AST/ALT Ratio Calculator (De Ritis)
Calculate the De Ritis ratio (AST divided by ALT) to analyze patterns of aminotransferase elevation and evaluate hepatic disease etiologies.
Interpretation Guide
These are patterns, not diagnoses. Always consult your healthcare provider.
What Is a AST/ALT Ratio Calculator (De Ritis)?
A AST/ALT Ratio Calculator (De Ritis) is a non-invasive hepatic biomarker reference tool designed to evaluate ratios and indices of liver health. By analyzing routine biochemical panel inputs such as AST, ALT, platelets, or bilirubin, it calculates validated clinical scores (such as the De Ritis ratio or FIB-4 index) to provide educational insight into liver health and warrant follow-up consultation with a physician.
How to Use This Calculator
- Input your Aspartate Aminotransferase (AST) level in U/L.
- Input your Alanine Aminotransferase (ALT) level in U/L.
- Click 'Calculate AST/ALT Ratio' to analyze the enzyme pattern and clinical likelihoods.
How This Calculator Works
Described by Fernando De Ritis in 1957: $\text{Ratio} = \frac{\text{AST (U/L)}}{\text{ALT (U/L)}}$. ALT is primarily localized in hepatocytes, whereas AST is found in both liver mitochondria and cardiac/skeletal muscle, giving their relative ratio diagnostic utility.
Understanding Your Results
In mild non-alcoholic fatty liver disease (NAFLD) and acute viral hepatitis, ALT typically exceeds AST (ratio < 1.0). A ratio > 2.0 strongly suggests alcoholic liver disease. In established cirrhosis of any etiology, the ratio frequently rises above 1.0 to 1.5.
Frequently Asked Questions
What does an AST/ALT ratio greater than 2.0 indicate?
An AST/ALT ratio exceeding 2.0—especially when transaminases are elevated under 300-400 U/L—is classic for alcoholic hepatitis, attributable to pyridoxal-5'-phosphate (vitamin B6) depletion which impairs ALT synthesis.
Can heavy muscle lifting elevate AST and ALT?
Yes. Intense resistance exercise causes benign, transient micro-tears in muscle fibers, releasing intramuscular AST (and to a lesser degree ALT) into circulation for 48 to 72 hours post-workout.
Is the De Ritis ratio meaningful if enzymes are in the normal range?
If both AST and ALT are completely within normal physiological reference limits (<35 U/L), variations in the mathematical ratio have minimal diagnostic significance.
Related Calculators
Important Limitations & Medical Disclaimer
Notice: The De Ritis ratio is an educational screening aid. Transaminase elevations must be interpreted by a gastroenterologist or hepatologist in conjunction with viral serologies, iron studies, and abdominal ultrasound.