Hypersensitivity and Autoimmune Disease

Question 1

What is autoimmune disease?

Answer 1

A failure or breakdown of immune system that maintains tolerance to self tissues

Question 2

What is the loss of tolerance to self tissues due to?

Answer 2

abnormal selection or lack of control of self-reactive lymphocytes (B and T-cells)

Question 3

What may damage in different autoimmune diseases may result from?

Answer 3

Different effector mechanisms

Question 4

What are two risk factor of developing autoimmune disease?

Answer 4

Environment and genetics

Question 5

What is usually used to cure autoimmune diseases?

Answer 5

Blanket immunosuppression.

Question 6

What is blanket immunosuppression?

Answer 6

Suppressing the immune system in order to supress the symptoms of the autoimmune disease.

Question 7

What is a side effect of blanket immunosupression?

Answer 7

Infection

Question 8

What is the tactic to tackle autoimmune diseases?

Answer 8

Come up with more targeted selective approach’s meaning target the aberrant immune activation while leaving the rest of the immune system intact

Question 9

Name the disadvantages of autoimmune disease.

yh ik that sounds weird haha, disease doesn’t have any advantages rlly but shhh get on w it

Answer 9

Typically chronic long-term disorders [low mortality but high morbidity]

Treatments limited to dealing with the symptoms rather than curing the disease

Treatments e.g., steroids carry their own risks

Patients require intense, careful management and treatment costs run into billions worldwide

Question 10

What do we not know aboout autoimmune diseases?

Answer 10

How it is caused
How to treat it

Question 11

What is the actual damage from autoimmune diseases caused by?

Answer 11

Hypersensitivity responses.

Question 12

There are four types of Hypersensitivity responses, what are they?

Answer 12

Type 1, 2 ,3 ,4

Question 13

Which types of Hypersensitivity responses are antibody mediated?

Answer 13

Types 1,2,3

Question 14

Which types of Hypersensitivity responses are T cell mediated?

Answer 14

Type 4

Question 15

Describe the sequence of events in immediate hypersensitivity reactions for Type 1.

Answer 15

Immediate hypersensitivity diseases are initiated by the introduction of an allergen, which stimulates TH2 reactions and IgE production. IgE sensitizes mast cells by binding to FcdeltaRI, and subsequent exposure to the allergen activates the mast cells to secrete the mediators that are responsible for the pathologic reactions of immediate hypersensitivity.

Question 16

Desribe Type 1.

Answer 16

1. Relies on presence of antibody IgE
   2.Produces allergy

Question 17

Describe type 2 and 3.

Answer 17

1. Reliant on antibody IgG
2. Type 2 can cause Rheumatic fever
3. Type 3 can cause Rheumatoid arthritis

Question 18

Out of type 2 and 3, which response is predictable and which is more spontaneous?

Answer 18

Type 2- predictable
Type 3- spontaneous

Question 19

Describe mast cell actiavtion.

Answer 19

1. Antigen binding to IgE cross-links FcΕRI molecules on mast cells, which induces the release of mediators that cause the hypersensitivity reaction
2. Other stimuli, including the complement fragment C5a, can also activate mast cells

Question 20

Define atopy

Answer 20

Predisposition to allergy

Question 21

Type 2 is about specificity. What does this mean?

Answer 21

It is targeting a specific antigen.

Question 22

Give an example of type 2/3 hypersensitivity.

Answer 22

Antibodies may bind specifically to tissue antigens and the recruited leukocytes cause tissue injury

Question 23

Where may complexes of antibodies and antigens be formed?
What do these complexes induce?

Answer 23

Formed in circulation and deposited in blood.
Can induce vascular inflammation, and subsequent ischemic damage to the tissues. Can also lead to depletion of the cells and functional abnormalities.

Question 24

What is the difference between type 2 and type 3?

Answer 24

Type 2 and type 3 hypersensitivity both result from the same class of antibody, called IgG. The difference between them lies in the form of antigens that generate a response.

Question 25

What is type 4?

Answer 25

Occur in response to contact with certain allergens resulting in contact dermatitis

Question 26

Name the two ways type 4 can be mediated.

Answer 26

Cytokine mediated inflammation T-cell mediated cytotoxicity

Question 27

Name some T-cell mediated immunologic diseases.

Answer 27

Type 1 diabetes Multiple sclerosis Rheumatoid artheritis

Question 28

If you have the allele DR4, what does this mean?

Answer 28

You are four times more likely to develop rheumatoid artheritis.

Question 29

Compare genetic factors and environmental factors relating to developing an autoimmune disease.

Answer 29

Genetic background of an individual may pre-dispose them to an autoimmune disease ->Complex, multi-factorial, but can be other independent factors not related to genetic background. Environmental factors- most likely is prior infection. ->Other factors may include drugs, trauma, food

Question 30

What is molecular mimicry?

Answer 30

The immune system makes a response against the pathogen but that response is then cross reactive with a self tissue and then causes autoimmune damage.

Question 31

Define immunological tolerance.

Answer 31

State of unresponsiveness to specific antigen, either self or foreign antigens. ->as a state of indifference or non-reactivity towards a substance that would normally be expected to excite an immunological response

Question 32

What does immunological tolerance prevent??

Answer 32

Adaptive responses that are damaging (immune pathology) like BSR responses, particularly B cells and T cells

Question 33

How can immunological tolerance be expolited?

Answer 33

Microbes and tumours. ->tumours create an environment that the T cells do not function as well in so tumour may escape from the immune system.

Question 34

For each T cell, how many specificities is there?

Answer 34

>1011 specificities

Question 35

Where do T cells develop?

Answer 35

Thymus, just above the heart

Question 36

Name the two categories of autoimmune disease.

Answer 36

Systemic or organ specific

Question 37

Describe the process of systemic autoimmune disease.

Answer 37

Autoimmune process is diffuse is spread throughout the body Affects more than one organ - not necessarily the same ones in different individuals

Question 38

Describe the process of organ specific autoimmune disease.

Answer 38

Autoimmune process directed against one organ For example, Type 1 Diabetes - pancreas

Question 39

Name some symptoms of Systemic lupus erythematosus

Answer 39

Butterfly rash on face, fever, mouth ulcers, arthritis, painful joints.

Question 40

Is Systemic lupus erythematosus systemic or organ specific?

Answer 40

Systemic

Question 41

Name some symtoms of type 1 diabetes.

Answer 41

Thirst, extreme urine output. ->renal failure, heart disease, blindness

Question 42

Why do individuals w type 1 diabetes pee a lot? lol for my own interest

Answer 42

Drink a lot to try and balance sugar in the body when im typing this it seems like common sense lollll

Question 43

What is loss of tolerance due to?

Answer 43

Due to abnormal selection or lack of control of self-reactive lymphocytes (B and T-cells)