8 Autoimmune diseases

Question 1

Differentiate between autoimmunity and autoimmune disease.

Answer 1

Autoimmunity is a theoretical concept of a break down of self tolerance.
Autoimmune disease is a clinical entity with environmental and genetic factors.

Question 2

What is central tolerance and where does it occur?

Answer 2

Destruction of self-recognising antigens. Occurs in the thymus.

Question 3

What are the causative associations of autoimmune disease?

Answer 3

Women»>Men.
Age - older>younger.
Environmental: tissue damage, smoking, infection.

Question 4

How does autoimmunity cause clinical disease?

Answer 4

B cells are directly cytotoxic, activate complement and interfere with function.
T cells are directly cytotoxic and produce inflammatory cytokines.
Inflammation and end organ damage.

Question 5

Differentiate between organ specific and systemic autoimmune diseases.

Answer 5

Affects single organ - thyroid is typical.

Affects several organs - connective tissue diseases air typical.

Question 6

Describe hashimotos thyroiditis.

Answer 6

Destruction of thyroid follicles.

Autoantibodies to thyroglobulin and thyroid peroxidase. Leads to hypothyroidism.

Question 7

Describe grave’s diseases.

Answer 7

Inappropriate stimulation of thyroid gland by ant-TSH-autoantibody. Leads to hyperthyroidism.

Question 8

What is the cause of myasthenia graves and how is it’s weakness circadian?

Answer 8

Autoantibodies to AChR preventing transmission. Gets worse throughout the day.

Question 9

What is pernicious anaemia?

Answer 9

Failure of vitamin B12 absorption due to autoantibodies to intrinsic factor. Leads to microcytic anaemia.

Question 10

Name four systemic autoimmune diseases.

Answer 10

Systemic lupus erythematosus.
Scleroderma.
Polymyositis.
Sjogrens syndrome.

Question 11

What is auto inflammation?

Answer 11

spontaneous attacks of systemic inflammation without infection or presence of autoantibodies/autoreactive T cell.

Question 12

What causes systemic lupus erythematous?

Answer 12

Defects in apoptosis lead to anti-nuclear antibody creation.

Question 13

What are ANCA antibodies and what do they lead to?

Answer 13

Anti-Neutrophil Cytoplasmic Antibodies. Lead to widespread neutrophil activation (granulomas - lung) and inflammation around the blood vessels (polyangitis-skin, kidney, lung, gut).

Question 14

What are the 3 forms of ANCA vasculitis?

Answer 14

Microscopic Polyangitis.
Granulomatosis with Polyangitis.
Eosinophilic Granulomatous with Polyangitis.

Question 15

What is Raynauds phenomenon? Significance of bimodal distribution?

Answer 15

Whitened fingertips.
Young: harmless, ANA -ve.
Odler: ANA +ve, associated with scleroderma and SLE.

Question 16

What is scleroderma?

Answer 16

Anti-Nuclear Antibodies lead to ischaemia and fibrosis - Raynauds, skin thickening and tightening in fingers, face, lungs, gut, kidneys.

Question 17

What are the symptoms of systemic lupus erythematosus? (7).

Answer 17

Photosensitive malaria rash.
Mouth ulcer.
Arthralgia.
Alopecia. 
Lupus nephritis.
Pleurisy.
Cerebral lupus.