Source / episode info

• **Episode:**503
• **Title:**Divine Intervention Episode 503: LFTs and The USMLEs
• **Published:**2024-01-15
• Source:Episode page

One-liner

Episode 503 is a comprehensive review of Liver Function Tests (LFTs), emphasizing the distinction between hepatocellular and cholestatic patterns of injury, understanding bilirubin metabolism (indirect vs. direct hyperbilirubinemia), and reviewing classic associations for specific liver diseases like Wilson's syndrome and Primary Sclerosing Cholangitis.

High-yield summary

• Hepatocellular Pattern: Characterized by elevated transaminases (ALT > AST). Causes include viral hepatitis, drug toxicity (e.g., INH, acetaminophen), NAFLD/NASH, and ischemia.
• Cholestatic Pattern: Characterized by disproportionately elevated Alkaline Phosphatase (ALP) and Gamma-Glutamyl Transferase (GGT). Suggests biliary obstruction or intrahepatic ductal disease (e.g., PBC, PSC).
• Synthetic Function Markers: The most reliable indicators of chronic liver failure are decreased Albumin and prolonged PT/INR.
• Indirect Hyperbilirubinemia: Caused by overproduction (hemolysis) or impaired conjugation (Gilbert syndrome, Crigler-Najjar syndrome). Newborn jaundice is often indirect due to polycythemia and immature UDPGT.
• Wilson's Disease: A copper storage disorder characterized by low serum copper/ceruloplasmin and deposition of copper in the putamen, leading to neuropsychiatric symptoms and proximal renal tubular acidosis (RTA).

Learning objectives

• Differentiate between the hepatocellular pattern of liver disease (elevated ALT/AST) and the cholestatic pattern (elevated ALP/GGT).
• Interpret bilirubin levels to determine if hyperbilirubinemia is due to overproduction, impaired conjugation, or obstruction.
• Recognize the clinical presentation and lab findings associated with Wilson's syndrome and other metal storage disorders.
• Understand the role of synthetic function tests (Albumin, PT/INR) in assessing chronic liver failure severity.
• Correlate specific risk factors (e.g., metabolic syndrome, IBD) with distinct patterns of liver injury.

Board exam buzzwords