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Chronic granulomatous disease oxidative burst — MRCPCH TAS MCQ

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HardImmunologyChronic granulomatous disease oxidative burstMRCPCH TAS

A 5-year-old has recurrent lymph node abscesses with Staphylococcus aureus and Serratia. Dihydrorhodamine flow cytometry shows impaired neutrophil oxidative burst. What is the most likely defect?

Educational content. Not a substitute for clinical judgement or local policy.

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Correct answer: E — NADPH oxidase dysfunction

Chronic granulomatous disease is caused by NADPH oxidase dysfunction, impairing the respiratory burst needed to kill catalase-positive organisms. BTK mutation causes antibody deficiency rather than neutrophil oxidative burst failure. The pearl is that DHR testing has largely replaced the older nitroblue tetrazolium test.

Reference: Nelson Textbook of Pediatrics; RCPCH Theory examination syllabi; Lissauer's Illustrated Textbook of Paediatrics