Lipid Biochemistry USMLE Step 1 Practice Question
A 42-year-old woman with systemic lupus erythematosus presents with recurrent bilateral lower extremity thromboses. Vital signs: BP 138/88 mmHg, HR 92/min, RR 18/min, temp 37.2°C, SpO2 98% on room air. Laboratory studies reveal fasting triglycerides 310 mg/dL, HDL 22 mg/dL, lipoprotein(a) 85 nmol/L, and lupus anticoagulant positivity. Platelet count remains normal. She takes hydroxychloroquine and prednisone. Which mechanism best explains the link between SLE and these lipoprotein abnormalities?
Answer choices
- ASLE-induced immune complex deposition in hepatocytes prevents cholesterol synthesis
- BLupus anticoagulant directly impairs lipoprotein lipase activity and apoA-I synthesis
- CAnti-phospholipid antibodies prevent LDL particle formation in the endoplasmic reticulum
- DHydroxychloroquine therapy blocks HMG-CoA reductase, reducing lipoprotein synthesis
- EChronic inflammation and oxidative stress increase lipoprotein(a) synthesis and impair HDL-mediated reverse cholesterol transportCorrect answer
- FGlucocorticoid-induced suppression of apolipoprotein A-I gene expression combined with increased hepatic CETP activity
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