Inflammation and Immune Pathology USMLE Step 1 Practice Question
A 6-year-old boy presents with recurrent skin and respiratory infections caused by Staphylococcus aureus and Serratia marcescens. Flow cytometry reveals normal T cell and B cell numbers, but neutrophils fail to produce reactive oxygen species. A nitroblue tetrazolium (NBT) test is negative. Which of the following is the most likely diagnosis?
Answer choices
- ALeukocyte adhesion deficiency type 1 with impaired integrin expression
- BChronic granulomatous disease due to NADPH oxidase deficiencyCorrect answer
- CSelective IgA deficiency affecting mucosal immunity
- DX-linked agammaglobulinemia with absent B cells
- EDiGeorge syndrome with thymic hypoplasia
- FMyeloperoxidase deficiency with impaired bacterial killing
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