A 3-year-old boy presents with failure to thrive and steatorrhea since infancy. Vital signs show HR 110, RR 22, normal BP and temperature. Laboratory studies reveal markedly elevated triglycerides (1,200 mg/dL), low HDL (18 mg/dL), and impaired chylomicron clearance on lipoprotein electrophoresis. Fat-soluble vitamin levels are reduced. Abdominal examination reveals hepatosplenomegaly without tenderness. A genetic defect in lipoprotein lipase is suspected. Which mechanism best explains his gastrointestinal symptoms?
- A)Defective uptake of chylomicron remnants by hepatocytes
- B)Increased fecal loss of bile acids
- C)Inability to digest dietary triglycerides into fatty acids and glycerolGABARITO
- D)Reduced activity of pancreatic lipase in the small intestine
- E)Impaired synthesis of apolipoprotein B-48 in intestinal epithelial cells
Explicação
Lipoprotein lipase, located on capillary endothelium in adipose tissue and muscle, hydrolyzes triglycerides in chylomicrons. Without functional enzyme, dietary fat cannot be mobilized for absorption, causing steatorrhea and fat-soluble vitamin malabsorption. Ver explicação completa e trilha adaptativa →