Amylase, Pancreatic, Serum
NY State Approved Indicates the status of NY State approval and if the test is orderable for NY State clients.
Diagnosing acute pancreatitis
Monoclonal Antibody Technique
Reporting Name A shorter/abbreviated version of the Published Name for a test; an abbreviated test name
Amylase, Pancreatic, S
P-AMY (Pancreatic Amylase)
P-AMY (Pancreatic Amylase)
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: Red top
Acceptable: Serum gel
Specimen Volume: 0.5 mL
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.
Mild OK; Gross reject
Mild OK; Gross reject
Mild OK; Gross reject
Specimen Stability Information Provides a description of the temperatures required to transport a specimen to the laboratory. Alternate acceptable temperature(s) are also included.
Clinical Information Discusses physiology, pathophysiology, and general clinical aspects, as they relate to a laboratory test
Amylases are a group of hydrolases that degrade complex carbohydrates into fragments.
Amylase is produced by the exocrine pancreas and the salivary glands to aid in the digestion of starch. It is also produced by the small intestine mucosa, ovaries, placenta, liver, and fallopian tubes.
Since the clinical use of amylase activity is usually to detect pancreatitis, the pancreatic amylase (p-amylase) form provides the single most useful test in the laboratory diagnosis of acute pancreatitis.
Total serum amylase continues to be the most widely used clinical test for the diagnosis of acute pancreatitis. Its use has been justified on the basis of its accuracy of 95%. The problem with its use is that it has relatively low specificity of between 70% and 80%.
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.
0-<24 months: 0-20 U/L
2-<18 years: 9-35 U/L
> or =18 years: 11-54 U/L
Pancreatic amylase is elevated in acute pancreatitis within 12 hours of onset and persists 3 to 4 days. The elevation is usually 4-fold to 6-fold the upper reference limit. Macroamylase may cause less dramatic and more persistent elevations of p-amylase over weeks or months. This is usually accompanied by a reduced amylase clearance.
Values over the normal reference interval in patients with histories consistent with acute pancreatitis are confirmatory. Peak values are often 200 U/L or higher. Macroamylasemia may cause small, but persistent elevations of amylase.
An elevation of total serum alpha-amylase does not specifically indicate a pancreatic disorder since the enzyme is produced by the salivary glands, mucosa of the small intestine, ovaries, placenta, liver, and the lining of the fallopian tubes. Two isoenzymes, pancreatic and salivary, are found in serum. Pancreatic amylase has been shown to be more useful than total amylase when evaluating patients with acute pancreatitis.
Cautions Discusses conditions that may cause diagnostic confusion, including improper specimen collection and handling, inappropriate test selection, and interfering substances
Pancreatic amylase results may be elevated in patients with macroamylase. This elevated pancreatic amylase is not diagnostic for pancreatitis. By utilizing serum lipase and urinary amylase values, the presence or absence of macroamylase may be determined.
Not useful for diagnosing pancreatic cancer.
Mild elevations up to 78 U/L may have little clinical significance.
Detection of chronic pancreatitis can only be aided by p-amylase during acute episodes.
Clinical Reference Provides recommendations for further in-depth reading of a clinical nature
Sternby B, O'Brien JF, Zinsmeister AR, DiMagno EP: What is the best biochemical test to diagnose acute pancreatitis? A prospective clinical study. Mayo Clin Proc 1996;71:1138-1144
Method Description Describes how the test is performed and provides a method-specific reference
After the inhibition of salivary amylase with a combination of 2 monoclonal antibodies, pancreatic alpha-amylase activity is assayed by a coupled kinetic colorimetric procedure which gives rise to 415 nm absorption proportional to the paranitrophenol released by the action of alpha-amylase and alpha-glucosidase.
In this procedure, the first incubation step results in the inhibition of human salivary alpha-amylase by 2 monoclonal antibodies which do not affect pancreatic alpha-amylase. After a second incubation with the substrate (G7)-p-nitrophenyl (G1)-alpha-D-maltohepatoside, the activity of pancreatic alpha-amylase is measured. The alpha-amylase cleaves the substrate into fragments G2, G3, and G4. Further fragment hydrolysis by alpha-glucosidase yields p-nitrophenol and glucose. Enzyme activity is determined by the rate of increase of absorbance at 415 nm. Chromophore production is equimolar.
The simplified reaction is as follows:
5 ET-G7PNP + 5 H20 -------> 2 ET-G5 + 2 G2PNP + 2 ET-G4
+ 2-G3PNP + ET-G3 + G4 PNP
2 G2PNP + 2 G3PNP + 14 H20 --------->5 PNP + 14G
Abbreviations: ET = ethylidene
G = glucose
PNP = p-nitrophenol
(Tietz NW, Burlina A, Gerhardt W, et al: Multicenter evaluation of a specific pancreatic isoamylase assay based on a double monoclonal-antibody technique, Clin Chem 1988;34:2096-2102)
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.
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.
1 day (not reported on Saturday or Sunday)
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
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.
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|
|PAMY||Amylase, Pancreatic, S||1805-1|