Immunoglobulin replacement and antimicrobial prophylaxis — formative SAQs

SAQ 1 (10)

A six-year-old boy with X-linked agammaglobulinaemia has been on intravenous immunoglobulin since infancy, given every four weeks in a hospital two hours from his home. He has had three proven pneumonias in the past year despite a trough IgG that sits in the lower half of the normal range. His family finds the travel and the missed school increasingly difficult. ^{[3] [2]}

a) What are the four structured questions you must ask before simply raising the dose, and why is the trough alone an incomplete target? (3 marks) ^[2]

b) Discuss the relative pharmacokinetic and practical advantages of switching this child to home subcutaneous immunoglobulin, and the evidence that supports it. (3 marks) ^{[5] [8]}

c) Outline a plan to dose this child's regimen to his clinical outcome rather than to a trough number alone, including the role of antimicrobial prophylaxis. (2 marks) ^{[2] [6]}

d) Describe the lung surveillance and the family capacity assessment that belong in the revised plan. (2 marks) ^{[3] [8]}