[Studies on serum CEA levels measured by enzyme immunoassay using monoclonal CEA-antibodies]

A double determinant enzyme immunoassay (EIA) using two monoclonal antibodies against CEA was established in the Abott laboratory. Serum CEA levels from patients with various cancers and benign diseases were measured using this EIA in comparison with the results obtained by radioimmunoassay (RIA) using polyclonal antibody against CEA. A significant correlation was noted between the values measured by the two methods. When serum CEA levels were more than 100 ng/ml, the values for EIA were found to be higher than those for RIA. However, this EIA was judged to be useful for monitoring cancer patients.