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

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.

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.

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.

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

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

Note: U/mL = units per milliliter

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

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)

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.