- AST and ALT are enzymes that are commonly used in conjunction to identify active hepatocellular injury.
- AST is found in the liver, cardiac muscle, skeletal muscle, kidneys, brain, pancreas, lungs, leukocytes and erythrocytes.
- ALT is found mainly in the liver, and is more specific for hepatocellular injury.
Causes of Elevated Transaminases
- Viral hepatitis - A, B, C, E, HSV, EBV, CMV, VZV
- Alcoholic liver disease - alcoholic hepatitis, steatohepatosis, cirrhosis
- Non-alcoholic hepatosteatosis (fatty liver disease)
- Drug or toxin-induced liver disease - paracetamol, NSAIDs, statins, ciprofloxacin, azole antifungals, methotrexate, amiodarone, isoniazid, phenytoin, sulfonylureas, rifampicin, anabolic steroids, cocaine, ecstasy, PCP, glues, solvents, certain herbal remedies
- Vascular disease - ischaemic hepatitis, portal venous thrombosis, congestive cardiac failure
- Infiltrative disease - sarcoidosis, amyloidosis, tuberculosis, Hodgin lymphoma, liver metastases
- Autoimmune liver diseases - autoimmune hepatitis, primary biliary cirrhosis, primary sclerosing cholangitis
- Wilson’s disease
- Alpha-1 antitrypsin deficiency
- Hepatocellular carcinoma
- Myopathy - vigorous exercise, myositis
- Coeliac disease
- Mild derangement (<5x normal)Non-alcoholic steatohepatosis, chronic viral hepatitis, liver metastases, drugs
- Moderate derangement (5-20x normal)Chronic viral hepatitis, alcoholic hepatitis, autoimmune hepatitis
- Severe derangement (>20x normal)Acute viral hepatitis, drug-induced hepatitis, ischaemic hepatitis