodies, but involved phagocytes and cytokines etc.

Question 31

What are autoimmune diseases?

Answer 31

group of clinical disordered characterised by tissue/ organ damage, mediated by incorrect immune mechanisms targeted at self antigens.

Question 32

What is broken down for autoimmune disorder to arise?

Answer 32

Tolerance

Question 33

What are the two types of tolerance

Answer 33

central tolerance - auto reactive t and b cells deleted during cell maturation
peripheral tolerance - inhibition of auto reactive cells that escape the central tolerance process

Question 34

what is physiological autoimmunity?

Answer 34

beneficial self recognition - like antibodies recognising other antibodies are regulating their production and activity.

Question 35

WHAT 5 factors are involved in aetiology of autoimmune disease?

Answer 35

1 - genetic
2 - immune regalarotry factors 
3 - hormonal factors
4- environmental factors 
5 - others - eg. age, disease, trauma

Question 36

Name four pathogenic mechanisms in autoimmunity.

Answer 36

1 - T cells or B cells activated
2 - (auto) antibody activation of complement mediated inflammation
3 - immune - complex formation
4 - recruitment of innate immune components

Question 37

what leads to broken tolerance

Answer 37

1 or more environmental factor (e.g. infection) + 1 or more genetic factor (specific HLA allele)

Question 38

what organs may be affected by autoimmune disorders”

Answer 38

thyroid
stomach
adrenal

Question 39

what non - organ specifics may be affected by autoimmune disorders?

Answer 39

muscles
skin
joints