title: Immunological heterogeneity of carcinoembryonic antigen: immunohistochemical detection of carcinoembryonic antigen determinants in colonic tumors with monoclonal antibodies.
abstract: The immunoperoxidase localization of carcinoembryonic antigen (CEA) determinants was studied in colonic adenocarcinomas using four murine monoclonal antibodies to CEA in a bridged avidin:biotin technique. One of the monoclonal antibodies, NP-1, recognizes a CEA epitope shared with the nonspecific cross-reacting antigen and meconium antigen. Two others, NP-2 and NP-3, discriminate two separate CEA epitopes shared with meconium antigen only, whereas NP-4 reacts with a unique determinant expressed on a subpopulation of CEA molecules. The monoclonal antibodies and polyclonal goat antisera against CEA and nonspecific cross-reacting antigen stained columnar epithelial cells in morphologically normal mucosa. Neutrophils were stained by only the NP-1 monoclonal antibody and goat anti-nonspecific cross-reacting antigen antiserum. All moderately differentiated colorectal adenocarcinomas and most of their nodal and liver metastases reacted with the goat antisera and cross-reactive monoclonal antibodies. Thirty % of these primary tumors and most of the nodal and/or liver metastases from six patients with NP-4-positive primary tumors failed to stain with NP-4. These results suggest heterogeneity in the expression of a CEA variant and/or determinant recognized by the NP-4 monoclonal antibody that perhaps identifies a subgroup of colonic cancers which differ in their functional differentiation.
mesh_terms: D000230:Adenocarcinoma / Q000276:immunology*; D000818:Animals; D000911:Antibodies, Monoclonal; D002272:Carcinoembryonic Antigen / Q000276:immunology*; D003110:Colonic Neoplasms / Q000276:immunology*; D000939:Epitopes / Q000032:analysis*; D006801:Humans; D007124:Immunoenzyme Techniques; D008113:Liver Neoplasms / Q000276:immunology / Q000556:secondary*; D051379:Mice
chemical_list: D000911:Antibodies, Monoclonal; D002272:Carcinoembryonic Antigen; D000939:Epitopes