The apparently well patient with chronically elevated aminotransferase levels is a medical challenge. A knowledge of the differential diagnosis permits rational investigation in such cases.

The causes of asymptomatic chronically elevated aminotransferase activity include:

• alcohol abuse
• drugs
• chronic hepatitis: B and C
• steatosis and non-alcoholic steatosis
  • non-alcoholic fatty liver disease (NAFLD) includes a wide spectrum of liver pathology, ranging from fatty liver alone to the more severe nonalcoholic steatohepatitis (1)
    • NAFLD is the most common cause of chronically elevated LFTs in the United States in both diabetic and nondiabetic individuals
      • with respect to patients with NAFLD, 60-95% are obese, 28-55% have type 2 diabetes, and 20-92% have hyperlipidemia (2)
• autoimmune hepatitis
• haemochromatosis
• Wilson's disease
• alpha1-antitrypsin deficiency

Non-hepatic causes include:

• coeliac disease
• inherited and acquired muscle diseases
• exercise

Reference:

1. Angulo P. Nonalcoholic fatty liver disease. N Engl J Med 2002;346: 1221-31.
2. Harris EH.Elevated Liver Function Tests in Type 2 Diabetes.Clinical Diabetes 2005; 23:115-119.