Hepatology

APRI (AST–Platelet Ratio)

Non-invasive estimate of liver fibrosis.

Education and reference only. Not a substitute for clinical judgement, local policy or product labelling. Always verify before clinical use. Values are calculated in your browser and never stored.

When to use

Use as a simple non-invasive marker of significant fibrosis/cirrhosis, e.g. in chronic viral hepatitis.

Why use

It uses only AST and platelets and helps rule fibrosis in or out.

Critical actions

APRI = (AST / AST-ULN) × 100 / platelets (×10⁹/L). Use your lab's AST upper limit of normal.

Evidence & references

  1. Wai CT et al. A simple noninvasive index can predict fibrosis and cirrhosis in chronic hepatitis C. Hepatology. 2003.

Related calculators

FIB-4 IndexNon-invasive estimate of liver fibrosis.NAFLD Fibrosis ScoreAdvanced fibrosis risk in fatty liver disease.

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