CA-50 in patients with pancreatic disease--an evaluation of three different laboratory techniques.

Plasma concentrations of CA-50 antigen in samples from patients suffering from pancreatic cancer, chronic pancreatitis and abdominal pain of unknown origin were analysed by three different techniques, using the same monoclonal antibody, C-50 Mab. These methods include an inhibition assay, an immunoradiometric assay (IRMA), and a dissociation-enhanced lanthanide fluoro-immunoassay (DELFIA). Whereas all three methods had high sensitivities for cancer, they displayed different specificities. With respect to the differential diagnosis between pancreatic cancer and chronic pancreatitis, all three methods are of value, with slightly better discrimination for the inhibition test, and easier performance and better analytic ranges for the IRMA and DELFIA methods.