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Test Code AMISO Amylase, Isoenzymes, Serum


Necessary Information


Age and sex of patient are required.



Specimen Required


Collection Container/Tube:

Preferred: Serum gel

Acceptable: Red top

Submission Container/Tube: Plastic vial

Specimen Volume: 1 mL

Collection Instructions:

1. Serum gel tubes should be centrifuged within 2 hours of collection.

2. Red-top tubes should be centrifuged and the serum aliquoted into a plastic vial within 2 hours of collection.


Secondary ID

604930

Useful For

Ruling out salivary amylase as the cause of elevated serum amylase

Profile Information

Test ID Reporting Name Available Separately Always Performed
AMYSE Amylase, Total, S Yes, (Order AMS) Yes
AMYPA Amylase, Pancreatic, S No Yes
AMYSA Amylase, Salivary, S No Yes

Testing Algorithm

Total and pancreatic amylase are measured in the submitted serum specimen. Salivary amylase is calculated as the difference between the two measured results (salivary amylase = total amylase-pancreatic amylase).

Method Name

AMYSE, AMYPA: Colorimetric Rate Reaction

AMYSA: Calculation

Reporting Name

Amylase, Isoenzymes, S

Specimen Type

Serum

Specimen Minimum Volume

See Specimen Required

Specimen Stability Information

Specimen Type Temperature Time Special Container
Serum Refrigerated (preferred) 30 days
  Frozen  30 days
  Ambient  7 days

Reject Due To

Gross hemolysis Reject

Clinical Information

The amylase enzymes are a group of hydrolases that degrade complex carbohydrates (starches) into simple sugars. The pancreas and salivary glands have amylase concentrations that are orders of magnitude greater than any other tissue. These two amylase isoenzymes, pancreatic and salivary, are present in serum.

 

Pancreatic and salivary amylase isoenzymes can be measured in serum at physiologic concentrations (within the age-specific reference interval), and elevated concentrations indicate hyperamylasemia. Hyperamylasemia can result from either increased rate of release of amylase into blood or decreased metabolic clearance of the enzyme (ie, macroamylase).

 

Routine amylase laboratory tests measure total amylase activity in serum and do not differentiate between amylase isoenzymes. Differentiation of amylase isoenzymes is useful in cases where amylase elevations are not thought to be from a pancreatic source.

 

Pancreatic amylase may be elevated due to pancreatitis as well as other conditions in which pancreatic amylase is released (eg, cannulation of the pancreatic duct) or absorbed (eg, loss of bowel integrity) into the blood. Serum pancreatic amylase should always be interpreted in a context of total amylase to determine the relative contribution of salivary and pancreatic isoenzymes.

 

Hyperamylasemia due to salivary amylase may occur when salivary gland disease is present. Salivary amylasemia may also be observed in conditions where there is no clinical evidence of salivary gland diseases, such as chronic alcoholism, postoperative states, lactic acidosis, anorexia nervosa or bulimia, and malignant neoplasms that secrete amylase.

Reference Values

AMYLASE, TOTAL

0-30 days: ≤6 U/L

31-182 days: 1-17 U/L

183-365 days: 6-44 U/L

1-3 years: 8-79 U/L

4-17 years: 21-110 U/L

≥18 years: 28-100 U/L

 

AMYLASE, PANCREATIC

0-<24 months: ≤20 U/L

2-<18 years: 9-35 U/L

≥18 years: 13-53 U/L

 

AMYLASE, SALIVARY

0-<18 years: Not established

≥18 years: ≤86 U/L

Interpretation

Increased concentrations of total amylase activity in conjunction with increased concentration of specific amylase isoenzymes may aid in differentiating the source of amylase (pancreatic versus salivary).

CPT Code Information

82150 x 2

LOINC Code Information

Test ID Test Order Name Order LOINC Value
AMISO Amylase, Isoenzymes, S 24333-7

 

Result ID Test Result Name Result LOINC Value
AMYPA Amylase, Pancreatic, S 1805-1
AMYSA Amylase, Salivary, S 1809-3
AMYSE Amylase, Total, S 1798-8

Forms

If not ordering electronically, complete, print, and send Gastroenterology and Hepatology Test Request (T728) with the specimen.