Vascular Disease USMLE Step 1 Practice Question
A 42-year-old woman with systemic lupus erythematosus presents with recurrent deep vein thrombosis in both lower extremities despite therapeutic warfarin (INR 2.5). Vital signs show BP 128/82, HR 92, RR 18, temp 37°C, SpO2 98%. Laboratory studies reveal prolonged activated partial thromboplastin time that does not correct on mixing study. D-dimer is elevated at 2.8 μg/mL. Anticardiolipin antibodies are negative. Which diagnosis best explains these findings?
Answer choices
- AAntiphospholipid syndromeCorrect answer
- BFactor VIII deficiency
- CHeparin-induced thrombocytopenia
- DDisseminated intravascular coagulation
- EVitamin K deficiency
- FProtein C deficiency
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