Immunology

Question 1

Hereditary angioedema
Cause?
Symptoms?
Lab investigations (during + in between attacks)?
Management?

Answer 1

Cause = Autosomal dominant. Low C1 inhibitor levels –> uncontrolled bradykinin release –> attacks of oedema

Symptoms

• Painful macular rash may precede
• Painless, non-pruritic swelling
• Urticatia usually not a feature

Investigations

• low C2 esterase during attack
• Low C2 and C4 during + between attacks. C4 commonly used to screen

Management

• Acute: C1 inhibitor concentrate (FFP if unavailable)
• Prophylaxis: Danazol (anabolic steroid)
• DOES NOT respond to adrenaline, antihistamine, glucocorticoid

Question 2

Cryoglobuminaemia - definition? General symptoms? General blood findings?
Type 1: clonality, associations, specific symptom?
Type 2: clonality, associations?
Type 3: clonality, associations?

Answer 2

Definition = Ig which undergo reversible precipitation at 4C and dissolve on heating to 37C
Symptoms = skin (purpura, ulceration), arthralgia, renal (diffuse glomerulonephritis)
Bloods = low complement (esp. C4), high ESR

Type 1

• Monoclonal
• Associated with Waldenstrom’s macroglobuminaemia
• Only type where Raynaud’s is seen

Type 2

• Mono/polyclonal
• Associations: hep C, Rh arthritis, Sjogrens
• Usually Rh factor +ve

Type 3

• Polyclonal
• Associations: Rh arthritis, Sjogrens
• usually Rh factor +ve

Question 3

Wiskott-Aldrich syndrome
Cause?
Inheritance?
Features?

Answer 3

WASP gene mutation –> Primary immunodeficiency caused by B & T cell dysfunction

Inheritance = X-linked recessive

Features

• Recurrent bacterial infections
• Eczema
• Thrombocytopenia
• Low IgM

Memory aid:
- Wiskott-Aldrich = WAsp mutation