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Amylase Creatinine Ratio, Blood and Urine

Amylase/Creatinine Clearance Ratio

Test Codes

Antrim: 13340, EPIC: LAB5434, AMYCR

Department

Chemistry

Instructions

• This test requires both a blood sample and a random urine sample. The urine sample cannot be a timed collection.
• Blood should be drawn just prior to the urine collection.

Specimen Collection Criteria

Collect: BOTH of the following specimens:

• Blood: One Gold-top SST tube.
• Urine: 5-10 mL random urine in a screw-capped container (preferred) or other sterile collection container.

Physician Office/Draw Specimen Preparation

• Blood: Let specimen clot 30-60 minutes then immediately centrifuge to separate serum from cells. Refrigerate (2-8°C or 36-46°F) the centrifuged SST tube within two hours of collection. (Min: 0.5 mL)
• Urine: Maintain specimen refrigerated (2-8°C or 36-46°F) prior to transport. (Minimum: 5.0 mL)

Preparation for Courier Transport

Transport: Centrifuged SST tube and random urine in a screw-capped container (preferred) or other sterile collection container, refrigerated (2-8°C or 36-46°F). (Minimum: 0.5 mL serum and 5.0 mL urine)

Rejection Criteria

• Moderate to grossly hemolyzed specimens.
• Specimens not collected and processed as indicated.

In-Lab Processing

Let SST specimens clot 30–60 minutes. Centrifuge SST tubes or Microtainers^® to separate serum from cells. Centrifuge urine specimen. Deliver serum and urine immediately to the appropriate testing station.

Storage

Specimen Stability for Testing:

Centrifuged SST Tubes and Microtainers^® with Separator Gel
Room temperature (20–26°C or 68–78.8°F): 2–4 hours
Refrigerated (2–8°C or 36–46°F): 7 days
Frozen (-20°C/-4°F or below): Unacceptable

Red-top Tubes and Microtainers^® without Separator Gel
Room temperature (20–25°C or 68–77°F): 2-4 hours
Refrigerated (2–8°C or 36–46°F): Unacceptable
Frozen (-20°C/-4°F or below): Unacceptable

Serum Specimens (Pour-Overs)
Room temperature (20–26°C or 68–78.8°F): 2-4 hours
Refrigerated (2–8°C or 36–46°F): 7 days
Frozen (-20°C/-4°F or below): 7 days

Urine Specimens
Room temperature (20–26°C or 68–78.8°F): 2–4 hours
Refrigerated (2–8°C or 36–46°F): 4 days
Frozen (-20°C/-4°F or below): 7 days

Specimen Storage in Department Prior to Disposal:

Refrigerated (2–8°C or 36–46°F): 7 days

Laboratory

Dearborn Chemistry Laboratory
Royal Oak Automated Chemistry Laboratory
Troy Chemistry Laboratory 

Performed

Sunday – Saturday, 24 hours a day.
Results available within 24 hours.

Reference Range

1.3 – 4.3%

Test Methodology

Enzymatic/Colormetric.

Interpretation

• The amylase/creatinine clearance is a ratio derived from serum amylase, serum creatinine, urinary amylase and urinary creatinine measurements.
• Elevated levels are seen in pancreatitis, in some cases of duodenal perforation, pancreatic cancer, large doses of corticosteroids, and hyperemesis or toxemia of pregnancy. Elevations have also been observed in ketoacidosis, renal insufficiency, myeloma, light-chain disease, and marked hemoglobinuria.

Clinical Utility

The amylase/creatinine ratio is used to aid in the diagnosis of acute pancreatitis. In acute pancreatitis, values greater than 8% are not uncommon. In macroamylasemia, the ratio is usually less than 2%.

CPT Codes

82150x2, 82565, 82570, 13706-7
LOINC:  70957-6

Contacts

Last Updated

10/3/2023