Acute Liver Injury - Differential Diagnosis Algorithm Vascular Causes of Acute Liver Injury: • Hepatic vein: Budd-chiari syndrome, Congestion/CHF, Venoocclusive disease • Hepatic artery: Shock liver, Thrombosis, Emboli Hepatocellular Acute Liver Injury: • Infectious: HAV, HBV, HCV, HEV, EBV, HSV, CMV, VZV • Trauma: Shock liver • Metabolic/Hereditary: Wilson Disease, Hemochromatosis, Celiac disease • Autoimmune: Autoimmune hepatitis, PBC, PSC, IgG4, HLH • Neoplasm - Infiltration: Often breast CA, small cell lung CA, lymphoma, melanoma, myeloma • Pregnancy: HELLP • Iatrogenic: DILI, Tyelenol, Mushroom poisoning, ETOH Cholestatic Acute Liver Injury: • Extrahepatic - Biliary: Choledocholithiasis, Biliary Stricture, Malignancy, Liver Fluke, Ascariasis, Choledochal cyst • Intrahepatic - Obstruction: Biliary stone, Malignancy, PBC, PSC, Cystic fibrosis, Sickle cell, GVHD, Infiltrative Labs in Hepatocellular Injury: • AST: Less specific to liver than ALT • ALT: Specific to liver than AST • GGT: - Specific to liver - Assists in liver specificity to elevated ALP • AST/ALT > ALP: Typical of hepatocellular injury • Bilirubin - +/- elevation Labs in Cholestatic Injury: • ALP - Surface of bile duct epithelia: - Cholestasis/Bile salts augment synthesis of ALP - Due to synthesis rises later - Half-life: 1 week • Direct bilirubin: ↑ • AST: ↑ • ALT: ↑ • GGT/5-NT: ↑ - ALP > AST/ALT: typical of cholestatic disease - If ALP ↑: Check GGT & 5-nucleotidase (5-NT) - If both are normal, ALP is from extrahepatic source - Tests of synthetic function may be abnormal AST:ALT Ratios: • Alcoholic liver disease: > 2 • NASH, Chronic viral hepatitis: < 1 • Cirrhosis: > 1 • Acute muscle injury: > 3 • Chronic muscle injury: ~ 1 Unconjugated Bili > 90% of Total Bili Etiology: • Gilbert's syndrome • Hemolysis Nonhepatic Source of Liver Enzyme Elevation: • Bilirubin: RBC (hemolysis, bleeding, hematoma) • AST: Skeletal muscle, cardiac muscle, RBC, kidney, brain • ALT: Skeletal muscle, cardiac muscle, kidneys • LDH: Heart, RBC (hemolysis) • ALP: Bone, first trimester placenta, kidneys, intestines, white blood cells #liver #injury #hepatitis #differential #diagnosis #algorithm #hepatology
