Alkaline Phosphatase, Total and Isoenzymes, Serum
NY State Approved Indicates the status of NY State approval and if the test is orderable for NY State clients.
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
Profile Information A profile is a group of laboratory tests that are ordered and performed together under a single Mayo Test ID. Profile information lists the test performed, inclusive of the test fee, when a profile is ordered and includes reporting names and individual availability.
|Test ID||Reporting Name||Available Separately||Always Performed|
|ALP||Alkaline Phosphatase, S||Yes||Yes|
|ALKE||Alkaline Phosphatase Isoenzymes, S||No||Yes|
ALP/8340: Photometric, p-Nitrophenol Phosphate
Reporting Name A shorter/abbreviated version of the Published Name for a test; an abbreviated test name
Alkaline Phosphatase, Tot and Iso,S
Specimen Type Describes the specimen type needed for testing
Specimen Required Defines the optimal specimen. This field describes the type of specimen required to perform the test and the preferred volume to complete testing. The volume allows automated processing, fastest throughput and, when indicated, repeat or reflex testing.
Preferred: Serum gel
Acceptable: Red top
Submission Container/Tube: Plastic vial
Specimen Volume: 1 mL divided into 2 tubes each containing 0.5 mL
Additional Information: Patient's age and sex are required.
Specimen Minimum Volume Defines the amount of specimen required to perform an assay once, including instrument and container dead space. Submitting the minimum specimen volume makes it impossible to repeat the test or perform confirmatory or perform reflex testing. In some situations, a minimum specimen volume may result in a QNS (quantity not sufficient) result, requiring a second specimen to be collected.
0.5 mL divided into 2 tubes each containing 0.25 mL
Mild reject; Gross reject
Mild OK; Gross OK
Mild OK; Gross OK
Specimen Stability Information Provides a description of the temperatures required to transport a specimen to the laboratory. Alternate acceptable temperature(s) are also included.
|Serum||Frozen (preferred)||14 days|
Clinical Information Discusses physiology, pathophysiology, and general clinical aspects, as they relate to a laboratory test
Alkaline phosphatase (ALP) is present in a number of tissues including liver, bone, intestine, and placenta. The activity of ALP found in serum is a composite of isoenzymes from those sites and, in some circumstances, placental or Regan isoenzymes. Serum ALP is of interest in the diagnosis of 2 main groups of conditions-hepatobiliary disease and bone disease associated with increased osteoblastic activity.
A rise in ALP activity occurs with all forms of cholestasis, particularly with obstructive jaundice. The response of the liver to any form of biliary tree obstruction is to synthesize more ALP. The main site of new enzyme synthesis is the hepatocytes adjacent to the biliary canaliculi.
ALP also is elevated in disorders of the skeletal system that involve osteoblast hyperactivity and bone remodeling, such as Paget's disease rickets and osteomalacia, fractures, and malignant tumors.
Moderate elevation of ALP may be seen in other disorders such as Hodgkin's disease, congestive heart failure, ulcerative colitis, regional enteritis, and intra-abdominal bacterial infections.
Reference Values Describes reference intervals and additional information for interpretation of test results. May include intervals based on age and sex when appropriate. Intervals are Mayo-derived, unless otherwise designated. If an interpretive report is provided, the reference value field will state this.
4 years: 149-369 U/L
5 years: 179-416 U/L
6 years: 179-417 U/L
7 years: 172-405 U/L
8 years: 169-401 U/L
9 years: 175-411 U/L
10 years: 191-435 U/L
11 years: 185-507 U/L
12 years: 185-562 U/L
13 years: 182-587 U/L
14 years: 166-571 U/L
15 years: 138-511 U/L
16 years: 102-417 U/L
17 years: 69-311 U/L
18 years: 52-222 U/L
> or =19 years: 45-115 U/L
4 years: 169-372 U/L
5 years: 162-355 U/L
6 years: 169-370 U/L
7 years: 183-402 U/L
8 years: 199-440 U/L
9 years: 212-468 U/L
10 years: 215-476 U/L
11 years: 178-526 U/L
12 years: 133-485 U/L
13 years: 120-449 U/L
14 years: 153-362 U/L
15 years: 75-274 U/L
16 years: 61-264 U/L
17-23 years: 52-144 U/L
24-45 years: 37-98 U/L
46-50 years: 39-100 U/L
51-55 years: 41-108 U/L
56-60 years: 46-118 U/L
61-65 years: 50-130 U/L
> or =66 years: 55-142 U/L
Reference values have not been established for patients that are <4 years of age.
ALKALINE PHOSPHATASE ISOENZYMES
0-6 years: 5.1-49.0%
7-9 years: 3.0-45.0%
10-13 years: 2.9-46.3%
14-15 years: 7.8-48.9%
16-18 years: 14.9-50.5%
> or =19 years: 27.8-76.3%
0-6 years: 7.0-112.7 IU/L
7-9 years: 7.4-109.1 IU/L
10-13 years: 7.8-87.6 IU/L
14-15 years: 10.3-75.6 IU/L
16-18 years: 13.7-78.5 IU/L
> or =19 years: 16.2-70.2 IU/L
0-6 years: 2.9-13.7%
7-9 years: 3.7-12.5%
10-13 years: 2.9-22.3%
14-15 years: 2.2-19.8%
16-18 years: 1.9-12.5%
> or =19 years: 0.0-8.0%
0-6 years: 3.0-41.5 IU/L
7-9 years: 4.0-35.6 IU/L
10-13 years: 3.3-37.8 IU/L
14-15 years: 2.2-32.1 IU/L
16-18 years: 1.4-19.7 IU/L
> or =19 years: 0.0-5.8 IU/L
0-6 years: 41.5-82.7%
7-9 years: 39.9-85.8%
10-13 years: 31.8-91.1%
14-15 years: 30.6-85.4%
16-18 years: 38.9-72.6%
> or =19 years: 19.1-67.7%
0-6 years: 43.5-208.1 IU/L
7-9 years: 41.0-258.3 IU/L
10-13 years: 39.4-346.1 IU/L
14-15 years: 36.4-320.5 IU/L
16-18 years: 32.7-214.6 IU/L
> or =19 years: 12.1-42.7 IU/L
0-6 years: 0.0-18.4%
7-9 years: 0.0-18.3%
10-13 years: 0.0-11.8%
14-15 years: 0.0-8.2%
16-18 years: 0.0-8.7%
> or =19 years: 0.0-20.6%
0-6 years: 0.0-37.7 IU/L
7-9 years: 0.0-45.6 IU/L
10-13 years: 0.0-40.0 IU/L
14-15 years: 0.0-26.4 IU/L
16-18 years: 0.0-12.7 IU/L
> or =19 years: 0.0-11.0 IU/L
Total Alkaline Phosphatase (ALP):
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, and 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's 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.
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 non-malignant 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's disease) increase the bone isoenzyme. Paget's 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 (carcinoplacental antigen) and Regan isoenzyme can be elevated in cancer patients.
Cautions Discusses conditions that may cause diagnostic confusion, including improper specimen collection and handling, inappropriate test selection, and interfering substances
No significant cautionary statements
Clinical Reference Provides recommendations for further in-depth reading of a clinical nature
1. Tietz NW: Textbook of Clinical Chemistry, Third edition. Edited by CA Burtis, ER Ashwood. Philadelphia, PA, WB Saunders Company, 1999
2. Moss DW: Alkaline phosphatase isoenzymes. Clin Chem 1982;28:2007-2016
Method Description Describes how the test is performed and provides a method-specific reference
Total Alkaline Phosphatase (ALP):
In the presence of magnesium and zinc ions, p-nitrophenyl phosphate is cleaved by phosphatases into phosphate and p-nitrophenol. The p-nitrophenol released is directly proportional to the catalytic alkaline phosphatase ALP activity. It is determined by measuring the increase in absorbance. (Package insert: Roche Alkaline Phosphatase reagent
package insert;, Indianapolis, IN, March February 19992012)
Serum samples are electrophoresed through alkaline buffered (pH 9.1) agarose gels. Almost all ALP isoenzymes can be separated by electrophoresis according to their charge difference. However, because the electrophoretic mobilities of the liver and bone isoenzymes are quite similar, a modification is required for separation. The Sebia system utilizes differences between liver and bone isoenzyme sialation in order to achieve separation. Each sample is applied to the agarose gel in duplicate. One sample is passed through wheat germ lectin (wheat germ agglutin:WGA) and is deposited anodally from the point of sample application. The bone isoenzyme, which is rich in sialic acids, reacts with WGA and precipitates adjacent to the lectin application point. The separated isoenzymes are visualized using a specific chromogenic substrate, 5-bromo-4-chloro-3-indolyl phosphate/nitro blue tetrazolium in aminomethyl propanol (AMP) buffer, pH 10.0. The dried gels are read on a densitometer for the quantification of tissue isoforms.(Package insert: Sebia Hydragel 7 and 15 ISO-PAL, Sebia, Norcross, GA)
Day(s) and Time(s) Test Performed Outlines the days and times the test is performed. This field reflects the day and time the sample must be in the testing laboratory to begin the testing process and includes any specimen preparation and processing time required before the test is performed. Some tests are listed as continuously performed, which means assays are performed several times during the day.
Alkaline Phosphatase: Monday through Sunday; Continuously
Alkaline Phosphatase Isoenzymes: Monday through Friday
Analytic Time Defines the amount of time it takes the laboratory to setup and perform the test. This is defined in number of days. The shortest interval of time expressed is "same day/1 day," which means the results may be available the same day that the sample is received in the testing laboratory. One day means results are available 1 day after the sample is received in the laboratory.
Maximum Laboratory Time Defines the maximum time from specimen receipt at Mayo Medical Laboratories until the release of the test result
Specimen Retention Time Outlines the length of time after testing that a specimen is kept in the laboratory before it is discarded
See Individual Unit Codes
Performing Laboratory Location The location of the laboratory that performs the test
Test Classification Provides information regarding the medical device classification for laboratory test kits and reagents. Tests may be classified as cleared or approved by the US Food and Drug Administration (FDA) and used per manufacturer's instructions, or as products that do not undergo full FDA review and approval, and are then labeled as an Analyte Specific Reagent (ASR), Investigation Use Only (IUO) product, or a Research Use Only (RUO) product.
This test has been cleared or approved by the U.S. Food and Drug Administration and is used per manufacturer's instructions. Performance characteristics were verified by Mayo Clinic in a manner consistent with CLIA requirements.
CPT Code Information Provides guidance in determining the appropriate Current Procedural Terminology (CPT) code(s) information for each test or profile. The listed CPT codes reflect Mayo Medical Laboratories interpretation of CPT coding requirements. It is the responsibility of each laboratory to determine correct CPT codes to use for billing.
Alkaline Phosphatase, Serum
Alkaline Phosphatase Isoenzymes, Serum
LOINC® Code Information Provides guidance in determining the Logical Observation Identifiers Names and Codes (LOINC) values for the result codes returned for this test or profile.
|Result ID||Reporting Name||LOINC Code|
|ALP||Alkaline Phosphatase, S||6768-6|
|89503||Alkaline Phosphatase Isoenzymes, S||49243-9|
|45488||Liver 1 %||15348-6|
|45489||Liver 2 %||15349-4|