AST to Platelet Ratio Index for liver fibrosis estimation.
Lab Markers
10⁹/L
Fibrosis Prediction
APRI Score1.00
InterpretationIndeterminate
Intermediate score. May require additional testing (e.g., FibroScan).
Metavir Equivalent
About this calculator
Overview
The AST to Platelet Ratio Index (APRI) is a non-invasive, low-cost calculation used to predict the presence of liver fibrosis and cirrhosis, particularly in patients with Hepatitis C. It uses two common laboratory values: AST and Platelet Count.
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Pro Tips
Normal AST ULN is often around 40 U/L but can vary by laboratory.
Clinical interpretation should always consider other markers like Fib-4 score or imaging.
APRI may be less accurate in acute hepatitis where AST is dramatically elevated.
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Fun Facts
"APRI is highly sensitive for excluding significant fibrosis if the score is low (NPV)."
"It is less expensive and invasive than a liver biopsy or FibroScan."
"Scores > 1.0 are often used as a threshold for significant fibrosis in clinical trials."
"Platelet count tends to drop as liver fibrosis progresses (due to portal hypertension and sequestration)."
