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APRI (Aspartate Aminotransferase to Platelet Ratio Index)

Published: July 27, 2026Updated: August 25, 2026

APRI is a biomarker used to assess liver fibrosis by calculating the ratio of aspartate aminotransferase (AST) to platelet count.

Quick summary

APRI measures liver fibrosis using AST and platelet ratio.

Medically reviewed by WellAlly Editorial TeamLast reviewed August 25, 2026Editorial policy

Key facts at a glance

Units
ratio
Clinical utility
diagnostic
Result kind
quantitative
FDA-cleared
FibroMeter APRI, APRI Calculator
interpretation: {"text":"Indicates a low likelihood of significant liver fibrosis.","label":"Low APRI (0–0.5)"}; {"text":"Suggests a high likelihood of significant liver fibrosis or cirrhosis.","label":"High APRI (>1.5)"}

APRI is calculated using the formula: (AST level / upper limit of normal AST) / platelet count (109/L) x 100. It is a non-invasive method to evaluate liver fibrosis, particularly in patients with chronic hepatitis C.

A higher APRI score indicates a greater likelihood of significant liver fibrosis or cirrhosis. The test is particularly useful in resource-limited settings where other diagnostic tools may not be readily available.

While APRI is a valuable screening tool, it is not definitive. Other tests and clinical assessments are often needed to confirm the diagnosis and severity of liver disease.

Frequently asked questions

What is a normal APRI score?
An APRI score between 0 and 0.5 is generally considered normal, indicating a low risk of significant liver fibrosis.
Can APRI diagnose liver disease on its own?
No, APRI is a screening tool. Additional tests and clinical evaluations are required for a definitive diagnosis.
  1. 1
    APRI Calculator and InterpretationSource
  2. 2
    APRI in Liver Fibrosis AssessmentSource

Click any link to access the full source. PubMed Central (PMC) links provide free full-text access.

This information is for educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment.

Medical Disclaimer

This content is for general informational and educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment. Always seek the guidance of a qualified healthcare provider with any questions you have about a medical condition, and never disregard professional medical advice or delay seeking it because of something you read here.

If you think you may have a medical emergency, call your local emergency number or go to the nearest emergency department immediately.

Medically reviewed by WellAlly Editorial Team Last reviewed August 25, 2026. · Read our editorial policy