title: An approach to the routine estimation of circulating carcinoembryonic antigen immune complexes in patients with carcinomata of the gastrointestinal tract.
abstract: The carcinoembryonic antigen (CEA) distribution obtained after fractionation of thirty sera of patients with gastrointestinal tumours by gel filtration in Sephadex G200 was compared with that resulting from extraction of the sera with perchloric acid. In all cases gel filtration yielded a fraction of free CEA and in twenty-three cases an additional fraction of CEA immune complexes. The amounts of free CEA corresponded fairly well to the fractions of CEA which could be extracted by perchloric acid. The CEA content of the fraction containing CEA immune complexes was comparable to the CEA content of the perchloric acid precipitates. The presence of CEA immune complexes in the perchloric acid precipitates could be demonstrated by gel filtration under dissociating andnon-dissociating conditions and after pre-incubation with 125I-CEA by radioimmuno-double-diffusion using monospecific rabbit antisera against human IgM and IgG.
mesh_terms: D000230:Adenocarcinoma / Q000276:immunology*; D000936:Antigen-Antibody Complex; D002272:Carcinoembryonic Antigen / Q000032:analysis*; D002850:Chromatography, Gel; D005770:Gastrointestinal Neoplasms / Q000276:immunology*; D006801:Humans; D010472:Perchlorates
chemical_list: D000936:Antigen-Antibody Complex; D002272:Carcinoembryonic Antigen; D010472:Perchlorates