Alkaline Phosphatase Isoenzymes

Alkaline Phosphatase (ALP) Isoenzymes

ALP has four main isoenzymes that are produced by the liver, bone, intestine and placenta. In most cases it is possible to identify the origin of a raised ALP from other routine testing and the clinical picture.

Where ALP remains persistently raised, and the cause cannot be identified, the measurement of ALP isoenzymes may be indicated.

Prior to requesting isoenzyme analysis, please ensure LFT, γGT and vitamin D have been measured and contact the Duty Biochemist to discuss the clinical indication for the request.

Sample Requirements

For adults, blood taken into a 5mL gold or rust top gel tube

Storage/transport

Send at ambient temperature to the laboratory. If unavoidable, samples can be stored refrigerated overnight.

Required information

Relevant clinical details including:

• If a liver or bone pathology is suspected
• If the patient is pregnant

Turnaround times

Samples are sent to King's College Hospital with results expected back within 5 weeks.

Reference Range

Qualitative report, reported as percentage of individual isoenzymes present.

Further information

To learn more about Alkaline Phosphatase visit Lab tests online

Page last updated: 14/07/2023