Amylase, Urine
Use
Work-up for abdominal pain, epigastric tenderness, nausea, and vomiting. An enzyme with molecular weight of 45 to 55 kilodaltons, urinary amylase is used in the differential diagnosis of pancreatitis. It is very useful in diagnosis of pseudocyst of the pancreas, where the urine amylase may remain elevated for weeks after the serum amylase has returned to normal, after a bout of acute pancreatitis.
Special Instructions
The test request form must state date and time collection started, date and time collection finished, and urine volume. Two-hour collections are more practical and provide results sooner than longer collections.
Limitations
Macroamylasemia is characterized by high serum amylase but normal urine amylase. The amylase:creatinine ratio remains useful for the diagnosis of macroamylasemia but is limited by its nonspecificity. Urine amylase levels are unaffected by renal failure, unlike serum amylase. While serum amylase usually returns to normal within three to five days without complications, urine amylase remains elevated longer in acute pancreatitis.
Methodology
Automated Analyzer (Clinical Chemistry)
Biomarkers
LOINC Codes
- 1799-6
- 1799-6
- 13362-9
- 38193-9
Result Turnaround Time
1-3 days
Related Documents
For more information, please review the documents below
Specimen
Urine
Volume
10 mL aliquot
Minimum Volume
0.5 mL aliquot
Container
Plastic urine container without preservative
Collection Instructions
Collect timed specimen. Instruct the patient to void at the beginning of the collection period and discard the specimen. Collect all urine including the final specimen voided at the end of collection period.
Storage Instructions
Room temperature
Causes for Rejection
Presence of acid preservative (pH <3); improper labeling
Stability Requirements
| Temperature | Period |
|---|---|
| Room Temperature | 14 days |
| Refrigerated | 14 days |
| Frozen | 3 days |