AST/ALT Ratio Prognostic Index Calculator

AST/ALT Ratio (De Ritis Ratio): Explanation and Clinical Context The AST/ALT ratio, also known as the De Ritis ratio, is a simple but valuable biomarker used in the assessment of liver injury and prognosis. It was first described by Fernando De Ritis in 1957 as the ratio between serum aspartate aminotransferase (AST) and alanine aminotransferase (ALT). A ratio less than 1 typically indicates acute hepatocellular injury, such as viral hepatitis, where ALT elevation predominates due to its cytoplasmic localization.

A ratio around 1 suggests chronic or mixed injury patterns, including nonalcoholic fatty liver disease (NAFLD) or nonalcoholic steatohepatitis (NASH). A ratio greater than 2 is a strong indicator of alcoholic liver disease, advanced fibrosis, or cirrhosis, and is also associated with higher mortality risk in both hepatic and non-hepatic conditions. Several studies have validated its prognostic role in chronic liver disease, acute-on-chronic liver failure, and even cardiovascular outcomes in systemic illness.

The AST/ALT ratio thus provides a cost-effective, easily measurable index for assessing liver injury severity, fibrosis progression, and overall prognosis.