CA 19-9 (Serum) Test

Carbohydrate Antigen 19 – 9 (CA 19 - 9) is known to be that one modified and modulated Lewis blood group antigen. Patients with gastrointestinal malignancies like pancreatic cancer, colon cancer or cholangiocarcinoma might suffer from elevated levels of CA 19 – 9. The concentrations of CA 19 – 9 are observed in an escalated nature in cases of benign conditions like cholestasis, cirrhosis and pancreatitis. The only exception here is that the levels are mostly below 1,000 U/ml.

Lewis negative individuals do/ can not express CA 19 – 9. This is due to the lack of an enzyme called fucosyltransferase that is a key component which influences the production of CA 19 – 9. Low levels of CA 19 – 9 do not potentially help in detecting cancerous cells. As a result, cancer detection in such individuals is difficult.

There are no special preparations needed for the test. But, there are few things that you need to keep in mind and inform to your doctor beforehand. Your doctor should be enlightened about the medications you’re currently undertaking. On the other hand, he should also be made aware about allergies you have.

If ever, past or present, any animal bit you, then you have that animal’s antibodies flowing through your blood. These antibodies might interfere with your test results and thus, manipulate them giving you inaccurate results. To avoid this, inform your doctor about such incidents.

The test is an effective way of detecting and indicating the presence of pancreatic cancer. Thus, it gives methods to diagnose pancreatic cancer. It differentiates patients suffering from a combination of cholangiocarcinoma and primary sclerosing cholangtis (PSC) from patients who suffer from primary sclerosing cholangtis alone.

Beckman Coulter DXI 800 is the instrument used for this testing. An Assay, called as the Access GI Monitor Assay has the nature of a 2 – site immunoenzymatic sandwich assay. Paramagnetic particles which are enveloped with mouse monoclonal biotin conjugate, goat – antibiotin antibody and buffered protein solution are used.

This mixture is added along with the sample collected in a reaction vessel. The reaction vessel is incubated. Separation of materials takes place in the presence of a magnetic field. Afterward, washing helps eliminate materials not bound to the solid phase. A Chemiluminescent substrate called Lumi – Phos 530 is added to the reaction vessel. A light is produced which is measured with a luminometer. Light produced is proportional to the concentration of CA 19 – 9. Thus, level can be measured.