Diseases

Question 1

Multiple sclerosis

Answer 1

Immune cells cause demyelination of the white matter of the brain. Trigger is thought to be viral. Symptoms wax and wane and include sensory and motor impairment. Treatment is with immunosuppressive drugs.

Question 2

Chronic thyroiditis

Answer 2

Patients with Hashimoto’s chronic thyroiditis have antibodies to thyroglobulin which cause fibrosis of the thyroid gland.

Question 3

Haemolytic anaemias

Answer 3

Various forms, caused by attachment of autoantibodies to cell surfaces and subsequent cell destruction. Pernicious anaemia caused by depleted vitamin B12 caused by antobodies to intrinsic factor, a protein secreted by gastric parietal cells which facilitates absorption of vitamin B12.

Question 4

Diabetes mellitus (Type I, insulin dependent)

Answer 4

Autoreactive T cells destroy the islet cells of the pancreas.

Question 5

Guillain-Barre syndrome

Answer 5

The most common cause of acute paralysis in the USA. Follows a variety of infectious diseases such as viral illnesses and diarrhoea caused by Campylobacter jejuni. Antibodies to myelin are formed resulting in ascending paralysis. Most recover completely in a few months.

Question 6

Coeliac disease

Answer 6

Characterised by diarrhoea, painful abdomen, fatty stools and failure to thrive in children. Caused by intolerance to gliadin, an antigen found in gluten that stimulate a cytotoxic T cell attack on enterocytes. Gluten free diet resolves symptoms

Question 7

Psoriasis

Answer 7

A chronic autoimmune skin disease characterised by raised red plaques with silvery scales, often on elbows or knees. Skin lesions are most common but arthritis also occurs. Genetic predisposition with unknown environmental trigger. Treatment with topical corticosteroids, UV phototherapy or systemic immune suppressants.