CA 72-4 radioimmunoassay for the detection of the TAG-72 carcinoma-associated antigen in serum of patients.
Monoclonal antibody (MAb)B72.3 has been used to detect the presence of TAG-72 in the serum of carcinoma patients. We have developed new anti-TAG-72 MAbs and have selected one of these, CC49, as the "catcher" MAb with 125I-B72.3 as the detecting antibody in a double-determinant immunoradiometric assay. This combination enabled the development of a sequential assay (designated CA 72-4) that showed optimal quantitative properties as demonstrated by such parameters as linear dose-response, high re-producibility, and lack of serum-matrix and "hook-back" effects. Only 3.5% of 744 normal sera and 6.7% of 134 sera from patients with benign gastrointestinal diseases had TAG-72 levels greater than 6 U/ml. Approximately 40% of 303 patients with gastrointestinal malignancies had serum TAG-72 levels of greater than 6 U/ml (55% of the patients with advanced disease). Thirty-six percent of patients with adenocarcinomas of the lung and 24% of patients with ovarian cancer (53% stage IV patients) also had elevated serum TAG-72 levels. A poor correlation was found between the carcinoembryonic antigen (CEA) and TAG-72 values of sera obtained from gastric cancer patients. Thirty-four percent of CEA negative cases were scored positive in the CA 72-4 assay, suggesting the complementarity of the CA 72-4 assay to CEA assays in the analysis of sera from patients with certain malignancies.
Gero
E J
EJ
In Vitro Research and Development, Centocor, Malvern, Pennsylvania.
Colcher
D
D
Ferroni
P
P
Melsheimer
R
R
Giani
S
S
Schlom
J
J
Kaplan
P
P
D000911:Antibodies, Monoclonal / Q000302:isolation & purification; D000937:Antigen-Antibody Reactions; D000951:Antigens, Neoplasm / Q000032:analysis*; D015153:Blotting, Western; D002272:Carcinoembryonic Antigen / Q000032:analysis; D004591:Electrophoresis, Polyacrylamide Gel; D005770:Gastrointestinal Neoplasms / Q000276:immunology; D006023:Glycoproteins / Q000032:analysis*; D006801:Humans; D008175:Lung Neoplasms / Q000276:immunology; D009369:Neoplasms / Q000276:immunology*; D011863:Radioimmunoassay; D012016:Reference Values; D013223:Statistics as Topic; D013696:Temperature
D000911:Antibodies, Monoclonal; D000951:Antigens, Neoplasm; D002272:Carcinoembryonic Antigen; D006023:Glycoproteins; C047052:tumor-associated antigen 72