Lecture 19 - Autoimmune Diseases

Question 1

What are autoimmune diseases?

Answer 1

When an immune response against one or more self-antigens is triggered

Question 2

How do autoimmune diseases develop?

Answer 2

Due to a failure to self-tolerate

Question 3

What are the two classes of autoimmune diseases? [2]

Answer 3

• Organ specific

- Systemic

Question 4

What do nearly all autoimmune diseases have in common?

Answer 4

The generation of autoreactive CD4+ Th cells

Question 5

What are two common features of autoimmuen diseases? [2]

Answer 5

• Generation of auto-antibodies

- Cellular infiltrate of T and B cells

Question 6

What are primary pathologies of autoimmune diseases?

Answer 6

A direct consequence of the autoimmune response

Question 7

What are secondary pathologies of autoimmune diseases?

Answer 7

Arises as a consequence of the primary pathology

Question 8

What are three ways damaged is caused by autoimmune diseases? [3]

Answer 8

• CD8 cytotoxic T cell function
• Macrophage mediated destruction
• Inflammatory responses

Question 9

What do mice develop when they are injected with Myelin basic protein (MBP)?

Answer 9

Experimental Autoimmune Encephalomyelitis (EAE)

Question 10

What is EAE mediated by?

Answer 10

Th1 and Th17 specific for MBP

Question 11

What are three mechanisms of auto-antibody mediated immune pathology? [3]

Answer 11

• Damage/destruction
• Alteration of function
• Deposition of immune complexes

Question 12

What forms does auto-antibody destruction come in?

Answer 12

• Complement mediated lysis

- Opsinisation

Question 13

How does auto-antibody mediated alteration of function lead to autoimmune diseases?

Answer 13

Alters the normal function of a process leading to GOF/LOF variants

Question 14

What causes autoimmunity?

Answer 14

• Genetics

- Environment

Question 15

What geographical influences affect autoimmunity?

Answer 15

Population movement to areas with high autoimmunity increases incidence

Question 16

What are five environmental influences that affect autoimmune diseases? [5]

Answer 16

• Pathogens
• Vitamin D levels
• Drugs
• Toxins
• Microbiota/Hygeine

Question 17

Most autoimmune diseases are a result of […] gene mutations.

Answer 17

Multigenic

Question 18

The degree to which an allele of a gene increases susceptibility is refered to?

Answer 18

The relative risk

Question 19

True or False? The multi-gene interactions between high risk genes is what causes autoimmunity.

Answer 19

True

Question 20

How do genetic factors affec autoimmunity?

Answer 20

They affect autoantigen availability and clearance

Question 21

Are sex-related genes a risk factor for autoimmune disease?

Answer 21

Yes

Question 22

Progression to an autoimmune disease is a multi-step process reflect whcih two factors? [2]

Answer 22

• Genetic predisposition

- Environmental factors

Question 23

How does the immune system lose the toerance to ‘self’?

Answer 23

• Production of high affinity auto-antibodies

- Generation of autoreactive T cells

Question 24

What stimulates the production of auto-antibody in the absence of Th?

Answer 24

• B cell mitogens

- E.g. LPS

Question 25

How can mibrobial infection lead to autoimmunity?

Answer 25

• The microbe has antigens similar to self-antigens

- When the microbe is fought off there is now auto-antibodies in the body

Question 26

What is an example of a microbial caused autoimunne disease?

Answer 26

Rheumatic fever

Question 27

How is chronic autoimmunity developed?

Answer 27

• Positive feedback from inflammation

- Inability to clear self antigen