What to do for a patient with elevated liver enzymes (AST and ALT)?

Management of Elevated Liver Enzymes (AST 55, ALT 67)

For a patient with mildly elevated liver enzymes (AST 55, ALT 67), the first step should be risk stratification using FIB-4 or NAFLD Fibrosis Score to determine the extent of liver fibrosis, followed by lifestyle modifications and monitoring every 3 months. 1, 2

Initial Assessment and Diagnosis

Pattern Recognition

• The patient has a hepatocellular pattern of injury (elevated AST and ALT)
• AST:ALT ratio <1 suggests NAFLD rather than alcoholic liver disease 2
• Mild elevation (AST 55, ALT 67) - less than 3× upper limit of normal (ULN)

Common Causes to Consider

1. Non-alcoholic fatty liver disease (NAFLD) - most common cause in developed countries 2
2. Alcohol-related liver disease - evaluate with AUDIT score
3. Medication-induced liver injury
4. Viral hepatitis
5. Autoimmune hepatitis

Management Algorithm

Step 1: Risk Stratification

• Calculate FIB-4 or NAFLD Fibrosis Score to assess fibrosis risk 1
• If intermediate/high risk, proceed to second-line testing (ELF measurement or Fibroscan/ARFI elastography) 1

Step 2: Lifestyle Modifications

• Implement Mediterranean diet
• Regular exercise (150 minutes/week of moderate activity)
• Weight loss if overweight/obese (target 7-10% of body weight) 2
• Alcohol cessation if consuming alcohol

Step 3: Monitoring

• Repeat liver enzymes every 3 months 2
• Monitor for 6 months to assess response to lifestyle changes

Step 4: Referral Criteria

Refer to hepatology if:

• Persistent elevation >6 months despite interventions
• ALT elevation >5× ULN
• Elevated bilirubin with elevated transaminases
• Signs of hepatic decompensation 2

Important Considerations

Avoid Common Pitfalls

1. Don't assume normal enzymes exclude significant liver disease - NAFLD/NASH can exist with normal enzymes 2
2. Don't overlook non-hepatic causes of enzyme elevation 2
3. Don't prematurely discontinue medications for mild, asymptomatic elevations without proper evaluation 2

Special Situations

• If patient is on methotrexate: Continue medication but monitor closely; discontinue only if ALT/AST >3× ULN 1
• If NASH suspected: An ALT elevation ≥5× ULN is rare in NASH and should prompt investigation for other causes 1
• If rapid weight loss or intensive exercise recently started: Consider these as potential causes of transient elevation 1

Follow-up Plan

• If enzymes normalize: Continue lifestyle modifications and annual monitoring
• If enzymes remain elevated but <3× ULN: Continue monitoring every 3 months and reinforce lifestyle changes
• If enzymes worsen or other concerning features develop: Refer to hepatology

Remember that NAFLD patients are at increased risk of developing diabetes and cardiovascular disease, so comprehensive metabolic evaluation and management is essential alongside liver-specific care 2, 3.