Leucine aminopeptidase - blood

Answer 1

Definition

Leucine aminopeptidase is a protein, called an enzyme, that is normally found in liver cells.

Serum leucine aminopeptidase is a test that measures how much of this protein is in your blood.

Your urine can also be checked for this protein. See: Leucine aminopeptidase - urine

Alternative Names

Serum leucine aminopeptidase

How the test is performed

Blood is drawn from a vein, usually from the inside of the elbow or the back of the hand. The site is cleaned with germ-killing medicine (antiseptic). The health care provider wraps an elastic band around the upper arm to apply pressure to the area and make the vein swell with blood.

Next, the health care provider gently inserts a needle into the vein. The blood collects into an airtight vial or tube attached to the needle. The elastic band is removed from your arm.

Once the blood has been collected, the needle is removed, and the puncture site is covered to stop any bleeding.

In infants or young children, a sharp tool called a lancet may be used to puncture the skin and make it bleed. The blood collects into a small glass tube called a pipette, or onto a slide or test strip. A bandage may be placed over the area if there is any bleeding.

How to prepare for the test

Your health care provider may tell you to stop taking any drugs that could affect the test. Drugs that can affect the results of this test include estrogen and progesterone. Never stop taking any medicine without first talking to your doctor.

How the test will feel

When the needle is inserted to draw blood, you may feel moderate pain, or only a prick or stinging sensation. Afterward, there may be some throbbing.

Why the test is performed

Your doctor may order this test to see if your liver is damaged. Leucine aminopeptidase is released into the blood when your liver cells are damaged. Drugs or infections such as hepatitis can damage liver cells.

Liver tumors may also release this protein into the bloodstream. This test may be used to look for signs of such tumors, but usually other tests are done instead.

See also:

• ALT
• AST
• ALP
• LDH
• GGT

Normal Values

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

Note: U/mL = units per milliliter

What abnormal results mean

• Cholestasis
• Cirrhosis
• Hepatitis
• Liver ischemia (reduced blood flow to the liver)
• Liver necrosis(death of liver tissue)
• Liver tumor and liver cancer

What the risks are

Veins and arteries vary in size from one patient to another and from one side of the body to the other. Obtaining a blood sample 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 light-headed
• Hematoma (blood accumulating under the skin)
• Infection (a slight risk any time the skin is broken)

References

Berk P, Korenblatt K. Approach to the patient with jaundice or abnormal liver test results. In: Goldman L, Ausiello D, eds. Cecil Medicine. 23rd ed. Philadelphia, Pa: Saunders Elsevier; 2007:chap 150.

Answer 2

Definition

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

Serum leucine aminopeptidase is a test that measures how much of this protein is in your blood.

Your urine can also be checked for this protein. See: Leucine aminopeptidase - urine

Alternative Names

Serum leucine aminopeptidase

How the test is performed

A blood sample is needed. For information on how this is done, see: Venipuncture

How to prepare for the test

Your health care provider may tell you to stop taking any drugs that could affect the test. Drugs that can affect the results of this test include estrogen and progesterone. Never stop taking any medicine without first talking to your doctor.

How the test will feel

When the needle is inserted to draw blood, you may feel moderate pain, or only a prick or stinging sensation. Afterward, there may be some throbbing.

Why the test is performed

Your doctor may order this test to see if your liver is damaged. An excess of leucine aminopeptidase is released into your blood when your liver cells are damaged, or if you have a liver tumor.

This test is done only rarely, because other tests, such as gamma glutamyl transpeptidase are as accurate and are more easily available.

See also:

• ALT
• AST
• ALP
• LDH
• GGT

Normal Values

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

Note: U/mL = units per milliliter

Note: Normal value ranges may vary slightly among different laboratories. Talk to your doctor about the meaning of your specific test results.

The examples above show the common measurements for results for these tests. Some laboratories use different measurements or may test different specimens.

What abnormal results mean

• Cholestasis
• Cirrhosis
• Hepatitis
• Liver cancer
• Liver ischemia (reduced blood flow to the liver)
• Liver necrosis(death of liver tissue)
• Liver tumor

What the risks are

Veins and arteries vary in size from one patient to another and from one side of the body to the other. Obtaining a blood sample 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 light-headed
• Hematoma (blood accumulating under the skin)
• Infection (a slight risk any time the skin is broken)

References

Berk P, Korenblatt K. Approach to the patient with jaundice or abnormal liver test results. In: Goldman L, Ausiello D, eds. Cecil Medicine. 23rd ed. Philadelphia, Pa: Saunders Elsevier; 2007:chap 150.

Pratt DS. Liver chemistry and function tests. In: Feldman M, Friedman LS, Brandt LJ, eds. Sleisenger and Fordtran's Gastrointestinal and Liver Disease. 9th ed. Philadelphia, Pa: Saunders Elsevier;2010:chap 73.

Reviewed By

Review Date: 02/21/2011

David C. Dugdale, III, MD, Professor of Medicine, Division of General Medicine, Department of Medicine, University of Washington School of Medicine. Also reviewed by David Zieve, MD, MHA, Medical Director, A.D.A.M., Inc.