Lab Test

Carbohydrate Antigen 19 9, Blood

Carbohydrate Antigen, Cancer Antigen-GI, GI Cancer Antigen, Cancer Antigen 19-9, CA 19-9, Serum

Test Codes

Antrim #19587, EPIC: LAB5027, CA199

Department

Chemistry

Specimen Collection Criteria

Collect: One Gold-top SST tube. (Minimum Whole Blood: 4.0 mL)

Contact the Laboratory for acceptability of other tube types.

Physician Office/Draw Specimen Preparation

Let SST 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.

Preparation for Courier Transport

Transport: Centrifuged SST tube, refrigerated (2-8°C or 36-46°F). (Minimum: 1.0 mL)

Rejection Criteria

  • Plasma specimens.
  • Severely hemolyzed specimens.
  • Specimens submitted at room temperature.
  • Red-top tubes with serum not separated from cells within two hours of collection.

In-Lab Processing

Let SST specimens clot 30-60 minutes. Centrifuge SST tubes or Microtainers® to separate serum from cells. Deliver 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): 5 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): 5 days
Frozen (-20°C/-4°F or below): 5 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

Performed

Monday, Wednesday, Friday, 7:00 am – 3:30 pm.
Results available within 24 hours of testing.

Reference Range

Less than 37.0 U/mL.

Test Methodology

Chemiluminescence Immunoassay.

Interpretation

  • The CA 19-9 assay value, regardless of the level, should not be interpreted as absolute evidence of the presence or absence of malignant disease.
  • Patients must possess the ability to express the Lewis blood group antigen or they will be unable to produce the CA 19-9 antigen.
  • This test should NOT be used for screening and should NOT be used interchangeably with other assay methods.

Clinical Utility

  • CA 19-9 is useful in monitoring pancreatic, hepatobiliary, gastric, hepatocellular, and colorectal cancer.
  • May be used for differentiating patients with cholangiocarcinoma and primary sclerosing cholangitis (PSC) from those with PSC alone.

CPT Codes

86301
LOINC: 24108-3

Contacts

Last Updated

5/5/2021

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