From the Guidelines
The recommended workup for mildly elevated liver enzymes, specifically for patients with elevated Alanine Transaminase (ALT) and Aspartate Transaminase (AST) levels, begins with a thorough history and physical examination, followed by repeat testing in 2-4 weeks to confirm persistence, as suggested by the most recent guidelines 1.
Initial Evaluation
Initial laboratory evaluation should include a complete metabolic panel, complete blood count, and additional liver tests including alkaline phosphatase, bilirubin, albumin, and prothrombin time.
- Specific testing should target common causes:
- hepatitis serologies (HBV, HCV)
- iron studies (ferritin, transferrin saturation)
- autoimmune markers (ANA, anti-smooth muscle antibody, immunoglobulins)
- alpha-1 antitrypsin levels
Imaging Studies
Ultrasound of the liver is recommended as the first-line imaging study to assess for structural abnormalities, fatty infiltration, or biliary obstruction, as per the latest recommendations 1.
Lifestyle Modifications
Lifestyle modifications are crucial, including:
- alcohol cessation
- weight management for those with metabolic risk factors
- review of all medications (including over-the-counter drugs and supplements) that might cause liver injury
Further Investigations
If these initial investigations don't reveal a cause and enzymes remain elevated, referral to a gastroenterologist or hepatologist may be warranted for consideration of liver biopsy or specialized testing, as indicated in the guidelines for managing abnormal liver function tests 1.
Key Considerations
- Mild elevations (less than 2-3 times upper limit of normal) often represent benign or reversible conditions, hence a systematic approach helps identify the underlying cause while avoiding unnecessary testing 1.
- The severity of abnormal aminotransferase can be classified as mild, moderate, or severe, which guides the intensity of the workup and management plan 1.
From the Research
Recommended Workup for Mildly Elevated Liver Enzymes
The workup for mildly elevated liver enzymes, specifically for patients with elevated Alanine Transaminase (ALT) and Aspartate Transaminase (AST) levels, involves a step-wise approach.
- The first step is to repeat the test to confirm the result 2.
- If the result is still abnormal, it is essential to differentiate between a predominant "necrotic pattern" of liver chemistry, as indicated by an elevation of ALT- or AST-activity, or a predominant "cholestatic pattern", as indicated by elevated activities of g-GT and alkaline phosphatase 2.
- In patients with elevated serum amino transferases, hepatic diseases should be excluded primarily with non-invasive serologic tests 2.
- The most common causes of elevated amino transferase levels are chronic hepatitis B and C, autoimmunhepatitis, non-alcoholic steatohepatitis, hemochromatosis, Wilson-disease, and celiac sprue 2.
Initial Investigations
Initial investigations for patients with mildly elevated liver enzymes should include:
- Non-invasive serologic tests to exclude hepatic diseases 2.
- Screening for hepatitis B and C, as recommended by the American Gastroenterological Association, Canadian Medical Association, and the Centers for Disease Control and Prevention 3.
- Discontinuing hepatotoxic medications such as acetaminophen or nonsteroidal anti-inflammatory drugs and reevaluating the patient in three months may not be the best approach, as it may miss a number of hepatitis patients 3.
Approach to Elevated Liver Enzymes
The approach to elevated liver enzymes should be guided by both the clinical presentation and the pattern of injury 4.
- An algorithmic approach can be taken to help narrow the spectrum of a differential diagnosis, based on the magnitude of enzymatic elevation and the underlying enzymatic roles 5.
- Understanding the biochemical basis of each liver function test can help correlate laboratory findings to a patient's clinical presentation 5.