Autoimmunity And Autoimmune Disease L11

Question 1

How can self tolerance mechanisms to distinguish between self and non-self breakdown

Answer 1

Through production of autoantibodies and autoreactive T cells

Question 2

What are two main categories of autoimmune diseases

Answer 2

Organ-specific and systemic

Question 3

In what gender is there a higher prevalence of autoimmune diseases

Answer 3

Females

Question 4

In organ-specific diseases what type of hypersensitivity reactions are important

Answer 4

Type II and type IV

Question 5

In non organ-specific diseases what type of hypersensitivity reactions are important

Answer 5

Type III

Question 6

3 ways that damage can be caused by autoimmune diseases

Answer 6

1) Complement activation by autoantibodies
2) Autoantibody recognition of self antigens
3) Autoreactive T cell recognition of self antigens

Question 7

What codes for histocompatibility antigens

Answer 7

The major histocompatibility complex which is a gene locus

Question 8

Our ……….. determine which foreign substance our immune system will be able to recognise and neutralise not the ………. they encounter

Answer 8

1) genes

2) antigens

Question 9

What induces different antigen receptors to be made

Answer 9

Genes

Question 10

How can roughly a billion different antigen receptors be produced from only 20000 genes

Answer 10

Antigen receptors are not coded by complete genes. They are coded by segments of genes; few hundred genetic blocks.

These can then be randomly pieced together to produce proteins that form billions of possible antigen receptors. This is called somatic recombination

Question 11

What is positive and negative selection and what is the process called

Answer 11

Postive selection is when T cells must recognise self MHC if not then they are induced to go through apoptosis

Negative selection is when T cells bind too tightly to self MHC leading to apoptosis

This is called self tolerance by clonal deletion

Question 12

How can misidentification occur in the selection porcess

Answer 12

When theres a bacteria in the thymus during the selection/maturation of T cells

Question 13

What is autoimmunity

Answer 13

A breakdown in these selection processes that allows ‘self’ reactive lymphocytes to mature and be released will result in your immune system attacking ‘self’ cells and chronic inflammation causing autoimmune disease

Question 14

Symptoms of dry eyes

Answer 14

Redness, dryness, gritty or foreign body sensation, burning snd photophobia

Question 15

What can links can be made through observing a cotton wool spot

Answer 15

Strong links between lupus retinopathy and renal nephropathy. They can also be associated with autoimmune diseases such as Diabetes Type I and SLE

Question 16

How can the cotton wool spot be observed

Answer 16

It may be isolated or surrounded by haemorrhage. It may also be seen in regions of retinal oedema and infarction

Question 17

Ocular autoimmunity tends to be associated with which particular HLA antigen

Answer 17

HLA-B27

Question 18

Example of ocular autoimmune diseases in the absence of systemic involvement

Answer 18

Sympathetic Ophthalmia which occurs after a penetrating wound to the eye, as the lymphocytes in the blood stream are exposed to the proteins in the retina and can sometimes regard them as foreign and then the T cells can become auto reactive. This can affect both eyes