Elevation of serum CA19-9 levels in benign diseases.

CA19-9 is a tumor-associated antigen which is recognized by monoclonal antibody 1 16NS19-9. This antibody was originally selected for its reactivity with a human colon cancer-derived culture cell line, SW-1 16. The antigenic determinant on CA19-9 that is recognized by 1 16NS-19-9 is a sialylated lactoN-fucopentaose II, the so-called sialyl-Lewis a antigen. In the serum, CA19-9exists as a large sialomucin with a molecular weight of greater than 5 million. CA19-9 is widely used as a tumor marker for cancers of the pancreas, stomach, colon, cholangial duct, ovaries, endometrium, and lung (adenocarcinoma). However, several benign conditions are also knownto increase serum CA19-9 levels. In one group of benign conditions, inflammation or proliferation of noncancerous tissue results in elevated serum CA19-9 levels. Pancreatitis, pancreatic cysts, cholangitis, bronchial cysts, bronchiectasis, pulmonary