Immunology USMLE Step 1 Practice Question
An 8 year old boy is brought to the physician because of frequent ear infections and progressive difficulty walking. His parents report that he often stumbles and has had several episodes of sinusitis and pneumonia. Physical examination shows conjunctival telangiectasias and a wide based gait. Laboratory studies show low IgA levels and elevated alpha fetoprotein. Which of the following cellular functions is most likely impaired in this patient?
Answer choices
- AExpression of MHC class II molecules on antigen presenting cells
- BGeneration of reactive oxygen species in neutrophils
- CDevelopment of thymic epithelium
- DAdhesion of neutrophils to vascular endothelium
- ERepair of DNA double strand breaksCorrect answer
- FMaturation of B cells in the bone marrow
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