Inflammation and Immune Pathology USMLE Step 1 Practice Question
A 29-year-old woman presents with recurrent oral thrush despite otherwise normal health. Vital signs are stable (BP 118/76, HR 82, RR 16, Temp 37.2°C, SpO2 98%). Laboratory evaluation reveals normal neutrophil oxidative burst but impaired myeloperoxidase activity and defective bleach generation within phagolysosomes. Serum immunoglobulin levels are normal. Which of the following enzyme defects is most likely responsible for this patient's recurrent candidiasis?
Answer choices
- AInability to form superoxide
- BInability to convert hydrogen peroxide to hypochlorous acidCorrect answer
- CInability to bind Fc receptors
- DInability to opsonize bacteria with C3b
- EInability to migrate through endothelium
- FInability to generate NADPH through the pentose phosphate pathway
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