Differential Diagnosis for Elevated AST, ALT, and Lactic Acid

Single Most Likely Diagnosis

• Viral Hepatitis: This condition is a common cause of elevated liver enzymes (AST and ALT) due to inflammation of the liver. The elevation of lactic acid can occur due to impaired liver function affecting metabolism.

Other Likely Diagnoses

• Alcoholic Liver Disease: Alcohol abuse can lead to liver inflammation and damage, causing elevated AST and ALT. Lactic acidosis can also occur, especially in the context of alcohol consumption, due to impaired hepatic metabolism and potential for alcoholic ketoacidosis.
• Non-Alcoholic Fatty Liver Disease (NAFLD): This condition, often associated with obesity and metabolic syndrome, can cause liver enzyme elevation. While less commonly associated with lactic acidosis directly, severe cases or those with advanced fibrosis might have impaired liver function contributing to metabolic disturbances.
• Medication-Induced Liver Injury: Certain medications can cause liver damage, leading to elevated liver enzymes. If the medication also affects mitochondrial function, it could potentially lead to lactic acidosis.

Do Not Miss Diagnoses

• Shock or Hypoperfusion: In states of shock or hypoperfusion, liver blood flow is compromised, leading to liver enzyme elevation. Tissue hypoxia can also cause lactic acidosis. Missing this diagnosis could be fatal due to the need for immediate intervention to restore perfusion.
• Sepsis: Sepsis can cause both liver dysfunction (elevating AST and ALT) and lactic acidosis due to tissue hypoperfusion and mitochondrial dysfunction. Early recognition and treatment of sepsis are critical for survival.

Rare Diagnoses

• Wilson's Disease: A genetic disorder leading to copper accumulation in the liver, which can cause liver enzyme elevation. While less common, it's a consideration in young patients with unexplained liver disease and could potentially lead to metabolic disturbances including lactic acidosis in advanced cases.
• Mitochondrial Disorders: These are a group of disorders affecting the mitochondria, which can lead to lactic acidosis due to impaired energy production. Some mitochondrial disorders can also affect the liver, causing enzyme elevations.
• Reye's Syndrome: A rare but serious condition that causes swelling in the liver and brain. It can occur in children and teenagers recovering from a viral infection, especially if they took aspirin. It leads to elevated liver enzymes and can cause metabolic disturbances including lactic acidosis.