Autoimmune Diseases

Question 1

What is autoimmune disease?

Answer 1

A pathological reaction against a normal body component

Question 2

Where does central tolerance and peripheral tolerance occur?

Answer 2

Primary lymphoid organs

Peripheral tissues

Question 3

What is AIRE and its function?

Answer 3

Autoimmune Regulator
To cause expression of what are normally tissue restricted antigens so those antigens are also expressed in the thymus to facilitate tolerance

Question 4

What can occur in the absence of AIRE due to mutations?

Answer 4

There will be failure to delete tissue specific T cells resulting in autoimmunity

Question 5

Which MHC gene is strongly associated with the development of ankylosing spondylitis?

Answer 5

HLA-B27

Question 6

What effect can environmental factors lead to?

Answer 6

Tissue injury which causes self presenting APCs and self reactive effector lymphocytes

Question 7

HLA-DQ6 is relatively protective against which autoimmune disease?

Answer 7

Type 1 diabetes

Question 8

What is molecular mimicry?

Answer 8

A sharing of structures or sequences between self antigens and microbial antigens, leading to autoimmunity

Question 9

What are the major autoimmune diseases?

Answer 9

Graves’ disease: hyperthyroidism
Rheumatoid arthritis: inflamed joints
Hashimotos disease: hypothyroidism
Sjögren’s syndrome: reduced secretory gland function
Pernicious anemia: vitamin B12 deficient anemia
Multiple sclerosis: demyelination
Ankylosing spondylitis: inflammation of spine and sacroiliac joints
Type 1 diabetes: hyperglycemia
Systemic lupus erythematosus: skin, heart, joint, lungs, kidney, brain

Question 10

Regarding autoimmune hemolytic anemia, what are the 2 types of antibody?

Answer 10

Cold: anti RBC autoantibodies that only bind at significantly below normal body temperature. Extremities affected. Usually IgM

Warm: anti RBC antibodies that only bind at normal body temperature. Usually IgG

Question 11

What happens in pernicious anemia?

Answer 11

There is an autoimmune attack that prevents the absorption of vitamin B12 from the gut

Question 12

A direct Coombs test detects?

Answer 12

Anti RBC autoantibody that is already bound to RBCs using anti human Ig

Question 13

Which auto antibodies would be present in someone suffering from pernicious anemia?

Answer 13

Anti intrinsic factor and anti parietal cell H+K+ATPase

Question 14

Which platelet glycoprotein is affected in autoimmune thrombocytopenic purpura?

Answer 14

GPllb-lla

Question 15

What are thyroid autoimmune diseases?

Answer 15

Hashimotos disease, Graves’ disease

Question 16

What is neonatal thyrotoxicosis?

Answer 16

A condition very similar to Graves’ disease

Question 17

An auto antigen that is characteristic of type 1 diabetes?

Answer 17

Glutamic acid decarboxylase

Question 18

A biopsy of thyroid was performed and was found to have profound lymphocyte infiltration. Autoantibodies against what would you expect to find as well?

Answer 18

Thyroid peroxidase

Question 19

The lack of insulin in patients with type 1 diabetes is due to?

Answer 19

Destruction of beta cells in islets of langerhans

Question 20

Rheumatoid arthritis has characteristic involvement of the?

Answer 20

Proximal interphalangeal and metacarpophalangeal joints

Question 21

Immune complex deposition in SLE can lead to?

Answer 21

Pleura and pericardial serositis, neurological morbidity, vasculitis, renal failure

Question 22

The percentage of patients with Guillain-Barré syndrome that develop respiratory insufficiency is?

Answer 22

25%

Question 23

A crucial step in multiple sclerosis is the degradation of the blood brain barrier which allows?

Answer 23

Th1 and Th2 cells to enter the CNS, leading to the degradation of myelin and anti myelin autoantibodies

Question 24

Autoimmunity in Myasthenia gravis causes muscle weakness and fatigue by?

Answer 24

Damaging/destroying ACh receptors as well as autoantibodies that block the remaining receptors

Question 25

Anti-TNF is often employed in the treatment of?

Answer 25

Rheumatoid arthritis

Question 26

Why would an injection of vitamin B12 be beneficial in pernicious anemia?

Answer 26

This treatment addresses the deficiency without depending on the intrinsic factor of H+K+ATPase