Inflammation and Immune Pathology USMLE Step 1 Practice Question
A 37-year-old woman presents with acute confusion, fever, and petechiae. Vital signs show temperature 38.9°C, BP 152/94 mmHg, HR 108/min, RR 22/min, SpO2 98% on room air. Laboratory studies reveal hemoglobin 8.7 g/dL, platelets 14,000/mm³, creatinine 1.8 mg/dL, elevated LDH 820 U/L, and numerous schistocytes on peripheral smear. Coagulation studies (PT, PTT) are normal. She denies recent antibiotic use. Which of the following is the most likely underlying mechanism?
Answer choices
- AVitamin K deficiency
- BInherited deficiency of factor XIII
- CAutoantibody mediated severe deficiency of ADAMTS13Correct answer
- DShiga like toxin mediated endothelial injury
- EEndothelial infection by Neisseria meningitidis
- FPlatelet consumption from disseminated intravascular coagulation secondary to sepsis
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