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25682 Alkaline Phosphatase, Total and Isoenzymes, Serum (ALKI)

Alkaline Phosphatase, Total and Isoenzymes, Serum (ALKI)
Test Code: ALKISO
Test Components

​Alkaline Phosphatase

​Alkaline Phosphatase Isoenzymes

Useful For
Diagnosis and treatment of liver, bone, intestinal, and parathyroid diseases
 
Determining the tissue source of increased alkaline phosphatase (ALP) activity in serum
 
Differentiating between liver and bone sources of elevated ALP
Specimen Requirements
Fasting Required Specimen Type Preferred Container/Tube Acceptable Container/Tube Specimen Volume Specimen Minimum Volume
(allows for 1 repeat)
Pediatric Minimum Volume
(no repeat)
​No ​Serum ​Serum Separator Tube (SST) ​Red Top Tube (RTT) ​1 mL (divided into 2 tubes, each containing 0.5 mL) ​0.5 mL (divided into 2 tubes, each containing 0.25 mL)
Specimen Stability Information
Specimen Type Temperature Time
​Serum ​ ​ ​Frozen (preferred) ​14 days
​Refrigerate ​7 days
​Ambient ​7 days
Rejection Criteria
Gross hemolysis
Performing Laboratory Information
Performing Location Day(s) Test Performed Analytical Time Methodology/Instrumentation
​Mayo Clinic Laboratories ​Monday through Friday ​2 days

ALP:  Photometric, p-Nitrophenol Phosphate

ALKE:  Electrophoresis

Reference Lab
Reference Range Information
Performing Location Reference Range
Mayo Clinic Laboratories ​Varies with age.  See Report.
Interpretation

​Total Alkaline Phosphatase:

Alkaline phosphatase (ALP) elevations tend to be more marked (more than 3-fold) in extrahepatic biliary obstructions (eg, by stone or cancer of the head of the pancreas) than in intrahepatic obstructions; the more complete the obstruction, the greater the elevation. With obstruction, serum ALP activities may reach 10 to 12 times the upper limit of normal, returning to normal upon surgical removal of the obstruction. The ALP response to cholestatic liver disease is similar to the response of gamma-glutamyltransferase (GGT) but more blunted. If both GGT and ALP are elevated, a liver source of the ALP is likely. 

Among bone diseases, the highest level of ALP activity is encountered in Paget disease, as a result of the action of the osteoblastic cells as they try to rebuild bone that is being resorbed by the uncontrolled activity of osteoclasts. Values from 10 to 25 times the upper limit of normal are not unusual. Only moderate rises are observed in osteomalacia, while levels are generally normal in osteoporosis. In rickets, levels 2 to 4 times normal may be observed. Primary and secondary hyperparathyroidism are associated with slight to moderate elevations of ALP; the existence and degree of elevation reflects the presence and extent of skeletal involvement. Very high enzyme levels are present in patients with osteogenic bone cancer. A considerable rise in ALP is seen in children following accelerated bone growth.

ALP increases of 2 to 3 times normal may be observed in women in the third trimester of pregnancy, although the reference interval is very wide and levels may not exceed the upper limit of normal in some cases. In pregnancy, the additional enzyme is of placental origin.

ALP Isoenzymes:

Liver ALP isoenzyme is associated with biliary epithelium and is elevated in cholestatic processes. Various liver diseases (primary or secondary cancer, biliary obstruction) increase the liver isoenzyme.

Liver 1 (L1) is increased in some nonmalignant diseases (such as cholestasis, cirrhosis, viral hepatitis, and in various biliary and hepatic pathologies). It is also increased in malignancies with hepatic metastasis, in cancer of the lungs and digestive tract, and in lymphoma.

An increase of liver 2 (L2) may occur in cholestasis and biliary diseases (eg, cirrhosis, viral hepatitis) and in malignancies (eg, breast, liver, lung, prostate, digestive tract) with liver metastasis.

Osteoblastic bone tumors and hyperactivity of osteoblasts involved in bone remodeling (eg, Paget disease) increase the bone isoenzyme. Paget disease leads to a striking, solitary elevation of bone ALP.

The intestinal isoenzyme may be increased in patients with cirrhosis and in individuals who are blood group O or B secretors.

The placental (carcino-placental antigen) and Regan isoenzyme can be elevated in cancer patients.

Outreach CPTs
CPT Modifier
(if needed)
Quantity Description Comments
​84080 ​1 ​​Isoenzymes
​84075 ​1 ​Alkaline Phosphatase
Test Components

​Alkaline Phosphatase

​Alkaline Phosphatase Isoenzymes

Ordering Applications
Ordering Application Description
If the ordering application you are looking for is not listed, contact your local laboratory for assistance.
Specimen Requirements
Fasting Required Specimen Type Preferred Container/Tube Acceptable Container/Tube Specimen Volume Specimen Minimum Volume
(allows for 1 repeat)
Pediatric Minimum Volume
(no repeat)
​No ​Serum ​Serum Separator Tube (SST) ​Red Top Tube (RTT) ​1 mL (divided into 2 tubes, each containing 0.5 mL) ​0.5 mL (divided into 2 tubes, each containing 0.25 mL)
Specimen Stability Information
Specimen Type Temperature Time
​Serum ​ ​ ​Frozen (preferred) ​14 days
​Refrigerate ​7 days
​Ambient ​7 days
Rejection Criteria
Gross hemolysis
Useful For
Diagnosis and treatment of liver, bone, intestinal, and parathyroid diseases
 
Determining the tissue source of increased alkaline phosphatase (ALP) activity in serum
 
Differentiating between liver and bone sources of elevated ALP
Test Components

​Alkaline Phosphatase

​Alkaline Phosphatase Isoenzymes

Reference Range Information
Performing Location Reference Range
Mayo Clinic Laboratories ​Varies with age.  See Report.
Interpretation

​Total Alkaline Phosphatase:

Alkaline phosphatase (ALP) elevations tend to be more marked (more than 3-fold) in extrahepatic biliary obstructions (eg, by stone or cancer of the head of the pancreas) than in intrahepatic obstructions; the more complete the obstruction, the greater the elevation. With obstruction, serum ALP activities may reach 10 to 12 times the upper limit of normal, returning to normal upon surgical removal of the obstruction. The ALP response to cholestatic liver disease is similar to the response of gamma-glutamyltransferase (GGT) but more blunted. If both GGT and ALP are elevated, a liver source of the ALP is likely. 

Among bone diseases, the highest level of ALP activity is encountered in Paget disease, as a result of the action of the osteoblastic cells as they try to rebuild bone that is being resorbed by the uncontrolled activity of osteoclasts. Values from 10 to 25 times the upper limit of normal are not unusual. Only moderate rises are observed in osteomalacia, while levels are generally normal in osteoporosis. In rickets, levels 2 to 4 times normal may be observed. Primary and secondary hyperparathyroidism are associated with slight to moderate elevations of ALP; the existence and degree of elevation reflects the presence and extent of skeletal involvement. Very high enzyme levels are present in patients with osteogenic bone cancer. A considerable rise in ALP is seen in children following accelerated bone growth.

ALP increases of 2 to 3 times normal may be observed in women in the third trimester of pregnancy, although the reference interval is very wide and levels may not exceed the upper limit of normal in some cases. In pregnancy, the additional enzyme is of placental origin.

ALP Isoenzymes:

Liver ALP isoenzyme is associated with biliary epithelium and is elevated in cholestatic processes. Various liver diseases (primary or secondary cancer, biliary obstruction) increase the liver isoenzyme.

Liver 1 (L1) is increased in some nonmalignant diseases (such as cholestasis, cirrhosis, viral hepatitis, and in various biliary and hepatic pathologies). It is also increased in malignancies with hepatic metastasis, in cancer of the lungs and digestive tract, and in lymphoma.

An increase of liver 2 (L2) may occur in cholestasis and biliary diseases (eg, cirrhosis, viral hepatitis) and in malignancies (eg, breast, liver, lung, prostate, digestive tract) with liver metastasis.

Osteoblastic bone tumors and hyperactivity of osteoblasts involved in bone remodeling (eg, Paget disease) increase the bone isoenzyme. Paget disease leads to a striking, solitary elevation of bone ALP.

The intestinal isoenzyme may be increased in patients with cirrhosis and in individuals who are blood group O or B secretors.

The placental (carcino-placental antigen) and Regan isoenzyme can be elevated in cancer patients.

For more information visit:
Performing Laboratory Information
Performing Location Day(s) Test Performed Analytical Time Methodology/Instrumentation
​Mayo Clinic Laboratories ​Monday through Friday ​2 days

ALP:  Photometric, p-Nitrophenol Phosphate

ALKE:  Electrophoresis

Reference Lab
For billing questions, see Contacts
Outreach CPTs
CPT Modifier
(if needed)
Quantity Description Comments
​84080 ​1 ​​Isoenzymes
​84075 ​1 ​Alkaline Phosphatase
For most current information refer to the Marshfield Laboratory online reference manual.