Alkaline Phosphatase: What To Think About

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What To Think About

• If the ALP level is high, other tests may be done to determine whether a liver or bone problem is present.
• If liver disease is suspected, more blood tests, an ultrasound, or a CT scan are generally recommended to find the problem.
• Other tests to check liver function, such as alanine aminotransferase, aspartate aminotransferase, and bilirubin, are often done at the same time as an alkaline phosphatase (ALP) test. For more information, see the medical tests Alanine Aminotransferase (ALT), Aspartate Aminotransferase (AST), and Bilirubin.
• Gamma glutamyl transferase (GGT), or gamma glutamyl transpeptidase, may be measured in the blood to check the difference between bone ALP and liver ALP. High levels of GGT are present when the liver is damaged but not present with bone disease. A high level of GGT may be caused by alcohol use or may mean that blocked bile ducts are causing inflammation. The level of GGT may be high with the use of certain medicines, such as phenytoin and phenobarbital. In some medical centers, a test that measures a substance called 5-nucleotidase is done instead of the GGT test because it is better at finding liver disease.

Last updated:	July 28, 2008
Author:	Caroline Rea, RN, BS, MS
Reviewed By:	Caroline S. Rhoads, MD - Internal Medicine, Alan C. Dalkin, MD - Endocrinology
Editors:	Maria Essig, Tracy Landauer