What is the management for elevated AST and ALT levels?

Management of AST 187 and ALT 156 in a 38-Year-Old Male

Repeat the liver function tests in 2-5 days while monitoring for symptoms, and simultaneously begin a systematic evaluation for common causes of mild transaminase elevation including medications, viral hepatitis, metabolic risk factors, and recent strenuous exercise. 1

Initial Assessment

These values represent mild elevations (both <3× ULN, assuming normal upper limit ~40 U/L), which require investigation but are not immediately concerning for severe liver injury. 1

Immediate Actions

• Repeat complete liver panel within 2-5 days including ALT, AST, alkaline phosphatase, total and direct bilirubin, gamma-glutamyl transferase (GGT), prothrombin time/INR, albumin, and complete blood count with platelets 2, 1
• Monitor for development of symptoms such as jaundice, abdominal pain, dark urine, or confusion 1
• If values remain stable or improve, continue monitoring every 2-4 weeks until normalized 1

Diagnostic Workup

Note the AST/ALT Ratio

The AST/ALT ratio is approximately 1.2 in this patient. An AST/ALT ratio >1.0 in nonalcoholic liver disease should raise suspicion for cirrhosis, though this is less specific in younger patients without chronic liver disease. 3 In most cases of chronic viral hepatitis and NAFLD, the ratio is typically <1.0. 3

Essential Initial Testing

Order the following tests to identify common etiologies: 2, 1

• Viral hepatitis serologies: Hepatitis B surface antigen, hepatitis B core antibody, hepatitis C antibody 2, 1
• Metabolic screening: Fasting glucose or HbA1c, lipid panel, BMI calculation 2, 1
• Autoimmune markers (if other causes excluded): Antinuclear antibody, anti-smooth muscle antibody, immunoglobulin levels 2
• Iron studies: Ferritin, transferrin saturation (to exclude hemochromatosis) 2
• Hepatic ultrasound to assess for steatosis, masses, or biliary obstruction 2

Critical History Elements

Specifically inquire about: 2, 4

• All medications including over-the-counter drugs, herbal supplements, and dietary supplements (major causes of drug-induced liver injury include amoxicillin-clavulanate, herbal-dietary supplements, and paracetamol) 5
• Alcohol consumption: Use AUDIT score; harmful drinking (>50 units/week for men) significantly increases liver disease risk 2
• Recent strenuous exercise or muscle injury (can transiently elevate AST) 1
• Metabolic risk factors: Obesity (BMI >25), type 2 diabetes, dyslipidemia, hypertension (suggest NAFLD) 2, 1
• Family history of liver disease 4

Most Likely Diagnoses in This Age Group

Non-Alcoholic Fatty Liver Disease (NAFLD)

NAFLD is the most common cause of mildly elevated transaminases in patients with metabolic risk factors (obesity, diabetes, hyperlipidemia). 1 The ALT is typically higher than AST in NAFLD, though this patient's ratio is slightly reversed. 1, 3

Viral Hepatitis

Test for hepatitis B and C, particularly if ALT >2× ULN or risk factors present (prior transfusions, injection drug use, high-risk sexual behavior). 1

Drug-Induced Liver Injury (DILI)

DILI accounts for approximately 8% of cases with elevated transaminases and should be considered with careful medication review. 5 Cessation of potentially hepatotoxic agents may be necessary. 4

Alcohol-Related Liver Disease

Assess alcohol intake carefully; the relationship between alcohol and cirrhosis is exponential, with synergy between alcohol and obesity. 2

Risk Stratification for Fibrosis

If NAFLD is suspected, perform risk stratification using FIB-4 or NAFLD Fibrosis Score as first-line testing. 2 These calculations should be incorporated into assessment:

• FIB-4 score uses age, AST, ALT, and platelet count 2
• If scores suggest intermediate or high risk, proceed to second-line testing with serum ELF measurements or transient elastography (FibroScan/ARFI) 2

Special Considerations

Macro-AST

In cases of isolated, persistently elevated AST with negative workup, consider macro-AST (a benign condition where AST binds to immunoglobulins). 6 This can be confirmed with polyethylene glycol (PEG) precipitation testing. 6

When to Refer

Refer to gastroenterology/hepatology if: 2

• Persistently elevated enzymes despite negative extended workup and no NAFLD risk factors 2
• Evidence of advanced liver disease or cirrhosis on imaging or non-invasive testing 2
• ALT >5× ULN (requires immediate evaluation for acute liver injury) 1
• Suspicion of autoimmune hepatitis or other complex liver disease 2

Monitoring Strategy

For this patient with mild elevations (<3× ULN): 1

• Repeat testing in 2-5 days initially 1
• If stable or improving, monitor every 2-4 weeks until normalized 1
• If values worsen or new symptoms develop, expedite full diagnostic workup 1

Common Pitfalls to Avoid

• Do not assume alcohol-related disease based solely on AST/ALT ratio >1.0 in the absence of cirrhosis, as this ratio becomes less reliable in distinguishing alcoholic from nonalcoholic causes when cirrhosis is present 3
• Do not overlook herbal and dietary supplements as potential causes of liver injury 5
• Do not dismiss mild elevations without appropriate follow-up, as they may represent early stages of progressive liver disease 2
• Do not order liver biopsy prematurely; non-invasive assessment should be completed first 2