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Leucine aminopeptidase blood test

The leucine aminopeptidase test measures how much of this enzyme is in your blood.

Your urine can also be checked for this substance.

How the Test is Performed

A blood sample is needed.

How to Prepare for the Test

The health care provider may tell you to temporarily stop taking certain medicines that can affect the test. Drugs that can increase albumin levels include estrogen and progesterone.

Do not stop taking any of your medicines without talking to your provider first.

How the Test will Feel

When the needle is inserted to draw blood, some people feel moderate pain. Others feel only a prick or stinging. Afterward, there may be some throbbing or a slight bruise. This soon goes away.

Why the Test is Performed

Leucine aminopeptidase is a type of protein called an enzyme. This enzyme is normally found in cells of the liver and small intestine.

Your provider may order this test to check if your liver is damaged. Too much leucine aminopeptidase is released into your blood when you have a liver tumor or damage to your liver cells.

This test is not done very often. Other tests, such as gamma-glutamyl transpeptidase, are as accurate and easier to get.

Normal Results

Normal range is:

  • Male: 80 to 200 U/mL
  • Female: 75 to 185 U/mL

Normal value ranges may vary slightly. Some labs use different measurements or may test different samples. Talk to your provider about the meaning of your specific test results.

What Abnormal Results Mean

An abnormal result may be a sign of:


There is very little risk involved with having your blood taken. Veins and arteries vary in size from one patient to another, and from one side of the body to the other. Taking blood from some people may be more difficult than from others.

Other risks associated with having blood drawn are slight, but may include:

  • Excessive bleeding
  • Fainting or feeling lightheaded
  • Hematoma (blood accumulating under the skin)
  • Infection (a slight risk any time the skin is broken)

Alternative Names

Serum leucine aminopeptidase



Pincus MR, Tierno PM, Fenelus M, Bowne WB, Bluth MH. Evaluation of liver function. In: McPherson RA, Pincus MR, eds. Henry's Clinical Diagnosis and Management by Laboratory Methods. 22nd ed. Philadelphia, PA: Elsevier Saunders; 2011:chap 21.

Pratt DS. Liver chemistry and function tests. In: Feldman M, Friedman LS, Brandt LJ, eds. Sleisenger and Fordtran's Gastrointestinal and Liver Disease: Pathophysiology/Diagnosis/Management. 10th ed. Philadelphia, PA: Elsevier Saunders; 2016:chap 73.

Update Date 2/8/2015

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