Lab Values for Nurses Practice Test 2026 - Free Nursing Exam Practice Questions and Study Guide

Transaminases rise when liver cells are damaged, but the pattern of which one rises more helps hint at the cause. ALT is more liver-specific, while AST is also found in other tissues and in mitochondria. In alcoholic liver disease, alcohol-related mitochondrial injury and B6 depletion tend to push AST up more than ALT, often yielding an AST:ALT ratio greater than 2:1. Here, AST is 128 U/L and ALT is 60 U/L, giving a ratio just over 2, which fits alcohol-related liver injury.

This pattern isn’t typical of cholestasis, where biliary obstruction drives a larger rise in alkaline phosphatase and GGT, and transaminases aren’t characteristically skewed toward AST. Viral hepatitis usually shows ALT higher than AST, often with much greater ALT elevations. Fatty liver can cause mild transaminase elevations but not with a pronounced AST > ALT ratio.