De Ritis Ratio (AST/ALT)
Understanding the De Ritis Ratio
The De Ritis Ratio, first described by Fernando De Ritis in 1957, is the ratio of aspartate aminotransferase (AST) to alanine aminotransferase (ALT). This ratio is a valuable tool in evaluating liver disease severity and differentiating between various causes of liver damage. It can also help predict outcomes in various medical conditions.
What is the De Ritis Ratio?
The De Ritis Ratio is calculated by dividing the AST level by the ALT level:
De Ritis Ratio = AST / ALT
Both AST and ALT are enzymes found primarily in liver cells. When liver cells are damaged, these enzymes leak into the bloodstream, causing elevated levels in blood tests.
Normal De Ritis Ratio Values
- Normal range for men: up to 1.3
- Normal range for women: up to 1.7
- Values may vary between laboratories and methods
Clinical Significance
Low Ratio (< 1.0)
Typically seen in:
- Non-alcoholic fatty liver disease (NAFLD) without fibrosis
- Early stages of chronic hepatitis C without fibrosis
- Metabolic syndrome risk (particularly with central obesity)
Moderate to High Ratio (1.0 - 1.5)
May indicate:
- Early liver fibrosis (≥ 1.0)
- Alcohol abuse without cirrhosis (≤ 1.1)
- Early stages of alcoholic liver disease
High Ratio (1.5 - 2.0)
Often suggests:
- Intrahepatic biliary obstruction (> 1.5)
- Critical limb ischemia risk (> 1.67)
- Progressive liver disease
Very High Ratio (≥ 2.0)
Usually indicates:
- Advanced cirrhosis
- Severe alcoholic liver disease (≥ 3.0)
- Acute muscle injury
- Myocardial damage
Important Considerations
- The ratio varies by gender (typically higher in women)
- Results can be affected by vitamin B6 deficiency, especially in alcoholic patients
- Serial measurements are more valuable than single results
- Should be interpreted alongside other clinical findings and liver tests
- Can identify liver fibrosis even when both AST and ALT are within normal range
- Different laboratory methods may affect the ratio
When to Seek Medical Attention
Consult a healthcare provider if:
- Your ratio is outside normal range
- You have unexplained symptoms
- You're being monitored for liver disease
- You're on medications that affect liver enzymes
Limitations
This calculator:
- Provides estimates based on input values
- Should not replace laboratory testing
- Must be interpreted within clinical context
- May not be accurate in all scenarios
Tips for Accurate Results
- Use recent laboratory values
- Double-check input numbers
- Ensure correct units selected
- Consider repeat testing if results unexpected
Clinical Applications
The De Ritis Ratio is particularly useful in:
- Differentiating causes of liver disease
- Monitoring disease progression
- Predicting prognosis in various conditions
- Screening for alcohol-related liver disease
Factors Affecting AST and ALT Levels
AST levels can be affected by
- Liver disease
- Heart problems
- Muscle damage
- Exercise
- Medications
ALT levels can be affected by
- Liver disease
- Medications
- Obesity
- Diet
- Exercise
Start calculating now to better understand your liver enzyme status!
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