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Test ID: AMS Amylase, Total, Serum

Reporting Name

Amylase, Total, S

Useful For

Diagnosis and management of pancreatitis

 

Evaluation of pancreatic function


Necessary Information


Patient's age and sex are required.



Specimen Required


Container/Tube:

Preferred: Serum gel

Acceptable: Red top

Specimen Volume: 0.5 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.


Specimen Minimum Volume

0.25 mL

Reference Values

0-30 days: 0-6 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

Day(s) and Time(s) Performed

Monday through Sunday; Continuously

Test Classification

This test has been cleared, approved or is exempt 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

82150

LOINC Code Information

Test ID Test Order Name Order LOINC Value
AMS Amylase, Total, S 1798-8

 

Result ID Test Result Name Result LOINC Value
AMS Amylase, Total, S 1798-8

Clinical Information

The amylase enzymes are a group of hydrolases that degrade complex carbohydrates into fragments. Amylase is produced primarily by the exocrine pancreas where the enzyme is synthesized by the acinar cells and then secreted into the intestinal tract by way of the pancreatic duct system. Amylases also are produced by the salivary glands, small intestine mucosa, ovaries, placenta, liver, and fallopian tubes. Pancreatic and salivary isoenzymes are found in serum.

Interpretation

In acute pancreatitis, a transient rise in serum amylase activity occurs within 2 to 12 hours of onset; levels return to normal by the third or fourth day. A 4- to 6-fold elevation of amylase activity above the reference limit is usual with the maximal levels obtained in 12 to 72 hours. However, a significant number of subjects show lesser elevations and sometimes none. The magnitude of the elevation of serum enzyme activity is not related to the severity of pancreatic involvement. Normalization is not necessarily a sign of resolution.

 

In acute pancreatitis associated with hyperlipidemia, serum amylase activity may be spuriously normal; the amylasemia may be unmasked either by serial dilution of the serum or ultracentrifugation.

 

A significant amount of serum amylase is excreted in the urine and, therefore, elevation of serum activity is reflected in the rise of urinary amylase activity. Urine amylase, as compared to serum amylase, appears to be more frequently elevated, reaches higher levels, and persists for longer periods. However, the receiver operator curves (ROC) of various serum and urine amylase assays demonstrated that all urine assays had poorer diagnostic utility than all serum assays. In quiescent chronic pancreatitis, both serum and urine activities are usually subnormal.

 

Because it is produced by several organs, amylase is not a specific indicator of pancreatic function. Elevated levels also may be seen in a number of nonpancreatic disease processes including mumps, salivary duct obstruction, ectopic pregnancy, and intestinal obstruction/infarction.

Clinical Reference

1. Soldin SJ: Pediatric Reference Ranges. 2nd ed AACC Press; 1997

2. Rifai N, Horvath AR, Wittwer CT, eds: Tietz Textbook of Clinical Chemistry and Molecular Diagnostics. 6th ed. Elsevier; 2018

3. Swaroop VS, Chari ST, Clain JE: Acute pancreatitis. JAMA. 2004;291:2865-2868

4. Azzopardi E, Lloyd C, Teixeira SR, Conlan, RS, Whitaker, IS: Clinical applications of amylase: Novel perspectives. Surgery. 2016;160(1):26-37

Analytic Time

Same day/1 day

Method Name

Colorimetric Rate Reaction

Specimen Type

Serum

Specimen Stability Information

Specimen Type Temperature Time Special Container
Serum Frozen (preferred) 30 days
  Refrigerated  30 days
  Ambient  7 days
Mayo Clinic Laboratories | Gastroenterology Catalog Additional Information:

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