Hypersensitivities

Question 1

Type IV - Delayed hypersensitivity

Answer 1

T-cell mediated

• Tuberculosis / tuberculin skin reaction
• Graft versus host disease
• Allergic contact dermatitis
• Scabies
• Extrinsic allergic alveolitis (especially chronic phase)
• Multiple sclerosis
• Guillain-Barre syndrome

Question 2

Type V

Answer 2

Antibodies that recognise and bind to the cell surface receptors.
Graves’ disease
* Myasthenia gravis

Question 3

Type III - Immune complex

Answer 3

• Serum sickness
• Systemic lupus erythematosus
• Post-streptococcal glomerulonephritis
• Extrinsic allergic alveolitis (especially acute phase)

Question 4

Type II - Cell bound

Answer 4

Autoimmune haemolytic anaemia
* ITP
* Goodpasture’s syndrome
* Pernicious anaemia
* Acute haemolytic transfusion reactions
* Rheumatic fever
* Pemphigus vulgaris / bullous pemphigoid

Question 5

Type I - Anaphylactic

Answer 5

Anaphylaxis
* Atopy (e.g. asthma, eczema and hayfever)

Question 6

Tuberculin skin tests are an example of type IV (delayed) hypersensitivity reactions. These are largely mediated by?

Answer 6

interferon-γ secreted by Th1