Immunology USMLE Step 1 Practice Question
A 4-year-old boy with recurrent Staphylococcus aureus and Streptococcus pneumoniae infections presents with fever (38.2°C), lymphadenopathy, and mild splenomegaly. Vital signs show BP 95/60, HR 110/min, RR 22/min, and SpO2 98% on room air. Phagocytic oxidase function and delayed-type hypersensitivity skin testing are normal. Serum immunoglobulin levels show absent IgG and IgA with normal IgM. Lymph node biopsy would most likely reveal which of the following?
Answer choices
- AAbsence of germinal centersCorrect answer
- BDepletion of paracortical areas
- CDepletion of thymus-dependent areas
- DDefective chemotactic response of neutrophils
- EAbsence of postcapillary venules
- FAbsence of follicular dendritic cells
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