Immunology USMLE Step 1 Practice Question
A 9-year-old boy recently immigrated from a tropical region presents with chronic abdominal discomfort and fatigue. Vital signs show BP 95/60, HR 102, RR 20, Temp 37.2°C, SpO2 98%. Laboratory evaluation reveals hemoglobin 8.2 g/dL with microcytic indices and iron studies consistent with iron deficiency anemia. Stool examination demonstrates hookworm ova. Eosinophil count is elevated at 8%. He denies fever or recent antiparasitic therapy. Which immune response is most important for host defense against this pathogen?
Answer choices
- ACD8 positive cytotoxic T cell response via MHC I
- BTh2 response with IL 5 driven eosinophil activation and IgE productionCorrect answer
- CTerminal complement mediated lysis
- DType IV delayed hypersensitivity
- ETh1 response with IFN gamma activated macrophages
- FOpsonization with IgG and complement-mediated phagocytosis by neutrophils
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