Allergy & Immunology

Question 1

Which primary immune deficiency is associated with anaphylactic blood transfusion reaction?

Answer 1

Selective IgA deficiency➡IgE antibodies against IgA (anti-IgA antibodies)▶transfusion of blood products with IgA (not washed)▶Anaphylaxis

Question 2

How do you identify aspirin-exacerbated respiratory disease?

Answer 2

Clinical triad:

• Asthma (often severe and presenting in adulthood)
• Bronchospasm or nasal congestion following the ingestion of aspirin or NSAIDs
• Chronic rhinosinusitis with nasal polyposis

Question 3

Which disease is characterized by C1 inhibitor deficiency? Which products from the complement cascade are elevated?

Answer 3

• Hereditary angioedema
• Edema producing factors→C2b, bradykinin
• C1q levels are normal, ↑in acquired angioedema forms
• ↓C4 in all forms of angioedema

Question 4

Most common metals alloys that trigger allergic contact dermatitis. Mechanism of the reaction.

Answer 4

• Nickel (jewerly or clothing fastener)➡neck, wrists, ear lobes, umbilicus; cobalt, chromium, beryllium, zinc
• Corrosion by electrolytes in sweat releases soluble metal ions➡type IV (cell-mediated) hypersensitivity reaction