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Test ID: Cancer Antigen 19-9 (CA 19-9)
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Cancer Antigen 19-9 (CA 19-9)
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Useful For
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To monitor response to pancreatic cancer treatment and aid in the diagnosis of pancreatic cancer
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Method name and description
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Electrochemiluminescence immunoassay (ECLIA) intended for use on the cobas e immunoassay analyzers. Patient sample, a biotinylated monoclonal CA 19‑9‑specific antibody, and a monoclonal CA 19‑9‑specific antibody labeled with a ruthenium complex form a sandwich complex. After addition of streptavidin-coated microparticles, the complex becomes bound to the solid phase via interaction of biotin and streptavidin. The reaction mixture is aspirated into the measuring cell where the microparticles are magnetically captured onto the surface of the electrode. Unbound substances are then removed with ProCell/ProCell M. Application of a voltage to the electrode then induces chemiluminescent emission which is measured by a photomultiplier.Results are determined via a calibration curve which is instrument specifically generated by 2‑point calibration and a master curve provided via the reagent barcode.
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Clinical information
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CA 19‑9 assay values can assist in the differential diagnosis and monitoring of patients with pancreatic carcinoma (sensitivity 70‑87 %). There is no correlation between tumor mass and the CA 19‑9 assay values. However, patients with CA 19‑9 serum levels above 10000 U/mL almost always have distal metastasis. The determination of CA 19‑9 cannot be used for the early detection of pancreatic carcinoma. As the mucin is excreted exclusively via the liver, even slight cholestasis can lead to clearly elevated CA 19‑9 serum levels in some cases. Elevated CA 19‑9 values are also found with a number of benign and inflammatorydiseases of the gastrointestinal tract and the liver, as well as in cystic fibrosis.
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Specimen type / Specimen volume / Specimen container
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Specimen type: Serum, Plasma
Minimum volume of sample: 1 mL
Serum: Plain tube (red or yellow top)
Plasma: Li‑heparin tube
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Collection instructions / Special Precautions / Timing of collection
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Collect blood by standard venipuncture techniques as per specimen requirements. When processing samples in primary tubes (sample collection systems), follow the instructions of the tube manufacturer.
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Storage and transport instructions
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Storage: 14 days at 2‑ 8 °C
5 days at 20‑ 25 °C
3 months at ‑ 20 °C (±5)
Transport: 2-25°C
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Specimen Rejection Criteria
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Grossly hemolyzed, icteric and lipemic samples, wrong collection container, insufficient sample and heat‑inactivated samples.
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Biological reference intervals and clinical decision values
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0-27 U/ml
(The testing method is an Electrochemiluminescence Immunoassay manufactured by Roche Diagnostics and performed on Cobas e801. Results determined by assays using different Manufactures or Methods may not be comparable.)
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Turnaround time / Days and times test performed / Specimen retention time
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Daily (24/7)
Turn-around time:
Routine: One working day
Specimen Retention: 4 days
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