Differential Diagnosis for Elevated AST, ALT, and Ammonia
Single Most Likely Diagnosis
- Viral Hepatitis: This is the most likely diagnosis given the significant elevation of both AST and ALT, which are liver enzymes, and an elevated ammonia level. Viral hepatitis can cause liver inflammation, leading to the release of these enzymes into the bloodstream. The elevated ammonia could be due to the liver's decreased ability to detoxify ammonia.
Other Likely Diagnoses
- Alcoholic Hepatitis: This condition can also lead to elevated liver enzymes and ammonia levels. The pattern of enzyme elevation (AST:ALT ratio > 2) can sometimes help differentiate alcoholic hepatitis from viral hepatitis, but this is not always reliable.
- Drug-Induced Liver Injury (DILI): Various medications and drugs can cause liver injury, leading to elevated liver enzymes. Some drugs can also affect the liver's ability to metabolize ammonia.
- Non-Alcoholic Fatty Liver Disease (NAFLD): Although NAFLD might not typically cause such high elevations of liver enzymes, it can lead to liver inflammation and potentially affect ammonia levels, especially in advanced cases.
Do Not Miss Diagnoses
- Acute Liver Failure: This is a medical emergency that requires immediate attention. Causes can include viral hepatitis, drug overdose (e.g., acetaminophen), and other toxins. Elevated ammonia levels can indicate severe liver dysfunction.
- Wilson's Disease: A genetic disorder that leads to copper accumulation in the liver, causing liver damage. It can present with elevated liver enzymes and ammonia levels, especially in young individuals.
- Budd-Chiari Syndrome: A condition caused by thrombosis of the hepatic veins, leading to liver congestion, enzyme elevation, and potentially elevated ammonia due to liver dysfunction.
Rare Diagnoses
- Autoimmune Hepatitis: Although not as common as viral hepatitis, autoimmune hepatitis can cause significant liver enzyme elevation and potentially affect ammonia metabolism.
- Alpha-1 Antitrypsin Deficiency: A genetic disorder that can lead to liver disease and potentially cause elevated liver enzymes and ammonia levels.
- Citrin Deficiency: A rare genetic disorder affecting the urea cycle, which can lead to elevated ammonia levels and liver enzyme elevations due to secondary liver damage.