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Leucine aminopeptidase - urine
Leucine aminopeptidase is a type of protein called an enzyme. It is normally found in liver cells and cells of the small intestine. This test is used to measure how much of this protein appears in your urine.
Your blood can also be checked for this protein .
Protein
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 24-hour urine sample is needed.
- On day 1, urinate into the toilet when you get up in the morning.
- Afterwards, collect all urine in a special container for the next 24 hours.
- On day 2, urinate into the container when you get up in the morning.
- Cap the container. Keep it in the refrigerator or a cool place during the collection period.
Label the container with your name, the date, the time of completion, and return it as instructed.
For an infant, thoroughly wash the area where urine exits the body.
- Open a urine collection bag (a plastic bag with an adhesive paper on one end).
- For males, place the entire penis in the bag and attach the adhesive to the skin.
- For females, place the bag over the labia.
- Diaper as usual over the secured bag.
This procedure may take more than one try. An active infant can move the bag, so that the urine leaks into the diaper.
Check the infant often and change the bag after the infant has urinated into it.
Drain the urine from the bag into the container given to you by your health care provider. Deliver the sample to the laboratory or your provider as soon as possible.
Your provider will tell you, if needed, to stop taking drugs that may interfere with the test.
How to Prepare for the Test
Your provider may tell you to stop taking any medicines 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
The test involves only normal urination, and there is no discomfort.
Why the Test is Performed
You may need this test to see if there is liver damage. It may also be done to check for certain tumors.
This test is only rarely done. Other tests (such as gamma glutamyl transpeptidase) are as accurate and are more easily available.
Normal Results
Normal values range from 2 to 18 units per 24 hours.
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
Increased levels of leucine aminopeptidase can be seen in several conditions:
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Cholestasis
Cholestasis
Cholestasis is any condition in which the flow of bile from the liver is slowed or blocked.
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Cirrhosis
Cirrhosis
Cirrhosis is scarring of the liver and poor liver function. It is the last stage of chronic liver disease.
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Hepatitis
Hepatitis
Hepatitis is swelling and inflammation of the liver.
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- Liver ischemia (reduced blood flow to the liver)
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Liver
necrosis
(death of live tissue)
Necrosis
Necrosis is the death of body tissue. It occurs when too little blood flows to the tissue. This can be from injury, radiation, or chemicals. Necro...
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Liver tumor
Liver tumor
Hepatocellular carcinoma is cancer that starts in the liver.
ImageRead Article Now Book Mark Article - Pregnancy (late stage)
Risks
There is no real risk.
References
Berk P, Korenblatt K. Approach to the patient with jaundice or abnormal liver test results. In: Goldman L, Schafer AI, eds. Goldman's Cecil Medicine . 25th ed. Philadelphia, PA: Elsevier Saunders; 2016:chap 147.
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: Elsevier Saunders; 2010:chap 73.
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Cirrhosis of the liver - illustration
A chronic liver disease which causes damage to liver tissue, scarring of the liver (fibrosis; nodular regeneration), progressive decrease in liver function, excessive fluid in the abdomen (ascites), bleeding disorders (coagulopathy), increased pressure in the blood vessels (portal hypertension), and brain function disorders (hepatic encephalopathy). Excessive alcohol use is the leading cause of cirrhosis
Cirrhosis of the liver
illustration
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Leucine aminopeptidase urine test - illustration
Leucine aminopeptidase (LAP) is a proteolytic enzyme that breaks chemical bonds in proteins at specific sites next to leucine amino acids. Serum (blood) LAP is measured to diagnose liver (hepatic) dysfunction.
Leucine aminopeptidase urine test
illustration
-
Cirrhosis of the liver - illustration
A chronic liver disease which causes damage to liver tissue, scarring of the liver (fibrosis; nodular regeneration), progressive decrease in liver function, excessive fluid in the abdomen (ascites), bleeding disorders (coagulopathy), increased pressure in the blood vessels (portal hypertension), and brain function disorders (hepatic encephalopathy). Excessive alcohol use is the leading cause of cirrhosis
Cirrhosis of the liver
illustration
-
Leucine aminopeptidase urine test - illustration
Leucine aminopeptidase (LAP) is a proteolytic enzyme that breaks chemical bonds in proteins at specific sites next to leucine amino acids. Serum (blood) LAP is measured to diagnose liver (hepatic) dysfunction.
Leucine aminopeptidase urine test
illustration
Review Date: 2/11/2015
Reviewed By: Subodh K. Lal, MD, gastroenterologist at Gastrointestinal Specialists of Georgia, Austell, GA. Review provided by VeriMed Healthcare Network. Also reviewed by David Zieve, MD, MHA, Isla Ogilvie, PhD, and the A.D.A.M. Editorial team.
