A 28-year-old woman with Tangier disease presents with hepatosplenomegaly, lymphadenopathy, and progressive peripheral neuropathy. Vital signs show BP 118/76, HR 88, RR 16, Temp 37°C, SpO2 98%. Laboratory studies reveal HDL cholesterol <5 mg/dL, triglycerides 280 mg/dL, and normal LDL cholesterol. Genetic testing confirms ABCA1 mutation. She denies recent infections. Which cellular process is primarily impaired in this condition?
- A)Hepatic synthesis of apolipoprotein B-100
- B)Efflux of cholesterol and phospholipid from macrophages to apolipoprotein A-1GABARITO
- C)Lecithin-cholesterol acetyltransferase activity in plasma
- D)Uptake of LDL cholesterol via hepatic receptors
- E)Lipoprotein lipase-mediated hydrolysis of triglycerides
Explicação
ABCA1 mediates cholesterol and phospholipid efflux from cells to apoA-I, forming nascent HDL. Defective ABCA1 prevents this initial step of reverse cholesterol transport, causing severe HDL deficiency and cholesterol accumulation in macrophages and tissues. Ver explicação completa e trilha adaptativa →