The phosphatases alcalines (PAL) are e which are found in most body tissues, especially bones, liver, intestine, kidneys, etc. They are also present in the placenta being pregnancy.

Alkaline phosphatase levels naturally increase during growth and during pregnancy. An increase outside of these periods may reflect the presence of liver or bone disease.

The alkaline phosphatase test is prescribed when the doctor suspects the presence of liver or bone disease.

Other enzymes are analyzed at the same time to assess liver function: alanine aminotransferase (ALAT), aspartate aminotransferase (ASAT) and gamma-glutamyl transferase (γGT). ALAT and ASAT are part of “transaminases” while PAL and γGT are called cholestatic enzymes.

This ” hepatic check Is prescribed for example during a complete blood test, but also in the event of unexplained weight loss, alcoholism and in the follow-up of numerous drug treatments. Certain symptoms such as jaundice (jaundice), nausea and vomiting can also lead to the prescription of such an assessment.

In addition to liver damage (hepatitis, abscess, etc.), the assay of PALs can detect a cholestase (stagnation or stopping the flow of bile in the bile ducts) and biliary obstructions, as well as bone disease.

The dosage is done from a venous blood sample. It is recommended to be on an empty stomach during the sample.

As an indication, the normal values ​​of alkaline phosphatases are between 30 and 100 IU / L (international units per liter).

The joint increase in PAL and gamma-GT is generally a sign of cholestase, except in a pregnant woman (the increase is then normal, as in adolescents). In addition, most liver diseases (viral or autoimmune hepatitis, cirrhosis, tumor, etc.) lead to an increase in alkaline phosphatase in the blood.

An increase in alkaline phosphatase may also reflect the presence of bone disease : Paget’s disease, bone metastases, osteomalacia, vertebral fracture or compression, etc.

Conversely, a low concentration of alkaline phosphatase is most often a sign of severe liver dysfunction (hepatocellular failure), caused by cirrhosis or hepatitis.

Only the doctor can interpret the results and guide the diagnosis.