What is the purpose of AST/ALT blood test ?

1 Answer
Apr 29, 2016

The AST/ALT ratio is a common blood test for liver disease.


It is often called the De Ritis ratio, after Fernando De Ritis, who first described it in 1957.

It is the ratio of the serum levels of aspartate transaminase (AST) and alanine transaminase (ALT).

In "normal" patients, the ratio is 1.1:1.

Abnormal ratios suggest possible liver conditions, but they require confirmation by other tests.

Some typical ranges of the ratio and associated conditions are:

  • 4 —Wilson's disease (excess copper)

  • 1.5 to 2.5 — alcoholic liver disease (ALD)
  • ~0.9 — non-alcoholic steatohepatitis (NASH or "fatty liver")
  • 0.5 to 0.7 — acute viral hepatitis