title: Comparative imaging and biodistribution studies with an anti-CEA monoclonal antibody and its F(ab)2 and Fab fragments in mice with colon carcinoma xenografts.
abstract: An IgG1 mouse monoclonal antibody directed against CEA has been digested with papain to yield F(ab)2 and Fab fragments. Following radioiodination, intact antibody and fragments showed specific binding to cells of a CEA-producing tumour, although the immune reactivities of the fragments were lower than that of intact antibody. Gamma scintigraphy of nude mice bearing CEA-producing human tumour xenografts and injected with 131I-labelled fragments showed earlier and superior imaging of tumours than did 131I-intact antibody, and this was most marked with the Fab fragment. Sequential dissection analyses showed that this was due to earlier and higher tumour-to-blood ratios with fragments than with intact antibody, but in absolute terms the degree of localization of both fragment types was significantly lower than that of intact antibody.
authors.forename: S M
authors.initials: SM
authors.lastname: Andrew
authors.forename: M V
authors.initials: MV
authors.lastname: Pimm
authors.forename: A C
authors.initials: AC
authors.lastname: Perkins
authors.forename: R W
authors.initials: RW
authors.lastname: Baldwin
mesh_terms: D000230:Adenocarcinoma / Q000000981:diagnostic imaging*; D000818:Animals; D000911:Antibodies, Monoclonal / Q000032:analysis / Q000378:metabolism; D002460:Cell Line; D003110:Colonic Neoplasms / Q000000981:diagnostic imaging*; D004591:Electrophoresis, Polyacrylamide Gel; D006801:Humans; D066298:In Vitro Techniques; D007457:Iodine Radioisotopes; D051379:Mice; D008819:Mice, Nude; D009368:Neoplasm Transplantation; D012516:Osteosarcoma / Q000000981:diagnostic imaging*; D011877:Radionuclide Imaging; D012004:Rectal Neoplasms / Q000000981:diagnostic imaging*; D013997:Time Factors; D014018:Tissue Distribution
chemical_list: D000911:Antibodies, Monoclonal; D007457:Iodine Radioisotopes